Source: UNIVERSITY OF NEW HAMPSHIRE submitted to
QUANTIFYING DECADAL TRENDS IN FOREST BIOGEOCHEMISTRY: LINKING FOREST DYNAMICS TO WATER QUALITY IN IMPORTANT WATER SUPPLY WATERSHEDS (2)
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
MCINTIRE-STENNIS
Reporting Frequency
Annual
Accession No.
1006760
Grant No.
(N/A)
Project No.
NH00083-M
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2015
Project End Date
Sep 30, 2019
Grant Year
(N/A)
Project Director
Mcdowell, W.
Recipient Organization
UNIVERSITY OF NEW HAMPSHIRE
(N/A)
DURHAM,NH 03824
Performing Department
Natural Resources and the Environment
Non Technical Summary
One of the major benefits of forested watersheds in humid climates is provision of clean drinking water and reduction in the delivery of undesirable nutrients to sensitive coastal ecosystems. This proposal is intended to leverage the results of ongoing research on water quality in forested watersheds of New Hampshire and Puerto Rico to address the drivers of nitrate, organic nitrogen, and sediment delivery to water supplies and estuaries. Both long-term high-frequency data sets collected with weekly grab samples, and high-frequency sensors with sampling every 15 minutes will be used to characterize water quality in forested watersheds. Understanding the drivers of water quality would significantly enhance efforts to maintain drinking water supplies and protect the health of coastal eel grass beds and coral reefs.
Animal Health Component
0%
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
11203201190100%
Knowledge Area
112 - Watershed Protection and Management;

Subject Of Investigation
0320 - Watersheds;

Field Of Science
1190 - Limnology;
Goals / Objectives
The work to be accomplished in this project focuses on understanding threats to water quality in forested landscapes, building on long-term studies in New Hampshire and Puerto Rico previously conducted by the principal investigator. The major goals of this project are to:Determine the importance of extreme runoff events on decadal-scale changes in water quality and nutrient flux in the Lamprey River, a forested suburban New England basinEstablish the impact of forest structure, hydrologic flow paths, and human population density on the importance of dissolved and particulate organic nitrogen in multiple streams draining forested New England watersheds.Quantify the effects of multiple hurricane disturbances and landscape-scale variation in forest composition on water quality in tropical rain forest watersheds.This project addresses McIntire-Stennis priority (2) management of forest and related watershed lands to improve conditions of waterflow and to protect resources against floods and erosion.The objectives for each goal are to:Continue weekly sampling and analysis of Lamprey river water quality and compare changes in water quality to documented changes in forest cover, population density and weather extremes over the study period.Continue to operate water quality sensors and collect and analyze weekly to monthly grab samples at eight small watersheds throughout New Hampshire. Assess the behavior of organic nitrogen over multiple seasons and during storms and compare fluxes of organic N to watershed attributes such as forest cover, human population density and agricultural land use.Continue to analyze the long-term data being collected from multiple watersheds in the Luquillo Mountains of Puerto Rico and compare differences in water quality to watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall and riparian geomorphology.
Project Methods
Objective 1: Continue weekly sampling and analysis of Lamprey river water quality and compare changes in water quality to documented changes in forest cover, population density and weather extremes over the study period.Site Description: The Lamprey River watershed is typical of southeastern New Hampshire, and is the largest tributary of Great Bay, New Hampshire's most significant estuary. The Lamprey River watershed is approximately 500 km2, with a high proportion of the basin in forest (68%) and water/wetlands (14%). Most development is concentrated in the southern tier of the basin with onsite drinking water and waste disposal systems. As a result of environmental concerns with on-site waste disposal, lot size is typically large (2 acres or more) in towns that have zoning ordinances.Approach: Weekly sampling of the Lamprey River began in 1999, and will continue with this project. Samples will be analyzed for pH, conductivity, and dissolved oxygen using field meters. Anions and cations (NO3, SO4, Cl, Na, K, Ca, and Mg) will be analyzed with ion chromatography (Dionex ion chromatographs with micromembrane suppression). Phosphorus (total and PO4), NH4, and SiO2 will be measured using colorimetric analysis with a Westco Smart Chem robotic analyzer or Lachat Quikchem. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) will be analyzed using a Shimadzu TOC-V carbon analyzer with nitrogen module. Dissolved organic nitrogen (DON) will be estimated as the difference between TDN and inorganic nitrogen. Total suspended sediments will be measured using standard gravimetric techniques. Particulate N will be measured as particles collected on glass fiber filters by elemental analysis with a Perkin Elmer 2400 CHN analyzer. A combination of Geographical Information System (GIS) analysis, Census data, daily rainfall, and remote sensing will be used to document changes in forest cover and population density, and weather extremes, over the study period. Various approaches to time series analysis such as wavelet analysis will be used to assess changes in river chemistry over time, with a particular emphasis on the importance of two 100-year floods in the late 2000s. Nutrient, sediment, and organic matter flux will be calculated with a modified version of the composite method (Aulenbach and Hooper 2006) that is currently under development in the PI's laboratory (Appling et al. in prep.). Sediment and nitrogen flux are of particular concern to environmental managers, as they impact drinking water quality as well as ecosystem health (Trowbridge et al. 2014).Objective 2: Continue to operate water quality sensors and collect and analyze weekly to monthly grab samples at eight small watersheds throughout New Hampshire. Assess the behavior of organic nitrogen over multiple seasons and during storms and compare fluxes of organic N to watershed attributes such as forest cover, human population density and agricultural land use.Site Description: Eight small watersheds throughout the state of New Hampshire have recently been instrumented with a state-of-the-art instrument package that provides real-time monitoring of stream chemistry from non-AES funding. The sites include five relatively undisturbed forested watersheds. Sensor packages are also deployed in three watersheds that are significantly impacted from human activities. One has significant agricultural operations (Burley-Demerritt Farm, Lee, NH), the second has suburban housing (Wednesday Hill Brook, Lee, NH) and the third is an urban site in Manchester, NH (McQuesten Brook) which has relatively intact riparian forest and a population of native brook trout.Approach: Water quality is measured continuously at each site with a sensor package consisting of a Satlantic SUNA nitrate analyzer and a YSI EXO sonde that includes pH, temperature, conductivity, turbidity (a proxy for total suspended solids), fluorescent dissolved organic matter (a proxy for dissolved organic N), and dissolved oxygen. Sensors are connected to a Campbell data logger and data are sent via Raven cell phone transmission to the Water Quality Analysis Laboratory. Grab samples are taken weekly to monthly at each site to verify field operation of the sensors and conduct additional analyses including dissolved organic carbon, ammonium, phosphate, and major cations and anions. Laboratory analysis will be identical to that employed in Objective 1 above. With continuous measurement of nitrate, dissolved organic matter, and turbidity, data will be available for direct or proxy assessment of each of the major fractions of nitrogen. This will allow an assessment of the two poorly constrained but potentially important organic components of the total nitrogen pool, particulate organic nitrogen and dissolved organic nitrogen. The behavior of organic nitrogen will be assessed over seasons and during storms to infer the likely importance of biotic processes and hydrologic flow paths on concentrations of organic nitrogen. Annual fluxes of organic N will be determined based on these continuous measurements of chemistry and stream flow at each site. The relative importance of organic nitrogen will be assessed by examining the fraction of total N transport that is associated with the organic fraction. Backwards stepwise regression will be conducted to determine if variability in organic nitrogen concentrations among the 8 sites is associated with variations in forest cover, human population density, or other landscape attributes.Objective 3: Continue to analyze the long-term data being collected from multiple watersheds in the Luquillo Mountains of Puerto Rico and compare differences in water quality to watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall and riparian geomorphology. Site Description: The Luquillo Mountains of Puerto Rico are one of the best-studied tropical landscapes in the world, with significant strengths in biogeochemistry and water quality (McDowell et al. 2012). Research has been conducted there since the 1930s by USDA Forest Service personnel (currently known as the International Institute of Tropical Forestry). In collaboration with the US Forest Service, weekly samples of stream water have been collected and analyzed under the direction of the PI since 1983, as part of projects funded by DOE, LTER (NSF), and more recently, the Luquillo Critical Zone Observatory (NSF). For individual streams, data sets of 25-30 years are available for forested watersheds that vary in geology (volcaniclastic and intrusive), soils (Inceptisols and Ultisols) and species composition. Recent analysis of two key study watersheds with the longest period of record, the Sonadora and Icacos, highlights the strong influence of geology on stream nitrate levels, apparently due to differences in the effectiveness of riparian zone processes in removing nitrogen from groundwater before it enters the stream (McDowell et al. 2013).Approach: This project will continue to analyze the long-term data being collected from multiple watersheds, to assess whether there are other differences in solute behavior beyond the obvious differences in nitrate concentrations across the two bedrock types noted by McDowell et al. (2013). In particular, this project will assess the response of stream chemistry to hurricanes in watersheds with different aspects and slopes but identical bedrock. Initial observations suggest that there may be legacies of past land use and forest management practices about 90 years ago that drive current spatial variation in stream chemistry, and the magnitude of hurricane response over the past 25 years. Response of nitrate concentrations and fluxes to hurricanes will be quantified for 5 small watersheds and related to slope, aspect, riparian geomorphology, and rainfall, and the abundance of Inga vera, a nitrogen fixing tree associated with earlier production of shade coffee in this forest.

Progress 10/01/15 to 09/30/19

Outputs
Target Audience: The scientific community where results were disseminated through peer-reviewed publications and at regional, national and international meetings and conferences. Local communities and decision-makers concerned with the effects of extreme precipitation events and forest and land management on water quality. Information was disseminated through public presentations at town meetings and at other local events or workshops. Information was also disseminated through press releases. Graduate, undergraduate and K-12 students with an interest in water resources. Data and insights from this project were incorporated into the lectures and laboratory exercises for the University of New Hampshire undergraduate and graduate course NR 703/803 Watershed Water Quality Management. Data and insights from this project were also incorporated into Data Jams designed for teachers and middle and high school students in Puerto Rico. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Opportunities for training and professional development included involvement of three post-doctoral researchers (Maria Chapela Lara, Qingtao Zhou and Hannah Fazekas), three PhD students (Bianca Rodriguez, Meaghan Shaw and Allison Herreid), four Master's students (Brian Saccardi, Allison Herreid, Katherine Perez and Anna Lowien), and 12 undergraduate hourly employees (Brooke Gauthier, Alex McGinn, Alexis Blanchard, Alexis Sims, Brooke Gauthier, Charles Basile, Daniel Okuniewicz, Danielle Chancey, Lexi Sims, Light McHaro, Mason Caceres and Sarah Carlson) in this research project. Danielle Chancey recently received her bachelor's degree from UNH and has worked in the UNH Water Quality Analysis Laboratory as a technician since graduation. How have the results been disseminated to communities of interest?Annual Lamprey River Symposium. The goal of the Annual Lamprey River Symposium is to facilitate discussion and collaboration among scientists working in the Lamprey River basin and to engage local, state and federal officials, watershed organizations, and concerned citizens with the science and its implications for Great Bay and the entire coastal watershed. The symposium attracts approximately 90 attendees. For additional dissemination to the scientific community, refer to the "Journal Articles" and "Conference Papers and Presentations" in the Products section. For the dissemination of results to local and regional communities and decision-makers, refer to the "Other Products" in the Products section. Dissemination to teachers and middle and high school students occurred through Data Jams in Puerto Rico In December 2018, 25 science teachers from private and public schools in Puerto Rico participated in a "Data Jam" workshop. Teachers had the opportunity to work with long-term hydrological data to investigate a basic ecology question and develop a claim-evidence-reasoning presentation to demonstrate their findings. Following the workshop, six teachers conducted data jams with 83 students back in the classroom, motivating them to use ecological data to create a project that presents the data in a non-traditional way (e.g. poetry, rap songs, models, TV skits). Twelve students and teacher representatives from 6 public and private high schools and middle schools participated in the annual Long-Term Ecological Research Schoolyard Program Symposium at the University of Puerto Rico in May 2019. For dissemination to undergraduate and graduate students, refer to the "What opportunities for training and professional development has the project provided?" section. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The work to be accomplished in this project focuses on understanding threats to water quality in forested landscapes, building on long-term studies in New Hampshire and Puerto Rico previously conducted by the principal investigator.The major goals of this project are to: Determine the importance of extreme runoff events on decadal-scale changes in water quality and nutrient flux in the Lamprey River, a forested suburban New England basin Establish the impact of forest structure, hydrologic flow paths, and human population density on the importance of dissolved and particulate organic nitrogen in multiple streams draining forested New England watersheds. Quantify the effects of multiple hurricane disturbances and landscape-scale variation in forest composition on water quality in tropical rain forest watersheds. Objective 1: Continue weekly sampling and analysis of Lamprey river water quality and compare changes in water quality to documented changes in forest cover, population density and weather extremes over the study period. The impacts of forest fragmentation and land use on water quality have been assessed through continued long-term sampling of a forested suburban water supply watershed, the Lamprey River in southeast New Hampshire. Results show there is considerable variability in stream water nitrogen concentrations at weekly to sub-daily timescales, with values ranging from well below thresholds for impairment of the Great Bay estuary to values well above the threshold. There is a statistically significant increase in annual nitrate concentrations over the entire period of record (2000-2018). At the beginning of the study period, mean annual nitrate concentration was 0.10 milligrams of nitrogen per liter (mg N/L) and in 2018, mean annual nitrate concentration was 0.15 mg N/L. The highest annual average nitrate concentration to date was recorded in 2014 (0.19 mg N/L). The spatial variability of nitrate concentration throughout the Lamprey watershed is negatively correlated with forest cover. Incremental forest loss and conversion to developed lands results in corresponding increases in nitrogen concentrations, as forest is the land cover that best reduces nitrogen pollution. Human waste, fertilizers and animal waste are sources of nitrogen that increase in developed and agricultural land areas. When forests are converted to development, sodium and chloride concentrations in groundwater and stream water also increase as a result of deicers used on roads, parking lots and driveways to maintain "free and clear" roads during winter months. When we combine our water quality data (2003 - 2018) with data collected by the United States Geological Survey (1978 - 1999), a long-term increase in sodium and chloride in the Lamprey River is apparent. We are uncertain if nitrate, sodium and chloride levels in the Lamprey will remain relatively constant, increase or decrease with changing climate, land use, and management in the watershed. This information on the effects of forests, and forest loss, on water quality, has been critically important in local management discussions and decision-making. The information has been eagerly sought by communities, state agencies, and private consultants as they assess the impacts of land-use change on water quality. Objective 2: Continue to operate water quality sensors and collect and analyze weekly to monthly grab samples at eight small watersheds throughout New Hampshire. Assess the behavior of organic nitrogen over multiple seasons and during storms and compare fluxes of organic N to watershed attributes such as forest cover, human population density, and agricultural land use. The impact of climate variability on water quality was assessed through continued operation and maintenance of instream water quality sensors that measure nitrogen, particles, organic matter, dissolved salts, acidity, dissolved oxygen and stream temperature every 15 minutes. Weekly to monthly grab samples were also collected to verify field operation of the sensors and conduct additional analyses. The 15-minute sensor data reveal a "first flush" of nitrate during storms in the Lamprey River where nitrate concentration increases and peaks just prior to peak streamflow and subsequently declines throughout the remainder of the storm event. This suggests that sources of nitrate are closer to the mouth of the Lamprey and reach the sample site prior to the bulk of the water moving through the watershed. In the suburban Wednesday Hill Brook (a headwater stream in Lee, NH) and in a headwater stream that drains the Burley-Demerritt Organic Dairy Farm (Lee, NH) stream water nitrate concentrations are diluted during storms suggesting that groundwater is an important source of nitrogen in these suburban and agricultural catchments. Objective 3: Continue to analyze the long-term data being collected from multiple watersheds in the Luquillo Mountains of Puerto Rico and compare differences in water quality to watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall, and riparian geomorphology. The tropical forested watersheds in the Luquillo Mountains of Puerto Rico are important water supply watersheds and experienced an extreme drought in the summer of 2015 and hurricanes, Irma and Maria, in September 2017. We have assessed the first 2 years of 15-minute in situ sensor data following Hurricanes Irma and Maria in the Quebrada Sonadora. As expected from past hurricanes, nitrate concentrations increased a few months after the storm. Contrary to expectations, the behavior of many solutes in response to discharge was radically changed after the hurricanes. Specific conductance, an indicator of the total dissolved salts in the water, flipped from a consistent dilution response during high flow to an enrichment response both during and after Maria, likely due to deposition of marine aerosols during the hurricane and subsequent flushing from the soil profile for several months after the storm. Nitrate also flipped its behavior. Pre-hurricane, storms had little to no effect on nitrate concentrations measured at 15-minute intervals. Following the hurricanes, large concentration increases (up to 1.8 mg N/L) were observed at high stream discharge during even small rainstorms. This responsiveness to flow declined over the course of the next year. Incorporation of this newly recognized sensitivity to discharge into watershed flux estimates results in 2 to 3-fold higher values than with weekly samples. The nitrate response to storms peaked 4 months after the hurricane but was still evident 9 months later, likely mirroring the time course of major biotic processes (leaf litter decomposition and vegetation regrowth) that control nitrate fluxes. The newly recognized sensitivity of nitrate to stream discharge has important implications for future climate change scenarios. With increased frequency and intensity of hurricanes, much greater export to nitrogen-limited coastal waters can be expected than previously estimated.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Dessu, S. B., Price, R., Wymore, A., Kominoski, J. S., Davis, S. E., McDowell, W. H., Gaiser, E. 2018. Development and Application of Percentile-Range Indexed Mapping and Evaluation (PRIME) Tool for Long Term Ecological Assessment. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Fazekas, H., Wymore, A., McDowell, W.H. 2019. High-frequency data reveals spatiotemporal variability in carbon and nitrogen concentration-discharge relationships across a stream network. 2019 Society for Freshwater Science Annual Meeting. Salt Lake City, UT. May 19-23, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Fazekas, H.M., Potter, J.D., Snyder, L., Shattuck., M.D. and McDowell, W.H. 2019. High-frequency in situ optical sensors reveal spatial, seasonal, and annual trends in nitrate export to the Great Bay Estuary. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Gutierrez-Fonseca, P.E., Ramirez, A., Pringle, C.M., Torres, P.J., Covich, A., Crowl, T.A., McDowell, W.H., Ballantyne, F. and Perez-Reyes, O. 2019. Ecological response of stream ecosystems to extreme climate events in Puerto Rico. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Herreid, A., Wymore, A. Varner, R. and McDowell, W.H. Controls on greenhouse gas production in streams across a land use gradient. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Herreid, A., Wymore, A., Varner, R. K., McDowell, W.H. 2018. Controls on greenhouse gas production in streams across a land use gradient. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Kr�ger, S., Wymore, A., McDowell, W.H. and Kalbitz, K. 2019. Linking composition of dissolved organic matter and nutrient cycling in forest streams. European Geosciences Union conference. Vienna, Austria. April 2019. Doi: 10.13140/RG.2.2.22490.59843.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Lopez-Lloreda, C., McDowell, W.H. and Potter, J.D. 2018. Dissolved greenhouse gases in streams and their response to Hurricanes Irma and Mar�a in a tropical forest in Puerto Rico. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Lopez-Lloreda, C., McDowell, W.H. and Potter, J.D. 2019. Dissolved greenhouse gases in streams and their response to Hurricanes Irma and Maria in a tropical forest in Puerto Rico. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Marcarelli, A.; Sponseller, R.; Kirk, L.; Arroita, M.; Arnon, S.; Grace, M.; Mart�, E.; McDowell, W.H.; Segura, C.; Subalusky, A.; Tank, J.L.; Tromboni, F.; Ulseth, A. 2019. Mirror Mirror: The role of heterotrophy in running waters informed by the strength and variation in the relationship between ER and GPP. 2019 Society for Freshwater Science Annual Meeting. Salt Lake City, UT. May 19-23, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McDowell, W.H, Lopez-Lloreda, C., Potter, J. 2018. Aquatic Sensors Provide New Insights into the Aquatic-Terrestrial Linkages that Govern Watershed Response to Major Hurricanes in a Tropical Montane Forest. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: McDowell, W.H. 2019. Disturbance and response: understanding the effects of extreme events on aquatic biogeochemistry. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rodriguez-Cardona, B., Wymore, A., Kortelainen, P., Argerich, A., Johnson, S. and McDowell, W.H. 2019. Long-term trends in dissolved organic carbon from fluvial systems across biomes. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rodriguez-Cardona, B., Wymore, A., McDowell, W.H. 2019. Carbon availability enhances nitrate removal in tropical montane streams. 2019 Society for Freshwater Science Annual Meeting. Salt Lake City, UT. May 19-23, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Saccardi, B., McDowell, W.H., Wymore, A. and Wollheim, W. 2019. New insights into the CO2 dynamics of streams from NDIR sensors. 2019 Society for Freshwater Science Annual Meeting. Salt Lake City, UT. May 19-23, 2019.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wymore, A., Krueger, S., Van Der Hout, J. and McDowell, W.H. 2019. Exploring the ecological duality of dissolved organic nitrogen with field based experimental evidence. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Zhou, Q., McDowell, W.H, Wymore, A. 2018. Exploring the drivers that affect nitrate in soil solution at Luquillo Experimental Forest, Puerto Rico. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Zhou, Q., Wymore, A. and McDowell, W.H. 2019. Comparing the impacts of two simulated hurricanes on soil nitrate concentrations: a multiple quantitative approach. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: Chapela Lara, M. 2019. The effect of lithology in Mg cycling at late stages of weathering: insights from the Luquillo Critical Zone Observatory. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: Leon, M. 2019. Migrating CZO data to HydroShare. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: Leon, M. 2019. Publishing your LCZO data online. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Shanley, J.B., Sebestyen, S. D., McDowell, W.H., Kram, P., Oulehle, F. 2018. The scientific and societal value of long-term watershed research (Invited). 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Shattuck, M.D. and McDowell, W.H. 2019. Human impacts on stream nitrogen chemistry and watershed N retention across a wide range of rural to urban catchments. ASLO 2019 Aquatic Sciences Meeting. San Juan, PR. 23 February - 2 March 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Vaughan, E., McDowell, W.H., Cusack, D., Marin-Spiotta, E.2018. Measuring the Effects of Long-term Nitrogen Fertilization on Soil Carbon Cycling in Two Tropical Forests. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: L�pez Lloreda, C. 2018. Hydrology and biogeochemistry in the Luquillo Critical Zone Observatory. El Verde Field Station, El Verde, PR. October 22, 2018.
  • Type: Other Status: Other Year Published: 2019 Citation: L�pez Lloreda, C. 2019. Building bridges: better linking UPR students and LCZO activities. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: L�pez Lloreda, C. 2019. Dissolved greenhouse gases in streams and their response to Hurricane Mar�a in a tropical forest in Puerto Rico. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: L�pez Lloreda, C. 2019. Hurricanes Irma and Mar�a drove a pulse of salts through soils and streams of a tropical watershed. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: L�pez Lloreda, C. and Barreto, T. 2019. Annual LTER Science Council Meeting. Assisted with field trip to LTER and LCZO sites, described LTER and LCZO research and presented LCZO overview poster. May 15, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019 Vision and opportunities for connecting LTER and CZO to coordinated open watershed networks. Leveraging distributed research networks to understand watershed systems. Workshop for the U.S. Dept. of Energy, Biological & Environmental Research Program. Rockville, MD. January 28-30, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Luquillo Critical Zone Observatory: Overview and response of stream chemistry to Hurricane Maria Seminar at the 33rd Geology Symposium, Geology Department, UPR Mayaguez. February 12, 2019.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Building land-water Observatories around the Earth: Wuyishan in a global context. Wuyishan National Park Administration, Wuyi, China. November 13, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Building land-water Observatories around the Earth: Wuyishan in a global context. Nanjing Forestry University, Nanjing, China. November 15, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. In the eye of the storm: Long-term nitrogen dynamics in a tropical landscape. Nanjing Forestry University, Nanjing, China. November 11, 2019
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. In the eye of the storm: Long-term nitrogen dynamics in a tropical landscape. Department of Geology Visiting Lecture Series, University of Vermont, Burlington, VT. November 18, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Lightning talk: Ecosystem Responses to Hurricane Stressors. Ecosystem Responses to Hurricanes  Synthesis Workshop. Corpus Christi, TX. April 28  May 1, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Long-term effects of Hurricane Maria on stream nutrient chemistry. Luquillo LTER annual meeting. R�o Piedras, San Juan, Puerto Rico. June 4-5, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Long-term, continuous stream chemistry records provide new insights into watershed function. Annual Meeting of the Hubbard Brook Ecosystem Study. North Woodstock, NH. July 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Overview: Luquillo CZO and stream chemistry. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: McDowell, W.H. 2019. Vision and opportunities for connecting NEON to coordinated open watershed networks. Leveraging distributed research networks to understand watershed systems. Workshop for the U.S. Dept. of Energy, Biological & Environmental Research Program. Rockville, MD. January 28-30, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: Shaw, M. 2019. Hurricane Influence on Redox-Active Metals in the Luquillo CZO. LCZO annual meeting 2019. Rio Grande, PR. June 5-7, 2019.
  • Type: Other Status: Other Year Published: 2018 Citation: Wymore, AS. 2018. Global patterns in stream energy and nutrient cycling. Long Term Ecological Research webinar. March 2018. (https://www.youtube.com/watch?v=suEFjtltbEE)
  • Type: Other Status: Other Year Published: 2018 Citation: Wymore, AS. 2018. Using long-term observational data to better understand carbon: nitrogen ratios in stream ecosystems. Departmental seminar. University of New Hampshire. April 2018.
  • Type: Other Status: Published Year Published: 2019 Citation: Hurricane Maria and Puerto Rico's Watersheds. WBUR-FM. 1/1/2019. 0101hurricaneresearch.wav
  • Type: Other Status: Published Year Published: 2018 Citation: Brown, L. and Nalpathanchil, L. 2018. NPR's Adrian Florido On More Than A Year On The Ground In Puerto Rico. Connecticut Public Radio. Where We Live. December 18, 2018. Interviewed William H. McDowell. https://www.wnpr.org/post/nprs-adrian-florido-more-year-ground-puerto-rico
  • Type: Other Status: Published Year Published: 2018 Citation: Camero, K. 2018. UNH researchers find high levels of nitrate in Puerto Rico streams after storms. Boston Globe Online. 12/17/2018. https://www.bostonglobe.com/metro/2018/12/17/unh-researchers-find-high-levels-nitrate-puerto-rico-streams-after-storms-see-climate-change-link/CKOc8an0jxHzmxu17UdiqL/story.html
  • Type: Other Status: Other Year Published: 2018 Citation: Dybas, C. 2018. After the hurricane: Marias far-reaching effects on Puerto Ricos watersheds and forests. NSF News Release December 10, 2018. Quoted Bill McDowell. https://nsf.gov/news/news_summ.jsp?cntn_id=297288
  • Type: Other Status: Published Year Published: 2018 Citation: Dybas, C. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Rico's watershed. National Science Foundation News From the Field. 12/14/2018. Quoted William H. McDowell.
  • Type: Other Status: Published Year Published: 2018 Citation: Eurasia Review. 2018. Maria's Far-Reaching Effects On Puerto Rico's Watersheds And Forests. Eurasia Review. 12/12/2018. Quoted William H. McDowell. http://www.eurasiareview.com/13122018-marias-far-reaching-effects-on-puerto-ricos-watersheds-and-forests/
  • Type: Other Status: Published Year Published: 2018 Citation: Health Medicine Network. 2018. Maria's far-reaching effects on Puerto Rico's watersheds and forests. Health Medicine Network. 12/13/2018. Quoted William H. McDowell. http://healthmedicinet.com/marias-far-reaching-effects-on-puerto-ricos-watersheds-and-forests/
  • Type: Other Status: Published Year Published: 2019 Citation: Hughes, M. 2019. Salem couple works to clean up swamp 'It just blows my mind how much trash there is'. The Eagle-Tribune. North Andover, Massachusetts. May 2, 2019. Interviewed William H. McDowell. https://www.eagletribune.com/news/salem-couple-works-to-clean-up-swamp/article_f40339af-4281-5940-bea0-88dce993055a.html
  • Type: Other Status: Published Year Published: 2018 Citation: Ives, J. 2018. High levels of nitrate detected on Puerto Rico's watershed after major hurricanes. News-Medical. 12/11/2018. Quoted William H. McDowell. https://www.news-medical.net/news/20181211/High-levels-of-nitrate-detected-on-Puerto-Ricoe28099s-watershed-after-major-hurricanes.aspx
  • Type: Other Status: Published Year Published: 2018 Citation: Kagubare, I. 2018. Puerto Rico's watershed still reeling in storms' wake  study, E&E News reporter Published: Tuesday, December 11, 2018. Quoted Bill McDowell https://www.eenews.net/climatewire/stories/1060109275/search?keyword=Puerto+Rico%27s+watershed
  • Type: Other Status: Published Year Published: 2018 Citation: Kalaugher, L. 2018. Hurricane Maria: a haircut, resilient palms and NASAs Black Marble. Physics World. 12/12/2018. Quoted William H. McDowell. https://physicsworld.com/a/hurricane-maria-a-haircut-resilient-palms-and-nasas-black-marble/
  • Type: Other Status: Published Year Published: 2018 Citation: Krajick, K. 2018. American Geophysical Union 2018: Key Events from the Earth Institute. The Earth Institute at Columbia University. 12/3/2018. https://blogs.ei.columbia.edu/2018/12/03/american-geophysical-union-2018-key-events-from-the-earth-institute/
  • Type: Other Status: Published Year Published: 2019 Citation: McDowell. W.H. 2019. Media Advisory: UNH Expert to Comment on EPA Change to Clean Water Act. NH WRRC director McDowell available for interviews. February 2019.
  • Type: Other Status: Published Year Published: 2018 Citation: National Science Foundation (NSF). 2018. After the Hurricane: Maria's Far-Reaching Effects On Puerto Rico's Watersheds And Forests. Water Online. December 10, 2018. Quoted William H. McDowell. https://www.wateronline.com/doc/after-hurricane-marias-reaching-effects-puerto-ricos-watersheds-forests-0001
  • Type: Other Status: Published Year Published: 2018 Citation: National Science Foundation. 2018. Maria's far-reaching effects on Puerto Rico's watersheds and forests. Scienmag. 12/12/2018. https://scienmag.com/marias-far-reaching-effects-on-puerto-ricos-watersheds-and-forests/
  • Type: Other Status: Other Year Published: 2018 Citation: National Science Foundation. 2018. Maria's far-reaching effects on Puerto Rico's watersheds and forests. BrightSurf.com. 12/12/2018. Quoted William H. McDowell. https://www.brightsurf.com/news/article/121218472281/marias-far-reaching-effects-on-puerto-ricos-watersheds-and-forests.html
  • Type: Other Status: Published Year Published: 2018 Citation: National Science Foundation. 2018. Tree species and stream and forest nutrients altered, with ecosystem-wide consequences. ScienceDaily. 12/13/2018. Quoted William H. McDowell. https://www.sciencedaily.com/releases/2018/12/181212160106.htm
  • Type: Other Status: Published Year Published: 2018 Citation: Ray, R. 2018. Environmental science professor William McDowell named AAAS fellow. UNH Today. November 26, 2018. https://www.unh.edu/unhtoday/2018/11/aaas-honor
  • Type: Other Status: Published Year Published: 2018 Citation: Ray, R. 2018. Hurricane Double-Shot - UNH research finds Hurricanes Irma, Maria had lasting impact on Puerto Rico's streams. UNH Today. December 10, 2018. Quoted Bill McDowell. https://www.unh.edu/unhtoday/2018/12/hurricane-double-shot
  • Type: Other Status: Published Year Published: 2018 Citation: Ray, R. 2018. UNH Professor Awarded the Honor of 2018 AAAS Fellow. UNH Newsroom. November 27, 2018. https://www.unh.edu/unhtoday/news/release/2018/11/27/unh-professor-awarded-honor-2018-aaas-fellow
  • Type: Other Status: Published Year Published: 2018 Citation: Ray, R. 2018. UNH Researchers Find Unexpected Impact of Hurricanes on Puerto Ricos Watershed. UNH Today. December 10, 2018. Interviewed Bill McDowell. https://www.unh.edu/unhtoday/news/release/2018/12/10/unh-researchers-find-unexpected-impact-hurricanes-puerto-ricos-watershed
  • Type: Other Status: Published Year Published: 2019 Citation: Schaier, S. 2019. Muddy Waters. Navigating potential changes to Clean Water Act. UNH Today January 2, 2019. Interviewed William H. McDowell. https://www.unh.edu/unhtoday/2019/01/muddy-waters
  • Type: Other Status: Published Year Published: 2018 Citation: ScienceDaily. 2018. Maria's far-reaching effects on Puerto Rico's watersheds and forests. LongRoom.com. 12/13/2018. Quoted William H. McDowell. https://www.longroom.com/discussion/1290799/marias-far-reaching-effects-on-puerto-ricos-watersheds-and-forests
  • Type: Other Status: Published Year Published: 2018 Citation: ScienceDaily. 2018. Maria's far-reaching effects on Puerto Rico's watersheds and forests. Times of News Russia. 12/13/2018. Quoted William H. McDowell. https://russia.timesofnews.com/marias-far-reaching-effects-on-puerto-ricos-watersheds-and-forests/
  • Type: Other Status: Published Year Published: 2018 Citation: ScienceDaily. 2018. Unexpected impact of hurricanes on Puerto Rico s watershed. NewsCaf. 12/10/2018. Quoted William H. McDowell. http://www.newscaf.com/science/unexpected-impact-of-hurricanes-on-puerto-rico-s-watershed_1023955.html
  • Type: Other Status: Published Year Published: 2018 Citation: Shepherd, M. 2018. The Startling Thing Hurricanes Are Doing To Puerto Rico Watersheds. Forbes. December 10, 2018. Quoted Bill McDowell. https://www.forbes.com/sites/marshallshepherd/2018/12/10/the-startling-thing-hurricanes-are-doing-to-puerto-rico-watersheds/#22b1c92c6604
  • Type: Other Status: Published Year Published: 2018 Citation: Skahill, P. 2018. Hurricanes Yield "Fundamental Change" In Puerto Rico's Watershed. Connecticut Public Radio. All Things Considered. December 11, 2018. Interviewed William H. McDowell. https://www.wnpr.org/post/hurricanes-yield-fundamental-change-puerto-ricos-watershed
  • Type: Other Status: Published Year Published: 2018 Citation: Skahill, P. 2018. Hurricanes Yield "Fundamental Change" In Puerto Rico's Watershed. New England Public Radio 12/11/2018. Quoted William H. McDowell. http://www.nepr.net/post/hurricanes-yield-fundamental-change-puerto-ricos-watershed
  • Type: Other Status: Published Year Published: 2018 Citation: Skahill, P. 2018. Hurricanes Yield "Fundamental Change" In Puerto Rico's Watershed. WSHU-AM Online. 12/12/2018. Quoted William H. McDowell. http://www.wshu.org/post/hurricanes-yield-fundamental-change-puerto-ricos-watershed
  • Type: Other Status: Published Year Published: 2018 Citation: Skahill, P. 2018. Researchers in Puerto Rico say hurricanes Irma and Mar�a made long-lasting and ongoing impacts to forest and coastal ecosystems. The Beaker - WNPR-FM. Quoted William H. McDowell. 12/12/2018. http://thebeaker.org/post/181044743269.
  • Type: Other Status: Published Year Published: 2018 Citation: TodayChan. 2018. Researchers discover surprising impression of hurricanes on Puerto Rico's watershed. TodayChan. 12/10/2018. http://www.todaychan.com/2018/12/10/researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed/
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. Researchers find unexpected impact of hurricanes on Puerto Rico's watershed. Phys.org. 12/10/2018. Quoted William H. McDowell. https://phys.org/news/2018-12-unexpected-impact-hurricanes-puerto-rico.html
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. Researchers find unexpected impact of hurricanes on Puerto Rico`s watershed. WorldNews. 12/11/2018. Quoted William H. McDowell. https://article.wn.com/view/2018/12/11/Researchers_find_unexpected_impact_of_hurricanes_on_Puerto_R/
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. Unexpected impact of hurricanes on Puerto Rico's watershed. ScienceDaily. ScienceDaily, 10 December 2018. Quoted William H. McDowell. https://www.sciencedaily.com/releases/2018/12/181210115759.htm
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Rico's watershed. Sciencecodex.com. 12/11/2018. Quoted William H. McDowell. https://www.sciencecodex.com/unh-researchers-find-unexpected-impact-hurricanes-puerto-ricos-watershed-624125
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Rico's watershed. Scienmag. 12/10/2018 Quoted William H. McDowell. https://scienmag.com/unh-researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed/.
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Ricos watershed. EnvironmentGuru. 12/13/2018. Quoted William H. McDowell.
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH Researchers Find Unexpected Impact of Hurricanes on Puerto Rico's Watershed. Caribbean Business Online. 12/11/2018. Quoted William H. McDowell. https://caribbeanbusiness.com/unh-researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed/
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Rico's watershed. Jersey Tribune. 12/10/2018. Quoted William H. McDowell. http://jerseytribune.com/2018/12/10/unh-researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed/
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Rico's watershed. 12/10/2018. BrightSurf.com. Quoted William H. McDowell. https://www.brightsurf.com/news/article/121018471978/unh-researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed.html.
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. UNH researchers find unexpected impact of hurricanes on Puerto Rico's watershed. Bioengineer. 12/10/2018. https://bioengineer.org/unh-researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed/
  • Type: Other Status: Published Year Published: 2018 Citation: University of New Hampshire. 2018. University of New Hampshire Researchers Find Unexpected Impact of Hurricanes on Puerto Rico's Watershed. Seed Today Online. 12/13/2018. Quoted William H. McDowell. http://www.seedtoday.com/article/159831/university-of-new-hampshire-researchers-find-unexpected-impact-of-hurricanes-on-puerto-ricos-watershed
  • Type: Other Status: Published Year Published: 2019 Citation: Wright, L. 2019. UNH Researchers Study Puerto Rico Hurricane to Understand Impact of New England Storms on Watersheds. September 3, 2019. https://colsa.unh.edu/nhaes/article/2019/09/maria. Interviewed Adam Wymore.
  • Type: Other Status: Published Year Published: 2019 Citation: Wymore, A. 2019. Interviewed by WMUR out of Manchester, NH in the wake of Hurricane Dorian and featured on the nightly news discussing Hurricane Maria and Puerto Rico. September 2019.
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Herreid, A.M. 2019. Divergent controls on stream greenhouse gas concentrations across a land use gradient. M.S. Dissertation, Department of Natural Resources & the Environment, College of Life Science and Agriculture, University of New Hampshire, Durham, New Hampshire, 43 pages.
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Saccardi, B. 2019. Disappearing temporal patterns: The spatial variability of CO2 in headwater streams. M.S. Dissertation, Department of Natural Resources & the Environment, College of Life Science and Agriculture, University of New Hampshire, Durham, New Hampshire, 26 pages.
  • Type: Websites Status: Published Year Published: 2019 Citation: Potter, J.D., Shattuck, M.D. and Swan, K. 2019. New Hampshire Water Resources Research Center. http://wrrc.unh.edu/. December 11, 2019.
  • Type: Websites Status: Published Year Published: 2019 Citation: Leon, M., McDowell, W.H. et al. 2019. Luquillo Critical Zone Observatory. https://criticalzone.org/luquillo/. December 11, 2019.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Djukic, I., Kepfer-Rojas, S., Schmidt, I. K., Larsen, K. S., Beier, C., Berg, B., et al. 2018. Early stage litter decomposition across biomes. Science of the Total Environment, 628-629, 1369-1394. DOI:10.1016/j.scitotenv.2018.01.012.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Farrell, K. J., Rosemond, A. D., Kominoski, J. S., Bonjour, S. M., Rugg, J., Koenig, L. E., et al. (2018). Variation in Detrital Resource Stoichiometry Signals Differential Carbon to Nutrient Limitation for Stream Consumers Across Biomes. Ecosystems, 21(8), 1676-1691.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: McDowell, W.H., McDowell, W.G., Potter, J.D., Ramirez, A. 2019. Nutrient export and elemental stoichiometry in an urban tropical river. Ecological Applications. 29(2) DOI: 10.1002/eap.1839.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sebestyen, S.D., Ross, D.S., Shanley, J.B., Elliott, E.M., Kendall, C., Campbell, J.L., Dail, D.B., Fernandez, I.J., Goodale, C.L., Lawrence, G. and Lovett, G.M., McHale, P.J., Mitchell, M.J., Nelson, S.J., Shattuck, M.D., Wickman, T.R., Barnes, R.T., Bostic, J.T., Buda, A.R., Burns, D.A., Eshleman, K.N., Finlay, J.C., Nelson, D.M., Ohte, N., Pardo, L.H., Rose, L.A., Sabo, R.A., Schiff, S.L., Spoelstra, J., Williard, K.W.J. 2019. Unprocessed atmospheric nitrate in waters of the Northern Forest Region in the USA and Canada. Environmental Science & Technology. Environmental Science and Technology, 53(7): 3620-3633.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wilhelm JF, Bain DJ, Green MB, Bush KF, McDowell WH (2019) Trace metals in Northern New England streams: Evaluating the role of road salt across broad spatial scales with synoptic snapshots. PLoS ONE 14(2): e0212011. https://doi.org/10.1371/journal.pone.0212011
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wymore, A.S., Leon, M.C., Shanley, J.B., & McDowell, W.H. 2019. Hysteretic Response of Solutes and Turbidity at the Event Scale Across Forested Tropical Montane Watersheds. Frontiers in Earth Science, 7. DOI 10.3389/feart.2019.00126.
  • Type: Book Chapters Status: Awaiting Publication Year Published: 2019 Citation: Wymore, AS and WH McDowell. Variable response of DOC and DON to discharge across critical zone gradients. Abstract submitted to: Biogeochemistry of the Critical Zone. Eds: Wymore AS, Yang W, Silver W, Chorover J, McDowell WH. To be published by Springer-Nature.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ardon, M.; Zeglin, L.; Utz, R.; Cooper, Scott; Dodds, W; Bixby, R.; Burdett, A.; Follstad S.J.; Griffiths, N.; Harms, T.; Johnson, L.; Johnson, S.; Jones, J.; Kominoski, J.; McDowell, W.H.; Rosemond, A.; Trentman, M.T.; Van Horn, D.; Ward, A. 2019. Experimental nutrient enrichment stimulates multipole trophic levels through algal and detrital food web pathways: A global meta-analysis from streams and rivers. 2019 Society for Freshwater Science Annual Meeting. Salt Lake City, UT. May 19-23, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Chancey, D.D. and W.H. McDowell. 2019. The influence of land use on wood decomposition and algal growth. University of New Hampshire Undergraduate Research Conference. Durham, NH. April 27, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chapela Lara, M., Schuessier, J. A., Buss, H. L., Henehan, M. J., McDowell, W. H. 2018. Extreme Li and Mg Isotope Fractionation during Tropical Weathering: From Dust to Minerals (and Everything in Between). 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Comas, X., Brocard, G. Y., Harrison, E. J., Sirianni, M.,Cornett, C., Vecchio, M., Wright, W., Brantley, S. L., McDowell, W. H. 2018. Near-surface geophysical methods at multiple scales of measurement to understand variation in erosion rates and water storage in the Luquillo CZO, Puerto Rico. 2018 Fall Meeting, AGU, Washington D.C., 10-14 Dec 2018.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Chapela Lara, M. Buss, H.L. and Pett-Ridge, J. 2018. The effects of lithology on trace element and REE behavior during tropical weathering. Chemical Geology. DOI: 10.1016/j.chemgeo.2018.09.024.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Coble, A.A., Koenig LE, Potter, J.D., Parham, L.M. and McDowell W.H. 2019. Homogenization of dissolved organic matter within a river network occurs in the smallest headwaters Biogeochemistry. 143(1):85-104.
  • Type: Book Chapters Status: Published Year Published: 2018 Citation: Dere, A., C. Engelmann, T. White, A. Wymore, A. Hoffman, J. Washburne and M. Conklin. 2018. Interdisciplinary Teaching about Earth and the Environment for a Sustainable Future Book Chapter: Implementing and Assessing InTeGrate Critical Zone Science Materials in an Undergraduate Geoscience Program, edited by A. E. E. David C. Gosselin, J. John Taber, Springer International Publishing, Springer Nature Switzerland.


Progress 10/01/17 to 09/30/18

Outputs
Target Audience: The scientific community where results were disseminated through peer reviewed publications and at regional, national and international meetings and conferences. Local communities and decision-makers concerned with effects of extreme precipitation events and forest and land management on water quality. Information was disseminated through public presentations at town meetings and at other local events or workshops. University of New Hampshire undergraduate and graduate students enrolled in NR 703/803 Watershed Water Quality Management. Data and insights from this project are incorporated into the lectures and laboratory exercises. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Opportunities for training and professional development included involvement of three post-doctoral researchers (Maria Chapela Lara, Qingtao Zhou and Hannah Fazekas), three PhD students (Lauren Koenig, Bianca Rodriguez and Meaghan Shaw), four Master's students (Ginny Hoyt, Brian Saccardi, Alison Herreid and Katherine Perez), and 9 undergraduate hourly employees (John Ciaburri, Liam Waldron, Kyle Seawards, Light Mcharo, Danielle Chancey, Brooke Gauthier, Mason Caceres, Sarah Carlson and Alexis Sims) in this research project. James Casey recently received his Bachelor degree from UNH and has worked in the UNH Water Quality Analysis Laboratory as a technician since graduation. How have the results been disseminated to communities of interest?Dissemination to teachers and middle and high school students occurred through Data Jams in Puerto Rico In January 2018, 16 science teachers from private and public schools in Puerto Rico participated in a "Data Jam" workshop. Teachers had the opportunity to work with data and parameters such as streamflow, rainfall, reservoir height, and soil moisture to investigate a basic ecology question and develop a claim-evidence-reasoning presentation to demonstrate their findings. Following the workshop, the teachers conducted data jams with their students back in the classroom, motivating them to use ecological data to create a project that presents the data in a non-traditional way (e.g. poetry, rap songs, models, TV skits). Student and teacher representatives from 10 public and private high schools and middle schools participated in the annual Long Term Ecological Research Schoolyard Program Symposium at the University of Puerto Rico in May 2018. For the dissemination of findings to the scientific community, refer to the "Journal Articles" and the "Conference Papers and Presentations" in the Products section. Dissemination of results to local and regional communities and decision makers refer to the "Other Products" in the Products section. What do you plan to do during the next reporting period to accomplish the goals? Continue data collection at long-term monitoring sites, in NH and in Puerto Rico Continue analysis of NH and Puerto Rico watershed characteristics using a geographical information system Report results at national and international meetings, meet with stakeholders and school children.

Impacts
What was accomplished under these goals? One of the major benefits of forested watersheds in humid climates is provision of clean drinking water and reduction in the delivery of undesirable nutrients to sensitive coastal ecosystems. Understanding the drivers of water quality would significantly enhance efforts to maintain drinking water supplies and protect the health of coastal eelgrass beds and coral reefs. Objective 1: Continue weekly sampling and analysis of Lamprey river water quality and compare changes in water quality to documented changes in forest cover, population density and weather extremes over the study period. The impacts of forest fragmentation and land use on water quality have been assessed through the continued long-term sampling of a forested suburban water supply watershed, the Lamprey River in southeast New Hampshire. Results show there is considerable variability in stream water nitrogen concentrations at weekly to sub-daily timescales, with values ranging from well below thresholds for impairment of the Great Bay estuary to values well above the threshold. There is a statistically significant increase in annual nitrate concentrations over the entire period of record (2000-2016). At the beginning of the study period, mean annual nitrate concentration was 0.10 milligrams of nitrogen per liter (mg N/L) and in 2017, mean annual nitrate concentration was 0.15 mg N/L. The highest annual average nitrate concentration to date was recorded in 2014 (0.19 mg N/L). The spatial variability of nitrate concentration throughout the Lamprey watershed is negatively correlated with forest cover. Incremental forest loss and conversion to developed lands results in corresponding increases in nitrogen concentrations, as forest is the land cover that best reduces nitrogen pollution. Human waste, fertilizers and animal waste are sources of nitrogen that increase in developed and agricultural land areas. When forests are converted to development, sodium and chloride concentrations in groundwater and stream water also increase as a result of deicers used on roads, parking lots and driveways to maintain "free and clear" roads during winter months. When we combine our water quality data (2003 - 2017) with data collected by the United States Geological Survey (1978 - 1999), a long-term increase in sodium and chloride in the Lamprey River is apparent. We are uncertain if nitrate, sodium and chloride levels in the Lamprey will remain relatively constant, increase or decrease with changing climate, land use, and management in the watershed. This information on the effects of forests, and forest loss, on water quality, has been critically important in local management discussions and decision-making. The information has been eagerly sought by communities, state agencies, and private consultants as they assess the impacts of land use change on water quality. Objective 2: Continue to operate water quality sensors and collect and analyze weekly to monthly grab samples at eight small watersheds throughout New Hampshire. Assess the behavior of organic nitrogen over multiple seasons and during storms and compare fluxes of organic N to watershed attributes such as forest cover, human population density, and agricultural land use. The impact of climate variability on water quality was assessed through the continued operation and maintenance of instream water quality sensors that measure nitrogen, particles, organic matter, dissolved salts, acidity, dissolved oxygen and stream temperature every 15 minutes. Weekly to monthly grab samples were also collected to verify field operation of the sensors and conduct additional analyses. The 15-minute sensor data reveal a "first flush" of nitrate during storms in the Lamprey River where nitrate concentration increases and peaks just prior to peak streamflow and subsequently declines throughout the remainder of the storm event. This suggests that sources of nitrate are closer to the mouth of the Lamprey and reach the sample site prior to the bulk of the water moving through the watershed. In the suburban Wednesday Hill Brook (a headwater stream in Lee, NH) and in a headwater stream that drains the Burley-Demerritt Organic Dairy Farm (Lee, NH) stream water nitrate concentrations are diluted during storms suggesting that groundwater is an important source of nitrogen in these suburban and agricultural catchments. Objective 3: Continue to analyze the long-term data being collected from multiple watersheds in the Luquillo Mountains of Puerto Rico and compare differences in water quality to the watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall and riparian geomorphology. The tropical forested watersheds in the Luquillo Mountains of Puerto Rico are important water supply watersheds and experienced an extreme drought in the summer of 2015 and hurricanes Irma and Maria in September 2017. We have assessed the first 9 months of 15-minute in situ sensor data following Hurricanes Irma and Maria in the Quebrada Sonadora. As expected from past hurricanes, nitrate concentrations increased a few months after the storm. Contrary to expectations, the behavior of many solutes in response to discharge was radically changed after the hurricanes. Specific conductance, an indicator of the total dissolved salts in the water, flipped from a consistent dilution response during high flow to an enrichment response both during and after Maria, likely due to deposition of marine aerosols during the hurricane and subsequent flushing from the soil profile for several months after the storm. Nitrate also flipped its behavior for at least eight months after Maria, with large concentration increases (up to 1.8 mg N/L) observed at high stream discharge during even small rainstorms. Incorporation of this newly recognized sensitivity to discharge into watershed flux estimates results in 2 to 3-fold higher values than with weekly samples. The nitrate response to storms peaked 4 months after the hurricane but was still evident 9 months later, likely mirroring the time course of major biotic processes (leaf litter decomposition and vegetation regrowth) that control nitrate fluxes. The newly recognized sensitivity of nitrate to stream discharge has important implications for future climate change scenarios. With increased frequency and intensity of hurricanes, much greater export to nitrogen-limited coastal waters can be expected than previously estimated.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Bernhardt , E. S., J. B. Heffernan, N. B. Grimm, E. H. Stanley, J. W. Harvey, M. Arroita, A. P. Appling, M. J. Cohen, W. H. McDowell, R. O. Hall, J. S. Read, B. J. Roberts, E. G. Stets and C. B. Yackulic. 2018. The metabolic regimes of flowing waters. Limnology and Oceanography 63: S99-S118. DOI: 10.1002/lno.10726.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Chorover , J., L. A. Derry and W. H. McDowell. 2017. Concentration-Discharge Relations in the Critical Zone: Implications for Resolving Critical Zone Structure, Function, and Evolution. Water Resources Research 53(11): 8654-8659. DOI: 10.1002/2017WR021111.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Clark , K. E., J. B. Shanley, M. A. Scholl, N. Perdrial, J. N. Perdrial, A. F. Plante and W. H. McDowell. 2017. Tropical river suspended sediment and solute dynamics in storms during an extreme drought. Water Resources Research 53(5): 3695-3712. DOI: 10.1002/2016WR019737.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Coble , AA, AS Wymore, MD Shattuck, JD Potter, and WH McDowell. 2018. Multi-year trends in solute concentrations and fluxes from a suburban watershed: evaluating effects of 100-year flood events. Journal of Geophysical Research  Biogeosciences. DOI: 10.1029/2018JG004657.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Contosta , A. R., A. Adolph, D. Burchsted, E. Burakowski, M. Green, D. Guerra, M. Albert, J. Dibb, M. Martin, W. H. McDowell, M. Routhier, C. Wake, R. Whitaker and W. Wollheim. 2017. A longer vernal window: the role of winter coldness and snowpack in driving spring transitions and lags. Global Change Biology 23(4): 1610-1625. DOI: 10.1111/gcb.13517.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Haase , P., J. D. Tonkin, S. Stoll, B. Burkharde, M. Frenzel, I. R. Geijzendorffer, C. Hauser, S. Klotz, I. Kuhn, W. H. McDowell, M. Mirtl, F. Muller, M. Musche, J. Penner, S. Zacharias and D. S. Schmeller. 2018. The next generation of site-based long-term ecological monitoring: Linking essential biodiversity variables and ecosystem integrity. Science of the Total Environment 613: 1376-1384. DOI: 10.1016/j.scitotenv.2017.08.111.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Hernes , P. J., R. Y. Dyda and W. H. McDowell. 2017. Connecting tropical river DOM and POM to the landscape with lignin. Geochimica Et Cosmochimica Acta 219: 143-159. DOI: 10.1016/j.gca.2017.09.028.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Koenig , L. E., C. Song, W. M. Wollheim, J. Rugg and W. H. McDowell. 2017. Nitrification increases nitrogen export from a tropical river network. Freshwater Science 36(4): 698-712. DOI: 10.1086/694906.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Hunt , C. W., L. Snyder, J. E. Salisbury, D. Vandemark and W. H. McDowell. 2017. SIPCO2: A simple, inexpensive surface water pCO(2) sensor. Limnology and Oceanography-Methods 15(3): 291-301. DOI: 10.1002/lom3.10157.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Koenig, L.E., Shattuck, M.D., Snyder, L.E., Potter, J.D. and McDowell, W.H. 2017. Deconstructing the effects of flow on DOC, nitrate, and major ion interactions using a high-frequency aquatic sensor network . Water Resources Research . 53: 10,65510,673. DOI: 10.1002/2017WR020739.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: McDowell , W.H., McDowell, W.G., Potter, J.D., Ramirez, A. 2018. Nutrient export and elemental stoichiometry in an urban tropical river. Ecological Applications. https://doi.org/10.1002/eap.1839
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Mirtl, M., E. T. Borer, I. Djukic, M. Forsius, H. Haubold, W. Hugo, J. Jourdan, D. Lindenmayer, W. H. McDowell, H. Muraoka, D. E. Orenstein, J. C. Pauw, J. Peterseil, H. Shibata, C. Wohner, X. Yu and P. Haase. 2018. Genesis, goals and achievements of Long-Term Ecological Research at the global scale : A critical review of ILTER and future directions. Science of the Total Environment 626: 1439-1462. DOI: 10.1016/j.scitotenv.2017.12.001.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Richter, D. D., et al. 2018. Ideas and perspectives: Strengthening the biogeosciences in environmental research networks. Biogeosciences. 15(15): 4815-4832. doi:10.5194/bg-15-4815-2018.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Snyder , L.E., Potter, J.D. and McDowell, W.H. 2018. An Evaluation of Nitrate, fDOM, and Turbidity Sensors in New Hampshire Streams. Water Resources Research. Special issue Continuous nutrient sensing in research and management: applications and lessons learned across aquatic environments and watersheds. DOI: 10.1002/2017WR020678
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Song, C., et al. 2018. Continental-scale decrease in net primary productivity in streams due to climate warming. Nature Geoscience. 11(6): 415. doi:10.1038/s41561-018-0125-5.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: White , T., A. Wymore, A. Dere, A. Hoffman, J. Washburne, and M. Conklin. 2017. Integrated Interdisciplinary Science of the Critical Zone as a Foundational Curriculum for Addressing Issues of Environmental Sustainability. Journal of Geoscience Education. 65(2):136-145. doi: 10.5408/16-171.1.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Wymore , A.S., N.R. West, K. Maher, P.L. Sullivan, A. Harpold, D. Karwan, J.A. Marshall, J. Perdrial, D.M. Rempe, and L. Ma (2017), Growing new generations of critical zone scientists. Earth Surface Processes and Landforms. doi: 10.1002/esp.4196.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wymore , AS, J Potter, L Snyder, B Rodr�guez-Cardona, and WH McDowell. 2018. Using in-situ optical sensors to understand the biogeochemistry of dissolved organic matter across a stream network. Water Resources Research. DOI: 10.1002/2017WR022168.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Wymore , AS, RL Brereton, DE Ibarra, K Maher, and WH McDowell. 2017. Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds. Water Resources Research. 53(7): 62796295. doi:10.1002/2016WR020016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Chapela Lara, M., J.A. Schuessler, H.L. Buss, W.H. McDowell. 2017. Decoupling of stream and vegetation solutes during the late stages of weathering: insights from elemental and Mg isotope trends at the Luquillo Critical Zone Observatory, Puerto Rico . 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 Dec.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Chorover, J., J. Gaillardet, W.H. McDowell, J.L. Druhan. 2017. Convened the B43E Concentration-Discharge Relations in the Critical Zone I and II Poster Session. 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 Dec.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Goodale, C. N. Ohte and WH McDowell. 2017. Convened the Biogeochemistry of nitrogen session at the 9th International Symposium on Ecosystem Behavior. BIOGEOMON August 20-24, 2017. Litomyal Chateau, Czech Republic.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Guti�rrez-Fonseca, P.E., A. Ramirez, C. Pringle, P. Torres, A. Covich, T. Crowl, W.H. McDowell, O. Perez-Reyes. 2017. When the rainforest dries up: Impacts of severe drought in a tropical stream . June 4-9, 2017 Society for Freshwater Science meeting, Raleigh, NC.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: L�pez-Lloreda, C., W.H. McDowell, J. Potter. 2017. Dissolved Greenhouse Gas Concentration Patterns and Relationships with Stream Chemistry in Tropical Headwater Streams . 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 Dec.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: McDowell, W.H., J. Potter, Lopez-Lloreda, C. 2017. Short-term impacts of Hurricanes Irma and Maria on tropical stream chemistry as measured by in-situ sensors . 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 Dec.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: McDowell, W.H., J. Potter. 2017. Tradeoffs in Greenhouse Gas Fluxes from Aquatic Ecosystems Along a Rural to Urban Gradient are Driven by N Loading . 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 Dec.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: McDowell, William H. 2017. Luquillo Critical Zone Observatory: linking spatial and temporal patterns in stream chemistry to underlying critical zone architecture. Institute of the Physics of the Globe of Paris. Paris, France. September 29, 2017.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: McDowell, W.H., C. Lopez-Lloreda, and J.D. Potter. Drivers of N2O flux from streams and rivers: searching for a better predictive model of N2O concentrations in inland waters . November 29, 2017, International Workshop on N2O Emissions in Various Ecosystems: Site-Based Research and Global Synthesis, Taichung, Taiwan.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Wymore, A., S. Kaushal, W.H. McDowell, P. Kortelainen, E. Bernhardt, P. Johnes, W. Dodds, S. Johnson, J. Brookshire, R. Spencer, B.Rodriguez-Cardona, A. Helton, R. Barnes, A. Algerich, S. Haq, P. Sullivan, C. Lopez-Lloreda, A. Coble, M.D. Shattuck. 2017. Carbon and nitrogen stoichiometry across stream ecosystems . 2017 Fall Meeting, AGU, New Orleans, LA, 11-15 Dec.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Wymore, AS, S Bernal, E Mart�, B Rodr�guez-Cardona, and WH McDowell. 2017. Changing perspectives on the biogeochemistry and ecology of dissolved organic nitrogen . Association for the Sciences of Limnology and Oceanography. Honolulu, Hawaii. 1 March 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Chapela Lara, M., J.A. Schuessler, H. Buss, W.H. McDowell. 2018. Decoupling of Shallow and Deep Sources of Nutrients at the Late Stages of Weathering: Insights from Traditional and Non-Traditional Tracers at the Luquillo CZO. Goldschmidt. Boston, MA. August 12-17, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Coble, A.A., A.S. Wymore, M.D. Shattuck, J.D. Potter, W.H. McDowell. Multi-year trends in solute concentrations and fluxes from a suburban watershed: Evaluating effects of 100-year flood events . Society for Freshwater Science. Detroit Michigan. May 20-24, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Guti�rrez-Fonseca, P.E., A. Ramirez, C. Pringle, P.J. Torres, A. Covich, W.H. McDowell T. Crowl, O.Perez. 2018. Hurricane impacts to a tropical stream ecosystem in the mountains of Puerto Rico. Society for Freshwater Science, Detroit, MI May 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McDowell, W.H., J. Potter, and C. Lopez-Lloreda. 2018. Short-term impacts of Hurricanes Irma and Maria on tropical stream chemistry as measured by in-situ sensors. Society for Freshwater Science, Detroit, MI May 2018
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McDowell, W.H., L.E. Koenig, L.E. Snyder, and J.D. Potter. 2018. Regional coherence of stream nitrate concentrations: implications for theory and management. 2018 meeting of the Northeast chapter of the Geological Society of America. Burlington, VT. 1820 March 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McDowell, W.H., J.D. Potter and C. Lopez-Lloreda. 2018. Sensors reveal flipping of biogeochemical behavior in a small tropical river after major hurricanes. International Association of Limnology meeting, Nanjing, China. August 23, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: McDowell, W.H. 2018. Invited participant and presenter at Parallel session 1C, Optimizing the use and outcomes of national Research Infrastructures through international participation , International Conference on Research Infrastructures, ICRI, September 12-14, 2018. Vienna, Austria.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Potter, J., A. Wymore, and W.H. McDowell. 2018. Greenhouse gas fluxes from aquatic ecosystems along a rural to urban gradient are driven by N loading . Society for Freshwater Science, Detroit, MI May 2018
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Wymore, A., A. Helton, R. Barnes, J. Brookshire, S. Kaushal, E. Bernhardt, W.K. Dodds, P. Johnes, S. Johnson, P. Kortelainen, W.H. McDowell, R. Spencer, B. Rodriguez-Cardona, A. Argerich, A. Coble, C. Lopez-Lloreda, P. Sullivan, S. Haq, M. Shattuck. 2018. (De)-coupling of dissolved organic carbon and dissolved organic nitrogen across stream ecosystems. Society for Freshwater Science, Detroit, MI May 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: L�pez Lloreda, C. 2018. Hydrology and biogeochemistry in the Luquillo Critical Zone Observatory. El Verde Field Station, El Verde, PR. October 22, 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: L�pez Lloreda, C. and W.H. McDowell, W.H. 2018. Luquillo Critical Zone Observatory. Exploring a University of Puerto Rico-R�o Piedras (UPRPR)/United States Geological Survey (USGS) Partnership to Foster Water Research. San Juan, PR. August 21, 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: McDowell, W.H. 2018. Graduate short course on watershed biogeochemistry, Beijing Normal University, 11-14 April 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: McDowell, W.H. 2018. In the eye of the storm: Long-term nitrogen dynamics in hurricane-dominated tropical montane ecosystems. Peking University, Beijing, 17 April 2018
  • Type: Other Status: Other Year Published: 2018 Citation: McDowell, W.H., J.D. Potter, C. Lopez-Lloreda. 2018. Sensors reveal new insights into controls on tropical stream chemistry after Hurricanes Irma and Maria. Nanjing Forestry University, Nanjing, China. College of Biology and the Environment. August 21, 2018
  • Type: Other Status: Other Year Published: 2018 Citation: McDowell, W.H. 2018. Clean Air Scientific Advisory Committee (CASAC) Oxides of Nitrogen, Oxides of Sulfur, and Particulate Matter - Ecological Criteria National Ambient Air Quality Standards (NAAQS) review panel.
  • Type: Other Status: Other Year Published: 2018 Citation: McDowell, W.H. 2018. Served on a panel for as part of a Pathway to Professorship program workshop. A panel of full professors shared their insights with Associate Professors who are interested putting a case forward for promotion. October 19, 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: Rodr�guez-Cardona, B. 2018. Carbon and nitrogen dynamics in streams across biomes. Seminar at the Centre d'Estudis Avan�ats de Blanes (CEAB), in Blanes, Spain. March 22, 2018.
  • Type: Other Status: Other Year Published: 2018 Citation: Wymore, AS. 2018. Global patterns in stream energy and nutrient cycling. Long Term Ecological Research webinar. March 2018. (https://www.youtube.com/watch?v=suEFjtltbEE)
  • Type: Other Status: Other Year Published: 2018 Citation: Wymore, AS. 2018. Using long-term observational data to better understand carbon: nitrogen ratios in stream ecosystems. Departmental seminar. University of New Hampshire. April 2018.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:1. The scientific community where results was disseminated through peer reviewed publications and at regional, national and international meetings and conferences 2. Local communities and decision-makers concerned with effects of extreme precipitation events and forest and land management on water quality. Information was disseminated through public presentations at town meetings and at other local events or workshops Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Opportunities for training and professional development included involvement of three post-doctoral researchers (Adam Wymore, Ashley Coble and Maria Chapela Lara), three PhD students (Lauren Koenig, Rich Brereton and Bianca Rodriguez), three Master's students (Ginny Hoyt, Brian Saccardi, Alison Herreid), and 5 undergraduate hourly employees (John Ciaburri, Christina Mroz, Casey McGrath, James Casey, Margaret Phillips and Justin Sherman) in this research project. Katie Swan received her Bachelor degree from UNH in 2014 and has worked in the UNH Water Quality Analysis Laboratory as a technician since graduation. 1. Students trained in the field of water resource management and data supported by this project were used in student projects. 2. Post-doctoral students mentored undergraduates in the field of water resource management. 3. Ph.D. student Bianca Rodriguez received a Chateaubriand Fellowship to work at the Institute of the Physics of the Globe in Paris See also "Other outcomes" in the "Accomplishments" section. How have the results been disseminated to communities of interest?Dissemination to teachers and middle and high school students occurred through Data Jams in Puerto Rico In November 2016, 24 science teachers from private and public schools in Puerto Rico participated in a six-hour "Data Jam" workshop. Teachers had the opportunity to work with 1994 and 2015 drought data and parameters such as stream flow, rainfall, reservoir height and soil moisture to investigate a basic ecology question and develop a claim-evidence-reasoning presentation to demonstrate their findings. Following the workshop, the teachers conducted data jams with their students back in the classroom, motivating them to use ecological data to create a project that presents the data in a non-traditional way (e.g. poetry, rap songs, models, TV skits). Student and teacher representatives from 10 public and private high schools and middle schools participated in the annual Long Term Ecological Research Schoolyard Program Symposium at the University of Puerto Rico in May 2017. The symposium was divided into two sessions. In the morning, there was a virtual symposium between the Puerto Rico Schools and several New Mexico schools. During the afternoon session, the Puerto Rico students presented their Data Jam projects on the 1994 and 2015 drought. What do you plan to do during the next reporting period to accomplish the goals? Continued data collection at long-termmonitoring sites, in NH and in Puerto Rico Report results at national and international meetings, meet with stakeholders and school children.

Impacts
What was accomplished under these goals? One of the major benefits of forested watersheds in humid climates is provision of clean drinking water and reduction in the delivery of undesirable nutrients to sensitive coastal ecosystems. Understanding the drivers of water quality would significantly enhance efforts to maintain drinking water supplies and protect the health of coastal eelgrass beds and coral reefs. Objective 1: Continue weekly sampling and analysis of Lamprey river water quality and compare changes in water quality to documented changes in forest cover, population density and weather extremes over the study period. The impacts of forest fragmentation and land use on water quality have been assessed through continued long-term sampling of a forested suburban water supply watershed, the Lamprey River in southeast New Hampshire. Results show there is considerable variability in stream water nitrogen concentrations at weekly to sub-daily timescales, with values ranging from well below thresholds for impairment of the Great Bay estuary to values well above the threshold. There is no statistically significant change in nitrate concentrations over the entire period of record (2000-2015), but mean annual nitrate concentrations increased from 0.10 to 0.14 milligrams of nitrogen per liter (mg N/L) during the first 10 years (2000-2009) of monitoring, declined to 0.11-0.12 mg N/L in 2010-2012 and in 2014 the highest annual average nitrate concentration to date was recorded (0.18 mg N/L). We are uncertain if nitrate levels in the Lamprey will remain relatively constant, increase or decrease with changing climate, land use and management in the watershed. The spatial variability of nitrate concentration throughout the Lamprey watershed is negatively correlated with forest cover. Incremental forest loss and conversion to developed lands results in corresponding increases in nitrogen concentrations, as forest is the land cover that best reduces nitrogen pollution and human waste, fertilizers and animal waste are sources of nitrogen that increase in developed and agricultural land areas. When forests are converted to development, sodium and chloride concentrations in groundwater and stream water also increase as a result of deicers used on roads, parking lots and driveways to maintain "free and clear" roads during winter months. This information on the effects of forests, and forest loss, on water quality, has been critically important in local management discussions and decision-making. The information has been eagerly sought by communities, state agencies, and private consultants as they assess the impacts of land use change on water quality. Data from the Lamprey River watershed, also known as the Lamprey River Hydrologic Observatory, were presented at the Annual Lamprey River Science Symposium in January 2017. This symposium is attended by scientists as well as local, state and regional managers and decision makers. See the presentations listed in the "How have the results been disseminated to communities of interest?" section. Objective 2: Continue to operate water quality sensors and collect and analyze weekly to monthly grab samples at eight small watersheds throughout New Hampshire. Assess the behavior of organic nitrogen over multiple seasons and during storms and compare fluxes of organic N to watershed attributes such as forest cover, human population density, and agricultural land use. The impact of climate variability on water quality was assessed through continued operation and maintenance of instream water quality sensors that measure nitrogen, particles, organic matter, dissolved salts, acidity, dissolved oxygen and stream temperature every 15 minutes. Weekly to monthly grab samples were also collected to verify field operation of the sensors and conduct additional analyses. The 15-minute sensor data reveal a "first flush" of nitrate during storms in the Lamprey River where nitrate concentration increases and peaks just prior to peak streamflow and subsequently declines throughout the remainder of the storm event. This suggests that sources of nitrate are closer to the mouth of the Lamprey and reach the sample site prior to the bulk of the water moving through the watershed. In the suburban Wednesday Hill Brook (a headwater stream in Lee, NH) and in a headwater stream that drains the Burley-Demerritt Organic Dairy Farm (Lee, NH) stream water nitrate concentrations are diluted during storms suggesting that groundwater is an important source of nitrogen in these suburban and agricultural catchments. Objective 3: Continue to analyze the long-term data being collected from multiple watersheds in the Luquillo Mountains of Puerto Rico and compare differences in water quality to watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall and riparian geomorphology. The tropical forested watersheds in the Luquillo Mountains of Puerto Rico are important water supply watersheds and experienced an extreme drought in the summer of 2015 and hurricanes Irma and Maria in September 2017. Using soil and stream sensor networks, we were able to document an intriguing flip-flop in biogeochemical conditions in soils and streams during the drought. After several months of near-record low rainfall, soils dried out and became more oxygenated at all hillslope positions. In contrast, the streams dried out and experienced declines in dissolved oxygen that appear to be due to in-stream or hyporheic metabolic processes as suggested by the strong diel periodicity in oxygen levels that is commonplace in streams with high ecosystem respiration. The drought increased soil carbon dioxide (CO2) emissions from hill slopes by 60% and valleys by 163%. Methane (CH4) fluxes declined by 90% in valleys after the drought but increased above pre-drought baseline by tenfold in ridges and hundredfold in hill slopes post-drought, offsetting the initial decline in soil CH4 emissions. Sensors in the Sonadora and Icacos Rivers, draining watersheds with different bedrock types, and in one small stream near the Sonadora watershed showed that as soil moisture decreased and soil oxygen increased, stream conductivity increased, and dissolved oxygen decreased as streams are fed by deeper and deeper groundwater. Streams also warmed as they dried out.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Cusack , D.F., J. Macy, and W.H. McDowell. 2016. Nitrogen additions mobilize soil base cations in two tropical forests. Biogeochemistry 128: 5165. DOI 10.1007/s10533-016-0195-7
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Hunt , C. W., Snyder, L., Salisbury, J.E., Vandemark, D., McDowell, W.H. 2017. SIPCO2: A simple, inexpensive surface water pCO2 sensor. Limnology and Oceanography Methods. doi: 10.1002/lom3.10157.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Oulehle , F., Chuman, T., Hruaka, J., Kr�m, P., McDowell, W.H., Myaka, O., Navr�til, T. and Tesa?, M. 2017. Recovery from acidification alters concentrations and fluxes of solutes from Czech catchments. Biogeochemistry Volume 132, Issue 3, pp 251272
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: R�egg , J., W.K. Dodds, M.D. Daniels, C.L. Baker, W.B. Bowden, K.J. Farrell, M.B. Flinn, T.K. Harms, J.B. Jones, L.E. Koenig, J.S. Kominoski, W.H. McDowell, S.P. Parker, A.D. Rosemond, K.R. Sheehan, M.T. Trentman, M.R. Whiles and W.M. Wollheim. 2016. Baseflow physical stream characteristics differ at multiple spatial scales in stream networks across diverse biomes. Landscape Ecology 31:119-136. DOI 10.1007/s10980-015-0289-y.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Wymore, A.S., Coble, A.A. Rodr�guez-Cardona, B., McDowell, W.H. 2016. Nitrate uptake across biomes and the influence of elemental stoichiometry: A new look at LINX II. Global Biogeochemical Cycles, 30, doi:10.1002/2016GB005468 .
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Wymore, AS, B Rodr�guez-Cardona, and WH McDowell. 2016. Understanding dissolved organic matter biogeochemistry through in situ nutrient manipulations in stream ecosystems. Journal of Visualized Experiments. 116: doi: 10.3791/54704 , http://www.jove.com/video/54704.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Wymore , AS, RL Brereton, DE Ibarra, K Maher, and WH McDowell. 2017. Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds. Water Resources Research. 53:62796295. doi:10.1002/2016WR020016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: McDowell, W.H., Potter, J.D., McDowell, W.G. and Ramirez, A. 2016. From City to Sea: Controls on Weathering Products and Limiting Nutrients in an Urban Tropical River. American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Clark, K.E., Shanley, J.B., Perdrial, N., Scholl, M.A., Perdrial, J.N., Plante, A.F. and McDowell, W.H. 2016. Tropical river suspended load and solute dynamics in storms within an extreme drought, Luquillo Critical Zone Observatory, Puerto Rico. American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Sullivan, B.N., Wymore, A., Schade, J.D. and McDowell, W.H. 2016. Dissolved Organic Carbon: Nitrate Ratios as a Driver of Methane Fluxes in Stream Ecosystems. American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Coble, A.C., Rodriguez-Cardona, B., Wymore, A., Prokushkin, A.S., Kolosov, R. and McDowell, W.H. 2016. Dissolved organic matter composition and biodegradability in a permafrost-dominated watershed network in central Siberia. American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Rodriguez-Cardona, B., Coble, A.A., Prokushkin, A.S., Kolosov, R., Spencer, R.G., Wymore, A. and McDowell, W.H. 2016. Nutrient dynamics across a dissolved organic carbon and burn gradient in central Siberia. American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wymore, W., Rodriguez-Cardona, B., Coble, A.A., Potter, J.D., Lopez Lloreda, C., Perez Rivera, K., De Jesus Roman, A. Bernal, S., Mart� Roca, E., Kram, P., Hruska, J., Prokushkin, A.S., and McDowell, W.H. 2016. Examining the role of dissolved organic nitrogen in stream ecosystems across biomes and Critical Zone gradients. American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: White, T.S, McDowell, W.H. and Brantley, S.L. 2016. Critical Zone Observatories: Platforms for Collaborative Science. Town Hall Session at the American Geophysical Union Fall Meeting. San Francisco, CA. December 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Contosta, A., D. Burchsted, E. Burakowski, M. Green, D. Guerra, M. Albert, J. Dibb, M. Martin, W.H. McDowell, M. Routhier, C. Wake, R. Whitaker, and W. Wollheim. 2107. A longer vernal window: how winter coldness and snowpack influence spring transitions and lags. Annual NERC meeting, Saratoga Springs, NY March 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Shanley, J., Risch, M., Brunette, R., McDowell, W.H., Gonzalez, G, Engle, M., DeWild, J., Krabbenhoft, D., Scholl, M. 2017. 13th International Conference on Mercury as a Global Pollutant. Providence, RI. July 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Oulehle, F., T. Chuman, J. Hruska, P. Kram, W.H. McDowell, O. Myska, T. Navratil, M. Tesar. 2017. Recovery from acidification alters concentrations and fluxes of solutes from Czech catchments. BIOGEOMON International Conference, Litomysl, Czech Republic. August 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: McDowell, William H. International Critical Zone Science: Opportunities to build a global understanding of land-water linkages. Nantes, France September 2017.
  • Type: Websites Status: Published Year Published: 2017 Citation: Potter, J.D. and Shattuck, M.D. 2016. New Hampshire Water Resources Research Center. http://wrrc.unh.edu/. November 2017.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience: The scientific community where results will be disseminated through peer reviewed publications and at regional, national and international meetings and conferences Local communities and decision-makers concerned with effects of extreme precipitation events and forest and land management on water quality. Information will be disseminated through public presentations at town meetings and at other local events or workshops. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Opportunities for training and professional development included involvement of two post-doctoral researchers (Adam Wymore and Ashley Coble), three PhD students (Lauren Koenig, Rich Brereton and Bianca Rodriguez), one Master's student (Ginny Hoyt), and 6 undergraduate hourly employees (John Ciaburri, Christina Mroz, Casey McGrath, James Casey, Margaret Phillips and Justin Sherman) in this research project. Katie Swan received her Bachelor degree from UNH in 2014 and has worked in the UNH Water Quality Analysis Laboratory as a technician graduation. Students trained in the field of water resource management and data supported by this project were used in student projects. Post-doctoral students mentored in the field of water resource management. Post-doc Adam Wymore and PhD student Bianca Rodriguez each received a fellowship from the Critical Zone Science Across Virtual Institutes (SAVI) NSF Program to support research on nitrogen and carbon cycling. Two former undergraduate students at the University of New Hampshire who previously used datasets from this project are now pursuing a PhD. PhD student Lauren Koenig was awarded the Mulholland Award from the Society for Freshwater Science. March 2016. PhD student Adam Wymore was awarded a grant from the LTER Network National Office to study elemental cycling in streams across the globe. See also "Other outcomes" in the "Accomplishments" section. How have the results been disseminated to communities of interest?Dissemination to teachers and middle and high school students occurred through Data Jams in Puerto Rico In November 2015, 22 science teachers from private and public schools in Puerto Rico participated in a six-hour "Data Jam" workshop. Teachers had the opportunity to work with 1994 and 2015 drought data and parameters such as stream flow, rainfall, reservoir height and soil moisture to investigate a basic ecology question and develop a claim-evidence-reasoning presentation to demonstrate their findings. Following the workshop, the teachers conducted data jams with their students back in the classroom, motivating them to use ecological data to create a project that presents the data in a non-traditional way (e.g. poetry, rap songs, models, TV skits). Student and teacher representatives from 10 public and private high schools and middle schools participated in the annual joint Critical Zone Observatory-Long Term Ecological Research Schoolyard Program Symposium at the University of Puerto Rico in May 2016. The symposium was divided into two sessions. In the morning, there was a virtual symposium between the Puerto Rico Schools and several New Mexico schools. During the afternoon session, the Puerto Rico students presented their Data Jam projects on the 1994 and 2015 drought. For the dissemination of findings to the scientific community, refer to the "Journal Articles" and the "Conference Papers and Presentations" in the Products section. Dissemination of results to local and regional communities and decision makers occurred through the following presentations, workshops and classes: Coble, A., Shattuck, M.D., Potter, J.D., McDowell, W.H. 2016. Concentration discharge relationships and long-term trends of solute fluxes vary among flood periods. Annual Lamprey River Science Symposium. University of New Hampshire, Durham, NH. January 8, 2016. Koenig, L. 2016.For the fourth consecutive year, Koenig served as the instructor for the STEM mini-course offered August 22-26th, 2016 through the CONNECT program at UNH (http://www.unh.edu/connect/). The course provides an opportunity for incoming freshmen that come from groups with historically low retention in STEM majors (e.g. low-income, multicultural, first-generation college students) to build community, discover college resources, and bolster skills that are needed to succeed in their academic programs (e.g. writing of lab/research reports, basic math and statistics for analyzing scientific data). There were 12 students in the class, but the broader CONNECT program serves approximately 100 students. Koenig, L., L.E. Snyder, C.W. Hunt, and W.H. McDowell. 2016. The contribution of aquatic metabolism to CO2 emissions from New Hampshire streams. Annual Lamprey River Science Symposium. University of New Hampshire, Durham, NH. January 8, 2016. McDowell, W.H. 2016. "Research Opportunities at the Critical Zone Observatories", presented at "Research Priorities to Incorporate Terrestrial-aquatic interfaces in Earth System Models" workshop. Department of Energy, Rockville, MD. September 8, 2016. McDowell, W.H. 2016. Long-term nitrogen dynamics in a tropical landscape. El Verde Field Station, University of Puerto Rico. February 18, 2016. McDowell, W.H. 2016. Participated in "Research Priorities to Incorporate Terrestrial-Aquatic Interfaces in Earth System Models" Department of Energy workshop. Rockville, MD. September 7-8, 2016. Shattuck, M.D. 2015. Understanding Water Quality Impacts of Farm Practices in Groundwater and Stream Water. Research field day at the University of New Hampshire Organic Dairy Research Farm. Lee, NH. November 4, 2015. Shattuck, M.D. 2015. Urbanization and suburbanization in New Hampshire watersheds. Presentation to University of New Hampshire class: Watershed Water Quality Management. October 6, 2015. Shattuck, M.D. 2015. Water Quality Research in the Lamprey River Hydrologic Observatory. Presentation to University of New Hampshire undergraduate class: Studio Soils. October 28, 2015. Shattuck, M.D. 2015. Watershed management in practice: Great Bay. Presentation to University of New Hampshire class: Watershed Water Quality Management. December 1, 2015. Shattuck, M.D. 2016. Organic dairy groundwater and stream water chemistry. Durham, NH. August 25, 2016. Shattuck, M.D., Potter, J., Snyder, L. and McDowell, W.H. 2016. Hydrologic controls on nitrate and specific conductivity in NH streams: New insights using sensor data. Annual Lamprey River Science Symposium. University of New Hampshire, Durham, NH. January 8, 2016. Wymore, A., Rodriguez-Cardona, B. and McDowell, W.H. 2016. Direct response of dissolved organic nitrogen to nitrate (NO3-) availability in headwater streams. Annual Lamprey River Science Symposium. University of New Hampshire, Durham, NH. January 8, 2016. Dissemination to a broader public audience occurred through the following press releases: McDowell, W.H. 2016. Spoke with reporter from the Manchester Union Leader on chemical perfluorooctanoic acid, or PFOA, which has been found in water sources in Merrimack and Litchfield. Article: "Bedford water samples detect low levels of PFOA contamination" by KIMBERLY HOUGHTON. March 25, 2016. http://www.unionleader.com/Bedford-water-samples-detect-low-levels-of-PFOA-contamination McDowell, W.H. 2016. WMUR interview. "Water contamination in NH towns by a local business -- a water expert weighs in". Apr 10, 2016. http://www.wmur.com/money/water-contamination-in-nh-towns-by-a-local-business-a-water-expert-weighs-in/38955394. McDowell, W.H. 2016. Spoke with a reporter from the Portsmouth Herald on the presence of lead in water in schools. Article: "Concerns grow over lead in drinking water" By Jeff McMenemy. May 1, 2016. http://www.fosters.com/article/20160501/NEWS/160509957 McDowell, W.H. and Potter, J.D. 2016. Interviewed for UNH Today article "Parched - Drought leaves some researchers thirsty for data." Written by Beth Potier. University of New Hampshire. September 7, 2016. https://www.unh.edu/unhtoday/2016/09/parched Shattuck, M.D. 2016. Interviewed by Max Sullivan from seacoast online for article: Going dry: Drought threatens homeowners' wells. July 31, 2016. http://www.seacoastonline.com/article/20160731/NEWS/160739950 Dissemination to local communities also occurred through invited meetings with US Senate staff members, US EPA, NH DES, local environmental consultants, and local town officials. McDowell, W.H. 2016. Attended a conservation commission meeting in Lee, NH on June 16, 2016 to discuss a clear-cut next to Wednesday Hill Brook. McDowell, W.H. 2016. Met with Kelsey Keegan, Legislative Assistant, Office of Senator Kelly Ayotte (R-NH), to discuss water resources issues in New Hampshire. Washington, D.C. February 9, 2016. McDowell, W.H. 2016. Met with Marissa Serafino, Legislative Correspondent, Office of Senator Jeanne Shaheen (D-NH), to discuss water resources issues in New Hampshire. Washington, D.C. February 10, 2016. McDowell, W.H. 2016. Met with Michelle Jelnicky, Legislative Director, Office of Representative Frank Guinta (R-NH-1), to discuss water resources issues in New Hampshire. Washington, D.C. February 10, 2016. McDowell, W.H. 2016. Met with Travis Krogman, Legislative Assistant, Office of Representative Ann Kuster (D-NH-2), to discuss water resources issues in New Hampshire. Washington, D.C. February 9, 2016. Shattuck, M.D. 2015. Met with NH Fish and Game, NRCS and Trout Unlimited to discuss water quality monitoring of adding wood to streams for stream restoration. Durham, NH. October 10, 2015. Multiple meetings 2015-2016. Shattuck, M.D. 2016. Attended a PREP technical advisory committee meeting for the State of Our Estuaries 2018 report. Portsmouth, NH. September 29, 2016. Shattuck, M.D. 2016. Attended NH EPSCoR stakeholders meeting. Concord, NH. May 17, 2016. Shattuck, M.D. 2016. Served on The Nature Conservancy Great Bay Resource Protection Partnership Coastal Conservation Plan Advisory Team. 2014-2016. What do you plan to do during the next reporting period to accomplish the goals?The impacts of forest fragmentation, land use and climate variability on water quality will continue to be assessed through weekly long-term sampling of a forested suburban watershed, the Lamprey River in southeast New Hampshire. The behavior of particles, nitrogen and other solutes over different seasons and during storms will continue to be assessed through continued operation of water quality sensors and the collection and analysis of monthly to weekly grab samples at eight stream sites throughout New Hampshire. The impacts of watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall, drought and riparian geomorphology on water quality in multiple tropical forested watersheds in the Luquillo Mountains of Puerto Rico will continue to be assessed through long-term water quality data collection and analysis of watershed characteristics using a geographical information system.

Impacts
What was accomplished under these goals? One of the major benefits of forested watersheds in humid climates is provision of clean drinking water and reduction in the delivery of undesirable nutrients to sensitive coastal ecosystems.Understanding the drivers of water quality would significantly enhance efforts to maintain drinking water supplies and protect the health of coastal eel grass beds and coral reefs. Objective 1: Continue weekly sampling and analysis of Lamprey river water quality and compare changes in water quality to documented changes in forest cover, population density and weather extremes over the study period. The impacts of forest fragmentation and land use on water quality have been assessed through continued long-term sampling of a forested suburban water supply watershed, the Lamprey River in southeast New Hampshire. Results show there is considerable variability in stream water nitrogen concentrations at weekly to sub-daily time scales, with values ranging from well below thresholds for impairment of the Great Bay estuary to values well above the threshold. There is no statistically significant change in nitrate concentrations over the entire period of record (2000-2015), but mean annual nitrate concentrations increased from 0.10 to 0.14 milligrams of nitrogen per liter (mg N/L) during the first 10 years (2000-2009) of monitoring, declined to 0.11-0.12 mg N/L in 2010-2012 and in 2014 the highest annual average nitrate concentration to date was recorded (0.18 mg N/L). We are uncertain if nitrate levels in the Lamprey will remain relatively constant, increase or decrease with changing climate, land use and management in the watershed. The spatial variability of nitrate concentration throughout the Lamprey watershed is negatively correlated with forest cover. Incremental forest loss and conversion to developed lands results in corresponding increases in nitrogen concentrations, as forest is the land cover that best reduces nitrogen pollution and human waste, fertilizers and animal waste are sources of nitrogen that increase in developed and agricultural land areas. When forests are converted to development, sodium and chloride concentrations in groundwater and stream water also increase as a result of deicers used on roads, parking lots and driveways to maintain "free and clear" roads during winter months. This information on the effects of forests, and forest loss, on water quality has been critically important in local management discussions and decision-making. The information has been eagerly sought by communities, state agencies, and private consultants as they assess the impacts of land use change on water quality. Data from the Lamprey River watershed, also known as the Lamprey River Hydrologic Observatory, were presented at the Annual Lamprey River Science Symposium in January 2016. This symposium is attended by scientists as well as local, state and regional managers and decision makers. See the presentations listed in the "How have the results been disseminated to communities of interest?" section. Objective 2: Continue to operate water quality sensors and collect and analyze weekly to monthly grab samples at eight small watersheds throughout New Hampshire. Assess the behavior of organic nitrogen over multiple seasons and during storms and compare fluxes of organic N to watershed attributes such as forest cover, human population density, and agricultural land use. The impact of climate variability on water quality was assessed through continued operation and maintenance of instream water quality sensors that measure nitrogen, particles, organic matter, dissolved salts, acidity, dissolved oxygen and stream temperature every 15 minutes. Weekly to monthly grab samples were also collected to verify field operation of the sensors and conduct additional analyses. The 15-minute sensor data reveal a "first flush" of nitrate during storms in the Lamprey River where nitrate concentration increases and peaks just prior to peak streamflow and subsequently declines throughout the remainder of the storm event. This suggests that sources of nitrate are closer to the mouth of the Lamprey and reach the sample site prior to the bulk of the water moving through the watershed. In the suburban Wednesday Hill Brook (a headwater stream in Lee, NH) and in a headwater stream that drains the Burley-Demerritt Organic Dairy Farm (Lee, NH) stream water nitrate concentrations are diluted during storms suggesting that groundwater is an important source of nitrogen in these suburban and agricultural catchments. Objective 3: Continue to analyze the long-term data being collected from multiple watersheds in the Luquillo Mountains of Puerto Rico and compare differences in water quality to watershed slope, aspect, bedrock type, forest cover, hurricane disturbance, rainfall and riparian geomorphology. The tropical forested watersheds in the Luquillo Mountains of Puerto Rico are important water supply watersheds and experienced an extreme drought in the summer of 2015. Using soil and stream sensor networks, we were able to document an intriguing flip­flop in biogeochemical conditions in soils and streams. After several months of near ­record low rainfall, soils dried out and became more oxygenated at all hillslope positions. In contrast, the streams dried out and experienced declines in dissolved oxygen that appear to be due to in­stream or hyporheic metabolic processes as suggested by the strong diel periodicity in oxygen levels that is commonplace in streams with high ecosystem respiration. The drought increased soil carbon dioxide (CO2) emissions from hill slopes by 60% and valleys by 163%. Methane (CH4) fluxes declined by 90% in valleys after the drought but increased above pre­drought baseline by tenfold in ridges and hundredfold in hill slopes post­drought, offsetting the initial decline in soil CH4 emissions. Sensors in the Sonadora and Icacos Rivers, draining watersheds with different bedrock types, and in one small stream near the Sonadora watershed showed that as soil moisture decreased and soil oxygen increased, stream conductivity increased and dissolved oxygen decreased as streams are fed by deeper and deeper groundwater. Streams also warmed as they dried out. Change in knowledge: Increased understanding of the long-term water quality trends in a suburban New Hampshire watershed. Increased understanding of the water quality response to storm events in New Hampshire watersheds with different land covers and land uses. Increased scientific understanding of the impact of forests, hydrologic flow paths, and human population density on water quality in water supply watersheds. Increased understanding of the effects of climatic extremes (2015 drought) on water quality and soil gas flux in tropical rain forest watersheds. Increased public awareness of the above knowledge.

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Appling, A.P., Leon, M.C. and McDowell, W.H. 2015. Reducing bias and quantifying uncertainty in watershed flux estimates: The R package loadflex. Ecosphere. 6(12): Article 269. DOI: 10.1890/ES14-00517.1.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Contosta , A. R., Adolph, A., Burchsted, D., Burakowski, E., Green, M., Guerra, D., Albert, M., Dibb, K., Martin, M., McDowell, W.H., Routhier, M., Wake, C., Whitaker, R., and Wollheim, W. 2016. A longer vernal window: the role of winter coldness and snowpack in driving spring transitions and lags. Global Change Biology. DOI: 10.1111/gcb.13517.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Figueroa-Nieves, D, McDowell, W. H., Potter. J.D. and Martinez, G. 2016. Limited uptake of nutrient input from sewage effluent in a tropical landscape. Freshwater Science. 35(1):1224. DOI: 10.1086/684992.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Rodriguez-Cardona, B., Wymore, A.S. and McDowell, W.H. 2016. DOC:NO3 ratios and NO3 uptake in forested headwater streams. Journal of Geophysical Research: Biogeosciences. 121(1):205-217. doi:10.1002/2015JG003146.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Wymore A.S., Rodriguez-Cardona B. and McDowell, W.H. 2015. Direct response of dissolved organic nitrogen to nitrate availability in headwater streams. Biogeochemistry. 126:1-10. DOI 10.1007/s10533-015-0153-9.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Wymore, A.S., Coble, A.A. Rodr�guez-Cardona, B., McDowell, W.H. 2016. Nitrate uptake across biomes and the influence of elemental stoichiometry: A new look at LINX II. Global Biogeochemical Cycles, 30, doi:10.1002/2016GB005468.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Clark, K.E., A.F. Plante, J.K. Willenbring, D.J. Jerolmack, G. Gonzalez, R.F. Stallard, S.F. Murphy, D.R. Vann, M. Leon and W.H. McDowell. 2015. River Suspended Sediment and Particulate Organic Carbon Transport in Two Montane Catchments in the Luquillo Critical Zone Observatory of Puerto Rico over 25 years: 1989 to 2014. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Contosta, A., A.C. Adolph, D. Burchsted, M. Green, W.H. McDowell, and the New Hampshire EPSCoR Ecosystems & Society Sensor Team. The Vernal Window Flow Path: a Cascade of Ecological Transitions Delineated at Scales from Points to Pixels. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Dodds, W.K., J. R�egg, K. Sheehan, C. Song, F. Ballantyne, C. Baker, W.B. Bowden, K. Farrell, M.B. Flinn, E. Garcia, T. Harms, J. Jones, L. Koenig, J.S. Kominoski, W.H. McDowell, D. McMaster, S. Parker, M.T. Trentman, M. Whiles, W.M. Wollheim, A. Argerich and B. Penaluna. 2015. Biome Context and Lotic Ecosystem Rates. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Hernes, P., R.Y. Dyda and W.H. McDowell. 2015. Seasonal variation and processing of vascular plant organic matter in tropical montane catchments as reflected by riverine DOC compositions. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Kalina Manoylov, Debora Figueroa-Nieves, William McDowell. 2016. Effects of sewage effluents on benthic algal communities in tropical streams. Society for Freshwater Science Annual Meeting. Sacramento, CA. May 2016.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Miller, M.P., Boyer, E.W., Diane M. McKnight, D.M., Brown, M.G., Gabor, R.S., Hunsaker, C.T., Iavorivska L., Inamdar, S., Johnson, D.W., Kaplan, L.A.,Lin, H., McDowell, W.H., Perdrial, J.N. 2016. Variation of organic matter quantity and quality in streams at Critical Zone Observatory watersheds. Water Resources Research. DOI: 10.1002/2016WR018970.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Koenig, L. 2016. Dissolved organic matter dynamics in a suburbanizing watershed: the importance of wetlands, people, and flowpaths. Graduate Research Conference. University of New Hampshire. Durham, NH. April 12, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Koenig, L., L.E. Snyder, W.H. McDowell and C.W. Hunt. 2015. The contribution of aquatic metabolism to CO2 emissions from New Hampshire streams. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Koenig, L., Ruegg, J., Wollheim, W., McDowell, W.H. 2016. Variation in ammonium uptake rates throughout a tropical watershed: Implications for scaling ecosystem processes. Society for Freshwater Science Annual Meeting. Sacramento, CA. May 24, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Mayol-Bracero, O.L., F. Morales-Garcia, G. Santos-Figueroa, L. Custals, M. Izaguirre, J.M. Prospero and W.H. McDowell. 2015. African Dust Concentrations in the Caribbean Island of Puerto Rico. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: McDowell, W.H. 2015. Integrating International LTER and CZO networks. Sino-US CZO Workshop, Guiyang, China. Oct 5-11, 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: McDowell, W.H. 2015. International Critical Zone Science: Opportunities to Build a Global Understanding of Land-Water Linkages. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: McDowell, W.H. 2016. International LTER and CZO networks: Opportunities to build a global understanding of land-water linkages. Invited presentation at the High Level Round Table Global Observatory meeting hosted by Australian Terrestrial Ecology Research Network (TERN), Brisbane, Australia. 7 March 2016. Presented remotely.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: McDowell, W.H. 2016. Long-term Nitrogen Dynamics in a Tropical Landscape. Technical University of Dresden, Dresden, Germany. May 10, 2016.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: McDowell, W.H. 2016. Unraveling the mystery of DON. Technical University of Dresden, Dresden, Germany May 4, 2016.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: McDowell, W.H., Potter, J., Nelson, S.J. 2015. DOC concentrations of New England (USA) lakes: Is there a response to changing atmospheric deposition? Acid Rain 2015. Rochester, NY. October 19-23, 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: McDowell, William H. Linking ILTER and Critical Zone Science: Opportunities to build a global understanding of land-water linkages. International LTER First Open Science Meeting. Kruger National Park, South Africa. 10 October 2016.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: McDowell, W.H. 2015. What makes a CZO a CZO? Sino-US CZO Workshop, Guiyang, China. Oct 5-11, 2015.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: McDowell, W.H. 2016. Critical Zone Science and the Luquillo Critical Zone Observatory. Florida Coastal Everglades Long Term Ecological Research meeting. Miami, Florida. March 15, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: McDowell, William H. Plenary talk, International LTER First Open Science Meeting. Kruger National Park, South Africa. 12 October 2016. Brothers in earth systems research: Convergence of Critical Zone and ecosystem science as used in LTER.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: McDowell, William H. 2015. Spatial and temporal variability in urban water quality on a tropical island. Second Conference on Water Resource Sustainability Issues on Tropical Islands. Honolulu, Hawaii. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Rodriguez-Cardona, B., A. Wymore, L. Koenig, A.A. Coble and W.H. McDowell. 2015. Response of non-added solutes during nutrient addition experiments in streams. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Schade, J.D., J. Bailio, and W.H. McDowell. Nitrate loading and CH4 and N2O Flux from headwater streams. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Shanley and McDowell. 2016. Making sense of in-stream sensors. Annual Hubbard Brook Cooperators' Meeting. Woodstock, NH. July 13-14, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Shanley, J.B., J. F. Saraceno, B.T. Aulenbach, A. Mast, D.W. Clow, K. Hood, J.F. Walker, S.F. Murphy, A. Torres-Sanchez, G. Aiken and W.H. McDowell. 2015. Comparing Stream DOC Fluxes from Sensor- and Sample-Based Approaches. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Shattuck, M.D. 2016. Non-Point Nitrogen Sources and Transport in the Great Bay Watershed. NH Water and Watershed Conference. Plymouth, NH. March 18, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Song, C., A. Argerich, C. Baker, W.B. Bowden, W.K. Dodds, M. Douglas, K. Farrell, M.B. Flinn, E. Garcia, K.B. Gido, T. Harms, J. Jones, L. Koenig, J.S. Kominoski, K.S. McDonald, W.H. McDowell, D. McMaster, S. Parker, A. Rosemond, J. R�egg, K. Sheehan, M.T. Trentman, W.M. Wollheim and F. Ballantyne. 2015. Temperature sensitivity of stream gross primary production and respiration from the tropics to the arctic. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Torres-Delgado, E., C.J. Valle-Diaz, D. Baumgardner, W.H. McDowell, G. Gonzalez and O.L. Mayol-Bracero. 2015. The Role of African Dust Particles on Cloud Chemistry and Microphysics in a Tropical Montane Cloud Forest in the Caribbean. American Geophysical Union Fall Meeting. San Francisco, CA. December 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wollheim, W., Dodds, W., Whiles, M., Sheehan, K., Stewart, R., Ballantyne, F., Baker, C., Bowden, W., Farrell, K.J., Flinn, M., Gido, K., Harms, K., Helton, K., Jones, J., Koenig, L., McDowell, W.H. 2016. Scaling laws for aquatic metabolism vs. watershed size. Society for Freshwater Science Annual Meeting. Sacramento, CA. May 22, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: McDowell, W.H., Potter, J., Ramirez, A. 2016. Export of carbon, nutrients, and weathering products from a highly urbanized tropical watershed. Society for Freshwater Science Annual Meeting. Sacramento, CA. May 25, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wymore, A., Rodriguez-Cardona, B., McDowell, W.H., Kram, P., Hruska, J. 2016. Examining the role of dissolved organic nitrogen in stream ecosystems across biomes. Society for Freshwater Science Annual Meeting. Sacramento, CA. May 24, 2016.
  • Type: Websites Status: Published Year Published: 2016 Citation: Potter, J.D. and Shattuck, M.D. 2016. New Hampshire Water Resources Research Center. http://wrrc.unh.edu/. November 29, 2016.