CLIMATE, CARBON AND LAND USE INTERACTIONS IN A MIXED AGRICULTURAL, RESIDENTIAL AND FORESTED LANDSCAPE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1006997
• Project No.: NH00634
• Project Start Date: Oct 1, 2015
• Project End Date: Sep 30, 2018

Project Director
Ollinger, S.

Recipient Organization
UNIVERSITY OF NEW HAMPSHIRE
(N/A)
DURHAM,NH 03824

Performing Department
Natural Resources and the Environment

Non Technical Summary
The topic of ecosystems and climate is often dominated by discussions about how climate change will impact ecosystems. However, natural, agricultural, and residential ecosystems play an important role in regulating climate in several ways. In the simplest terms these can be thought of as "breathing" (exchange of carbon dioxide and other greenhouse gases), "sweating" (exchange of heat through evapotranspiration of water), and "reflectivity" (the amount of incoming sunlight that is absorbed as heat or reflected back towards space). Understanding the climate impact of different land-use and land management activities requires knowledge of all three of these processes across a variety of land cover types. This project will provide real-time measurements of the full suite of processes in four different land cover types (forest, hayfield, cornfield, and urban), allowing UNH researches and farm managers to gain a more complete understanding of land-climate interactions in New Hampshire.

Animal Health Component

0%

Research Effort Categories

Basic

70%

Applied

30%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
132	0199	1060	80%
102	0613	1060	10%
102	1699	1060	10%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 132 - Weather and Climate;

Subject Of Investigation
1699 - Pasture and forage crops, general/other; 0199 - Soil and land, general; 0613 - Mixed conifer-broadleaf forests;

Field Of Science
1060 - Biology (whole systems);

Keywords

climate change

carbon dioxide

albedo

heat exchange

ecosystem-climate interactions

Goals / Objectives
Residents of New Hampshire have a close relationship with their landscape and ecosystems, relying on forest and agricultural land for their economic, cultural and personal well-being. The natural, agricultural and residential ecosystems in New Hampshire also play an important role in climate, through regulation of carbon dioxide and other greenhouse gases, as well as through their effects on surface heat fluxes and albedo. However, New Hampshire's ecosystems are facing increased pressures from a suite of environmental, social and economic factors that impact the provisioning, regulating and cultural services for which these ecosystems are relied upon.New Hampshire, along with the rest of northern New England, has already experienced changes in climate over the past thirty years, with conditions becoming both warmer and wetter on average, albeit with longer period of drought. More precipitation is occurring as large events, separated by longer periods with no precipitation, and a greater amount of future precipitation is projected to occur in winter, with hotter, drier summers. Predicted changes in climate clearly have substantial implications for New England's natural, agricultural and residential ecosystems. Moreover, development pressures and increasing suburbanization in New Hampshire have led to complex patterns of urban, suburban, forested and agricultural landscapes. These mixed landscapes play an important role in influencing the environment, economy, and human well-being. For this reason, understanding how greenhouse gas and energy fluxes vary over different land cover types will help us better assess the impacts of interactions between climate and land use under future climate and land use scenarios.Previous work on this topic funded by NHAES (#NH00550; NIFA accession 223368) integrated plot-level field measurements, remote sensing and modeling to examine the interactions between climate change, greenhouse gases and land use in the Durham, NH area. Over the past year, instrumented flux towers have been installed at four sites used in our previous AES project. Operating continuously since January 2014 at four sites on UNH property, these systems measure carbon dioxide (CO2), water and heat fluxes, as well as albedo, over forest, hayfield, corn and impervious surfaces. These data will allow for more accurate estimates of how ecosystems influence climate over each component of the landscape. Additionally, the eddy flux systems will allow for effects on carbon fluxes as a result of management activities (e.g. fertilizing, harvesting, watering) to be examined. The work proposed here will (1) provide an improved understanding of how each component of a mixed landscape contributes to the surface energy budget; (2) highlight the tradeoffs among multiple land management strategies in terms of their net climate effect; and (3) allow for better estimates of climate forcing under various land-use scenarios. Comprehensive studies of net climate impacts as proposed here are of critical importance for preparing effective land management policies that balance climate mitigation with food production, forest resources and many other services for which New Hampshire's ecosystems are relied upon. As such, this proposal is particularly responsive to the NHAES priorities and NIFA emphasis on activities that focus on climate change and supporting rural economies.The overarching goal of the proposed research is to better understand interactions between ecosystems, land use and climate in a mixed-use landscape consisting of agriculture, forest, residential areas and impervious surfaces. Whereas our previous NHAES investigation focused on the influence of greenhouse gas exchange, the proposed work will focus on surface energy fluxes and their relative importance in the overall radiative forcing budget. We will accomplish this through the following objectives:1. Measure ecosystem-atmosphere exchanges of CO2 and water in agricultural, forested and suburban landscapes using instrumented canopy flux towers and compare these data across sites and with those previously collected from plot-level field measurements in the same area.2. Measure solar radiation, albedo, sensible heat and latent heat exchange in agricultural, forested and suburban landscapes using eddy flux data and compare these to previous estimates derived from modeling and remote sensing.3. Evaluate the impact of land management (e.g. fertilizing, watering, harvesting) on CO2, water and heat fluxes in agricultural systems.4. Incorporate measurements of surface energy fluxes for agricultural, forested and residential landscape units into the Community Land Model (CLM; http://www.cgd.ucar.edu/tss/clm/) to simulate the effect of land cover on climate.Our work will focus primarily on the southern part of the state where we have an established network of field plots, flux towers and high resolution remote sensing data. These data will serve as the basis for estimating how ecosystems influence climate inthe major components of the New Hampshire landscape.

Project Methods
The proposed work will be carried out using the following methods and procedures:1. Measure CO2 and water fluxes in agricultural, forested and suburban landscapes using eddy flux data and compare these data across sites and with those previously collected from field measurement in the same area. We will use eddy flux measurements from four towers located on UNH property that broadly represent the major components of the New Hampshire landscape to quantify CO2 fluxes and water fluxes. Where possible, these data will be validated with field measurements from plots established as part of prior NHAES funding. These span a combination of agricultural (4 plots), forested (8 plots), and residential (4 plots) land-use types, where plant biomass, carbon and nitrogen pools, and greenhouse gas fluxes were measured. Instrumentation for each of the four flux systems includes a LI-COR LI-7200 Enclosed CO2/H2O Analyzer and Gill WindMaster Sonic Anemometer, as well as a full suite of biometeorological sensors that include air and soil temperature/humidity probes, a rain gauge tipping bucket, a quantum sensor, and a net radiometer. The systems operate continuously and record raw data in 30-minute intervals. At present, these data are manually downloaded and brought back to PI Ollinger's laboratory for processing the raw data into CO2 and water fluxes with the eddy covariance method. The continuous nature of these data will allow for a comparison of net ecosystem CO2 exchange (NEE) across sites and over time.2. Measure net radiation, albedo, sensible heat and latent heat in agricultural, forested and suburban landscapes using eddy flux data and compare these to previous estimates derived from modeling and remote sensing. We will derive sensible and latent heat fluxes from each flux tower site with direct measurements from the CO2/H2O gas analyzer and sonic anemometer. We will use the eddy covariance method to calculate sensible and latent heat fluxes from measurements of sonic temperature and water concentration at each site. A Kipp & Zonen CNR4 Net Radiometer at each site will measure incoming and outgoing total shortwave and longwave radiation, from which we will calculate net radiation and albedo. Together, these surface energy flux measurements stand to improve estimates of climate forcing over those derived previously from model results and remote sensing as they represent the first direct measurements of surface energy fluxes. We still plan to derive remotely sensed estimates of latent heat fluxes and albedo in order to evaluate patterns across the mixed landscape; however, the flux tower measurement will serve as validation of these remotely sensed estimates.3. Evaluate the impact of management (e.g. fertilizing, watering, harvesting) on CO2, water and heat fluxes in agricultural systems. The continuous data captured by the eddy flux systems over each site provide a unique opportunity for agricultural system monitoring, with implications for evaluating impacts of management both on productivity and on climate interactions. For instance, the potential to monitor soil moisture and evaporative water losses throughout a day, a week or a month can provide practical farm management data. Simultaneous measurements of carbon uptake or losses from the system also provide the possibility to monitor in real time the effects of particular treatments such as fertilization--which has implications both for management and for climate interactions. While data are being collected continuously over each site, we currently lack the ability to monitor fluxes in real time. Funding from the NHAES Hatch program here would allow us to install SmartFlux software (http://www.licor.com/env/products/eddy_covariance/smartflux.html) at each flux tower site that would provide automated processing of raw data on-site; fully processed fluxes of sensible heat, latent heat, evapotranspiration, CO2 and H2O at the site and in real time; and GPS time synchronization to keep instrument clocks in sync within and across all four sites. It would also provide funding for installation of wireless communication devices at each site to transfer these processed data directly to PI Ollinger's laboratory. These improvements to the eddy flux systems would eliminate the need for weekly site visits to download data and manually process the raw data into fluxes, and would allow for continuous data streaming of real-time carbon, water and energy fluxes for each system. The real-time data would be made accessible to UNH Farm Services management and the UNH community. As such they will facilitate monitoring and management applications, course curricula exercises and student projects.4. Incorporate measurements of surface energy fluxes for agricultural, forested and residential landscape units into the Community Land Model (CLM) to simulate the effect of land cover on climate. Whereas previous modeling efforts that examined tradeoffs among multiple land uses in their ability to either contribute to or mitigate climate change involved a biogeochemical model, we will build on an existing partnership with the National Center for Atmospheric Research (NCAR) established through the NSF NH-EPSCoR project and incorporate our data in the Community Land Model (CLM). Data from the newly operational flux tower sites over four land cover types within the same landscape offers a unique opportunity to evaluate how well the CLM model simulates the effects of land cover on surface energy fluxes. Here, we will evaluate surface energy fluxes (latent heat, sensible heat) using CLM over all four flux tower sites; quantify changes in surface temperature due to biophysical mechanisms using the CLM and compare these to measured values; identify sources of error or uncertainty in CLM simulations that may contribute to differences in partitioning of biophysical factors compared to the flux tower sites.

Progress 10/01/15 to 09/30/18

Outputs
Target Audience:Our target audiences include scientists involved with understanding climate effects of ecosystems and land management. members of the public, including forest, farm and land managers with a stake in climate effects of ecosystems, and students studying areas of natural resources and environmental sciences related to climate change and ecosystems. Specific examples of each are listed below. Members of the agricultural, forestry and earth science communities reached via professional presentations and publications (see Products). Members of the public who attended a presentation on forests and climate by Dr. S. Ollinger at the Hubbard Brook Experimental Forest, NH, Aug 7, 2018 Junior and senior class students from a local high school (Phillips Exeter Academy CHE 343 Chemistry of the Environment tour and demonstration of eddy flux tower data collection at Thompson Farm Research Site). 8th Grade Class, The Blue School, New York City, NY - April 2018 - skype a scientist with Dr. Rebecca Sanders-DeMott 9th Grade Class, Mountain View High School, Mesa, AZ - Oct 2018 - skype a scientist with Dr. Rebecca Sanders-DeMott 3rdGrade Class, Bibb County School District, Macon, GA - Nov 2018 - skype a scientist with Dr. Andrew Ouimette Bishop Guertin High, Nashua, NH; Old Town High, Old Town, ME; Newport Middle and High, Newport, NH; Portsmouth High, Portsmouth, NH; Dover High, Dover, NH Training for "Tracking the Vernal Window with a Low-cost Instrumentation Suite" Undergraduate students from UNH in research internships: UNH Environmental Sciencesenior, Kyle MacDonald, focusing on usingleaf traits to estimate photosynthetic capacity of vegetationfor his seniorproject leading to poster presentation; UNH Earth Science junior,Emily Wilcox, focusing onthe effect of snow and frost on the patterns of carbon dioxide uptake and loss from forests and grasslands for her senior thesis; UNH Environmental Science undergraduates Emily Perry and Kaitlyn Baillargeon focusing on the relationship between carbon fluxes and leaf traits, and UNH Sustainable Agriculture and Food Systems senior focusing on measurement of carbon, water, and energy fluxes in forest and agricultural ecosystems. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training The project director, science staff and postdoc provided mentoring and training forKyle MacDonald, UNH Environmental Science undergraduate student (class of 2018), in writing and presenting his work on the project as part of his senior project. He presented his work at the UNH Undergraduate Research Conference in Spring 2018 We worked one-on-one with Sean Fogarty, UNH undergraduate in Sustainable Agriculture and Food Systems, to develop and enact protocols for eddy flux tower maintenance, calibration, data streaming,and communication. We trained UNH undergraduates and research technician, Kyle MacDonald, Eliza Mullen, Kaitlyn Baillargeon, Emily Perry, Emily Wilcox, Sarah Cantwell and Mikayla Jacobs on instruments (Licor 6800, Licor 2200-C, Licor 3100-C) used for plot-level measurements of photosynthesis, leaf area index, and leaf size, as well as in the collection of field and laboratory data. Professional Development Participation by Rebecca Sanders-DeMott, UNH AES Postdoctoral Research Associate, in several professional conferences including the Fall 2018 AGU Meeting in Washington D.C., the Hubbard Brook Ecosystem Study Annual Meeting, Woodstock, NH in July 2018, the Preparing for a Northwest Passage: The Role of New England in Navigating the New Arctic conference in Durham, NH on March 25, 2018, and in the 11th Annual Lamprey River Research Symposium, Durham, NH on January 8, 2018. Participation by early career research staff, Andrew Ouimette in the Fall 2018 AGU Meeting in Washington D.C. How have the results been disseminated to communities of interest? Research presentations at academic and professional conferences, including UNH Undergraduate Research Conference, American Geophysical Union Conference, the Hubbard Brook Ecosystem Study Annual Meeting, the Preparing for a Northwest Passage: The Role of New England in Navigating the New Arctic conference, and in the 11th Annual Lamprey River Research Symposium. Publication of research articles to peer-reviewed journals including Agricultural and Forest Meteorology, Theoretical and Applied Climatology, and Remote Sensing. Presentation and tour of Thompson Farm flux tower site for 2 Phillips Exeter Academy Chemistry of the Environment (CHE 343) classes April 2018. Outreach via skype a scientist to the 8th Grade Class at The Blue School, New York City, NY (April 2018), the 9th Grade Class at Mountain View High School, Mesa, AZ (Oct 2018) two 3rd Grade Classes at the Bibb County School District in Macon, GA (Nov 2018). 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 goal of this project wasto measure how different landscapes and vegetation types in New Hampshire affect climate, locally as well as globally. Typically, we think in terms of the effect of climate on plants,animals, or our own activities. But something we're trying to better understand is the impact vegetation--and how it is managed by humans--has on climate. By understanding these processes more thoroughly, we hope to improve the accuracy of models and better understand how our climate will change as patterns of land use change in the future. We also hope the information we collect will help land managers make decisions about how best to use the landscapes they're responsible for. OBJECTIVE 1 Continuous measurements of carbon dioxide (CO2) and water exchange between ecosystems and the atmosphere were made at the forest, field pasture, and cornfield sites in Durham, NH. In this past year, we automated procedures for quality control and filling gaps in the data and produced a complete, up-to-date dataset for analysis and publication. We have continued to collect measurements of aboveground productivity and canopy leaf area to compare with flux tower measurements. We expanded work at the forested site in two ways. First, we applied data analysis techniques derived from our work to examine the impacts of winter/spring climate on ecosystem carbon fluxes in a broader set of forested sites. Second, we assessed the influence of biodiversity on ecosystem carbon and water fluxes. To do this we collected a spatially and temporally rich dataset of leaf structural, chemical, and physiological traits for dominant and co-dominant tree species at the Thompson Farmflux tower site. Leaf traits were collected through the canopy, across the growing season, and scaled to the stand scale using measurements of canopy and stand structure, and compared to eddy covariance derived estimates of stand C fluxes. Previously, we found that carbon fluxes in the hayfield and forest responded differently to variation in winter conditions. Specifically, the warm winter temperatures and low snowpack during the winter of 2016 led to relatively large losses of carbon from the deciduous forest and relatively large carbon uptake in the perennial hayfield. Preliminary results from the regional analysis of forested sites parallel those found between landcover types locally. In deciduous forests, soil temperature ramp-up precedes carbon uptake in the spring, while in evergreen forests the start of carbon uptake precedes springtime increases in soil temperature. Together, these findings suggest that, as winters continue to warm the length of the growing season (or carbon uptake) may increase in evergreen or perennial systems, while in deciduous systems ecosystem respiration (springtime carbon loss) could outpace the extension of the growing season. OBJECTIVE 2: Concurrent with continuous measurements of CO2and water fluxes, solar radiation, albedo, and heat fluxes have been made at all three of our flux tower sites: forest (Thompson Farm, Durham), field/pasture (Kingman Farm, Madbury) corn/agriculture (Moore Fields, Durham). OBJECTIVE 3. Nothing new to report in addition to previous years. Objective 4. Over the past several years we reported on the results of using surface energy flux measurements at our Durham, NH flux sites to validate and test the Community Land Model (CLM).During the past year, these findings were published in two manuscripts that used local flux data and CLM to assess the role of surface energy fluxes in regulating local climate, and the feasibility of using local site data to test a global scale earth system model. CHANGE IN KNOWLEDGE: When looking at surface energy fluxes across land cover types, we find that forested sites are darker than all other land cover types, and absorb even more of the sun's energy than a dark asphalt parking lot. Compared to the albedo (reflectivity) of other land cover types, the low reflectivity of forests has a warming effect on climate. However, despite absorbing more of the sun's energy, forests have the coolest surface (or skin) temperature of any other land surface in our study because forests have a very roughsurface compared to other sites with shorter vegetation.Surface roughness of forests promotes turbulent mixing of air that carries heat away from the surface of the forest. So it's a forest's ability to "sweat" as well as its rough surface that allows it to exchange heat with the air and enables it to maintain cooler surface temperatures than other land surfaces. We find that different land cover types and different vegetation types (deciduous versus perennial or evergreen vegetation) respond differently to climate. This is especially true during warming winter climate where different land cover types can release more or less CO2 into the atmosphere, potentially impacting climate at the global scale. For example, in 2016 warm winter temperatures and minimal snowpack led to large cumulative losses of carbon from the deciduous forest site in Durham, NH during February/March 2016. In contrast, during this same period, the (perennial) grassland was able to begin growing in February (much earlier than normal) and was able to act as a moderate sink for carbon.Resultsstudies suggest that carbon losses to the atmosphere in deciduous systems may increase during warm, snow-free winter conditions when vegetation growth is restricted by phenology. However, in perennial or evergreen systems (e.g. hayfield, evergreen forest), vegetation has a greater potential to activate photosynthesis during warmer winters and is able to take up carbon during the "dormant season," perhaps moderating increasing winter carbon losses with warmer temperatures. We have also begun research examining the influence of forest biodiversity on ecosystem carbon uptake and productivity. Preliminary results have shown that the dominant tree species within NH forests display a high diversity of both chemical and physical leaf traits and that these traits vary across species, height in the canopy, and time. However, contrary to expectations, preliminary results show a lack of evidence for mechanisms relating a high diversity in leaf traits to increased productivity within a forest stand. We know that at some scale diversity has a positive influence on ecosystem productivity and stability. Moving forward we are investigating the influence of differences other tree species properties such as crown shape, differences in nutrient demand and mechanisms of nutrient acquisition, and differences in the amount of carbon various species allocate to foliage, wood and roots. The challenge---and novelty---of our work is trying to integrate all these factors (vegetation type, biodiversity, greenhouse gases, reflectivity, evaporative cooling, and surface roughness) to determine their combined effect on local and global climate.

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Sanders-DeMott R, Ouimette A, Lepine L, Fogarty S, Burakowski L, Ollinger S. Contrasting response of forest and grassland to an extremely warm winter. Conference: Preparing for a Northwest Passage: The Role of New England in Navigating the New Arctic, Durham, NH (poster, March 25, 2018)
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Sanders-DeMott R, Burakowski E, Ouimette A, Lepine L, Fogarty S, Wilcox E, Conte T, Contosta A, Ollinger S. Contrasting effects of a warm winter on carbon fluxes across land cover types in NH, USA. 11th Annual Lamprey River Research Symposium, Durham, NH (oral, January 8, 2018)
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Macdonald K, Ollinger S, Ouimette A. Using Leaf Traits to Estimate Photosynthetic Capacity. College of Life Science and Agriculture Undergraduate Research Conference (COLSA URC). April 21st,2018.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2019 Citation: Burakowski E, Tawfik A, Ouimette A, Lepine L, Zarzycki C, Novick K, Ollinger S, Bonan B. Simulating surface energy fluxes using the Variable Resolution Community Earth System Model (VR-CESM). Theoretical and Applied Climatology. In Press.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Burakowski EA, Tawfik A, Ouimette A, Lepine L, Novick K, Ollinger SV, Zarzycki C, Bonan GB. 2017. The role of surface roughness, albedo, and Bowen ratio on ecosystem energy balance in the Eastern United States. Agricultural and Forest Meteorology: Ameriflux 20th Anniversary Special Issue, 249: 367-376. doi: 10.1016/j.agrformet.2017.11.030
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Levy C, Burakowski EA, Richardson A. Small-scale albedo measurements: A UAV approach. Remote Sensing, 10(8): 1303. doi: 10.3390/rs10081303
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Ouimette AP, Ollinger SV, Sanders-DeMott R, Zhou Z, Hastings J, Baillargeon K, Wilcox E, Perry E. Does Diversity in Species Specific Leaf Traits Promote Stability of Forest Ecosystem Carbon and Water Fluxes? Fall 2018 AGU Meeting, Washington D.C.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Sanders-DeMott R , Ouimette AP, Ollinger SV. The Role of Winter in Forest Ecosystem Carbon Metabolism Across the Northeastern United States. Fall 2018 AGU Meeting, Washington D.C.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Sanders-DeMott R, Ouimette A, Ollinger S. Determining the influence of winter on ecosystem carbon metabolism across the northeast US. July 2018 Hubbard Brook Ecosystem Study Annual Meeting, Woodstock, NH.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Burakowski EA. Remote Sensing and modeling of snow and vegetation. Arctic Science and Integration Quest 2, Tokyo, Japan. October 2018.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Burakowski EA. New England Climate, Forests, and Farms. Upper Valley Adaptation Workgroup (UVAW). Dartmouth Hitchcock Center, Lebanon, NH. May 2018.

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

Outputs
Target Audience: Junior and senior class students from a local high school (Phillips Exeter Academy CHE 343 Chemistry of the Environment tour and demonstration of eddy flux tower data collection at Thompson Farm Research Site) Undergraduate students from UNH in research internships: UNH phsyics senior, Patrick Hampson, focusing on eddy covariance for his senior thesis project leading to poster presentation and thesis; UNH senior, Taylor Conte, using soil temperature and moisture data to assess the influence of snowpack on soil environement in winter leading to poster presenttaion; UNH junior, Kyle MacDonaldinterested in developing senior thesis toured and trained in eddy covariance measurements and led collection ofancillary leaf area index data at Thompson Farm research site. Undergraduate students in UNH Terrestrial Ecosystems Coure (NR 730/830): Guest lecture given on the theory behind eddy covariance measurements and the results of from the four research sites explaining the influence on land cover on climate. UNH NREN Graduate Program External and Internal Review Committee: Tour and demonstration of eddy covariance tower at Thompson Farm to both internal faculty and staff and external experts from academic and government institutions. Members of the public, USDA staff subscribing to Hubbard Brook ResearchFoundation Newsletter: Feature on the effects of the August 2017 partial solar eclipse on solar radiation, surface temperature, and carbon and water fluxes at Thompson Farm. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training Mentor to Patrick Hampson, UNH physics undergraduate student (class of 2017), in writing and presenting senior thesis (PHYS 799) focused on improving methods for both filtering raw data as well as calculating CO2 and water fluxes over surfaces with diverse surface roughness. Thesis was presented at UNH Undergraduate Research Conference in Spring 2017. Work one-on-one with Sean Fogarty, UNH undergraduate in Sustainable Agriculture and Food Systems, and Jack Hastings, UNH undergraduate in Natural Resources and the Environment, to develop and enact protocols for eddy flux tower maintenance and calibration. Train UNH undergraduates and research technician, Kyle MacDonald, Eliza Mullen, Kaitlyn Baillargeon, and Mikayla Jacobs on instruments (Licor 6800, Licor 2200-C, Licor 3100-C) used for plot level measurements of photosynthesis, leaf area index, and leaf size. Professional Development Participation by Rebecca Sanders-DeMott, UNH AES Postdoctoral Research Associate, in the 10th Annual Fluxcourse at the University of Colorado, July 2017, a two-week workshop for graduate students, postdocs and early career scientists. Participation byRebecca Sanders-DeMott, UNH AES Postdoctoral Research Associate,in the Northeastern Ecosystem Research Cooperative Meeting in Saratoga Springs, NY on Match 28-29, 2017. How have the results been disseminated to communities of interest? Presentation and tour of Thompson Farm flux tower site for 2 Phillips Exeter Academy Chemistry of the Environment (CHE 343) classes, April 15, 2017 Publicly disseminated online newsletter article on the effects of the August 2017 partial solar eclipse on solar radiation, surface temperature, and carbon and water fluxes at Thompson Farm Forest. https://hubbardbrook.org/articles/eclipse-science-hubbard-brook-solar-radiation-and-carbon-dioxide-flux Presentation and tour of Thompson Farm flux tower site for UNH NREN Internal and External Review Committees, October 19, 2017 Research presentations at academic and professional conferences, including UNH Undergraduate Research Conference, Northeast Regional Ecosystem Collaborative Conference, and American Geophysical Union Conference. Submission of research articles to peer reviewed journals including Agricultural and Forest Meteorology and Theoretical and Applied Climatology. What do you plan to do during the next reporting period to accomplish the goals?In order to accomplish our project goals, we plan to focus on the following during the next reporting period: (1) prepare manuscripts; (2) continuous data collection from flux towers, with gapfilling, as necessary; (3) continued data analyses of flux tower measurements with remote sensing and plot-level field measurements, upscaling, and modeling; and (4) uploading our data to the Ameriflux network.

Impacts
What was accomplished under these goals? Our overall goal is to measure how different landscapes in New Hampshire affect climate, locally as well as globally. Typically, we think in terms of the effect of climate on vegetation, on animals, on our own activities. But something we're trying to better understand is the impact vegetation--and how it is managed by humans--has on climate. By understanding these processes more thoroughly, we hope to improve the accuracy of models and better understand how our climate will change as patterns of land use change in the future. We also hope the information we collect will help land managers make decisions about how best to use the landscapes they're responsible for. OBJECTIVE 1. Ecosystem-atmosphere exchanges of CO2 and water in agricultural, forested and suburban landscapes Continuous measurements of CO2 and water fluxes have been made at all four of our flux tower sites: forest (Thompson Farm, Durham), field/pasture (Kingman Farm, Madbury) corn (Moore Fields, Durham), and impervious (West Edge Parking Lot, Durham). In this past year, we have quality-checked and gapfilled all data according to standard procedures and have produced a complete, up-to-date dataset for analysis and publication that is updated regularly as new data is recorded. We have also maintained the record of plot-level field measurements of aboveground productivity and initiated measures of canopy leaf area to compare with flux tower measurements. We found that carbon fluxes in the hayfield and forest responded differently to variation in winter conditions from 2014-2017, a period that included an anomalous warm winter (air temperatures ~3 degreesC warmer than 14-year mean) with low snowpack in 2016. Warm winter temperatures and low snow conditions led to relatively large cumulative losses of carbon from the forest (~2.5 times losses in 2015 and 2017) in February-April 2016 driven by increased ecosystem respiration, while the grassland was a moderate net sink for carbon during the same period. OBJECTIVE 2:Solar radiation, albedo, sensible heat and latent heat exchange in agricultural, forested and suburban landscapes. Concurrent with continuous measurements of CO2 and water fluxes, solar radiation, albedo, and heat fluxes have been made at all four of our flux tower sites: forest (Thompson Farm, Durham), field/pasture (Kingman Farm, Madbury) corn/agriculture (Moore Fields, Durham), and residential/paved (West Edge Parking Lot, Durham). We have used the data from these sites to understand the mechanisms through which ecosystems influence climate at local to regional scales. Our initial hypothesis was that the higher albedo of agricultural systems relative to forests would facilitate local cooling, but that this would be partially or wholly offset by differences in evapotranspiration between trees, grasses and crops. Although these hypotheses were partially validated, we found that differences in surface roughness--caused by the height and physical structure of vegetation--had an equal or greater role on local temperatures. In open land, surface temperature is typically cooler (-4.8°C to -0.05°C) than forest at night and warmer (+0.16°C to +8.2°C) during the day, a difference that is consistent throughout the year. This finding has interesting implications for the potential to manage local temperatures by varying the planting densities of trees versus grasses and crops. OBJECTIVE 3. Impact of land management on CO2 , water and heat fluxes in agricultural systems. Last year we showedthat there may be a tradeoff between different ecosystem services (e.g. biomass production and net carbon sequestration) provided by these different land cover types. Specifically, the managed cornfield annually provides the largest amount of usable biomass (1382 g/m2 /yr), followed by the hayfield (860 g/m2 /yr) and mixed forest (wood production is 275 g/m2 /yr), while net carbon sequestration is highest in the mixed forest (909 g C/m2 /yr), followed by the hayfield (234 g C/m2 /yr), and cornfield (-4 g C/m2 /yr).In growing season 2017 the cornfield was managed as fallow, providing us with an opportunity to compare how this additional management strategiesalters CO2, water, and heat fluxes in agricultural systems. Preliminary results suggest increased sensible heat flux resulting from dark dry surfaces compared to previous years, with implications for local climate. Objective 4. Incorporate measurements of surface energy fluxes into the Community Land Model Land surface attributes measured at our flux towers were compared to those derived from Point-based Community Land Model (PTCLM) simulations. Preliminary results are as follows: Summer surface albedo was very well simulated with PTCLM over cropland (Moore Fields), hayfield (Kingman farm), and forest (Thompson Farm); in winter, snow cover modeled with PTCLM persisted longer in spring than observed at the tower sites, resulting in higher average winter and spring albedo; latent heat did not vary significantly among the tower sites; PTCLM underestimated forest latent heat and overestimated cropland and hayfield summer latent heat. In order to explore the effects of winter snow at each land cover type in greater detail, we also used the Simultaneous Heat and Water (SHAW) model to simulate snow depth, snow water equivalent, and soil temperature and frost depth at each of the sites. Snow depth, snow water equivalent, and soil temperature were well simulated at the Thompson Farm forest site, however at the Kingman Farm site melt and accumulation of snow were both overestimated leading to higher magnitude of changes in snow depth throughout the winter than observed. CHANGE IN KNOWLEDGE:We find that forested sites are darker than all other land cover types, and absorb even more of the sun's energy than a dark asphalt parking lot. Compared to the albedo of other land cover types, the low reflectivity of forests has a warming effect on climate. However, despite absorbing more of the sun's energy than other land cover types, forests have the coolest surface (or skin) temperature of any other land surface in our study because forests have a very rough (bumpy) surface compared to parking lots and other sites with shorter vegetation. The high surface roughness of forests promotes a lot of turbulent mixing of air that carries heat away from the surface of the forest. So it's a forest's ability to "sweat" as well as its rough surface that allows it to exchange heat with the air, and enables it to maintain cooler surface temperatures than other land surfaces. We also find that different land cover types respond differently to climate, especially in winter, releasing more or less CO2 into the atmosphere and therefore potentitally impacting climate at the global scale.During winter 2016, which was very warm (air temperatures ~3o C warmer than 15-year mean) with low snowpack, we found that warm winter temperatures and low snow conditions led to relatively large cumulative losses of carbon from the forest in February/March 2016, while the grassland was a moderate net sink for carbon during the same period.These results suggest that carbon losses to the atmosphere in deciduous forests may increase during warm, snow-free winter conditions when vegetation is restricted in winter carbon uptake capacity by phenology. However, non-forested vegetation such as perennial grasses in managed ecosystems have a greater potential to activate photosynthesis in winter and to take up carbon in the "dormant season," perhaps moderating increasing winter carbon losses through respiration due to increasing winter temperatures. The challenge---and novelty---of our work is trying to integrate all these factors (greenhouse gases, reflectivity, "sweating", and surface roughness) to determine their combined effect on local and global climate.

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Burakowski, EA, Tawfik AB, Ouimette A, Lepine LC, Ollinger SV, Bonan GB, Zarzycki CM, Novick KA. Does surface roughness dominate biophysical forcing of land use and land cover change in the eastern United States? Fall 2016 AGU Meeting, San Francisco, CA, December 12, 2016.
• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Sanders-DeMott R, A Ouimette, L Lepine, S Fogarty, S Ollinger. Investigating land-climate interactions across land cover types using an eddy flux tower cluster in NH. Northeastern Ecosystem Research Cooperative, Saratoga Springs, NY, March 28, 2017
• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Hampson P, A Ouimette, D Mattingly. 2017. Eddy Flux Data Analysis of Four Durham Area Ecosystems. Undergraduate Research Conference, Durham, NH, April 29, 2017.
• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Conte T, EA Burakowski. The Influence of Snow Density on CO2 Flux Measured with Eddy Covariance over a Forested Canopy. Undergraduate Research Conference, Durham, NH, April 29, 2017.
• Type: Theses/Dissertations Status: Other Year Published: 2017 Citation: Hampson P, A Ouimette, D Mattingly. 2017. Eddy Flux Data Analysis of Four Durham Area Ecosystems. Undergraduate Research Conference, Durham, NH, April 29, 2017.

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

Outputs
Target Audience: Regional farmers, cooperative extension educators and specialists, USDA staff, members of NHAES advisory board, members of the NH State Legislature, farm consultants, UNH Trustees (e.g. through Research Field Day and Twilight Tour) Junior and senior class students from a local high school (Phillips Exeter Academy CHE 343 Chemistry of the Environment tour and demonstration of eddy flux tower data collection at Thompson Farm Research Site) Undergraduate students from UNH and St. Anselm College (UNH phsyics senior focusing on eddy covariance for his senior thesis project; tour and demonstration of in situ eddy flux data at Thompson Farm Research Site for two St. Anselm students beginning senior year and interested in learning about the AES project work to incorporate in their senior thesis projects) Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Training activities: Mentor to Patrick Hampson, UNH physics undergraduate student (class of 2017), whose senior thesis (PHYS 799) focuses on improving methods for both filtering raw data as well as calculating CO2 and water fluxes over surfaces with diverse surface roughness. Work one-on-one with Sean Fogarty, UNH undergraduate in Sustainable Agriculture and Food Systems, and Jack Hastings, UNH undergraduate in Natural Resources and the Environment, to install and maintain wireless communication devices and software at each flux tower site to enable remote data monitoring, processing, and sharing. Professional development: Participation by Elizabeth Burakowski, UNH Research Assistant Professor, in the 9th Annual Fluxcourse at the University of Colorado, July 2016, a two-week workshop for graduate students, postdocs and early career scientists. Participation by Andrew Ouimette in the AmeriFlux Annual meeting, September 21-23, 2016 in Golden, CO, a workshop of presentations, round-table discussions, and best practices for flux tower data analysis and applications. How have the results been disseminated to communities of interest? Presentation at Research Field Day at Organic Dairy Research Farm Nov. 4, 2015 Presentation and tour of Thompson Farm flux tower site for 2 Phillips Exeter Academy Chemistry of the Environment (CHE 343) classes, April 18 & 21, 2016 Presentation at Twilight Tour of Kingman Farm, Sep. 28, 2016 What do you plan to do during the next reporting period to accomplish the goals?In order to accomplish our project goals, we plan to focus on the following during the next reporting period: (1) development of a website for real-time public data access to our flux tower network; (2) continuous data collection from flux towers, with gap-filling, as necessary; (3) continued data analyses of flux tower measurements with remote sensing and plot-level field measurements, upscaling, and modeling; and (4) manuscript preparation.

Impacts
What was accomplished under these goals? Our overall goal is to measure how different landscapes in New Hampshire affect climate, locally as well as globally. Typically, we think in terms of the effect of climate on vegetation, on animals, on our own activities. But something we're trying to better understand is the impact vegetation--and how it is managed by humans--has on climate. Understanding how ecosystems affect climate is important for a number of reasons. First, although computer models designed to predict weather and climate have improved considerably over the years, they still often fall short when predicting local-scale patterns that are affected by land use.By understanding these processes more thoroughly, we hope to improve the accuracy of models and better understand how our climate will change as patterns of land use change in the future. We also hope the information we collect will help land managers make decisions about how best to use the landscapes they're responsible for. OBJECTIVE 1. Measure ecosystem-atmosphere exchanges of CO2 and water in agricultural, forested and suburban landscapes using instrumented canopy flux towers and compare these data across sites and with those previously collected from plot-level field measurements in the same area. Continuous measurements of CO2 and water fluxes have been made at all four of our flux tower sites: forest (Thompson Farm, Durham), field/pasture (Kingman Farm, Madbury) corn (Moore Fields, Durham), and impervious (West Edge Parking Lot, Durham). We have begun quality checking the data, and will begin filling gaps in the data record, as necessary. OBJECTIVE 2. Measure solar radiation, albedo, sensible heat and latent heat exchange in agricultural, forested and suburban landscapes using eddy flux data and compare these to previous estimates derived from modeling and remote sensing. Concurrent with continuous measurements of CO2 and water fluxes, solar radiation, albedo, and heat fluxes have been made at all four of our flux tower sites: forest (Thompson Farm, Durham), field/pasture (Kingman Farm, Madbury) corn/agriculture (Moore Fields, Durham), and residential/paved (West Edge Parking Lot, Durham). We have also developed a land surface temperature map from remotely sensed data (Landsat 8) for the study area, which will enable comparison of heat fluxes across the landscape to those derived from the flux towers. OBJECTIVE 3. Evaluate the impact of land management (e.g. fertilizing, watering, harvesting) on CO2, water and heat fluxes in agricultural systems. By combining measurements from the flux towers with biomass production and management (fertilization and harvest data) we have been able to quantify both net carbon sequestration as well as rates of usable biomass production. At the managed (cornfield and hayfield) sites, quantifying carbon added via fertilization and removed by harvest is critical for determining net ecosystem carbon exchange. Our preliminary data suggest that there may be a tradeoff between different ecosystem services (e.g. biomass production and net carbon sequestration) provided by these different land cover types. Specifically, the managed cornfield annually provides the largest amount of usable biomass (1382 g/m2/yr), followed by the hayfield (860 g/m2/yr) and mixed forest (wood production is 275 g/m2/yr), while net carbon sequestration is highest in the mixed forest (909 g C/m2/yr), followed by the hayfield (234 g C/m2/yr), and cornfield (-4 g C/m2/yr). Objective 4. Incorporate measurements of surface energy fluxes for agricultural, forested and residential landscape units into the Community Land Model (CLM; http://www.cgd.ucar.edu/tss/clm/) to simulate the effect of land cover on climate. Land surface attributes measured at our flux towers were compared to those derived from Point-based Community Land Model (PTCLM) simulations. Preliminary results are as follows: Summer surface albedo was very well simulated with PTCLM over cropland (Moore Fields), hayfield (Kingman farm), and forest (Thompson Farm); in winter, snow cover modeled with PTCLM persisted longer in spring than observed at the tower sites, resulting in higher average winter and spring albedo; latent heat did not vary significantly among the tower sites; PTCLM underestimated forest latent heat and overestimated cropland and hayfield summer latent heat. We also evaluated temperature differences between forested and nonforested sites due to differences in surface albedo, surface roughness, and latent and sensible heat. Surprisingly, temperature differences resulting from radiative forcing due to changes in surface albedo were relatively minor at the flux tower sites, and generally too high in PTCLM. This suggests that the increased surface roughness of forests contributes strongly to nighttime cooling over nonforested sites in winter, and daytime warming in summer. CHANGE IN KNOWLEDGE: Ecosystems can have a large effect on climate as they "breathe," "sweat," reflect light, and exchange heat throughout the day and night. For instance, we know that if a land surface removes more CO2 from the atmosphere than it releases then it has a cooling effect on climate. However, this "breathing" (or uptake and release of CO2 through photosynthesis and respiration) is not the only way land surfaces affect climate. Land surfaces also reflect sunlight to varying degrees. The reflection of light is what's known as albedo and is basically a function of how bright or dark a surface is. Albedo is why we wear light-colored clothing on a hot, sunny day. Forests, which are thought to have a cooling effect because they remove CO2 from the atmosphere, have very low albedo. In fact, in our work, we find that forested sites are darker than all other land cover types, and absorb even more of the sun's energy than a dark asphalt parking lot. Compared to the albedo of other land cover types, the low reflectivity of forests has a warming effect on climate. However, despite absorbing more of the sun's energy than other land cover types, forests have the coolest surface (or skin) temperature of any other land surface in our study. There are two reasons for this that are important for local climate. First, vegetated surfaces can "sweat" or evapotranspire to cool themselves. Because a parking lot cannot "sweat" it is much hotter than other land surfaces. However, in our study, we found that a forest and a hayfield do about the same amount "sweating". Why, then, is the forest consistently cooler than a hayfield despite absorbing twice as much of the sun's energy than the hayfield? The answer is that forests have a very rough (bumpy) surface compared to parking lots and other sites with shorter vegetation. The high surface roughness of forests promotes a lot of turbulent mixing of air that carries heat away from the surface of the forest. So it's a forest's ability to "sweat" as well as its rough surface that allows it to exchange heat with the air, and enables it to maintain cooler surface temperatures than other land surfaces. The challenge---and novelty---of our work is trying to integrate all these factors (greenhouse gases, reflectivity, "sweating", and surface roughness) to determine their combined effect on local and global climate.

Publications

• Type: Other Status: Other Year Published: 2015 Citation: Ouimette, A. L. Lepine, S. Ollinger, S. Fogarty. 2015. Poster: Land-Climate Interactions Across 4 Land Cover Types in New Hampshire. Organic Dairy Research Field Day, Burley-Demeritt Farm, Lee, NH, November 4, 2015.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Bernier, S., A. Ouimette, L. Lepine, S.V. Ollinger. 2016. Measuring Carbon Flux and Energey using Alternative Methods to Determine an Ecosystem Service Based Carbon Use Efficiency. Undergraduate Research Conference, Durham, NH, April 23, 2016.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Ouimette, A., L. Lepine, S. Ollinger, E. Burakowski. 2016. Assessing the climate impacts of land cover and land management using an eddy flux tower cluster in New England. (Poster) AmeriFlux Annual meeting, September 21-23, 2016 in Golden, CO.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Burakowski, E.B., S.V. Ollinger, G. B. Bonan, C.P. Wake, J.E. Dibb, D.Y. Hollinger. Evaluating the climate effects reforestation in New England, USA, using a Weather Research and Forecasting (WRF) Model Multi-Physics Ensemble. Journal of Climate. In Press.
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Xiao, J., A. Contosta, J. Deng, L.C. Lepine, C. Li, S.V. Ollinger, A. Ouimette, J. Tang, R.K. Varner. 2015. B31B-0551 (Poster): Influences of Land Use on Greenhouse Gas Fluxes within Mixed Landscapes. Fall 2015 AGU Meeting, San Francisco, CA, December 16, 2015.
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Burakowski, E.A., S.V. Ollinger, G.B. Bonan, A. Ouimette, L.C. Lepine, A. B. Tawfik, C.M. Zarzycki, S. Fogarty, K.A. Novick. 2015. B34A-04 (Oral): Using Eddy Covariance Tower Clusters To Evaluate Biogeophysical Impacts Of Land Cover In The Community Land Model (CLM). Fall 2015 AGU Meeting, San Francisco, CA, December 16, 2015.
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Ouimette, A., L.C. Lepine, S.V. Ollinger, E.A. Burakowski, S. Fogarty. B43D-0589 (Poster): Coupling Eddy Covariance Measurements with Remote Sensing to Upscale Net Carbon Flux Across a Heterogeneous Landscape. Fall 2015 AGU Meeting, San Francisco, CA, December 17, 2015.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Pellissier P.A., S.V. Ollinger, L.C. Lepine, M.W. Palace, W.H. McDowell. 2015. Remote sensing of foliar nitrogen in cultivated grasslands of human dominated landscapes. Remote Sensing of Environment, 167: 8897. doi:10.1016/j.rse.2015.06.009