Source: OKLAHOMA STATE UNIVERSITY submitted to NRP
VEGETATION & LAND USE IMPACT ON VADOSE SOIL MOISTURE DYNAMICS & GROUNDWATER RECHARGE IN OKLAHOMA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
MCINTIRE-STENNIS
Reporting Frequency
Annual
Accession No.
1004135
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2014
Project End Date
Sep 30, 2019
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
OKLAHOMA STATE UNIVERSITY
(N/A)
STILLWATER,OK 74078
Performing Department
Natural Resource Ecology & Management
Non Technical Summary
Oklahoma possesses tremendous climate variability, which has a strong impact on Oklahoma's economy and social fabric. Oklahoma experienced several major droughts in the last century including the Dust Bowl in the 1930s, one of the greatest social and ecological disasters in U.S. history. As a result, water resource management for drought is especially important in long-term water planning in Oklahoma. Ecosystem resilience will be enhanced by maintaining soil moisture and groundwater during a drought. Understanding the vegetation and groundwater interaction and its potential to improve soil moisture and groundwater storage will assist water resources management for Oklahoma.The rangeland of the south and south-central Great Plains is a heterogeneous landscape with patches of grassland, woodlands of varying tree densities, and forests. Beginning in the early 20th century, a general trend has been the decline in cropland area resulting in an increase in rangeland in Oklahoma. However, rangeland has subsequently been encroached by woody plants. In north-central Oklahoma, two processes are contributing to an increase in the woody cover. One is the expansion of riparian gallery forest towards the upland and the other is the encroachment of woody species into the upland, primarily by a juniper species (Junipers virginiana, redcedar). A recent study estimated that woody plants are expected to cover 11.6 million acres of the state by 2015.Rapid change in land cover in the south Great Plains has revitalized interest in managing land cover for water supply. A controlled small watershed experiment in central Oklahoma by a USGS funded project to OSU reported loss in streamflow (combined surface and subsurface flow) after redcedar encroachment. However, trees tend to increase preferential flow, improve soil infiltration capacity and therefore hasten downward movement of water. As a result, forests are critical in reducing surface runoff and postponing flash floods through shifting flow paths from the surface to subsurface flows. Analysis of streamflows of multiple rivers in Edwards plateau, TX showed a positive correlation between streamflow and a general recovery of rangeland from once over-grazed rangelands. This general recovery in vegetation was concurrent with a steady increase in woody coverage in last several decades. Those two pieces of evidence lead to speculation that conversion of herbaceous vegetation to woody vegetation in a water-limited system might enhance local recharge at the cost of surface runoff. If this is the case, then the hydrological impact of woody encroachment and its implication in water resource management needs to be re-evaluated
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
11102101070100%
Knowledge Area
111 - Conservation and Efficient Use of Water;

Subject Of Investigation
0210 - Water resources;

Field Of Science
1070 - Ecology;
Goals / Objectives
The overarching goal of this project is to quantitatively assess the effects of vegetation types on soil moisture dynamic and groundwater recharge potential in upland ecosystems. There are three specific objectives:Objective 1: Quantify soil moisture for the rooting zone under three contrasting vegetation types - grassland, post oak (Quercus stellata) dominated deciduous forest and juniper woodland with the same precipitation input.Objective 2: Monitor the level of water table and evaluate interflow under different vegetation types and their seasonal variations.Objective 3: Directly assess long-term water efflux out of rooting zone using chloride mass balance - proximity for recharge potential.
Project Methods
We will estimate soil moisture using transient multi-electrode surface resistivity. Graphite electrodes will be used on soil surface as fixed lines of 56 electrodes, regularly spaced at 1.0m interval up to 55 meters along each transect to measure electrical resistivity utilizing the Halihan/Fenstemaker method. The apparent resistivity data will be converted into inverted resistivity data using soil resistivity model and developed into conductivity maps using proprietary methods. Soil water content will be derived using Archie's relationship.A Geoprobe hydraulic drilling machine will be used to install nested observation wells (i.e., various lengths of screen pipe section) in the subsurface. Depths of the observation wells will be based on soil core samples collected from the site based on observed layering and potential confining layers and will extend to the depth of penetration. Bentonite clay will be packed around the well bore in the topsoil to guarantee that water and solutes are not traveling laterally through the topsoil and then vertically down the well hole. Prepacked wells will be installed to limit clogging due to fine-grained aquifer sediments.Shallow and deeper groundwater recharge and/or lateral groundwater flow will be modeled with HYDRUS-3D, a three-dimensional, finite-element model for flow and contaminant transport (both equilibrium and physical/chemical nonequilibrium transport) through soils. HYDRUS-3D can simulate both small- and large-scale water and contaminant transport through unsaturated and saturated soils.Soil samples collected from installing piezometers will be analyzed using chloride mass balance method to estimate the long-term recharge dynamics associated with each vegetation type. Gravimetric water content will be determined by oven drying soil samples for 48 hours at 80C. Soil samples will be mixed with deionized water and shaken for 4 hours followed by centrifugation and filtration. Chloride anion in the soil will be determined by ion chromatography. Cl content in the pore water will be estimated by dividing soil Cl by gravimetric water.

Progress 10/01/14 to 09/30/19

Outputs
Target Audience:The targeted audiences during this final project year are research communities, and natural resources, water, and environmental management professionals. During the last year, synthesis works based on results from this project and other studies were produced to inform the municipal water supply authority, energy production industry, farmer and ranchers of vegetation impact on streamflow, especially during a period of below-average precipitation. We also extended our audience to the general public through extension materials and publications in open-access journals. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project through NSF, USDA, and USGS Southcentral Climate Science Center grants have partially supported two master students, two Ph.D. students, and two postdocs. The project provided its research site and facilities as field trip sites for undergraduate coursesat OSU. How have the results been disseminated to communities of interest?The results from the project have been disseminated in regional and national meetings through posters and oral presentations. We focused on meeting with good participation of natural resource and environmental management professionals from the local, state government and the profession. These meetings include Oklahoma Natural Resources Conference, the National Convention of Society of American Foresters, and the American Geophysical Union annual meeting. We produced one segment of Sunup program to disseminate the hydrological impact of vegetation conversion including eastern redcedar encroachment and switchgrass production. We also hosted several field days for visiting professionals and the public. In the final year, we have focused on synthesizing our results for targeting the research communities, natural resources, water resources, and environmental management professionals. We published two synthesis papers in open access journals making our results broadly available to our targeted audience (Zou et al., 2018; Acharya et al. 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? During the entire project period, extensive field studies and modeling simulations were performed to improve our understanding and assessment of the effects of vegetation types on soil moisture dynamics and groundwater recharge potential in upland ecosystems in the forest grassland transition zone in southern Great Plains. We measured soil moisture content using soil moisture sensor arrays, explored the subsurface flow path and groundwater recharge using electrical resistivity imaging (ERI) technique, and quantified soil chloride concentrations from multiple soil depths using ion chromatography. These data are further analyzed using statistical, proprietary software, and modeling approaches to successfully address the three specific objectives in the project. Specifically, Objective 1: Quantify soil moisture for the rooting zone under three contrasting vegetation types - grassland, post oak (Quercus stellata) dominated deciduous forest and juniper woodland with the same precipitation input. Time-lapse electrical resistivity imaging technique was used to monitor soil moisture dynamics toa depth of 9 m in a grassland, a grassland encroached by a juniper species (eastern redcedar, Juniperus virginiana), a juniper woodland, and oak forest. A site-specific relationship between moisture content and electrical conductivity data was developed for the soil zone. Results showed that (a) change in soil moisture content was linearly correlated to change in electric conductivity in the soil zone; (b) vegetation cover type induced differences in vertical bulk electrical resistivity (ER) profiles and influenced the temporal evolution of soil moisture profiles. Our results suggest land use and vegetation cover type, as opposed to rock properties, controls deepwater drainage for the vegetation transition zone. Methods used to measure hydrogeophysical changes, such as ERI, can be used for a broader understanding of geological, physical, and biological processes and their links in Earth's critical zones (Acharya et al., 2017a). The launch of the SMAP mission by NASA has laid the foundations for large-scale soil moisture mapping and catalyzed the geophysical community in studying spatial patterns of soil moisture for accurate weather predictions and hydrological forecasting. The critical challenge in improving the mapping is to bridge remotely sensed information and in situ observations for areas with different vegetation cover. We addressed this challenge by wavelet analysis of multiyear observations of soil moisture profiles from adjacent areas with contrasting plant functional types and precipitation. In this study, we use six years of precipitation and soil moisture data collected from 2011 to 2016 collected in the range research station, Oklahoma State University. We addressed this challenge by wavelet analysis of multiyear observations of soil moisture profiles from adjacent areas with contrasting plant functional types (grassland, woodland, and encroached) and precipitation. We used the continuous wavelet transform (CWT), cross-wavelet transform (XWT), and wavelet coherence (WTC) to compare three different PFTs at four different soil depths. Our results showed that the pattern of soil moisture dynamics is associated with plant functional type. The coherence at high-frequency periodicities between precipitation and soil moisture generally decreases with depth but this is much more pronounced under woodland compared to grassland. Our research provides new insights on soil moisture dynamics of both surface soil and rooting zone soil across plant functional types and is powerful for assessing differences and similarities in landscapes with heterogeneous vegetation cover for dynamic soil moisture mapping based on in situ soil moisture network or remote sensing information (Liu et al., 2017) Objective 2: Monitor the level of the water table and evaluate interflow under different vegetation types and their seasonal variations. Two groundwater monitoring wells of 3 m depth were drilled in tallgrass prairie and juniper-encroached watersheds. Results show that juniper encroachment lowered the water level in the perched groundwater aquifer (Acharya et al., 2017a). Results showed that the runoff coefficient in eastern redcedar encroached watersheds was significantly lower than that in grassland watersheds during period of below average precipitation. Eastern redcedar encroachment resulted in a reduction of both surface and subsurface flows and the magnitude of reduction depended on annual precipitation. While there were nearly equal contributions between overland flow and subsurface flow, 87% of the total runoff from grassland watersheds occurred under saturated or nearly saturated soil condition, while 86% of runoff under encroached watersheds was generated under unsaturated soil condition, suggesting a shift from saturation excess overland flow to infiltration excess overland flow. These results permitted the reconciliation of observed differences of streamflow responses associated with Juniperus spp. encroachment in the region and provided insights to better predict a change in water resources under vegetation changes in subhumid regions of the south-central USA (Qiao et al. 2018). Objective 3: Directly assess long-term water efflux out of the rooting zone using chloride mass balance - proximity for recharge potential. The chloride ion (Cl-) was used to estimate the deep drainage rate because of its conservative nature. Mean soil chloride concentration in the encroached site was significantly higher than that in tallgrass prairie. The estimated deep drainage rate based on the CMB method was 9.0 mm yr-1 in the tallgrass prairie and 0.3 mm yr-1 in the encroached site. Eastern redcedar encroachment resulted in more frequent depletion of soil water in the deep soil layer (Acharya et al., 2017b). ?

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Zou, C.B., Will, R.E., Torquato, P. 2019. Increase of stand level transpiration after eastern redcedar encroachment into the midstory of oak forest. Ecological Society of America Annual Meeting. Aug. 11  15, 2019. Louisville, KY.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Schmidt. K., Will, R.E., Zou, C.B., Zhong, Y., and Stebler, E. 2019. Tradeoff between water yield and biomass production associated with eastern redcedar encroachment into grassland ecosystems of northcentral Oklahoma. Ecological Society of America Annual Meeting. Aug. 11  15, 2019. Louisville, KY.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Joshi,O., Zou, C.B., Adhikari, A., Mishra, B., Will, R. E. 2019. How resilience of forests to drought and climate change might affect management outcomes for different objectives? Ecological Society of America Annual Meeting. Aug. 11  15, 2019. Louisville, KY.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Will, R. E., Adhikari, A., Joshi,O., Masters, R. E.. Zou, C.B., Waymire, J. Response of understory vegetation to inter-annual weather variation and fire along the forest-grassland ecotone of the southcentral US. Ecological Society of America Annual Meeting. Aug. 11  15, 2019. Louisville, KY.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Joshi, O., Will, R.E., Zou, C.B. and Kharel, G., 2019. Sustaining cross-timbers forest resources: current knowledge and future research needs. Sustainability, 11(17), p.4703.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sun, X., Wilcox, B.P. and Zou, C.B., 2019. Evapotranspiration partitioning in dryland ecosystems: a global meta-analysis of in situ studies. Journal of Hydrology 576 (2019) 123136
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Nunes Biral, V.C., Will, R.E. and Zou, C.B., 2019. Establishment of Quercus marilandica Muenchh. and Juniperus virginiana L. in the Tallgrass Prairie of Oklahoma, USA increases litter inputs and soil organic carbon. Forests, 10(4), p.329.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Starr, M., Joshi, O., Will, R.E., Zou, C.B. and Parajuli, R., 2019. Understanding market opportunities utilizing the forest resources of the Cross-timbers ecoregion. Journal of Forestry, 117(3), pp.234-243.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Law, D.J., Adams, H.D., Breshears, D.D., Cobb, N.S., Bradford, J.B., Zou, C.B., Field, J.P., Gardea, A.A., Williams, A.P. and Huxman, T.E., 2019. Bioclimatic envelopes for individual demographic events driven by extremes: plant mortality from drought and warming. International Journal of Plant Sciences, 180(1), pp.53-62.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Starr, M., Joshi, O., Will, R.E. and Zou, C.B. 2019. Perceptions regarding active management of the Cross-timbers forest resources of Oklahoma, Texas, and Kansas: A SWOT-ANP analysis. Land Use Policy, 81, pp.523-530.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Zou, B.C., Twidwell, D., Bielski, C.H., Fogarty, D.T., Mittelstet, A.R., Starks, P.K., Will, R.E., Zhong Y., Acharya B.S. 2018. Impact of eastern redcedar proliferation on water resources in the Great Plains USACurrent state of knowledge. Water 2018, 10(12), 1768; https://doi.org/10.3390/w10121768
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Kharel, G., Joshi, O., Miller, R. and Zou, C. 2018. Perceptions of government and research expert groups and their implications for watershed management in Oklahoma, USA. Environmental Management 62:1048-1059.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Acharya, B., Kharel, G., Zou, C., Wilcox, B. and Halihan, T. 2018. Woody plant encroachment impacts on groundwater recharge: A review. Water, 10(10), p.1466. https://doi.org/10.3390/w10101466
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Torquato, Patricia: Photosynthetic performance and water use change in Cross Timbers forest due to eastern redcedar encroachment. M.S. (co-advised with Dr. Will R), Aug 16, 2016  May 2019. Oklahoma State University, Stillwater, OK


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

Outputs
Target Audience:The targeted audiences of this project include the research communities, the federal, state, and local governmental agencies related to natural resources, water, and environmental management. Such information is becoming essential for municipal water supply authority, energy production industry, farmer and ranchers to manage water supply during a protracted period of drought. That information is also fundamental for sustainable management of the ecotone under the framework of food, energy, and water nexus. We also extended our audience to the general public through extension materials and mass communication. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project through NSF, USDA, and USGS Southcentral Climate Science Center grants have partially supported two master students, one Ph.D. students, and two postdocs. The project provided its research site and facilities as field trip sites for undergraduate courses. How have the results been disseminated to communities of interest?We have disseminated our results in regional and national meetings through posters and oral presentations. We focused on meeting with good participation of natural resource and environmental management professionals from the local, state government and the profession. These meetings include Oklahoma Natural Resources Conference, the National Convention of Society of American Foresters, and the American Geophysical Union annual meeting. We produced one segment of Sunup program to disseminate the hydrological impact of vegetation conversion including eastern redcedar encroachment and switchgrass production. What do you plan to do during the next reporting period to accomplish the goals?The next reporting period will be the final year. The focus during that period will be to finish a few manuscripts related to the objective 2, then produce synthesis work based on results from this project and other studies in the region.

Impacts
What was accomplished under these goals? The overarching goal of this project is to quantitatively assess the effects of vegetation types on soil moisture dynamics and groundwater recharge potential in upland ecosystems, which includes three specific objectives. The critical components including quantification of soil moisture under three contrasting vegetation types (Obj. 1), monitoring the level of the water table (Obj. 2) and assessment of long-term water efflux out of rooting zone (Obj. 3) have been completed during the previous reporting period. The primary research emphasis during this reporting period has been to build on results from previous results and focus on the theoretical understanding of the precipitation, vegetation and soil moisture connection which was achieved through time domain analysis with collaborators. The launch of the SMAP mission by NASA has laid the foundations for large-scale soil moisture mapping and catalyzed the geophysical community in studying spatial patterns of soil moisture for accurate weather predictions and hydrological forecasting. The critical challenge in improving the mapping is to bridge remotely sensed information and in situ observations for areas with different vegetation cover. Large-scale soil moisture information is usually indirect and is computed from remote sensing technology and it remains a challenge to link the direct measurement at point level to the large scale estimation due to the vegetation difference along with soil and topographic complicity. In addition to the spatial attribute, soil moisture is also a transient property dynamically controlled by precipitation. As a result, it is hard to define the relationship or algorithm between climate, vegetation and soil moisture using processed based approaches. Such information would improve our modeling capability in weather predictions and hydrological forecasting. We addressed this challenge by wavelet analysis of multiyear observations of soil moisture profiles from adjacent areas with contrasting plant functional types and precipitation. In this study, we use six years of precipitation and soil moisture data collected from 2011 to 2016 collected in the range research station, Oklahoma State University. We addressed this challenge by wavelet analysis of multiyear observations of soil moisture profiles from adjacent areas with contrasting plant functional types (grassland, woodland, and encroached) and precipitation. We used the continuous wavelet transform (CWT), cross-wavelet transform (XWT), and wavelet coherence (WTC) to compare three different PFTs at four different soil depths. Our results showed that the pattern of soil moisture dynamics is associated with plant functional type. The coherence at high-frequency periodicities between precipitation and soil moisture generally decreases with depth but this is much more pronounced under woodland compared to grassland. Our research provides new insights on soil moisture dynamics of both surface soil and rooting zone soil across plant functional types and is powerful for assessing differences and similarities in landscapes with heterogeneous vegetation cover for dynamic soil moisture mapping based on in situ soil moisture network or remote sensing information. Our research was published in Geophysical Research Letters, a highly reputable journal and has attracted over 200 reads since its publication. Our research addressed a foundational question to link climate, vegetation and water resources with the broad ecological, hydrological and soil societies in mind. The specific research objectives, the grassland and forest ecotone is relevant to the south-central Great Plains of the USA. Also, the effort has been made to assess the degree of conversion of land surface condition, particular encroachment of eastern redcedar into the Cross-timbers forest (Hoff 2018). Extensive collaboration with other institute has been conducted to study the ecological and hydrological impact associated with invasion and encroachment species.

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Wan, L., S.S. Qi, C.B. Zou, Z.C. Dai, G.Q. Ren, Q. Chen, B. Zhu and D.L. Du. Nitrogen addition promotes the growth and competitive ability of invasive Solidago canadensis in the calcareous soils. Ecological Society of America Annual Meeting. Aug. 5 ⿿ 10, 2018. New Orleans, LA.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Zhong Y., C.B. Zou, R.E. Will, G. Kakani, and E. Stebler. Runoff responses to conversion of encroached juniper woodland to native prairie and Panicum virgatum biofuel feedstock production. Ecological Society of America Annual Meeting. Aug. 5 ⿿ 10, 2018. New Orleans, LA.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Torquato P., R.E. Will, C.B. Zou and H.D. Adams. Does anisohydric behavior/traits assist eastern redcedar (Juniperus virginiana) to successfully encroach into the Cross Timbers? Ecological Society of America Annual Meeting. Aug. 5 ⿿ 10, 2018. New Orleans, LA.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Wilcox B.P., S. Basant, X. Sun, and C.B. Zou. Woody Plant Expansion is Modifying the Regional Hydrology of the Southern Great Plains, USA. The EGU General Assembly, April 8 -13, 2018
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wan, L., S.S. Qi, C.B. Zou, C. Dai, B. Zhu, Y.G. Song, D.L. Du. 2018. Phosphorus addition reduces the competitive ability of the invasive weed Solidago canadensis under high nitrogen conditions. Flora 240:68-75.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Ren, J., W. Dai, C. Yang, X. Ma, and C.B. Zou. 2018. Physiological regulation of poplar species to experimental warming differs between species with contrasting elevation ranges. New Forests. DOI: 10.1007/s11056-017-9622-4.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wan, L. Y., S. S. Qi, Z. C. Dai, C. B. Zou, Y. G. Song, Z. Y. Hu, B. Zhu, and D. L. Du. 2018. Growth responses of Canada goldenrod (Solidago canadensis L.) to increased nitrogen supply correlate with bioavailability of insoluble phosphorus source. Ecological Research 33:261-269.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Chen, S., T.J. Cao, N. Tanaka, T. Gao, L. Zhu, C.B. Zou*. 2018. Hydrological properties of litter layers in mixed forests in Mt. Qinling, China. iForest - Biogeosciences and Forestry 11(2):243-250.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Li, C.W., Y.J. Zhang, G. Kharel, C.B. Zou. 2018. Climate variability and changing landscape pattern impact water budget and nutrient loads in a peri-urban watershed: A coupled analysis using process-based hydrological model and landscape indices. Environmental Management 61(6):954-967
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Sun, X, C.B. Zou, B.P. Wilcox, E. Stebler. 2018. Effect of vegetation on energy balance and evapotranspiration in tallgrass prairie: a paired study with eddy covariance systems. Journal of Boundary Layer Meteorology. doi.org/10.1007/s10546-018-0388-9.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Hoff, D.L. R.E. Will, C.B. Zou, N.D. Lillie. 2018. Encroachment dynamics of Juniperus virginiana L. and mesic hardwood species into Cross Timbers forests of north-central Oklahoma, USA. Forests 2018 (9): 75; doi:10.3390/f9020075
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Liu, Q., Y. Hao, E. Stebler, N. Tanaka, C.B. Zou. 2018. Impact of plant functional types on coherence between precipitation and soil moisture⿿a wavelet analysis. Geophysical Research Letters. DOI: 10.1002/2017GL075542: 12197-12207.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wilcox, B.P., A. Birt, S.R. Archer, S.D. Fuhlendorf, U.P. Kreuter, M.G. Sorice, W. J.D. van Leeuwen, C.B. Zou. 2018. Viewing woody-plant encroachment through a social⿿ecological lens. BioScience 68(9):691-705.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Li, J., Z.W. Du, C.B. Zou, Z.C. Dai, D.L. Du, C.L.Yan. 2018. The mutual restraint effect between the expansion of Alternanthera philoxeroides (Mart.) Griseb and cadmium mobility in aquatic environment. Ecotoxicology and Environmental Safety 148: 237-243.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Chen, Q., Z.L. Wang, C.B. Zou, S. Lin. 2018. Biotic and abiotic legacy effects of grazed steppes depend on water and nitrogen availability. Applied Vegetation Science 21(2):229-239.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wang, Y.D., Z.L. Wang, Q.Z. Zhang, N. Hu, Z. F Li, Y.L. Lou, Y. Li, Y. Chen, C.Y Wu, C.B. Zou, Y. Kuzyakov. 2018. Long-term effects of nitrogen fertilization on aggregation and localization of microbial activities in soil. Science of the Total Environment 624:1131-1139.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Hoff, D. L., R.E. Will, C.B. Zou, J.W. Weir, M.S. Gregory, and N.D. Lillie. 2018. Estimating increased fuel loading within the Cross Timbers forest matrix of Oklahoma, the USA due to an encroaching conifer, Juniperus virginiana, using leaf-off satellite imagery. Forest Ecology and Management 409: 215-224.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Chen, Q., Y.D. Wang, C.B. Zou, and Z. L. Wang. 2017. Aboveground biomass invariance masks significant belowground productivity changes in response to salinization and nitrogen loading in reed marshes. Wetlands 37:985-995.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: DeRoin, R., A. Saenz, W. Lisenbee, D. Storm, E. Stebler, C.B. Zou, and R. Will. Hydrologic and sediment yield modeling of native prairie and encroached eastern redcedar watersheds. National Council on Undergraduate Research, Apr 4-7, 2018. University of Central Oklahoma. OK.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Sun, X., C.B. Zou, B.P. Wilcox, E. Stebler. Effect of vegetation on energy balance and evapotranspiration in tallgrass prairie ⿿ a paired study with eddy covariance systems. AGU Fall Meeting. Dec 11-15, 2017. New Orleans, LA.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Hoff, D.L., R.E. Will, C.B. Zou, N. Lillie. Dynamics of eastern redcedar (Juniperus virginiana) encroachment in the Cross Timbers of Oklahoma. Society of American Forester National Convention. Nov. 15-18, 2017. Albuquerque, NM.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Torquato, P.R., R. Will, C.B. Zou, and H. Adams. Physiological performance contrast of Quercus stellata and Juniperus virginiana in the Cross Timbers. Society of American Forester National Convention. Nov. 15 -19, 2017. Albuquerque, NM.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Will, R.E., C.B. Zou, E. Stebler, G. Fox, R. Huhnke, D. Storm, V.G. Kakani, A. Saenz. Increasing water yield and quality through an integrated woody and herbaceous biofuel feedstock production system. USDA-NIFA AFRI Bioeconmy, Climate Agroecosystems. Annual Project Director Meeting. Oct. 20-22, 2017. Tampa, FL.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Saenz, A.A., W.A. Lisenbee, G.A. Fox, D.E. Storm, E. Stebler, C.B. Zou, R. Will. Hydrologic modeling of runoff and sediment yield for eastern redcedar encroached grassland and native prairies. Southwest Section of the American Water Works Association. Oct. 15-17, 2017. Oklahoma City, OK.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Saenz, A.A., W.A. Lisenbee, G.A. Fox, D.E. Storm, E. Stebler, C. Zou, and R. Will. Hydrologic modeling of sediment yield, and runoff for native prairie and encroached eastern redcedar watersheds. Society for the Advancement of Chicanos and Native Americans in Science National Conference. Oct. 18-21, 2017. Salt Lake City, UT
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: DeRoin, R., A. Saenz, D. Storm, C.B. Zou, E. Stebler, and R.Will. Hydrologic and sediment yield modeling of native prairie and encroached eastern redcedar watersheds. Oklahoma Clean Lakes and Watershed Association 27th Annual meeting, Oklahoma State University, Stillwater OK, April 4 - 5, 2018
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Zhong Y., C.B. Zou, R.E. Will, and E. Stebler. Runoff responses to conversion of encroached juniper woodland to native prairie and Panicum virgatum biofuel feedstock production. April. 4, 2018. Stillwater, OK.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Saenz, A.A., D.E. Storm, G.A. Fox, C.B. Zou, R. Will. Online hydrologic modeling: determining the utility of WEPP and RHEM predictions in Northern Oklahoma catchments. Oklahoma Clean Lakes and Watersheds Conference. April. 4, 2018. Stillwater, OK.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Qiao, L., C.B. Zou, R. Will, D. Engle, E. Stebler, X. Sun. ET simulations for the subhumid and semiarid grasslands of the Southern Great Plains. Oklahoma Clean Lakes and Watersheds Conference. April. 4, 2018. Stillwater, OK.


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

Outputs
Target Audience:The targeted audiences of this project are state and local governmental agencies related to natural resources, water and environmental management. Such information is becoming important for municipal water supply authority, energy production industry, farmer and ranchers to manage water supply during protracted period of draught. This information is also fundamental for sustainable management of the ecotone under the framework of food, energy, and water nexus. We also extended our audience to thegeneral public through extension materials and mass communication. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project partially supports two master students and two Ph.D. students. The research project provided field trip sites for undergraduate course (NREM 4443) and graduate courses (NREM 5443 and 5483) at OSU. How have the results been disseminated to communities of interest?We have disseminated our results in regional and national meetings through posters and oral presentations. We focused on meeting with a good participation of natural resource and environmental management professionals from the local, state government and the profession. These meeting include Oklahoma Natural Resources Conference, the National Convention of Society of American Foresters, and American Geophysical Union annual meeting. What do you plan to do during the next reporting period to accomplish the goals?The next reporting period will be the fourth year for this project. We will continue data collection for metrological, soil moisture, streamflow and groundwater well. We will focus on finishing the papers related to the lateral movement. We will also work on the paper relating vegetation types (functional types) to the spatiotemporal dynamics of soil moisture at shallow soil and subsoils. We will publish those results in high impact, peer-reviewed journals.

Impacts
What was accomplished under these goals? Objective 1: Time-lapse electrical resistivity imaging (ERI) was used to monitor soil moisture dynamics to a depth of 9 m in a grassland, a grassland encroached by a juniper species (eastern redcedar, Juniperus virginiana), a juniper woodland and an oak forest. A site-specific relationship between moisture content and electrical conductivity data was developed for the soil zone. Results showed that (a) change in soil moisture content was linearly correlated to change in electric conductivity in the soil zone; (b) vegetation cover type induced differences in vertical bulk electrical resistivity (ER) profiles and influenced the temporal evolution of soil moisture profiles. Our results suggest land use and vegetation cover type, as opposed to rock properties, controls deep water drainage for the vegetation transition zone. Methods used to measure hydrogeophysical changes, such as ERI, can be used for broader understanding of geological, physical, and biological processes and their links in Earth's critical zones (Acharya et al., 2017a) Objective 2: Two groundwater monitoring wells of 3 m depth were drilled in a tallgrass prairie and a juniper-encroached catchment. Results show that juniper encroachment lowered the water level in the perched groundwater aquifer (Acharya et al.,2017a). Results showed that the runoff coefficient was 1.460.6% in eastern redcedar encroached watersheds, significantly lower than 4.460.7% in grassland watersheds for the four water years from 2011 to 2014. Eastern redcedar encroachment resulted in reduction of both surface and subsurface flows and the magnitude of reduction depended on annual precipitation. While there were nearly equal contributions between overland flow and subsurface flow, 87% of the total runoff from grassland watersheds occurred under saturated or nearly saturated soil condition, while 86% of runoff under encroached watersheds was generated under unsaturated soil condition, suggesting a shift from saturation excess overland flow to infiltration excess overland flow. These results permitted reconciliation of observed difference of streamflow responses associated with Juniperus spp. encroachment in the region and provided insights to better predict change in water resources under vegetation changes in subhumid regions of the south-central USA. Objective 3: The chloride ion (Cl-) was used to estimate deep drainage rate because of its conservative nature. Mean soil chloride concentration in encroached site was significantly higher than that in tallgrass prairie. The estimated deep drainage rate based on CMB method was 9.0 mm yr-1 in the tallgrass prairie and 0.3 mm yr-1 in the encroached site. Eastern redcedar encroachment resulted in more frequent depletion of soil water in deep soil layer.

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: E. Stebler, R. Will, C. Zou. 2017. Increasing water yield by changing land cover. Oklahoma Natural Resources Conference, Tulsa, OK February 22-24, 2017.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Zou CB. 2017. Juniper encroachment and hydrological responses in the southern Great Plains, USA. The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, the University of Tokyo. July 21, 2017.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Zou CB. 2017. Ecohydrology  A new paradigm in watershed and ecosystem management. The University of Tokyo Forests, Graduate School of Agricultural and Life Sciences, the University of Tokyo, June 22, 2017.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Wilcox BP, S Archer, A Birt, S Fuhlendorf, K Hartfield, U Kreuter, M Sorice, W van Leeuwen, and CB Zou. 2017. Slowing the expansion of woodlands and increasing the resilience of grasslands in the Southern Great Plains. Annual Meeting of the American Association of Geographers, Boston MA. April 5-9, 2017
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Acharya BS, Zou CB, Halihan T. 2016. Quantifying and contrasting spatial and temporal dynamics of vadose zone moisture under different vegetation types using electrical resistivity imaging. AGU Fall Meeting, San Francisco, CA. December 12-16, 2016.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Sun X, Wilcox BP, Zou CB, Stebler E, West J, Hyodo A. 2016. Control study on evapotranspiration partitioning through on-situ isotopic measurement. AGU Fall Meeting, San Francisco, CA. December 12-16, 2016
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Hoff D, Will R, Gregory M, Zou CB, Lillie N. 2016. Effect of eastern redcedar (Juniperus virginiana L.) encroachment into the Cross Timbers forest of central OK. National SAF Convention. Nov 2-5, 2016. Madison, WI.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Will R, Zou CB, Stebler E., Fox G., Penn C, Huhnke R, Storm D, Kakani VG, Engle D. 2016. Increasing water yield and quality through an integrated woody and herbaceous biofuel feedstock production system. NIFA Bioenergy Project Directors Meeting, Oct 18-20, 2016, New Orleans, LA
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Acharya, B. S., T. Halihan, C. B. Zou, and R. E. Will. 2017 (a). Vegetation controls on the spatio-temporal heterogeneity of deep moisture in the unsaturated zone: a hydrogeophysical evaluation. Scientific Reports 7. doi:10.1038/s41598-017-01662-y.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Qiao, L., C. B. Zou, E. Stebler, and R. E. Will. 2017. Woody plant encroachment reduces annual runoff and shifts runoff mechanisms in the tallgrass prairie, USA. Water Resources Research 53:4838-4849.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Qiao, L., C. B. Zou, C. F. Gaitan, Y. Hong, and R. A. McPherson. 2017. Analysis of precipitation projections over the climate gradient of the Arkansas Red River Basin. Journal of Applied Meteorology and Climatology 56:1325-1336.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Loss, S. R., S. Paudel, C. M. Laughlin, and C. Zou. 2017. Local-scale correlates of native and non-native earthworm distributions in juniper-encroached tallgrass prairie. Biological Invasions 19:1621-1635.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Acharya, B. S., Y. H. Hao, T. E. Ochsner, and C. B. Zou. 2017 (b). Woody plant encroachment alters soil hydrological properties and reduces downward flux of water in tallgrass prairie. Plant and Soil 414:379-391.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Biral V: Soil carbon storage and inputs under different types of vegetation at the grassland/forest ecotone. M.S. (co-advised with Dr. Will R), Jan 15 May 2017, Oklahoma State University.


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

Outputs
Target Audience:The targeted audiences of this project are state and local governmental agencies related to natural resources, water and environmental management. Such information is becoming important for municipal water supply authority, energy production industry, farmer and ranchers to manage water supply during protracted period of draught. We also extended our audience to general public through extension materials and mass communication. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project supports two master students and two Ph.D. students. We provided our research projects as field trip sites for multiple graduate and undergraduate courses at OSU. How have the results been disseminated to communities of interest?We have disseminated our results in regional and national meetings. We focused on meeting with a good participation of natural resource and environmental management professionals from the local and state government. These meeting include the Oklahoma Clean Water Association Annual Meeting, the Oklahoma Governor's Water Conference and Research Symposium. We also presented our results in American Geophysical Union annual meeting. What do you plan to do during the next reporting period to accomplish the goals?We will continue data collection for metrological, soil moisture, streamflow and groundwater well. We will focus on data analysis and preparation of peer-reviewed publications.

Impacts
What was accomplished under these goals? The overarching goal of this project is to quantitatively assess the effects of vegetation types on soil moisture dynamic and groundwater recharge potential in upland ecosystems. There are three specific objectives: Objective 1: Quantify soil moisture for the rooting zone under three contrasting vegetation types - grassland, post dominated deciduous forest and juniper woodland with the same precipitation input. Our electrical resistivity imagery (ERI) results indicated: (a) vegetation induced differences in vertical conductivity profiling, (b) increased spatial-temporal variability in root zone conductivity under juniper-encroachment compared to grassland cover type and (c) two-layered conductivity profiles. Electrical resistivity images were converted to volumetric moisture maps based on site-specific relationship between moisture content and inverted resistivity. Although volumetric moisture content was lower in the top 3 m in tallgrass prairie, the moisture increased in deep soil layers and ranged between 25 to 45%. Volumetric moisture in juniper-encroached catchment ranged 0 to 5% in deep soil layers. However, oak forest showed 15 to 35% moisture content below 2.5 m depth. Objective 2: Monitor the level of water table and evaluate interflow under different vegetation types and their seasonal variations Two groundwater monitoring wells of 3 m depth were drilled in a tallgrass prairie and a juniper-encroached catchment. In a perched aquifer, water level in the monitoring wells was several folds lower under juniper encroachment than under the prairie. Objective 3: Directly assess long-term water efflux out of rooting zone using chloride mass balance - proximity for recharge potential. The chloride ion (Cl-) was used to estimate deep drainage rate because of its conservative nature. Mean soil chloride concentration in encroached site was significantly higher than that in tallgrass prairie. The estimated deep drainage rate based on CMB method was 9.0 mm yr-1 in the tallgrass prairie and 0.3 mm yr-1 in the encroached site. Eastern redcedar encroachment resulted in more frequent depletion of soil water in deep soil layer.

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Acharya B, Halihan T, Zou CB, Fox G, Will R. 2015. Time-lapse electrical resistivity imaging following berm infiltration shows subsurface lateral flow in grassland. 2015 Oklahoma Governor's Water Conference and Research Symposium. Norma, Oklahoma. December 1-2, 2015.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: West AL, Zou CB, Stebler E, Fuhlendorf SD, Allred B. 2016. Pyric-herbivory and hydrological responses in Tallgrass Prairie. Rangeland Ecology & Management 69:20-27.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Acharya BS, Stebler E, Zou CB. 2016. Monitoring litter interception of rainfall using leaf wetness sensor under controlled and field conditions. Hydrological Processes. DOI 10.1002/hyp.11047
  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Bharat Sharma Acharya. 2016. Hydrogeophysical evaluation of vegetation influence on ecohydrological processes. Ph.D. Dissertation.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Ecohydrology  a new paradigm for water resources research and management. Tianjin Key Laboratory of Water Resources and Environment, Tianjin, China. July 1, 2016
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Managing Prairies to Sustain Water Provisions. Yunnan Agricultural University, Kunming, Yunnan, China, June 20, 2016
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Acharya BS, Zou CB, Halihan T, Fox G. 2016. Wonders of deep moisture and subsurface lateral flow. Oklahoma State University Student Conference, March 24-25, 2016, Stillwater, OK
  • Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Qiao L, Zou CB, Stebler E. 2016. Runoff mechanisms associated with woody plant encroachment in the mesic grassland of Oklahoma. The 25th OCWA Annual Meeting, Stillwater, March 28-29, 2016, Stillwater, OK
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Qiao L, Zou C, Stebler E, Will R. 2015. Woody plant invasion changes soil water storage dynamics and shifts runoff generation mechanisms. 2015 AGU Fall Meeting, San Francisco, CA. December 9-13.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Sun X, Wilcox BP, Zou CB. 2015. Evapotranspiration partitioning with sub-daily isotopic measurement in a sub-humid grassland ecosystem. 2015 AGU Fall Meeting, San Francisco, CA. December 9-13.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Zou CB, Melstrom RT, Kharel G, Fox G. 2015. Vulnerability and resiliency of wetlands under changing climate in the Cimarron River basin of Oklahoma. Annual NSF EPSCoR Meeting, Norman, Oklahoma. December 3, 2015
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Rahal R, Zou CB, Fox G, Ochsner T. 2015. Streamflow responses to climate variability across a gradient of precipitation in Oklahoma. 2015 Oklahoma Governor's Water Conference and Research Symposium. Norma, Oklahoma. December 1-2, 2015.


Progress 10/01/14 to 09/30/15

Outputs
Target Audience:The targeted audiences of this project include land and water management agencies, land managers such as USDA Natural Resources Conservation Service, USGS, Oklahoma Conservation Commission, Bureau of Reclamation, Bureau of Land Management, Corp of Engineers, and extension educators of Oklahoma Cooperative Extension Service, Nature Conservancy, and ranchers. We also extended our audience to general public through extension materials and mass communication. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project supports two master students and two Ph.D. students. We provided our research projects as field trip sites for multiple graduate and undergraduate courses at OSU. How have the results been disseminated to communities of interest?We have disseminated our results in regional and national meeting including Oklahoma Clean Water Association Annual Meeting, Oklahoma Governor's Water Conference and Research Symposium, American Geophysical Union annual meeting. What do you plan to do during the next reporting period to accomplish the goals?Continue data collection for metrological, soil moisture, streamflow and groundwater well. Data analysis for report and publications.

Impacts
What was accomplished under these goals? The overarching goal of this project is to quantitatively assess the effects of vegetation types on soil moisture dynamic and groundwater recharge potential in upland ecosystems. There are three specific objectives: Objective 1: Quantify soil moisture for the rooting zone under three contrasting vegetation types - grassland, post dominated deciduous forest and juniper woodland with the same precipitation input. We collected and archived a range of time-lapse electrical resistivity images (ERI) to track moisture change to a depth of 9 m in grassland and juniper encroached, and oak forest catchments under different precipitation and soil moisture conditions. Analysis based on those images showed a two-layer moisture migration profile: non-wetted and wetted in grassland, juniper-encroached catchments, and oak forest after rainfall event. Percent change in conductivity was lower in the top 3-m and higher below 3-m depth in the electrical resistivity data across vegetation. However, the eastern redcedar-encroached catchment showed higher spatial-temporal variability in the root zone electrical conductivity and reduced deep drainage and recharge potential compared with grassland catchment. Direct observation of subsurface hydrologic flow pathways using point measurements is relatively difficult in soils underlying porous bedrock. Passive seasonal temporal ERI thus provided clues of lateral flow in tallgrass prairie. The flow was largely controlled by differences in lithologic properties with depth. Based on drilling and ERI images, the groundwater table is deeper than 9 meters at the grassland, eastern redcedar encroached and oak woodland sites. This suggests that vegetation impact on groundwater at these upland sites is mainly through reducing net rainfall reaching the groundwater table. This limits our ability to quantify vegetation cover on groundwater through mentoring groundwater table fluctuation at these upland sites. This suggests that ERI method is a necessary approach to explore recharge process in order to further detect change in moisture content below different vegetation rooting zone in these heterogeneous sites. Objective 2: Monitor the level of water table and evaluate interflow under different vegetation types and their seasonal variations Monitoring wells show temporal variability in water level in a tallgrass prairie and juniper catchment. Water level was higher under grassland than under juniper woodland for all times. Peak water level of 2485 mm was recorded during 16-May 2015. In contrast, the water level in woodland peaked up to 10 mm during 20-May 2015. Results indicate that vegetation can modulate deep drainage of water, and woody plants can decrease water level in a perched aquifer by a significant amount. Objective 3: Directly assess long-term water efflux out of rooting zone using chloride mass balance - proximity for recharge potential. Evaluation of soil chloride concentration indicates different chloride profiles under grassland catchment and juniper encroached site. Soil chloride content varied between 5 to 162 mg/l in grassland and 88 to 612 mg/l in juniper encroached prairie across depths with greater Cl near the surface. Steady State flux indicates greater recharge potential in the grassland catchment. High soil chloride accumulation under juniper indicates reduced percolation and potentially subsurface interflow flow and groundwater recharge potential associated with juniper encroachment. In conclusion, different vegetation types control vadose zone soil moisture dynamics in the upland. ERI data confirms the existence of horizontal soil water migration (interflow) at the interface of soil and sandstone bedrock under grass cover, however, Juniper encroachment results in increased spatial and temporal variability of soil moisture in rooting zone, reducing both horizontal subsurface soil water movement (interflow) and vertical subsurface soil water movement (groundwater recharge). The results are consistent to the chloride data showing higher chloride concentration therefore less soil water percolation through the upper 100 cm soil profile for juniper encroached site in comparison with grassland.

Publications

  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Lisenbee W, Fox G, Zou CB, Storm D, Penn C, Stebler E, Mittelstet A. 2015. Predicted influence of eastern redcedar removal on water quantity and quality using the Water Erosion Prediction Project (WEPP). 2015 ASABE Annual International Meeting. New Orleans, Louisiana. July 26  29, 2015
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Qiao L, Zou CB, Will R, Stebler E. 2015. Hydrological responses across spatial scales: the impact of woody plant encroachment in the south-central Great Plains. 15th Annual Meeting of the American Ecological Engineering Society, Stillwater, OK, June 3-5, 2015
  • Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Acharya BS, Halihan T, Zou CB, Will R, Fox G. 2015. Time-lapse electrical resistivity imaging for spatio-temporal monitoring of vadose zone moisture. The 24rd OCWA Annual Meeting, Stillwater, April 2-3, 2014, Stillwater, OK. Poster Award
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Zou CB, Caterina GL*, Will RE, Stebler E, Turton D. 2015. Canopy Interception for a Tallgrass Prairie under Juniper Encroachment. PLOS One, 10(11), e0141422.45.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Zou BC, Qiao L, Wilcox BP. 2015. Woodland expansion in central Oklahoma will significantly reduce streamflowsA modeling analysis. Ecohydrology. doi: 10.1002/eco.1684
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Dale J, Zou CB, Andrews WJ, Long JM, Liang Y, Qiao, L. 2015. Climate, water use, and land surface transformation in an irrigation intensive watershedStreamflow responses from 1950 through 2010. Agricultural Water Management 160:144-152