Research
Current Projects
Click any project name for more information on the research involved.
Water stress and ecohydrologic change in riparian woodlands
(Southwestern USA and Rhône Basin, France) Together with collaborators at Cardiff University, UC Santa Barbara, and CNRS (France), our lab is developing a suite of multi-disciplinary water stress indicators for riparian forests to assess the impacts of hydrologic change from both natural causes and human manipulation. We have several projects in the Southwestern U.S. and the Rhône River Basin (France), with funding from the National Science Foundation and SERDP, the U.S. Strategic Environmental Research and Development Program. Our approach is to couple field-based tree-ring research, stable isotope analysis, and high-resolution remote sensing to calibrate water stress indicators across a range of geographic scales from individual trees to forest stands to an entire riparian corridor. The ultimate goal of the project is to identify trends and thresholds in forest response to groundwater decline and drought that can be used to protect groundwater-dependent ecosystems in multiple-use river basins. |
Riparian forest dynamics in semi-arid river basins
(California & Mediterranean Europe) Along the middle reach of the Sacramento River, CA, California's largest river, we are studying the community dynamics of forests dominated by Fremont cottonwood (Populus fremontii), a foundation riparian tree in river ecosystems of the U.S. southwest. We documented a little-known pathway for forest initiation in abandoned channels, developed a forest succession and development model to predict stand age, structure and and are using quantitative simulation models to predict corridor-wide forest response to likely scenarios of flow regulation and floodplain development. We are using extensive forest inventories to develop a forest succession model that predicts stand size structure and large wood inputs based on floodplain age, and quantifies carbon storage in riparian forests. Along the Rhône River in SE France, we are documenting riparian forest structure and community dynamics on reaches impacted by 19th century navigation infrastructure and 20th century flow regulation. Together with collaborators in California and France, we are providing this research as guidance for river corridor planning and conservation under multiple management constraints. |
Feedbacks between riparian vegetation and hydrogeomorphic processes in sand-bed rivers
Riparian vegetation communities co-evolve with hydrogeomorphic processes in dynamic river systems. Feedbacks between plants and channel morphology vary spatially and temporally but are especially strong when plants are small enough to be scoured or buried during floods but large enough to influence flow hydraulics and sediment transport within channels and on bars. This NSF-funded project (EAR-1024820) coupled laboratory flume experiments at the St. Anthony Falls Laboratory at the University of Minnesota and UC Berkeley with field investigations on the Bill Williams River (AZ) in the Colorado Basin to quantify the effect of native (willow, cottonwood) versus non-native (Tamarisk) plants on flow and sediment transport, as well as the reciprocal ecological effects on plant removal via scour and burial. Through this work, we can better understand feedbacks at scales ranging from individual plants to channel reaches, with the goal of improving management of arid-land river systems. |
Urban tree community structure and function across an urban gradient
Urban forests may experience a number of stressors either unique to or exaggerated by urban conditions. Variables including land cover, land use, city management, and population dynamics have the opportunity to influence the ability of trees to grow across a city. Since many of these variables can vary in spatially within a city, it is important to understand how these variations influence urban tree communities. Since these discrepancies will result in inadequate distribution of urban tree ecosystem services, understanding which urban variables influence the communities, and how they impact those communities, will be paramount for the future. The project will be undertaken in three phases: (1) develop an urban gradient based on socioeconomic and environmental variables; (2) Use historical forest data collected by the U.S. Forest Service's Urban Forest Effects (UFORE) Model to measure differential community composition across the urban gradient; (3) Use dendrochronology to measure differential growth of Acer saccharum (sugar maple) over time across an urban gradient. |
Past Projects
Impact of land use change and best management practices on the Chesapeake Bay watershed in New York
(Upper Susquehanna River and Chemung River, NY, USA)
The Chesapeake Bay has been plagued by nutrient pollution issues which has led to formations of large dead zones in the bay. A Total Daily Maximum Load (TMDL) was established by the US Environmental Protection Agency (EPA) in 2010 to guide restoration efforts for the watershed. In collaboration with the New York State Department of Environmental Conservation Division of Water, Upper Susquehanna Coalition and other stakeholders, our lab is working to understand the impact of land use changes and best management practices along the Upper Susquehanna and Chemung River in New York, which are both part of the wider Chesapeake Bay watershed.
(Upper Susquehanna River and Chemung River, NY, USA)
The Chesapeake Bay has been plagued by nutrient pollution issues which has led to formations of large dead zones in the bay. A Total Daily Maximum Load (TMDL) was established by the US Environmental Protection Agency (EPA) in 2010 to guide restoration efforts for the watershed. In collaboration with the New York State Department of Environmental Conservation Division of Water, Upper Susquehanna Coalition and other stakeholders, our lab is working to understand the impact of land use changes and best management practices along the Upper Susquehanna and Chemung River in New York, which are both part of the wider Chesapeake Bay watershed.
Impacts of ecosystem engineers on riparian community biodiversity, structure and function
The widespread reforestation of the Northeastern United States has been accompanied by a reintroduction of beaver (Castor canadensis) throughout the region, resulting in profound changes to stream and meadow ecosystems. At a SUNY-ESF research forest in the Adirondack Mountains of New York State, we are using a 30-year record of beaver lodge occupancy to (1) test a process-based model of landscape controls on the duration of beaver occupancy; and (2) quantify the spatially-varying impacts of beaver foraging on forest tree composition and structure. This research will help to better understand the widespread and long-term effects on forests from a keystone species that is increasing in influence throughout North American and Europe.
The widespread reforestation of the Northeastern United States has been accompanied by a reintroduction of beaver (Castor canadensis) throughout the region, resulting in profound changes to stream and meadow ecosystems. At a SUNY-ESF research forest in the Adirondack Mountains of New York State, we are using a 30-year record of beaver lodge occupancy to (1) test a process-based model of landscape controls on the duration of beaver occupancy; and (2) quantify the spatially-varying impacts of beaver foraging on forest tree composition and structure. This research will help to better understand the widespread and long-term effects on forests from a keystone species that is increasing in influence throughout North American and Europe.
Vernal pool restoration in forest ecosystems
Tree structure and growth in wetland forests along a hydrological gradient in southern Europe
Ecological constraints to re-establishing native trees on severely-degraded floodplains
Water relations of hybrid willows used for commercial biomass and groundwater remediation
Watershed Nutrients and Stoichiometry in Multi-use Catchments
Water Regulation and Muskrat Effects on Wetland Plant Assemblages
Tree structure and growth in wetland forests along a hydrological gradient in southern Europe
Ecological constraints to re-establishing native trees on severely-degraded floodplains
Water relations of hybrid willows used for commercial biomass and groundwater remediation
Watershed Nutrients and Stoichiometry in Multi-use Catchments
Water Regulation and Muskrat Effects on Wetland Plant Assemblages