Research
Spring-fed wetlands structure and function; Grazing management of spring-fed wetlands in California oak woodlands
Funding Sources: USDA & Private GiftsWatershed Dynamics in California Oak Woodlands
Funding Agency: USDA & Private GiftsEcological impacts of Sudden Oak Death on coast live oak and tanoak/redwood ecosystems
Funding Agency: USDA, Pacific Southwest Research StationVegetation Type Mapping
Funding Agency: US Forest ServiceNet primary productivity of blue oak woodlands: implications for ecosystem health and management (Lead PI: John Battles)
Funding Agency: USDA-NRI Watersheds ProgramCarbon dynamics of California grasslands affected by climate change (Lead PI: Whendee Silver)
Funding Agency: Kearney Soil Foundation
This is a long-term (10+ years) study at Sierra Foothill Research and Extension Center to assess multi-scale effects of grazing intensity levels. We are monitoring spring ecosystem responses in plant composition, diversity, cover, water quality, aquatic insects, and greenhouse gases. We have also collected channel morphology data. The greenhouse gas portion of this study relates environmental and anthropogenic (cattle grazing) factors affecting methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) flux in spring-fed wetland ecosystems of California’s foothill oak woodlands.
Watershed Dynamics in California Oak Woodlands
Collaborators: Dr. Randy Dahlgren (UC Davis), Dr. Ken Tate (UC Davis), Dr. E. Robert Atwill (UC Davis), Dr. Michael J. Singer (UC Davis)
The effects of grazing and prescribed fire on water quality in California rangeland watersheds are being examined at sites in the Sierra Nevada foothills and Coast Ranges of northern California. This project uses a paired watershed design to determine the watershed scale effects of fire and grazing intensity on water quality, hydrology, nutrient cycling, and plant community dynamics on annual rangelands. Our lab focuses on the plant community dynamics portion of the project.
Ecological impacts of Sudden Oak Death on coast live oak and tanoak/redwood ecosystems
Sudden Oak Death, or SOD, results from a newly described fungal pathogen, Phytophthora ramorum. The occurrence of this new disease in coastal woodlands of California provides a unique opportunity to examine the effects of this disease on the community level. This study will provide data on the early effects of the disease on the vegetation and vertebrates in forest communities as well as provide baseline information that would allow researchers to interpret the long-term effects of the disease.
Collaborator: Dr. Maggi Kelly (UCB)
This is a long term, collaborative project to create a complete database of an historic data set recording the vegetation types of California. The data consists of US Forest Service VTM plots collected as part of a state-wide effort to map forest vegetation in the 1920s and 1930s. These historic records contain data regarding tree stand structure, percent cover of dominant understory vegetation by species, soil type, parent material and environmental elements for each site. Along with these data, photographs of representative plots were taken.
http://vtm.berkeley.edu/Net primary productivity of blue oak woodlands: implications for ecosystem health and management
Collaborators: Dr. John Battles (Lead PI, UCB), Dr. Randall Jackson (UW, Madison)
The goal of this proposed research is to examine the effect of typical range management practices on NPP. Using a watershed-scale approach, we plan to obtain robust baseline estimates of NPP for 3 research watersheds at the Sierra Foothill Range and Extension Center (SFREC) and then to measure ecosystem health in the wake of grazing and fire treatments based on observed changes in NPP. Because we seek an integrated estimate of NPP for an entire management unit (i.e., the watershed), we will measure across this mosaic using techniques from landscape and community ecology to efficiently allocate our sampling effort and to properly extrapolate our plot-level results. By necessity, we will also partition the contributions to productivity from 1) different life forms (herbaceous, shrub, and tree), 2) above- and below-ground pools (stems and roots), and 3) various tissue qualities (leaves, acorns, and wood). The result will be the first watershed-level productivity budget for oak woodlands. Thus, we will not only monitor the overall influence of management on NPP, but also gain insight into what components of primary production are most sensitive to grazing.
Carbon dynamics of California grasslands affected by climate change
Collaborators: Dr. Whendee Silver (Lead PI, UCB), Dr. Randall Jackson (UW, Madison)
California grassland soils store large C pools. The relative balance of C inputs and loss is likely to be highly sensitive to changes in soil moisture in these ecosystems due to the strong summer drought that limits both plant and microbial activity. Recent modeling scenarios predict that soil moisture is likely to change under conditions of elevated CO2 and climate change in California, although the direction of that change is still being debated. In this study we will use a series of field manipulations to examine the effects of altered water regimes on soil C storage and loss in California grasslands.
We are examining the effects of early wet-up and a sustained growing season length on soil C pool and fluxes in well-drained and wetland soils and provide estimates of greenhouse gas (CO2 and CH4) production and emission. This project provides a framework for evaluating the consequences of water management for C sequestration and loss, and generates baseline information on the impacts of changes in grazing or other land uses on soil water and C dynamics.