California Project: Assessing the effects of USDA conservation practices on wetland ecosystem services in CA's Central Valley

California Project

Assessing the effects of USDA conservation practices on wetland ecosystem services in CA's Central Valley

September 2006 - August 2011

Personnel

Participating Agencies

Natural Resources Conservation Service

The California Central Valley (CCV) was historically an ecosystem consisting of grassland, prairie, and oak-grass savanna habitats. Interspersed within these primary habitats were riparian woodland, freshwater marsh, and vernal pool wetlands. These wetlands were integral in supporting the diverse flora and fauna of the historic CCV. Riparian forest wetlands supported many neotropical migratory birds, Chinook salmon and other woodland associated species. Freshwater marshes in the CCV once supported enormous populations of wintering waterfowl, while vernal pool wetlands supported unique plant and invertebrate communities. Most, if not all, these habitats in the CCV have been altered by human activity. Area of wetland habitats in the CCV prior to 1900 has been estimated to be 1.6-2.0 million ha. In the 1980's, wetland area in the CCV had been reduced to 153,000 ha. Human activities leading to wetland loss in the CCV are many and varied, but agricultural development and urbanization are chief among them. The USDA, Natural Resource Conservation Service (NRCS) administers a variety of programs intended to assist farmers and ranchers in addressing natural resource concerns on private lands. Among these programs is the Wetland Reserve Program (WRP) which focuses on restoring degraded wetlands or those that have been converted to agricultural production. In California, NRCS has focused their WRP activities on restoring a variety of wetlands, including seasonal wetlands, semi-permanent marshes, vernal pools, riparian and tidally-influenced wetlands. Recent information suggests that at least 52 CCV wetlands totaling more than 11,000 ha have been at least partially restored. The NRCS initiated an assessment of the effects of conservation practices on wetland ecosystem services. This conservation effects assessment of wetland ecosystems (CEAP-Wetlands) objectives are to: Produce estimates of wetland ecosystem services, Quantify effects (of agriculture on wetlands), with and without implementation of USDA conservation practices, Develop predictive wetland functional condition indicator models, Quantify and compare effects of alternative environmental or program scenarios on regional wetland services, and Develop scientific and technological tools that improve the sustainability of wetlands on agricultural landscapes. CEAP-Wetland assessments will be conducted in 10 regions throughout the coterminous United States (USDA-NRCS 2006) and the CCV is one of these regions. The research described here supports the CEAP-Wetland assessment in the CCV. Objectives: 1. Organize and conduct a regional workshop involving multiple agencies and collaborators. The purpose of this workshop will be to identify ecosystem functions and services most important in CCV wetlands. 2. Complete preliminary research to identify and select wetland assessment sampling sites to be used in a CCV wetlands assessment. 3. Develop a study plan for completing a CEAP-Wetlands assessment of the CCV.

Research Publications

Research Publications	Publication Date
Duffy, W.G., Kahara, S.N. and Records, R.M., eds., 2011, Conservation Effects Assessment Project-Wetlands assessment in California's Central Valley and Upper Klamath River Basin: U.S. Geological Survey Open-File Report 2011-1290, 128 p. \| Abstract \| Download \| Publisher Website	October 2011	The Wetlands Reserve Program (WRP) is one of several programs implemented by the U.S. Department of Agriculture (USDA). Since the WRP's inception in 1990, it has resulted in the restoration of approximately 29,000 hectares in California's Central Valley (CCV) and roughly 12,300 hectares in Oregon's Upper Klamath River Basin (UKRB). Both the CCV and UKRB are agricultural dominated landscapes that have experienced extensive wetland losses and hydrological alteration. Restored habitats in the CCV and UKRB are thought to provide a variety of ecosystem services, but little is known about the actual benefits afforded. The U.S. Geological Survey (USGS) California Cooperative Fish and Wildlife Unit in collaboration with the USDA Natural Resources Conservation Service surveyed 70 WRP sites and 12 National Wildlife Refuge sites in the CCV, and 11 sites in the UKRB to estimate ecosystem services provided. In the CCV, sites were selected along three primary gradients: (1) restoration age, (2) management intensity, and (3) latitude (climate). Sites in the UKRB were assessed along restoration age and management intensity gradients where possible. The management intensity gradient included information about the type and frequency of conservation practices applied at each site, which was then ranked into three categories that differentiated sites primarily along a hydrological gradient. Information collected was used to estimate the following ecosystem services: Soil and vegetation nutrient content, soil loss reduction, floodwater storage as well as avian, amphibian, fish and pollinator use and habitat availability. Prior to this study, very little was known about WRP habitat morphology in the CCV and UKRB. Therefore in this study, we described these habitats and related them to ecosystem services provided. Our results indicate that although WRP in the CCV and UKRB provide a number of benefits, there may be management mediated trade-offs among ecosystem services. In this report, we considered ecosystem services at the site-specific scale; however, future work will extend to include effects of WRP relative to surrounding cropland.

Cooperative Fish and Wildlife Research Units Program: California Education, Research and Technical Assistance for Managing Our Natural Resources