Creekside Science, in collaboration with the Santa Clara Valley Habitat Agency, has been awarded a Natural Community Conservation Planning (NCCP) Local Assistant Grant for researching nitrogen deposition trends in the HCP area of Santa Clara County.
Added nitrogen drives annual grass invasions on serpentine soils and threatens many of the covered species, especially the Bay checkerspot butterfly (Weiss 1999). Indirect impacts of continued N-deposition on natural communities are anticipated to result from the development covered under the NCCP and serpentine habitat types are the focus of preservation and management/enhancement actions to offset the effects of nitrogen deposition. All other land cover types in the permit area have also been identified as sensitive or potentially sensitive to N-deposition (Weiss 2006, Fenn et al. 2010), including northern mixed and serpentine chaparral, mixed oak woodland, foothill pine-oak woodland, mixed evergreen forest, redwood forest, California annual grassland, valley oak woodland, blue oak woodland, coast live oak forest and woodland, freshwater marsh, seasonal wetland, and ponds. Understanding and monitoring this primary driver of ecological change is the primary goal of this project.
Consistent elevated nitrate in shallow groundwater is a prime symptom of terrestrial nitrogen saturation (Fenn and Poth 1999, Fenn et al. 2008). Excess N leaches below the root zone as nitrate. Low-productivity serpentine soils have very limited capacity to retain N (Fenn et al 2010). There are dozens of springs fed by serpentine grassland catchments within the Plan Area and beyond, and spatial gradients and trends in N-deposition can be monitored efficiently through sampling of selected springs for nitrate.
This grant will fund work on this project into 2019.