Changes affecting our environment increasingly stress the ecosystems vital both to wildlife and people. But a hugely promising means of buffering our landscape and communities from some impacts of climate change resides in the vast acreage of open land in agricultural production—notably the rangelands that support cattle production.
|Rangelands in the foothills of California can store the equivalent of two Hetch Hetchy reservoirs—the goal of a cooperative program co-led by PRBO. Photo by Melany Aten / PRBO.|
To optimize these working lands’ potential in California, PRBO has launched an ambitious program with key partners that include private landowners and the USDA Natural Resources Conservation Service (NRCS). Building on the success of a model project in the hills bordering the Sacramento Valley (see box), our Rangeland Watershed Initiative is now bringing PRBO science together with an evolving land-use practice.
Our goal is to enhance 1.1 million acres of foothill rangelands throughout the Great Valley of California over the next five years. Changing grazing practices on these ranch lands can increase the soil’s ability to retain water by an estimated 15%. Over the subsequent five years, this will represent a gain of 725,000 acre-feet of water, the same amount as two Hetch Hetchy reservoirs (San Francisco’s main water supply). Recent climate scenarios project far less snowpack in the Sierra in the near future, underscoring the importance of this conservation approach.
|PRBO Partner Biologists Alicia Young, Tiffany Russell, and Melany Aten (L to R) discuss stream conservation with Tim Viel of the NRCS. Photo by Wendell Gilgert / PRBO.|
We now are working very closely with the NRCS, embedding PRBO Partner Biologists at county NRCS field offices to build relationships with ranchers (see Observer 168, Spring 2012) and help implement the enhanced rangeland management practices.
Another of PRBO’s crucial roles is to provide the science to evaluate these practices’ environmental outcomes. We will measure the soil’s capacity to soak up and store water, the diversity and productivity of grassland plants, the quality of streambank habitat, and the use of varied habitats by birds and other wildlife. To measure “ecosystem services,” we have begun working with U.C. Davis’s California Rangeland Watershed Laboratory. The U.C. scientists will measure changes such as soil attributes, stream flow, and the quantities of carbon that vegetation keeps out of the atmosphere (perennial native grasses store more carbon than introduced annual grass species).
Keys to this program will be the complete transparency of our science and the thorough involvement of landowners. By helping evaluate the program, landowners will have greater trust in the results (good or bad) and be more willing to further modify their practices—the essence of adaptive management. Ranchers we work with could also gain abilities to better adapt to changing environmental conditions—and stay in the business of food production and land conservation.
For the public, whose tax dollars help pay for the Rangeland Watershed Initiative through the federal Farm Bill, our results will produce new ways of sustaining ranching in the future and greatly enhancing supplies of water for humans and wildlife.