Vernal pools exist in areas of a grassland where there is an isolated area of compacted clay or bedrock. This is because the water cannot penetrate it and therefore, stays on the surface instead of absorbing into the soil. Depending on their size and amount of rainfall, they may fill and dry up many times within a season, or may not fill at all in a drought. Many species of wildlife, including birds and amphibians, depend on these pools. They are a cache of fresh water and food and, for some, a good place to lay their eggs because they are safe from predation by fish.
For the first time in four years, US Fish and Wildlife Service (FWS) opened grazing permits for several properties in the Santa Rosa plains, allowing grazing. Grazing was returned to these properties because its removal caused vegetation to over grow, reducing habitat for the endangered species present. Not having this grazing “disturbance” resulted in a species loss; the very species that were to be protected. Two examples of grazing benefits are listed below.
California Tiger Salamander
Managed livestock grazing is thought to benefit the habitat for California tiger salamander (Ambystoma californiense) (Fig 1). Some Bay Area populations of these salamanders depend on ground squirrel burrows for refuge sites. Livestock grazing keeps vegetation low, making the grasslands more suitable for California ground squirrels (USFWS 2003). Salamanders that inhabit vernal pools may also benefit from grazing. These ephemeral pools are wet only during the winter/spring rainy season, and too much vegetation in and around their edges can cause drying pools to lose depth too quickly. Because it reduces this vegetation, grazing can keep the pools wet longer, giving salamander larvae more time to grow up (USFWS 2004).
Opportunities for Native Plants
Grazing of non-native vegetation is essential to create opportunities for many native grassland plants. For example, there is only a single remaining natural population of the federally-endangered Sonoma spineflower (Chorizanthe valida) (Fig 2) and it declined dramatically after livestock was removed from its habitat area (Davis and Sherman 1992). Similarly, populations of the federally-endangered Contra Costa goldfields (Lasthenia conjugans) and Santa Cruz tarplant (Holocarpha macradenia) plummeted and died out when grazing was removed from their habitats (USFWS 2005; Hayes 1998).
Nowadays, 90% of the US's vernal pools have disappeared due to human encroachment and land conversion. Like the rangelands they exist on, they can be beautiful and vital places if properly managed! With the arrival of the Spanish missionaries, Sonoma County's grasslands changed dramatically. They became dominated by non-native annual plants, mostly from the grasslands of the Mediterranean Basin. Despite the general replacement of native plants by these non-natives, enough native species have survived to prompt global recognition of our grasslands as hot spots of biodiversity.
Because livestock grazing (primarily by cattle) can effectively reduce the biomass, height, and thatch accumulation produced by non-native annual plants, it has become an essential tool for managing our local grasslands. Grazing has been shown to be a benefit by
reducing the risk of a catastrophic wildfire, maintaining and enhancing habitat for many native grassland plants and animals,
and maintaining the open character of our iconic grasslands and oak savannas.
Ranchers should be encouraged to continue their sustainable livestock production practices and their long history of good stewardship. In addition, they should be compensated for implementing other conservation services on rangelands./h2>/h2>/table>
The class learned about the direct link between urban consumers and local food producers, providing a powerful conduit for educating the public about the importance of local food production and rangeland management. Sonoma and Marin Counties are perfect models for demonstrating how
preserving family farms contribute to
social, economic and ecological sustainability at
local, regional and even national levels.
Ranching PRNS, albeit smaller scale, remains a local industry, which provides job creation, training and business succession, and market expansion for many other ranchers and farmers.
Through the 1980s and 1990s and into the early 2000s, efforts to conserve threatened and endangered (special status) species on western rangelands often meant removing livestock ranching. Research findings, demonstration results, and failed conservation efforts in recent years involving endangered species has supported the continuation of livestock ranching and the reintroduction of grazing to some rangelands that were “protected” through grazing removal. At the landscape level,
research has demonstrated that livestock ranching
maintains extensive, open spaces by
reducing land use conversion, fragmentation of habitat,
and vegetation type conversion from invasion of brush.
Threats to native biodiversity, including special-status species, are likely to increase with removal or decrease of grazing. Research and experience have shown that grazing is strongly linked to maintaining habitat for some special-status species on PRNS lands, while they have been inconclusive for others. Sonoma alopecurus (Alopecurus aequalis var. sonomensis) is found in eight naturally occurring populations in Sonoma and Marin Counties; the four sites in Marin County all occur at PRNS and are all grazed by cattle; Sonoma spineflower found solely in a grazed pasture at PRNS. Tiburon paintbrush and Marin dwarf flax occur on serpentine grasslands, with six occurrences of Marin dwarf flax on Golden Gate National Recreation Area (GGNRA) grazing lands. PRNS staff concluded, “Marin dwarf flax may benefit from a moderate level of cattle grazing through the reduction of taller competing vegetation as the flax is subject to shading by competing grasses or may be suppressed by build-up of thatch from previous year's herbage if left ungrazed.” (USNPS 2001).
Documented research, along with good stewardship provided by generational ranchers, has demonstrated the benefits provided to the ecosystems at Point Reyes National Seashore.
U.S. National Park Service. 2001. Biological Assessment on the Renewal of Livestock Grazing Permits in Point Reyes National Seashore and the North District of Golden Gate National Recreation Area Marin County, California. 65 pp.
In 2013, Pepperwood initiated a Conservation Grazing Program using electric fencing to control herd density, manage seasonal timing and increase rest periods between animal impact events. Rangeland research and practical experience has demonstrated that animal disturbance can have a positive impact on grasslands and some native fauna if properly managed for conservation goals.
Grazing is a tool many land managers use to create disturbance in grasslands to improve soil health, reduce thatch cover, combat invasive weeds, increase native species diversity and restore historical impacts once created by native fauna.
The use of domestic grazing animals to achieve conservation goals is not new and is sometimes referred to as targeted or prescribed grazing or holistic grazing. Pepperwood prefers the term “conservation grazing” because it speaks directly to the goals of their grazing program.
Cattle managers use electric fencing and portable water systems to maximize the ability to control animal density and duration on varying grassland types and environmental conditions. The Conservation Grazing Program at Pepperwood intends to demonstrate that by using variable density, short duration grazing and adequate periods of recovery, rangeland managers can make progress towards conservation goals.
References available upon request.
- Author: Stephanie Larson
The University of California Cooperative Extension recognized rangelands and their importance in Sonoma County, creating the “Ecosystem Services Interpretative Signage” to increase awareness and knowledge of park visitors, mangers and decisions makers of working rangelands and the ecosystem services. Rangelands are also referred to as working landscapes, are locally managed and provide essential biological, scenic, economic, and recreational values locally and throughout the world. Working landscapes are threatened in many areas by development, conversion to
Beyond the obvious benefits of beef cattle grazing such as food production, grazing can benefit individual plant and animal species, can help manage fire hazards, and, in the absence of natural disturbance regimes, help maintain Sonoma County's landscape structure. Beef cattle not only provide beef as food, they are also used as grazing tools, keeping weed or shrub invasion at bay, enhancing wildflower displays, or maintaining a low grassland canopy height to allow visibility, foraging, and movement of small mammals such as voles and ground squirrels. Rangelands not grazed or otherwise managed, especially where they abut or intergrade with shrublands, will become shrub invaded, which converts grasslands to coastal scrub. As well as increasing fire hazards, this conversion results in loss of coastal grasslands and; thus, loss of the species that occupy them. Fire and livestock grazing are the two main tools we can use to maintain grassland ecosystems. In Sonoma County, fire has become more difficult to use, livestock grazing is the most common and practical option. Maintaining rangelands has several benefits associated with water, including increasing water infiltration and increasing vernal pool inundation period for fairy shrimp and the California tiger salamander. In addition to ecosystems services associated with water, livestock grazing can also improve habitat for native annual forbs & grassland birds, control invasive weeds, reduce fire hazard, etc.
As the instructor for the Santa Rosa Junior College Range Class, I give students an education about using livestock grazing as a tool in Sonoma County to manage resources; especially in our regional and state parks. I took my class to Point Reyes National Seashore to experience rangelands and the use of grazing. The following blog post was written by student Nicko Wilde.
While much attention is currently being focused on the impacts of the elk sharing land with cattle, the views on this dynamic, mixed in opinion and criticism as they are, still do not focus primarily on a more general concern of overgrazing via poor practices, which ought to retain more attention. The impacts of irresponsible grazing include some of the following: reduced nesting sits for birds & wildlife, nest trampling, reduced cover, reduced floral biodiversity, and attractiveness to predators, parasites, and diseases.
Those who argue that no cattle should graze in point Reyes due to its ecological and protected status, should similarly step back and consider grazing done well can promote the following: watering sources for cattle can also provide water for wildlife, more public input and interest in water district activity, a transition from economically viable ranches based on meat production solely, to ranching done with land restoration productive capacity goals, and therefore a renewed focus on managing for plants with a higher forage value, managing for ornamentals, erosion control, etc.