Chapter 4: Biotic Resources
San Lorenzo Valley Water District Watershed Management Plan, Final Version Part I: Existing Conditions Report CHAPTER 4: BIOTIC RESOURCES 4.0 Introduction This chapter provides an overview of the biotic resources of the region, the San Lorenzo River watershed, and to the degree possible, on District-owned lands. Because most District-owned lands have not yet been biologically surveyed, the description at this level relies on personal observations of District staff and consultants--as well as the findings of other local studies--to identify communities of plants and animals, to estimate habitat conditions, and to assess future needs for biological surveys. The District has not yet established measurable baselines of biotic resource quantities, conditions, and locations. This chapter begins with a brief discussion of biodiversity, and then identifies major plant communities, wildlife habitats, and fisheries. Next, it describes some of the ecosystem functions and natural services provided by these local biotic resources. Finally, the chapter discusses the role of human activities and their impacts to plant communities, wildlife and fisheries habitats, and ecosystem functions. It should be noted that climate change has the potential to significantly alter fundamental natural processes that biotic resources depend on, such as the carbon cycle and the hydrologic cycle. Thus, the impacts of climate change on biotic resources are likely to be significant at all landscape scales, though the scope and severity of the impacts are as yet not fully known. 4.1 Biodiversity at regional and watershed scales As discussed in Chapter 2, the Santa Cruz Mountains is defined as a bioregion (Santa Cruz Mountains Biodiversity Council, 2007), which is home to plant communities, such as those of the sandhills, which are found nowhere else in the world.
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