Environmental Conditions Appendix II
Environmental Conditions Environmental Conditions Appendix II The unique geology, hydrology and climates of the Deschutes River Subbasin create a diverse mix of habitat conditions for fish and wildlife. These populations are linked to the ecosystems in which they live and their health, individual characteristics and abundance reflect the diversity ― and quality ― of their environments. Fish populations, for instance, developed complex life histories through time that responded to the subbasin’s considerable variation in habitat conditions. Stream flows, water temperatures, substrate characteristics and other combined attributes affected anadromous fish distribution within the subbasin and timing of migration. Wildlife population abundance and distribution also developed in response to habitat conditions. Native grasslands once covered vast areas and supported species such as sage grouse, which once occurred exclusively in this habitat. Loss of grassland habitat greatly reduced such populations. Today subbasin habitat conditions continue to influence fish and wildlife production, distribution and survival. These habitats and their attributes ― as well as the aquatic and terrestrial populations they support ― are affected by both natural watershed processes and human activities that influence flow, water quality, upland and riparian conditions and instream habitat. This chapter examines how environmental conditions in the Deschutes watershed affect the subbasin’s fish and wildlife populations. Building on the more general review provided in the Overview, the discussion characterizes the environmental conditions within three watershed areas: the Lower Deschutes watershed (below RM 100), Crooked River watershed, and Upper Deschutes watershed (above RM 100). It characterizes the natural watershed environments, such as geology, climate and hydrology, and the focal fish species they support.
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