watervulnerability

Shasta Trinity National Forest Watershed Vulnerability Assessment, Pacific Southwest Region (R5)
Watershed Vulnerability Results
Fisheries
This assessment considered increase in water temperature considered to be the primary risk to fisheries
and fisheries habitat. Fish values were characterized by the density of fish presence with higher weighting
for threatened, endangered and sensitive species than for resident species. The result of the analysis for
fish is shown in Figure 18. Areas in green contain habitats that may provide greatest resilience, and
watersheds in red support habitats that may be the most vulnerable to impacts associated with climate
change. Watersheds shown in yellow are considered to have moderate resilience.
Figure 18. Combined ratings of resources, stressors and exposure produce relative ratings of watershed vulnerability
Investing in fish habitat or watershed improvement projects is expected to be most effective in watersheds
with high resilience (green), or moderately resilient watersheds (yellow) adjacent to watersheds with high
resilience, because these would provide a greater level of connectivity. Enhancement of connectivity is a
vitally important form of restoration in response to climate change. Restoration has traditionally been
driven by a combination of political and biological considerations. It is highly important that scarce
restoration funds for species recovery be allotted based on a hierarchy that considers resource values and
includes long-term sustainability in the face of climate change. Site selection should prioritize areas of
high resource value, tempered by considerations of resiliency to climate change. Areas of high resource
value would include both population strongholds and habitat that will act as refugia from the change.
202 Assessing the Vulnerability of Watersheds to Climate Change