watervulnerability

Shasta Trinity National Forest Watershed Vulnerability Assessment, Pacific Southwest Region (R5)
Figure 10. Distribution of salmonid and resident fishes on the Shasta-Trinity NF. Density of TES fish species are
shown for HUC-4, HUC-5 and HUC-6.
Sensitive Species
There are 28 USFS sensitive species on the Forest; over 70% of these are aquatic species (Table 2). Most
of these species are already at risk due to loss of habitat and habitat fragmentation. Additional stress to
species is probable due to influences of warming on hydrologic processes. Periods of extended drought
would also exacerbate the effects of drying on small aquatic habitats. Timing and volume of hydrographs
are likely to shift. These increased stresses could result in loss of habitats and the species they support.
The non-fish species are strongly associated with springs and other water bodies less than one acre in size
(Figure 11). This analysis uses impacts to these habitats as the proxy for species effects.
194 Assessing the Vulnerability of Watersheds to Climate Change