watervulnerability

Grand Mesa, Uncompahgre and Gunnison National Forest Watershed Vulnerability Assessment, Rocky
Mountain Region (R2)
Figure 14. Coldwater Fisheries and Known Cutthroat Trout Occurrences
Initially, the list of aquatic ecological values to be evaluated in this WVA was more extensive. Springs
were identified as an important resource value likely to be affected by climate change; however, the
spring inventory for the Forest is very limited. Boreal toad (Anaxyrus boreas boreas, a sensitive species)
was not included because known occurrences are limited to very few sites on the Forest, and evaluation of
effects to riparian habitats would address the effects to boreal toads and other amphibian species. Four
warm water-sensitive fish species (bluehead sucker (Catostomus discobolus), flannelmouth sucker (C.
latipinnis), mountain sucker (C. platyrhynchus), and roundtail chub (Gila robusta)) were also not
included in the WVA because of limited data on occurrence and stream temperatures. Botanical species
and communities were eliminated from consideration because general effects to their habitat would also
be addressed through riparian habitats.
Aquatic ecological value metrics were designed to compare subwatersheds in a more relative way. For
each individual value, the results were standardized (results for each subwatershed were divided by the
largest result of all the subwatersheds). The standardized results for each value were then summed to get a
cumulative aquatic ecological value (Fen/wetland/riparian habitat + coldwater fisheries + cutthroat trout
fisheries = Aquatic Ecological Value Ranking). The cumulative Aquatic Ecological Value Rankings were
classified into quartiles. The top 25% were classified 3 (high), middle 50% were classified 2 (moderate),
lowest 25% were classified 1 (low). Figure 15 shows the resulting Aquatic Ecological Values Ranking.
80 Assessing the Vulnerability of Watersheds to Climate Change