Peak & Prairie

Rocky Mountain Chapter's
Online Newsletter
October / November 1998


Are Mosquitoes Conservation Priorities?

by Jean Smith, Chapter Ecosystems Cochair


Looking across South Park, west of Fairplay the Mosquito Range forms a long ridge which divides the headwaters of the Arkansas from the South Platte. Further west, Leadville sits among the reminders of the mining days. The twin humps of Buffalo Peaks Wilderness anchor the south end of the ridge, and the north end rises to the Continental Divide. Should this area be protected for the sake of native biodiversity? Should it be part of the network of reserves and connecting corridors which will one day rewild Colorado and North America?

State of today's ecosystems
To help answer this question, it is helpful to know how today's ecosystems compare with their more "natural" conditions of several hundred years ago. Today our power-multiplying machines and burgeoning numbers are radically affecting our surroundings, and some sense of the amount and rate of change will inform our land use decisions. The Southern Rockies Ecosystem Project (SREP) will publish a "State of the Ecosystem Report" late in 1998 as a tool for land use planners and conservationists.

Conservation priorities
However, knowing what was and what is does not automatically identify priority conservation areas. "Where is the best?" is a complicated question, and later there are decisions about how to protect the high priority areas. To answer the "where," SREP is assessing several biological factors in the 5th level watersheds of the Southern Rockies bioregion. It takes computerized analysis and modeling to deal with the complexity of the process. Data on roads, vegetation types, rare and imperiled species and riparian quality were used in the preliminary analysis. Other factors, such as suitable habitat for indicator species, will be applied in the next few months. Each watershed is rated for each factor and results are grouped into five conservation priority classes from "very high" to "very low." A composite score of all the factors reveals which watersheds have higher biological value. After review by scientists and local conservationists, the analysis can be displayed on maps and used to help build a reserve design.

Back to the Mosquitoes
So, should the Mosquitoes be protected as a core reserve? The conservation priorities might help decide. Each map on these pages shows the same geography around Weston and Buffalo Peaks. It includes parts of four watersheds.

Weston Peak and Buffalo Peaks Wilderness are large roadless areas which stand out in contrast to the network of roads at Fairplay and around Leadville and down the Arkansas Valley. Many of you have done mapping of roadless area boundaries or ghost roads, so you know this is important. The road density analysis for three watersheds in this area are in the range of 0.5-1.0 miles per square mile, and the watershed west of Buffalo Peaks Wilderness is less than 0.5 miles per square mile.

Biologically rich sites
The Colorado Natural Heritage Program's data base shows important biological sites, and the watersheds rank high on occurrences of rare and imperiled species according to SREP's analysis.

An important factor is whether the area contains vegetation types that are not well represented in regional protected areas. Just looking at a topographic relief map of Colorado's Wilderness areas reveals that high elevation types such as tundra and spruce-fir are well protected. This is borne out by the analysis, as is our sense that low elevation types and wetlands are under-represented. Some very important habitats for lower elevation species, as well as wintering range for many animals, is vulnerable to future housing construction, road building, recreation development, timber cutting and other activities.

Southern Rockies Bioregion
% of Total Acres in Protected Areas


Aspen 27.6
Spruce-fir 23.8
Douglas fir 23.1
Tundra 22.0
Lodgepole pine 19.8
Mixed conifer 14.4
Oak 7.9
Ponderosa pine 7.5
Wetlands 6.5
Pinyon-juniper 4.7
Shrublands 3.3
Grasslands 1.5


As for the Mosquito Range, there is a lot of tundra, but, there are also areas of ponderosa pine, wetlands and grasslands, as well as some high quality riparian areas.

Composite rankings
The composite score for all the indicator factors for the Mosquito Range shows that one of the four watersheds in this area falls into the "very high" priority rank, and the other three are "high priority."

Is there an answer?
Not yet! The analysis described here is a valuable tool, but it does not tell us the final answer to which areas should become core reserves. Many people will review these analyses, and finally a reserve design will emerge. And it certainly doesn't tell us how to effect on-the-ground management of public and private lands that genuinely leads to the long-term viability of all Colorado's native species. There are no easy answers, but the search itself is exciting.