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Alpine Vegetation Impact Assessment
Barb Smith, Wildlife Biologist, Manti-La Sal National Forest
The La Sal Mountains above Moab, Utah support a unique alpine vegetation community featuring several endemic plant species. The extent of true alpine ecosystems is limited on the Colorado Plateau, as the type occurs only on isolated sky islands. One Forest Service sensitive plant species, the La Sal daisy (Erigeron mancus), is found nowhere else in the world. There are also at least 10 plant species that represent the only populations in the state of Utah. These species include Androsace chamaejasme (also a USFS sensitive species), Podistera eastwoodiae, Oreoxis bakeri, Besseya alpina, Saxifraga bronchialis and Carex perglobosa. All of these species have a NatureServe (2008) state ranking as imperiled or critically imperiled. Recreation, mainly from trampling effects, has been well documented as an impact on alpine soils and vegetation (Whinam and Chilcott 2003, Rochefort and Swinney 2000, Hartley 2000, Willard and Marr 1970). The alpine ecosystem, with short growing seasons, shallow soils and steep slopes, is a harsh environment for plants. The subsequent long-term recovery times, limited restoration potential and specialized, endemic species make any impacts significant. With increasing recreation use, and also increasing requests for outfitter/guide and special event permits, a need to access the extent of impacts on the La Sal Mountains, especially in the Mt. Peale Research Natural Area (RNA) has been identified. Research natural areas are part of a national network of ecological areas designated in perpetuity for research and education and/or to maintain biological diversity on National Forest System lands. Research natural areas are for nonmanipulative research, observation, and study. Forest Service objectives (FSM 4063) for these areas include protection against serious environmental disruptions and serving as baseline areas for measuring long-term ecological changes. The Mt. Peale RNA was established specifically to protect ecosystem structure and function in representative alpine and subalpine habitats. The Manti-La Sal National Forest Land and Resource Management Plan (1986) requires management of the designated area with an emphasis on research, interpretation and protection against use that could jeopardize the diversity and pristine condition that led to original establishment of the RNA. It is important to maintain pristine conditions so that long-term changes can be monitored. Due to a lack of funding, permanent study plots have never been established in the Mt. Peale RNA. Information on current conditions would help in protection and management of the area. The main research question identified was: Is recreation increasing bare soil, leaving evidence of human activity and possibly impacting natural processes that the RNA was established to protect? A study to access the current impacts to the La Sal Mountain alpine environment from human recreational activities was proposed by the Moab District of the Manti-La Sal National Forest, and funded by Canyonlands Natural History Association. The study was conducted by Dr. James Fowler from the Southwest Forest Science Complex of the Rocky Mountain Research Station, USFS, in Flagstaff, in cooperation with the Manti-La Sal National Forest.
Five broadly defined types of habitat have been identified in the Mt Peale RNA, three in the alpine zone and two in the forested, subalpine zone (100 acres). The well-developed alpine turf communities are uncommon. Combined with the alpine turf-rock community type, there is a total of 360 acres of herbaceous alpine vegetation. The majority of the area is dominated by talus and barren rock (2020 acres).
The plots were established and read in July 2008 by a crew of 5 researchers, including Dr. James Fowler, 3 biological technicians from RMRS and 1 biological technician from the Manti-La Sal National Forest. The plots were not physically marked, but UTMs of the center point were located with global positioning system equipment and photo points were established (Appendix 2). Within the 0.1 acre plots, basic site data (slope, aspect, elevation, dominant vegetation, % bare ground, % vegetative cover) was collected. Condition classes, as tested by Rochefort and Swinney (2000) for a study on Mt. Rainier, were used to identify the level of human impact in the plot. The 5 condition classes range from pristine (0) with no signs of human use to (4) 50% or more of the site with permanent impacts. Polygons of Forest Service sensitive plants (Erigeron mancus and Androsace chamaejasme var carinata) were located and mapped.
Out of the 33 sensitive plant polygons, 3 were rated as showing evidence of human impact. Two are on the "Laurel Highway", a commonly used approach to the peaks from the northwest. One study plot with a (1) rating is on a ridge below Mt. Mellenthin. The (1) little change ratings were all related to evidence of trails and associated trampling. Approximately10.5 acres of Erigeron mancus and 7.8 acres of Androsace chamaejasme occupied habitat were mapped (Appendix 1). While it was planned to count and then sample sites with evidence of obvious heavy human impact such as camping, fire rings, human waste, litter and severe plant damage, this level of use was not identified in the areas sampled. Social trails, with some plant trampling and displacement of rocks contributed the majority of the human sign observed.
The plots rated as showing impact (4 sites or 8% of sites sampled) included 3 on the Laurel Highway, a trail accessing the peaks from the Gold Basin road, and one site on a ridge below Mt. Mellenthin used as an approach route. Two of these areas are within the RNA, the other two occur below the RNA boundary. Other areas that may receive heavy recreational use as approaches to the peaks, such as the south side of Mt. Peale and the head of Dark Canyon, were not sampled. The need for additional baseline sampling areas was identified, and the local Moab District office of the MLNF plans to establish several more plots in the 2009 season. The plots established in this study can be relocated, photographed and monitored in future years. The information from this research will be used on a District, Forest and Region level. It will inform Manti-La Sal National Forest planning efforts. The Forest Service can use the information and results from the project as a greatly needed assessment of recreation use and potential impacts in the area, and to inform future monitoring of the area. The data has implications for management of the area, especially as related to permitted activities (outfitter/guides), designated trails and dispersed camping. The data provides a preliminary impact assessment, and a baseline for monitoring and management of alpine areas and the Mt Peale Research Natural Area. The information will be used to direct education efforts for users of the alpine communities, and specifically the permitted outfitters/guides who want to use the area. As social trails are largely established on the peak, management can encourage their use and avoid the establishment of new routes. Based on the information gathered from this study, and from Manti-La Sal National Forest and RNA management direction, current policy and management of the area regarding outfitter/guides and special events will be continued. In addition to continued monitoring and more human impact plots on the south side of the range, a desire for further research on sensitive plant species distribution and possible climate change effects was identified. |