Ecological Archives E089-075-A3

David W. Roberts. 2008. Statistical analysis of multidimensional fuzzy set ordinations. Ecology 89:1246–1260.

Appendix C. Descriptions of the Bryce Canyon National Park and Shoshone National Forest data sets.

Bryce Canyon National Park exhibits a mixture of Rocky Mountain Cordillera and Colorado Plateau floras. Vegetation in the Park ranges from small areas of exposed shale badlands dominated by Eriogonum corymbosum and Elymus salinus, through a large expanse of pinyon-juniper woodlands (Pinus edulis - Juniperus osteosperma), through a sequence of conifer woodlands and forests dominated with increasing elevation by {Pinus ponderosa, Pseudotsuga menziesii, and Abies concolor with scattered communities of Picea pungens, Pinus flexilis, Pinus longaeva, and Populus tremuloides. The Bryce Canyon data set consists of one hundred and forty-five 375 m2 circular plots stratified by elevation, exposure, and geographic distribution. Environmental data include elevation, aspect, aspect value ((1+cos(aspect+30))/2) (Roberts and Cooper 1986), slope, annual direct solar radiation, growing season direct solar radiation (equinox to equinox), and soil depth (deep vs. shallow). The cover of 169 non-tree vascular plant species was recorded according to the Pfister cover scale (Pfister et al.\ 1977): present, but < 1% cover = 0.5, 1–5% = 1.0, 5–25% = 2.0, 25–50% = 3.0, 50–75% = 4.0, 75–95% = 5.0, 95–100% = 6.0.

The coniferous forests of the Shoshone National Forest range from lower elevation woodlands dominated by Pinus flexilis, through forests of Pseudotsuga menziesii, Pinus contorta, Picea engelmannii, Abies lasiocarpa, and Pinus albicaulis with increasing elevation (Steele et al. 1983). One hundred and fifty 375 m2 sample plots were chosen at random from a larger set for this analysis; the larger set was stratified by elevation, exposure, surficial geology, and geographic distribution. Environmental data collected or calculated included: elevation, aspect, slope, site water balance (a tipping bucket model of water-year soil water), seasonal direct and diffuse solar radiation (correcting for topographic shading), precipitation, and potential evapotranspiration, frost-free days, degree day heat sum, and the mean monthly temperature of the coldest month of the year. The cover of all vascular plant species was recorded according to the following scale: present but < 1% = 0.1, 1–5% = 0.5, 5–15% = 1.0, 15–25% = 2.0, 25–35% = 3.0, 35–45% = 4.0, 45–55% = 5.0, 55–65% = 6.0, 65–75% = 7.0, 75–85% = 8.0. No species exhibited greater than 80% cover in the data set.

LITERATURE CITED

Pfister, R. D., B. L. Kovalchik, S. F. Arno, and R. C. Presby. 1977. Forest habitat types of Montana. 174 p. USDA Forest Service Gen. Tech. Rep. INT-34. Intermountain Forest and Range Experiment Station, Ogden, Utah, USA.

Roberts, D. W., and S. V. Cooper. 1989. Vegetation mapping and inventory: Concepts and techniques. Pages 90–96 in Land classifications based on vegetation: applications for resource managers. D. Ferguson, P. Morgan, and F. D. Johnson, editors. USDA Forest Service Gen. Tech. Rep. INT-257, Intermountain Forest and Range Experiment Station, Ogden, Utah, USA.

Steele, R., S. V. Cooper, D. M. Ondov, D. W. Roberts, and R. D. Pfister. 1983. Forest habitat types of eastern Idaho and western Wyoming. 122 p. USDA Forest Service Gen. Tech. Rep. INT-144. Intermountain Forest and Range Experiment Station, Ogden, Utah, USA.



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