DOI: 10.6073/pasta/e6f71accdb618958c99f5bad09534c5e
title: Langenheim Plant Species Data (1953) and Associated Resurvey Datasets (2014), Gunnison Basin, Colorado, USA

description: Quantitative plant abundance data were collected from the same 121 sites at two time periods separated by 65 years (1948-1952 and 2012-2014) in the Colorado Rocky Mountains to examine changes in plant community composition. The sites range in elevation from 2600m to 4100m. Approximately 30 sites were sampled from each of four habitat types: sagebrush (2528-3119m, n=27 sites), spruce-fir forest understory (3001-3520m, n=31 sites) , upland herb = montane meadow (3124-3850m, n=30 sites), and alpine (3549-4013m, n=33 sites).
 
 The earlier data set was collected by Jean H. Langenheim (1953, 1962) and consisted of counts of species occurrences along approximately 100m paced transects, noting species touching her boot tip every pace (n=100 sampled points per site). The later data set was collected by Stephanie D. Zorio (2015, 2016) consisting of counts of species occurrences every 1m along 300m transects (n=300 sampled points per site). The sites resurveyed by Zorio (2015, Zorio et al. 2016) were placed as close as possible to the original sites based on the written descriptions of Langenheim, but are only approximate. The GPS coordinates given for the resurveyed sites are the centerpoint of 2 perpendicular 150m transects, one across the slope and the other perpendicular to the slope. GPS coordinates for alpine sites along narrow ridges are the start and end points of three 100m transects along the ridge. Georeferenced localities and environmental site data are presented in Table 2: Lang Zorio Env Site Data.
 
 Langenheim’s original data were extracted from tables in her thesis (Langenheim 1953). These data omitted species that occurred in fewer than 14% of sites of a given habitat type (constancy). Species that occurred at very low frequencies (&lt;1% per site) were only denoted as an x in the tables. Zorio converted these to frequencies of 0.5 for quantitative comparative purposes. This data set contains 157 species from 27 families across all sites and habitats. Species in several difficult to identify genera were lumped at the genus level. The original taxonomic nomenclature is retained. This data set is presented in Table 1: Lang Data 1953 Thesis. Data are given with species in rows and sites in columns for each habitat separately. Data are raw counts of species/site.
 
 For comparison with the more recent survey results, taxonomomy was updated to that of Weber and Wittmann (2012). All taxa (n=199) are combined into one data matrix with sites in rows and species in columns. These data are presented in Table 3: Langenheim data for use with Zorio Data. 
 
 Complete species counts from the 2012-2014 resurveys (n=300 samples per site) are presented in Table 4: Zorio Veg Matrix All Species. As in Table 3, sites are in rows and species (n=311) are in columns. These data will be the most appropriate for comparison with future resurveys.
 
 The reduced data set of 2012-2014 surveys used to compare with Langenheims original data is presented in Table 5: Zorio_AAAR_Div by 3 & 14% Constancy. As noted above, all species with less than 14% constancy were dropped from the dataset and counts were divided by 3 to standardize the sampling effort between surveys. 
 
 Literature Cited:
 Langenheim, J.H. 1953. Plant-Ecological Reconnaissance of the Crested Butte Area, Gunnison County Colorado. Draft of published doctoral dissertation, Dept. of Biological Sciences, University of Minnesota, Minneapolis, 235 pp. 
 Langenheim, J.H. 1962. Vegetation and environmental patterns in the Crested Butte area, Gunnison County, Colorado. Ecological Monographs, 32:249-285.
 Weber, W.A., & Wittmann, R.C. 2012. Colorado Flora: Western Slope. Fourth Ed. Boulder: University Press of Colorado, 608pp.
 Zorio, S.D. 2015. 70 Years of Vegetation Change in the East River Basin, CO, USA. Master’s thesis, Department of Biological Sciences, Idaho State University, Pocatello, 127 pp.
 Zorio, S.D, Williams, C.F., & Aho, K.A. 2016. Sixty-five years of change in montane plant communities in western Colorado, USA. Arctic, Antarctic and Alpine Research, 48: 703-722.