English

Abstract

Oil and Gas (O&G) site reclamation in the Western United States has expanded greatly with the onset of gas development in the last decade. This study compares three different vegetation sampling methodologies to determine which methodology provided the most consistent, repeatable data, as well as resulted in the highest vegetation diversity on reclaimed well sites in southwestern Wyoming. The study area is located in Sweetwater County near Wamsutter, Wyoming. The three methodologies compared were the Bureau of Land Management (BLM) Rawlins Field Office (RFO) Point Method, Point-Line Intercept Transect Method, and a Modified Daubenmire Line Transect Method. Each sampling methodology was field tested on 30 reclaimed O&G well sites. Quantitative vegetation data variables including total vegetation cover, litter cover, rock cover, total cover (total vegetation plus litter plus rock), lifeform cover, and the number of each lifeform were collected. Multi-Response Permutation Procedure (MRPP) and cluster analysis were used to statistically analyze the quantitative data. Based on the MRPP results, total cover, bare ground, and litter plus rock cover were not significantly different at p < 0.10 for the BLM RFO Point Method and the Modified Daubenmire Line Transect Method. For those same parameters, the Point-Line Intercept Transect Method was significantly different from the other two methodologies at p = 0.01 to 0.10. All three methodologies were not significantly different at p < 0.10 for total vegetation cover. The cluster analysis demonstrated that the Point-Line Intercept Transect Method had more similar total cover values than the other two methodologies. Qualitative time data was also collected to compare data collection and data summarization time requirements. Overall, the Point-Line Intercept Transect Method is the preferred methodology based on the statistical analyses and the reduced sampling and data summarization time required to perform this method.