Characterizing Condition in At-Risk Wetlands of Western Utah: Phase I  

Abstract / Description

ABSTRACT
This report represents the first phase in development of a rapid wetland condition assessment tool for Utah wetlands and an extension of baseline data collection and analysis for spring-fed wetlands in the Snake Valley of Utah’s West Desert. This initial phase of sampling and reporting had three main objectives: 1) test wetland mapping methodologies, 2) evaluate the efficacy of two rapid condition assessment methods, and 3) develop a simple conceptual model relating hydrology to biota.
We gathered all available spatial layers pertinent to wetland condition that could be used in a quantitative landscape-scale condition assessment to provide a first look at land use and stressors in the watersheds contributing to target wetland resources. We found that the surrounding uplands and wetlands are predominantly used for ranching and agriculture with a combination of private and public ownership across the entire study area. We tested two distinct mapping methods based on an existing vegetation map to evaluate automated schemes and proof of concept for a previously developed crosswalk from National Wetland Inventory standard classes to modified hydrogeomorphic classes. These additional mapping methods were both very accurate and efficient and will be useful tools in future mapping projects. We assessed two existing rapid assessment methods for use in Snake Valley, spring-fed wetlands: 1) the Utah Wetland Ambient Assessment Method, which was developed for wetlands around Great Salt Lake, and 2) USA-RAM, which was developed in conjunction with the National Wetland Condition Assessment program for wetlands at the national scale. The two methods generally indicated that wetlands in the northern reach of the study area are in good condition with a few notable exceptions. The limited condition gradient detected made it difficult to quantitatively assess the sensitivity of metrics. Condition assessment sampling will be expanded into the southern reach of the study area to capture a broader gradient for metric calibration. Finally, we developed a simple conceptual model relating hydrology to extant vegetation. This model represents the foundation of our understanding of how changes in hydrology may impact wetland biota and will be used to test relationships between hydrology, wetland condition, and wildlife habitat in future research. The second phase of sampling and reporting will expand on the objectives initiated in this report with additional data, specifically focusing on assessing metric sensitivity to condition in wetlands in the study area.