Wetland drying linked to variations in snowmelt runoff across Grand Teton and Yellowstone national parks

In Grand Teton and Yellowstone national parks wetlands offer critical habitat and play a key role in supporting biological diversity. The shallow depths and small size of many palustrine wetlands in these protected areas and elsewhere make them vulnerable to changes in climate compared with larger and deeper aquatic habitats. Here, we use a simple water balance model to generate estimates of biophysical drivers of wetland change. We then examine the relationship between wetland inundation status and four principal drivers (i.e., temperature, precipitation, evapotranspiration, and runoff) spanning varying meteorological conditions over an 8-year time series from Grand Teton and Yellowstone national parks. We found that models containing snowmelt runoff outperformed models with other meteorological drivers and determined that a higher percentage of surveyed wetlands were dry in years characterized by lower runoff. Our work further shows that wetland drying was widespread across both parks, but sub-regional variations were best described at the hydrologic subbasin-level. Documenting the varying responses of wetlands to meteorological drivers is a necessary first step to identifying which subbasins are most sensitive to recent climatic change and contemplating how future change may alter the distribution of wetlands and their dependent taxa. [Display omitted] •In protected areas climate change is the greatest threat to wetland persistence.•Water balance models provide estimates of the primary drivers of wetland change.•Temporal and spatial variations in runoff best explained wetland drying.•Subbasin differences in wetland drying were documented.