Water Resources Research Act Program

Details for Project ID 2012WY82B

Decadal Scale Estimates of Forest Water Yield After Bark Beetle Epidemics in Southern Wyoming

Institute: Wyoming
Year Established: 2012 Start Date: 2012-03-01 End Date: 2015-02-28
Total Federal Funds: $63,510 Total Non-Federal Funds: $511,785

Principal Investigators: Brent Ewers, Urszula Norton, Elise Pendall, Ramesh Sivanpillai

Project Summary: Terrestrial ecosystems are key components of major river watersheds and any disturbance could magnify impacts on downstream water users. The hydrologic partitioning of precipitation in the forests of Wyoming is undergoing profound change due to an epidemic of bark beetles. Recent research at the forest stand-scale has shown that while the trees die over the first several years of an outbreak, evapotranspiration declines, soil moisture increases, soil nitrogen concentrations increase and snowpack increases and melts faster. These changes in forest hydrology strongly suggest that streamflow will be increased. However, ongoing measurements of the streamflow in watersheds affected by recent bark beetle outbreaks show no increase. This conundrum between stand-level and watershed processes will be directly addressed by this project. Further, the length of time in which hydrological changes at the stand scale will persist is unclear because of lack of knowledge about the post bark beetle infestation stand recovery and successional development. To address these issues we will 1) quantify tree, seedling, sapling and other understory species composition in forest stands to characterize succession and 2) utilize multiple remote sensing tools to improve scaling between well-instrumented forest stands and watersheds to test a variety of hydrologic models operating at multiple temporal and spatial scales. As a third objective, we will synthesize a large amount of prior and ongoing data collection into an explicit data informatics framework. This framework will serve two purposes 1) novel data syntheses can occur in near real-time, enabling model-data fusion to improve predictions of streamflow and 2) rapidly serve data and model results for public and land manager use. This project builds on ongoing work that is quantifying and predicting water yield from bark beetle infested stands in the first five years of an outbreak and extends the time frame of predictions out to multi-decades. This work will enable both State and Federal water managers to make crucial predictions of streamflow from infested mountain ranges on time-frames that are relevant to land management decisions.