Our study consists of 14 headwater wetlands dominated by black ash and located on the Ottawa National Forest in the western upper peninsula of Michigan. These wetlands are small, less than 1.5 ha, have little or no defined channels entering them, and are seasonally inundated. They have organic soils, from 0–6m in depth, over top of a confining layer of mineral soil. The canopies are composed primarily of black ash, red maple, and yellow birch.



The sites were assigned on of three treatments, a control, where no action was taken, a girdle treatment, to simulate short-term impacts of infestation, or an ash cut treatment to simulate long-term impacts of infestation. In treatment sites all ash stems greater than 1” diameter were impacted in the winter of 2012-2013. Since that time we have continued to collect and analyze data.


The sites are divided into three types depending on the focus of the research at each site. Nine sites are considered ecological processes sites, where research included water levels, source water, vegetation dynamics, nitrogen allocation and availability, canopy hydrology, and greenhosue gas fluxes. Three sites are used to evaluate alternative canopy species as replacements for black ash, and to identify the best planting strategies for these difficult growing conditions. The final two sites are used as a paired watershed experiment to study changes in water yield and nutrient loads that will impact first order and intermittent streams draining these sites.