Fisk Lab - Current Research Projects

photo of students fertilizing plot

Multiple Element Limitation in Northern Hardwood Ecosystems

We are testing whether productivity in forest ecosystem is co-limited by nitrogen and phosphorus, and are examining the plant and soil mechanisms that are likely to minimize limitation by any single nutrient (more about the co-limitation project).

photo of students working on lysimeter in snow

Winter Climate Change and Soil Nutrient Retention

Snow in northern ecosystems insulates soil, promoting nutrient recycling activity throughout the winter. We are investigating changes in nutrient processing and retention related to later snow accumulation and shallower snowpacks (more about the winter climate project).

photo of Ca-fertilized forest plot

Calcium Depletion and Nutrient Recycling Processes

Acid deposition has depleted Ca from soils in the northeastern US. Our research shows surprising interactions between Ca and nitrogen that slow the recycling of N. These interactions are likely mediated through plant root and mycorrhizal responses to the availability of Ca, with important implications for the accumulation of soil carbon (more about calcium depletion).

photo of worm researchers in field

Exotic Earthworms in North Temperate Forests

Non-native earthworms introduced to forest ecosystems eliminate organic horizons and homogenize soil profiles, profoundly altering the soil environment and changing the ways in which C and nutrients are processed (more about earthworm research).