Dr. Tsz-Ki Tsui (Biology) received new funding from the National Science Foundation for the project “Collaborative Proposal: Response of mercury cycling to disturbance and restoration of low-gradient forested watersheds.”
Atmospheric deposition of mercury (Hg) to forested watersheds can be through a combination of wet and dry deposition, with the latter pathway considered to be more important due to enhanced dry deposition to the forest canopy. Thus, alteration of the forest canopy is expected to result in changes in the relative contribution of wet vs. dry deposition as well as the amount of deposited Hg. Once deposited, Hg can be exported by streams and can potentially contaminate downstream ecosystems. A portion of this deposited Hg can be microbially converted to methylmercury (MeHg) under anoxic conditions. MeHg, a potent neurotoxin, can strongly bioaccumulate and biomagnify in natural food webs, posing a serious threat to natural populations of wildlife and humans.
Forest restoration is a common practice for restoring native species, protecting endangered species, and improving ecosystem services. Since there is an intimate relationship between Hg cycling behavior and various properties of forested watersheds (including canopy cover, soil saturation, etc.), it is important to examine if and how forest restoration, a common forest management tool, may affect Hg cycling in forested watersheds.