From salamanders to greenhouse gases: does upland management affect wetland functions?

Although the effects of forest management on watershed hydrology are well recognized, little is known about how upland management affects the hydrology and functions of wetlands embedded within upland forests (hereafter, embedded wetlands). We simulated the effects of upland tree basal area (ie total cross-sectional area of trees per land area) and different upland management approaches on wetland hydrological, biogeochemical, and habitat functions. Increases in upland basal area and associated forest evapotranspiration reduced wetland inundation depth and duration. Wetland global warming potential decreased with higher upland basal area, driven by lower methane production in drier wetlands. Amphibian habitat suitability decreased with increasing basal area due to reduced wetland inundation. Simulations of three common 25-year management scenarios – namely, constant basal area, fire management, and pine plantation – highlighted impacts of forest structure that vary over time. Prescribed fires that recurred every 3 years generated cyclic patterns in wetland hydrology and function, whereas pine plantations transitioned from wet to dry regimes with stand growth. This work represents a first step to linking upland management, wetland hydrology, and wetland functions, highlighting opportunities for optimizing forest management to provide landscape-scale ecosystem services.