| Summary: | Winter vegetation decomposition promotes leachate release at spring thaw, which represents an important substrate for aquatic microbes and aquatic biogeochemical cycling. However, it is unknown how this leachate impacts microbial processes at the terrestrial source. In this study we investigated the impact of litter leachate on microbial process rates and soil biogeochemical pools in several tundra ecosystems during spring thaw. We collected frozen winter soil cores and vegetation from three ecosystem types (heath, tall shrub and tussock) and from a disturbed landscape (Lake NE-14 thermokarst recovery chronosequence), and incubated these soils through thaw (-10 oC to +4 oC) with the addition of native vegetation leachate, or water (control). The data presented here are microbial process rates (as cumulative carbon dioxide-CO2 processed over the six-day incubation and as gross ammonium-NH4 mineralization at the end of the incubation) and soil and microbial carbon-C, nitrogen-N and phosphorus-P pools. We present the pool sizes in the leachate -added and the water-added soil cores. We also present the "potential" pool sizes, which are the maximum potential C, N or P pool if all the C, N or P added were found in that pool (for graphical reasons, calculated as control pool + added pool - leachate treatment pool).
|
|---|