|Title||Above and below-ground nutrient cycling: a criteria for assessing the biogeochemical functioning of a constructed fen|
|Publication Type||Journal Article|
|Year of Publication||2016|
|Authors||Nwaishi F, Petrone RM, Macrae ML, Price JS, Strack M, Slawson R, Andersen R|
|Journal||Applied Soil Ecology|
|Keywords||Athabasca oil sands, Microbial activity, nutrient dynamics, Peatland function, Peatland reclamation|
Recent peatland restoration studies have highlighted the need to modify the conventional approach of monitoring the recovery of biogeochemical functions through above-ground processes by integrating below-ground components, which are potentially sensitive indicators of reclamation trajectory in long-term monitoring programs. In this study, the recovery of nutrient cycling processes were assessed from both above and below-ground perspectives in a fen constructed on a post-mining landscape in the Athabasca oil sands region, Canada. The goal of this study was to understand if and how different revegetation strategies (seedlings (SDL); moss layer transfers (MLT); seedlings with moss transfer (SMLT) and a control treatment (CTRL)) influence the evolution of biogeochemical functions in the constructed fen relative to a natural reference (REF). The treatments were replicated 6 times and monitored over 2 growing seasons. Our results showed that revegetation facilitated both above-ground productivity and the cycling of below-ground nutrients, especially in the species-rich SMLT plots. Supply of labile substrates in the re-vegetated plots increased microbial potential activity. This was reflected in higher rates of respiration (c.7.8g CO2m−2day−2), nutrient acquisition (net immobilization) and productivity (c. −16.3g CO2m−2day−2) among revegetated plots relative to the CTRL. Nutrient dynamics within the constructed fen suggest that phosphorus limitation (N:P ratio>20) could hamper the establishment of a diverse plant community, whereas the build-up of microbial biomass appears to be NO3− limited. Our results also emphasize the need to track the evolution of nutrients cycling processes through long-term monitoring programs, and identify the potential use of ammonification, nitrogen mineralization and phosphorus availability as functional indicators of a fen’s recovery trajectory towards conditions present in natural fens.
|Short Title||Appl. Soil Ecol.|