Linking leaf nutrient resorption and litter decomposition to plant mycorrhizal associations in boreal peatlands

Abstract

Mycorrhizal type has been proposed as an effective trait integrator capturing varying biogeochemical syndromes in terrestrial ecosystems. However, for boreal peatlands, it is still unclear whether mycorrhizal associations of vascular plants can indicate leaf nutrient resorption patterns and litter decomposition rates. We determined leaf nitrogen (N) and phosphorus (P) resorption efficiency and proficiency of 11 common vascular plants belonging to three mycorrhizal types (ectomycorrhizal, ECM; ericoid mycorrhizal, ERM; and non-mycorrhizal, NM) in boreal peatlands of Northeast China, and measured leaf litter mass loss and N remaining of these 11 species after one and 3 years of decomposition using the litterbag method. Leaf nutrient resorption and litter decomposition rates varied significantly among the three mycorrhizal types. Specifically, ECM plants had greater green leaf nutrient (N and P) concentrations and lower leaf nutrient resorption efficiency and proficiency than ERM and NM plants. Moreover, ECM plants had higher leaf litter mass loss and lower N remaining than ERM and NM plants after one and 3 years of decomposition, respetively. In addition, both leaf litter mass loss and N remaining significantly correlated with N and P resorption efficiency and proficiency, indicating that plant nutrient resorption and litter decomposition were coupled. These results suggest that leaf nutrient resorption and litter decomposition are tightly linked to the mycorrhizal associations of vascular plants, and highlight that mycorrhizal type can be applied to explain and predict the dynamics of plant-mediated carbon and nutrient cycles in boreal peatlands.