Soil extracellular enzyme activities in plots dominated by trees that associate with arbuscular mycorrhizal or ectomycorrhizal fungi in the N fertilized and reference watershed at the Fernow Experimental Forest, WV.

Our objective was to detect possible differences in N fertilization responses of soil extracellular enzymes in plots dominated by trees that associate with arbuscular mycorrhizal fungi (AM) or ectomycorrhizal fungi (ECM). To do this, we established a plot network of 6 AM and 6 ECM dominated 10 x 10 m plots in both the reference and N fertilized watersheds (N=24 plots) at the Fernow Experimental Forest, Parsons, WV. We assayed the potential activity of hydrolytic enzymes that release N (N-acetylglucosaminidase; NAG), phosphorus (acid phosphatase; AP), and simple carbon (ß-glucosidase; BG). In addition, we measured microbial allocation to complex C degrading oxidative enzymes phenol oxidase and peroxidase. The activities of these enzymes were measured separately in bulk mineral, rhizosphere, and organic horizon soils during the growing season in 2017.

本研究旨在探究以与丛枝菌根真菌（arbuscular mycorrhizal fungi，AM）或外生菌根真菌（ectomycorrhizal fungi，ECM）共生的树木为优势种的样地中，土壤胞外酶对氮（N）施肥的响应差异。为此，我们在西弗吉尼亚州帕森斯市的费诺实验林（Fernow Experimental Forest）的对照流域与施氮流域中，各设置6个以AM共生树木为优势种、6个以ECM共生树木为优势种的10×10米样地，总计24个样地。我们测定了参与释放氮、磷与简单碳的水解酶潜在活性，涉及的酶类包括：β-N-乙酰氨基葡萄糖苷酶（N-acetylglucosaminidase，NAG）、酸性磷酸酶（acid phosphatase，AP）以及β-葡萄糖苷酶（ß-glucosidase，BG）。此外，我们还测定了微生物对降解复杂碳的氧化酶类的分配情况，此类酶包括酚氧化酶与过氧化物酶。2017年生长季期间，我们分别在矿质原状土壤、根际土壤与土壤有机层中，对上述酶的活性进行了单独测定。