Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy(MANE), a...Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy(MANE), and tested it using nutrient addition experiments conducted in two tropical rainforests. We selected two tropical rainforests dominated by arbuscular mycorrhizal(AM) and ectomycorrhizal(ECM) trees, and established eighteen20 m×20 m plots in each rainforest. Six nitrogen(N) and phosphorus(P) addition treatments were randomly distributed in each rainforest with three replicates. We examined the differences in soil carbon(C) and nutrient cycling, plant and litter productivity between the two rainforests and their responses to 10-year inorganic N and P additions. We also quantified the P pools of plants, roots, litter, soil and microbes in the two rainforests. Overall,distinct MANE frameworks were applicable for tropical rainforests, in which soil C, N and P were cycled primarily in an inorganic form in the AM-dominated rainforest, whereas they were cycled in an organic form in the ECMdominated rainforest. Notably, the effects of mycorrhizal types on soil P cycling were stronger than those on C and N cycling. The intensified N and P deposition benefited the growth of AM-dominated rainforests instead of ECMdominated rainforests. Our findings underpin the key role of mycorrhizal types in regulating biogeochemical processes, and have important implications for predicting the ecological consequences of global changes.展开更多
基金supported by the National Natural Science Foundation of China(No.31988102)National Key Research and Development Program of China(No.2017YFC0503906)。
文摘Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy(MANE), and tested it using nutrient addition experiments conducted in two tropical rainforests. We selected two tropical rainforests dominated by arbuscular mycorrhizal(AM) and ectomycorrhizal(ECM) trees, and established eighteen20 m×20 m plots in each rainforest. Six nitrogen(N) and phosphorus(P) addition treatments were randomly distributed in each rainforest with three replicates. We examined the differences in soil carbon(C) and nutrient cycling, plant and litter productivity between the two rainforests and their responses to 10-year inorganic N and P additions. We also quantified the P pools of plants, roots, litter, soil and microbes in the two rainforests. Overall,distinct MANE frameworks were applicable for tropical rainforests, in which soil C, N and P were cycled primarily in an inorganic form in the AM-dominated rainforest, whereas they were cycled in an organic form in the ECMdominated rainforest. Notably, the effects of mycorrhizal types on soil P cycling were stronger than those on C and N cycling. The intensified N and P deposition benefited the growth of AM-dominated rainforests instead of ECMdominated rainforests. Our findings underpin the key role of mycorrhizal types in regulating biogeochemical processes, and have important implications for predicting the ecological consequences of global changes.
