Production and turnover of ectomycorrhizal extramatrical mycelial biomass and necromass under elevated CO2 and nitrogen fertilization
Production and turnover of ectomycorrhizal extramatrical mycelial biomass and necromass under elevated CO2 and nitrogen fertilization
复制标题
DOI：
10.1111/nph.13961
复制
发表时间：
2016-08-01
期刊：
影响因子：
9.4
通讯作者：
Eriksson, Ulrika
中科院分区：
文献类型：
--
作者：
Ekblad, Alf;Mikusinska, Anna;Eriksson, Ulrika
外生菌根真菌的基质外菌丝体（EMM）在森林的碳（C）和氮（N）循环中非常重要，但缺乏对EMM生物量和坏死物质周转量的了解，使其作用的量化存在问题。研究了CO2浓度升高和氮肥施用量增加对火炬松林电解金属锰生产和周转的影响。EMM C的测定是通过分析填充砂的菌丝体在生长袋中的麦角甾醇（生物量）、几丁质（总生物量和坏死量）和总有机碳（TOC）来进行的。通过建模估计了EMM生物和坏死物质以及总C的生产和周转。施氮使固定的EMM生物量C减少到对照的57%，其产量减少到对照的51%（从238到122 kgCha（-1）yr（-1）），而CO2浓度升高则没有明显的影响。生物量周转率高（13年（-1）），处理不变。死物质周转缓慢，从对照的1.5年（-1）减少到施氮处理的0.65年（-1）。然而，TOC数据并不支持N对necromass营业额的影响。估计EMM生产范围从2.5%到6%的净初级生产力强调其列入C模型的重要性。一个缓慢的EMM necomass周转表明在建立森林腐殖质的重要性。
Extramatrical mycelia (EMM) of ectomycorrhizal fungi are important in carbon (C) and nitrogen (N) cycling in forests, but poor knowledge about EMM biomass and necromass turnovers makes the quantification of their role problematic. We studied the impacts of elevated CO2 and N fertilization on EMM production and turnover in a Pinus taeda forest. EMM C was determined by the analysis of ergosterol (biomass), chitin (total bio- and necromass) and total organic C (TOC) of sand-filled mycelium in-growth bags. The production and turnover of EMM bio- and necromass and total C were estimated by modelling. N fertilization reduced the standing EMM biomass C to 57% and its production to 51% of the control (from 238 to 122kgCha(-1)yr(-1)), whereas elevated CO2 had no detectable effects. Biomass turnover was high (13yr(-1)) and unchanged by the treatments. Necromass turnover was slow and was reduced from 1.5yr(-1) in the control to 0.65yr(-1) in the N-fertilized treatment. However, TOC data did not support an N effect on necromass turnover. An estimated EMM production ranging from 2.5 to 6% of net primary production stresses the importance of its inclusion in C models. A slow EMM necromass turnover indicates an importance in building up forest humus.