Modelling the influence of ectomycorrhizal decomposition on plant nutrition and soil carbon sequestration in boreal forest ecosystems
Modelling the influence of ectomycorrhizal decomposition on plant nutrition and soil carbon sequestration in boreal forest ecosystems
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DOI：
10.1111/nph.14213
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发表时间：
2017-02-01
期刊：
影响因子：
9.4
通讯作者：
Manzoni, Stefano
中科院分区：
文献类型：
--
作者：
Baskaran, Preetisri;Hyvonen, Riitta;Manzoni, Stefano
北方森林中树木的生长受到氮（N）有效性的限制。大多数北方森林树木与外生菌根（ECM）真菌形成共生关系，这提高了无机N的吸收，并且还具有分解土壤有机质（SOM）和动员有机N（ECM分解）的能力。为了研究ECM分解对生态系统碳氮平衡的影响，我们对植物、有机质、腐养生物、ECM真菌和无机氮库之间的碳氮流动模型进行了敏感性分析。分析表明，C和N平衡是敏感的模型参数调节ECM生物量和分解。在低氮条件下，最佳的C分配到ECM真菌，上面的共生开关从互惠共生寄生，增加ECM真菌在SOM分解的相对参与。在低氮条件下，增加ECM有机氮开采促进树木生长，但降低土壤碳储量，导致地上和地下碳储量之间的负相关。植物生产和土壤碳储量之间的相互作用是敏感的ECM真菌和腐食菌之间的分解分配。更好地了解土壤真菌功能团之间的相互作用，可以显着提高生态系统对环境变化的响应预测。
Tree growth in boreal forests is limited by nitrogen (N) availability. Most boreal forest trees form symbiotic associations with ectomycorrhizal (ECM) fungi, which improve the uptake of inorganic N and also have the capacity to decompose soil organic matter (SOM) and to mobilize organic N (ECM decomposition'). To study the effects of ECM decomposition' on ecosystem carbon (C) and N balances, we performed a sensitivity analysis on a model of C and N flows between plants, SOM, saprotrophs, ECM fungi, and inorganic N stores. The analysis indicates that C and N balances were sensitive to model parameters regulating ECM biomass and decomposition. Under low N availability, the optimal C allocation to ECM fungi, above which the symbiosis switches from mutualism to parasitism, increases with increasing relative involvement of ECM fungi in SOM decomposition. Under low N conditions, increased ECM organic N mining promotes tree growth but decreases soil C storage, leading to a negative correlation between C stores above- and below-ground. The interplay between plant production and soil C storage is sensitive to the partitioning of decomposition between ECM fungi and saprotrophs. Better understanding of interactions between functional guilds of soil fungi may significantly improve predictions of ecosystem responses to environmental change.