Mycorrhizal and environmental controls over root trait-decomposition linkage of woody trees
Mycorrhizal and environmental controls over root trait-decomposition linkage of woody trees
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菌根和环境对木本树木根性状分解联系的控制
DOI：
10.1111/nph.16844
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发表时间：
2020-09-01
期刊：
影响因子：
9.4
通讯作者：
Kou, Liang
中科院分区：
文献类型：
--
作者：
Jiang, Lei;Wang, Huimin;Kou, Liang
在预测生态系统中推动碳和养分循环的分解时，特征是至关重要的。然而，我们对根部性状-分解联系的了解仍然有限，特别是它对菌根类型和环境背景的依赖。研究了中国温带和亚热带森林中与丛枝菌根(AM)和外生菌根(ECM)真菌相关的30种树种的形态和化学特性(与碳和营养有关)对吸收根分解的控制。与碳有关的性状(酸解残留物(AUR)和纤维素浓度)主要控制AM树种的根系分解，而与营养相关的性状(镁浓度)则主要控制ECM树种的根分解。较厚的吸收根在AM植物中分解较快，这是因为其AUR浓度较低，但在ECM被子植物中较慢，可能是由于其较高的镁浓度。在两种森林中，根分解与根营养经济有关，而根直径-分解协调只出现在亚热带森林中，那里的根直径和分解表现出相似的跨物种变异。我们的研究结果表明，根的性状-分解关系因菌根类型和环境的不同而有很大差异，根直径可以预测AM和ECM的分解，但方向相反，机制不同。
Traits are critical in predicting decomposition that fuels carbon and nutrient cycling in ecosystems. However, our understanding of root trait-decomposition linkage, and especially its dependence on mycorrhizal type and environmental context, remains limited. We explored the control of morphological and chemical (carbon- and nutrient-related) traits over decomposition of absorptive roots in 30 tree species associated with either arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi in temperate and subtropical forests in China. Carbon-related traits (acid-unhydrolysable residue (AUR) and cellulose concentrations) had predominant control of root decomposition in AM species while nutrient-related traits (magnesium concentration) predominately controlled that in ECM species. Thicker absorptive roots decomposed faster in AM species as a result of their lower AUR concentrations, but more slowly in ECM angiosperm species potentially as a result of their higher magnesium concentrations. Root decomposition was linked to root nutrient economy in both forests while root diameter-decomposition coordination emerged only in the subtropical forest where root diameter and decomposition presented similar cross-species variations. Our findings suggest that root trait-decomposition linkages differ strongly with mycorrhizal type and environment, and that root diameter can predict decomposition but in opposing directions and with contrasting mechanisms for AM and ECM species.