Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education; School of Geographical Sciences, Northeast Normal University, Changchun, China.
Key Laboratory of Vegetation Ecology, Ministry of Education, Northeast Normal University, Changchun, China.
Ecol Lett. 2024 Jan;27(1):e14346. doi: 10.1111/ele.14346. Epub 2023 Nov 27.
Nitrogen (N) resorption is an important pathway of N conservation, contributing to an important proportion of plant N requirement. However, whether the ratio of N resorption to N requirement may be affected by environmental factors, mycorrhizal types or atmospheric CO concentration remains unclear. Here, we conducted a meta-analysis on the impacts of environmental factors and mycorrhizal types on this ratio. We found this ratio in ectomycorrhizal (EM) trees decreased with mean annual precipitation, mean annual temperature, soil total N content and atmospheric CO concentration and was significantly lower than that in arbuscular mycorrhizal (AM) trees. An in situ N tracing experiment further confirmed that AM trees have a stronger reliance on N resorption than EM trees. Our study suggests that AM and EM trees potentially have different strategies for alleviation of progressive N limitation, highlighting the necessity of incorporating plant mycorrhizal types into Earth System Models.
氮（N）吸收是氮保护的重要途径，对植物氮需求的重要比例有贡献。然而，氮吸收与氮需求的比例是否可能受到环境因素、菌根类型或大气 CO 浓度的影响尚不清楚。在这里，我们对环境因素和菌根类型对这一比例的影响进行了荟萃分析。我们发现，外生菌根（EM）树木的这一比例随着年平均降水量、年平均温度、土壤总氮含量和大气 CO 浓度的增加而降低，明显低于丛枝菌根（AM）树木。一项原位氮示踪实验进一步证实，AM 树木比 EM 树木更依赖于氮吸收。我们的研究表明，AM 和 EM 树木可能具有不同的策略来缓解逐渐增加的氮限制，这凸显了在地球系统模型中纳入植物菌根类型的必要性。
