Microbial necromass under global change and implications for soil organic matter

作者：Junxi Hu, Meilin Du, Jun Chen, Liehua Tie, Shixing Zhou, Kate M. Buckeridge, J. Hans C. Cornelissen, Congde Huang, Yakov Kuzyakov · 发表于：Global Change Biology · 年份：2023 · DOI：10.1111/gcb.16676 · 被引用次数：160 · 研究领域：Soil Carbon and Nitrogen Dynamics、Mycorrhizal Fungi and Plant Interactions、Microbial Community Ecology and Physiology

Abstract Microbial necromass is an important source and component of soil organic matter (SOM), especially within the most stable pools. Global change factors such as anthropogenic nitrogen (N), phosphorus (P), and potassium (K) inputs, climate warming, elevated atmospheric carbon dioxide (eCO 2 ), and periodic precipitation reduction (drought) strongly affect soil microorganisms and consequently, influence microbial necromass formation. The impacts of these global change factors on microbial necromass are poorly understood despite their critical role in the cycling and sequestration of soil carbon (C) and nutrients. Here, we conducted a meta‐analysis to reveal general patterns of the effects of nutrient addition, warming, eCO 2 , and drought on amino sugars (biomarkers of microbial necromass) in soils under croplands, forests, and grasslands. Nitrogen addition combined with P and K increased the content of fungal (+21%), bacterial (+22%), and total amino sugars (+9%), consequently leading to increased SOM formation. Nitrogen addition alone increased solely bacterial necromass (+10%) because the decrease of N limitation stimulated bacterial more than fungal growth. Warming increased bacterial necromass, because bacteria have competitive advantages at high temperatures compared to fungi. Other global change factors (P and NP addition, eCO 2 , and drought) had minor effects on microbial necromass because of: (i) compensation of the impacts by opposite processes, and (ii) the sh...