Litter quality controls tradeoffs in soil carbon decomposition and replenishment in a subtropical forest

作者：Maokui Lyu, Peter M. Homyak, Jinsheng Xie, Josep Peñuelas, Michael G. Ryan, Xiaoling Xiong, Jordi Sardans, Weisheng Lin, Minhuang Wang, Guangshui Chen, Yusheng Yang · 发表于：Journal of Ecology · 年份：2023 · DOI：10.1111/1365-2745.14167 · 被引用次数：116 · 研究领域：Soil Carbon and Nitrogen Dynamics、Ecology and Vegetation Dynamics Studies、Soil and Water Nutrient Dynamics

Abstract Species‐rich forests can produce litter of varying carbon (C) and nitrogen (N) composition (i.e. quality), which can affect decomposition and play a central role in long‐term soil organic carbon (SOC) accumulation. However, how differences in litter quality affect SOC decomposition and formation remains unclear over the full litter decomposition trajectory. We followed the in situ complete decomposition of added 13 C‐labelled high‐ (low C:N) and low‐quality (high C:N) leaf‐litter and its effect on particulate organic matter (POM) and mineral‐associated organic matter (MAOM) fractions over 2 years in a natural subtropical forest. We found that during early stages of decomposition, low‐quality litter inputs decreased SOC via a positive priming effect (i.e. new C inputs favoured decomposition of native SOC), but these SOC losses were offset by SOC gains observed via a negative priming effect during decomposition of high‐quality litter. In contrast, this pattern reversed during late stages of decomposition—SOC losses via a positive priming effect induced by high‐quality litter were offset by SOC gains via a negative priming effect induced by low‐quality litter. Over the full decomposition of litter, both high‐ and low‐quality litter stimulated microbial breakdown of SOC tied to POM, but also replenished more persistent SOC that associated with soil minerals (MAOM). Altogether, we observed that low‐quality litter formed twice as much new SOC as high‐quality litter (24% vs...