Resolving the Intricate Effects of Multiple Global Change Drivers on Root Litter Decomposition

作者：Qingzhou Zhao, Grégoire T. Freschet, Tingting Tao, Gabriel Reuben Smith, Peng Wang, Lingyan Hu, Miaojun Ma, David Johnson, Thomas W. Crowther, Shuijin Hu · 发表于：Global Change Biology · 年份：2024 · DOI：10.1111/gcb.17547 · 被引用次数：18 · 研究领域：Soil Carbon and Nitrogen Dynamics、Ecology and Vegetation Dynamics Studies、Plant Water Relations and Carbon Dynamics

Plant roots represent about a quarter of global plant biomass and constitute a primary source of soil organic carbon (C). Yet, considerable uncertainty persists regarding root litter decomposition and their responses to global change factors (GCFs). Much of this uncertainty stems from a limited understanding of the multifactorial effects of GCFs and it remains unclear how these effects are mediated by litter quality, soil conditions and microbial functionality. Using complementary field decomposition and laboratory incubation approaches, we assessed the relative controls of GCF-mediated changes in root litter traits and soil and microbial properties on fine-root decomposition under warming, nitrogen (N) enrichment, and precipitation alteration. We found that warming and N enrichment accelerated fine-root decomposition by over 10%, and their combination showed an additive effect, while precipitation reduction suppressed decomposition overall by 12%, with the suppressive effect being most significant under warming-alone and N enrichment-alone conditions. Significantly, changes in litter quality played a dominant role and accelerated fine-root decomposition by 15% ~ 18% under warming and N enrichment, while changes in soil and microbial properties were predominant and reduced decomposition by 7% ~ 10% under precipitation reduction and the combined warming and N enrichment. Examining only the decomposition environment or litter properties in isolation can distort global change ef...