Grassland ecosystems are important for the provision of food, fuel and fibre. They represent globally important carbon (C) reservoirs that are under pressure from intensive management and ongoing climate change. How these drivers of change will interact to affect grassland soil C and nitrogen (N) cycling and heterotrophic and autotrophic respiration remains uncertain. Roots and mycelia in grassland soil are important regulators of ecosystem functioning and likely to be an influential determinant of CO2 fluxes responses to global change. The aim of this study was to investigate the interactive effect of climate warming and grassland management on soil respiration originating from roots rhizosphere, mycelia and free‐living microbes. The experiment used a block design to measure the interactive effects of warming, nitrogen addition, aboveground biomass (AGB) removal on belowground respiration in a temperate grassland ecosystem. An in‐growth core method using cores with different mesh sizes was used to partition belowground respiration due to its simplicity of design and efficacy. We found that basal respiration (free‐living microorganisms) was the highest (58.5% of the total emissions), followed by that from roots (22.8%) and mycelia (18.7%) across all treatments. Warming reduced basal respiration whilst AGB removal increased it. An antagonistic interaction between warming and nitrogen addition reduced root respiration, and a three‐way interaction between warming, nitrogen addition and AGB removal affected mycelial respiration. The results show different contributions of belowground biota to soil respiration, and how interactions between climate change and grassland management may influence effects on soil respiration.

中文翻译：

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气候变暖与管理对草地土壤呼吸分配的交互影响


草原生态系统对于提供食物、燃料和纤维非常重要。它们代表了全球重要的碳（C）库，面临着集约化管理和持续气候变化的压力。这些变化驱动因素如何相互作用以影响草原土壤碳和氮（N）循环以及异养和自养呼吸仍然不确定。草原土壤中的根和菌丝体是生态系统功能的重要调节剂，并且可能是二氧化碳通量对全球变化响应的有影响力的决定因素。本研究的目的是调查气候变暖和草原管理对根际根际、菌丝体和自由微生物的土壤呼吸的相互作用。该实验采用区组设计来测量温带草原生态系统中变暖、氮添加、地上生物量（AGB）去除对地下呼吸的交互影响。由于其设计简单且功效强，使用具有不同网格尺寸的核心的向内生长核心方法被用于划分地下呼吸。我们发现所有处理中基础呼吸（自由生活的微生物）最高（占总排放量的 58.5%），其次是根部呼吸（22.8%）和菌丝体（18.7%）。变暖减少了基础呼吸，而 AGB 的去除则增加了基础呼吸。变暖和氮添加之间的拮抗相互作用减少了根系呼吸，而变暖、氮添加和AGB去除之间的三向相互作用影响了菌丝体呼吸。结果显示了地下生物群对土壤呼吸的不同贡献，以及气候变化和草地管理之间的相互作用如何影响土壤呼吸的影响。