Global patterns of soil heterotrophic respiration - A meta-analysis of available dataset
Global patterns of soil heterotrophic respiration - A meta-analysis of available dataset
复制标题
土壤异养呼吸的全球模式 - 可用数据集的荟萃分析
DOI：
10.1016/j.catena.2020.104574
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发表时间：
2020
期刊：
影响因子：
6.2
通讯作者：
Pei Xiangjun
中科院分区：
文献类型：
--
作者：
Tang Xiaolu;Du Jie;Shi Yuehong;Lei Ningfei;Chen Guo;Cao Longxi;Pei Xiangjun
土壤异养呼吸（RH）是指微生物分解凋落物碎屑和土壤有机质所产生的碳损失。尽管当地研究对主要气候、土壤和植被控制相对湿度的研究结果相互矛盾，但对全球相对湿度模式和这些模式背后的潜在驱动因素知之甚少。基于更新的全球土壤呼吸数据库，我们进行了荟萃分析，以评估地球仪范围内的气候，土壤和植被控制对RH的直接和间接影响，使用结构方程模型（SEM）。结果表明，全球加权平均相对湿度为457 ± 139 g C m−2a−1（平均值±标准差），但不同生态系统类型的相对湿度差异显著，且与初级生产总值正相关，突出了植被对相对湿度控制的重要性。气候是相对湿度最重要的环境控制因子。土壤有机碳（SOC）含量在全球范围内对相对湿度有负面影响，这对目前认为SOC在站点或生态系统尺度上对相对湿度有正面影响的认识提出了挑战，进一步表明SOC数量可能在局部尺度上主导相对湿度，而SOC质量和可用性可能在区域或全球尺度上主导相对湿度。结果表明，不同全球植被模型（DGVM）的相对湿度观测值和动态相对湿度观测值存在较大差异，不同DGVM的相对湿度观测值之间存在较大差异，DGVM的参数化效果更好，尤其是模型输出没有经过实地观测验证，从而更好地理解相对湿度和地下碳动态。
Soil heterotrophic respiration (RH) represents the carbon losses from the decomposition of litter detritus and soil organic matter by microorganisms. Despite conflicting findings on the dominant climatic, soil and vegetation controls on RH from local studies, little is known on the global patterns of RH and the potential drivers behind these patterns. Based on the updated Global Soil Respiration Database, we conducted a meta-analysis to evaluate the direct and indirect effects of climatic, soil and vegetation controls on RH across the globe using structure equation model (SEM). Our results showed that the global weighted mean RH was 457 ± 139 g C m−2a−1(mean ± standard deviation), but RH differed significantly among ecosystem types and positively correlated with gross primary production, highlighting the importance of the vegetation control on RH. Climate was the most important environmental control on RH indicated by SEM. Soil organic carbon (SOC) content had a negative influence on RH at the global scale, challenging the current understanding that SOC leads to a positive effect on RH at site or ecosystem scale, further indicating that SOC quantity may dominate RH at local scales, while SOC quality and availability may dominate RH at regional or global scales. Great differences were found not only between observed and dymanic global vegetation model (DGVM)-based RH, but also among different DGVMs, highlighting a better parameterizing of DGVMs, particularly the model output not validated by field observations, to better understand RH and belowground carbon dynamics.