Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management - Ministry of Education, Northeast Forestry University, Harbin 150040, China; Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China.
Center for Ecological Research, Northeast Forestry University, 26 Hexing Road, Harbin 150040, China; Key Laboratory of Sustainable Forest Ecosystem Management - Ministry of Education, Northeast Forestry University, Harbin 150040, China; Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China.
Sci Total Environ. 2024 May 15;925:171754. doi: 10.1016/j.scitotenv.2024.171754. Epub 2024 Mar 15.
Temperature sensitivity (Q) of soil microbial respiration serves as a crucial indicator for assessing the response of soil organic carbon (SOC) to global warming. However, the biogeographic variation in Q remains inconsistent. In this study, we examined Q and its potential drivers in nine old-growth mixed broad-leaved Korean pine (Pinus koraiensis Sieb. et Zucc.) forests (the climax community of Asian temperate mixed forest) under a wide range of climatic conditions. We found that stand characteristics (arbuscular mycorrhizal tree basal area to ectomycorrhizal tree basal area ratio and root to shoot ratio) contributed to soil C sequestration by facilitating the accumulation of soil recalcitrant C components. Contrary to the C quality-temperature hypothesis, Q was not correlated with C quality (soil C to nitrogen ratio and recalcitrant C to labile C ratio). Soil mineral protection parameters (Fe/Al oxides) had negative effect on Q because they inhibited microbial activities by decreasing substrate accessibility. Additionally, soils with high microbial biomass C and microbial biomass C to soil organic C ratio had high Q. Overall, understanding the complex relationships among Q, mineral protection, and microbial attributes on a spatial scale is essential for accurately predicting soil C cycling in forest ecosystems.
土壤微生物呼吸的温度敏感性 (Q) 是评估土壤有机碳 (SOC) 对全球变暖响应的关键指标。然而，Q 的生物地理变异性仍然不一致。在这项研究中，我们在广泛的气候条件下，研究了九个原始阔叶红松（Pinus koraiensis Sieb. et Zucc.）林（亚洲温带混合林的顶极群落）中的 Q 及其潜在驱动因素。我们发现，林分特征（丛枝菌根树与外生菌根树的基本面积比和根冠比）通过促进土壤难降解 C 成分的积累，有助于土壤 C 的固存。与 C 质量-温度假说相反，Q 与 C 质量（土壤 C 与氮比和难降解 C 与易降解 C 比）无关。土壤矿物保护参数（铁/铝氧化物）对 Q 有负面影响，因为它们通过降低基质可及性来抑制微生物活性。此外，微生物生物量 C 和微生物生物量 C 与土壤有机 C 比高的土壤具有高 Q。总的来说，在空间尺度上理解 Q、矿物保护和微生物特性之间的复杂关系，对于准确预测森林生态系统中的土壤 C 循环至关重要。
