Biology and Fertility of Soils:中科院华南植物园研究发现气温上升对土
森林土壤是陆地生态系统最大的C库。研究表明气候变暖将改变土壤C循环的过程，从而影响大气CO2的浓度。土壤微生物是陆地生态系统C循环的主要驱动者。目前，大量的土壤增温对土壤微生物量、群落组成以及功能影响的研究结果尚存在较大争议。这其中一个重要原因可能是忽略了土壤不同团聚体中微生物具有不同的温度敏感性这一因素。
针对这一状况，中科院华南植物园方熊博士在周国逸研究员和刘菊秀研究员的指导下，在鼎湖山野外台站自然增温平台，开展了增温对针阔叶混交林土壤不同团聚体的微生物量、群落组成及酶活性影响的研究。经过长期观察和研究发现：土壤增温(~1°C)对不同团聚体的微生物总量没有显著影响，但显著改变了大团聚体(250–2000 μm)的微生物群落组成。同时，土壤增温显著增加了土壤三个粒径团聚体的多酚氧化酶和过氧化物酶活性。
该相关研究已发表在土壤学主流期刊biology and Fertility of Soils上。
图：土壤增温对针阔叶混交林不同粒径团聚体微生物量的影响
原文链接：
Warming effects on biomass and composition of microbial communities and enzyme activities within soil aggregates in subtropical forest
原文摘要：
This study investigated the effects of warming (about 1 °C) on the biomass and composition of microbial communities and enzyme activities in soil macroaggregates and microaggregates. We fractionated the bulk soils from the control and warming treatments into large macroaggregates (>2000 μm), small macroaggregates (250–2000 μm) and microaggregates (<250 μm) using the optimal moist sieving approach. Warming did not significantly affect soil microbial biomass in all aggregate fractions, but significantly altered the soil microbial community composition in the large macroaggregates. The G+:G− ratio was significantly higher in the small macroaggregates and microaggregates than that in the large macroaggregates in warmed soils, while the stress ratio was significantly higher in the large and small macroaggregates than that in the microaggregates. Soil warming did not significantly affect β-glucosidase, cellobiohydrolase and N-acetylglucosaminidase activities, but significantly decreased acid phosphomonoesterase activity and increased oxidase activities. Our results suggest that soil microbial community composition in the large macroaggregates might be more sensitive to warming. The differential responses of soil microbial communities and enzyme activities in different aggregate fractions in the warmed soils may have important implications for C cycling in subtropical forest ecosystems.
作者：秩名
