Carbon input manipulation affects soil respiration and microbial community composition in a subtropical coniferous forest
Carbon input manipulation affects soil respiration and microbial community composition in a subtropical coniferous forest
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DOI：
10.1016/j.agrformet.2013.04.021
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发表时间：
2013-09
影响因子：
6.2
通讯作者：
Qingkui Wang;Tongxin He;Silong Wang;Liting Liu
中科院分区：
文献类型：
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作者：
Qingkui Wang;Tongxin He;Silong Wang;Liting Liu
以中国南方亚热带典型森林为研究对象，采用地上凋落物添加、去除和根沟法，通过磷脂脂肪酸分析，研究了地上和地下C输入对土壤CO2排放和微生物群落组成的影响。2011年1月至12月，土壤呼吸随土壤温度和含水量的季节变化而变化，但其模式没有被C输入操纵所改变。碳输入调控对土壤呼吸温度敏感性的影响具有季节性，休眠期的影响大于生长期。凋落物的添加使土壤呼吸增加了33%，而凋落物的去除使土壤呼吸降低了22.6%。根沟处理使土壤呼吸降低20.4%。凋落物分解、根际呼吸和矿质土壤呼吸分别占土壤CO2排放总量的22.3%、20.1%和57.6%。我们还发现，增加凋落物诱导的土壤CO2排放量的增加是10.4%，比减少凋落物清除。与对照相比，凋落物去除使革兰氏阳性菌浓度增加了21.6%，细菌/真菌比降低了32.8%。根沟处理使土壤中细菌、真菌和放线菌的含量分别增加了28.8%、161.2%和32.5%，但使革兰氏阴性菌与革兰氏阳性菌的比值和细菌与真菌的比值分别降低了57.4%和107.9%。C输入处理没有增加革兰氏阳性菌，但也没有降低革兰氏阴性菌与革兰氏阳性菌的比例。16：0 PLFA浓度和革兰氏阴性菌与革兰氏阳性菌比值与土壤呼吸呈显著正相关。说明根系碳输入对土壤微生物群落组成的影响大于地上部凋落物碳输入。
We determined the effects of aboveground and belowground C inputs on soil CO2efflux and microbial community composition by phospholipid fatty acids using aboveground litter addition or removal and root trenching in a subtropical forest in Southern China. From January 2011 to December 2011, soil respiration varied with the seasonal changes in soil temperature and water content, but its pattern was not altered by C input manipulation. The effects of C input manipulation on the temperature sensitivity of soil respiration was season-dependent, which were greater in the dormant season than in the growing season. Litter addition increased the soil respiration by 33% compared with the control, whereas litter removal decreased it by 22.6%. Root trenching decreased soil respiration by 20.4%. Aboveground litter decomposition, root and rhizosphere respiration, and mineral soil respiration contributed to 22.3%, 20.1%, and 57.6% of total soil CO2efflux, respectively. We also found that increase in soil CO2efflux induced by litter addition was 10.4% greater than decrease by litter removal. Litter removal increased 21.6% of the concentration of Gram-positive bacteria and decreased 32.8% of the bacteria to fungi ratio, compared with the control. Root trenching increased the concentrations of bacteria, fungi, and actinomycetes by 28.8%, 161.2% and 32.5%, respectively, but decreased the Gram-negative to Gram-positive bacteria and the bacteria to fungi ratios by 57.4% and 107.9%. C input treatment did not increase the Gram-positive bacteria but nor decreased the Gram-negative to Gram-positive bacteria ratio. The concentration of the 16:0 PLFA and the Gram-negative to Gram-positive bacteria ratio were significantly correlated with soil respiration. These results suggest that root C input has greater influence on soil microbial community composition than the aboveground litter C input.