Influence of vegetation types and soil properties on microbial biomass carbon and metabolic quotients in temperate volcanic and tropical forest soils
Influence of vegetation types and soil properties on microbial biomass carbon and metabolic quotients in temperate volcanic and tropical forest soils
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DOI：
10.1111/j.1747-0765.2007.00146.x
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发表时间：
2007-08
影响因子：
2
通讯作者：
Xingkai Xu;Lin Han;Yuesi Wang;K. Inubushi
中科院分区：
文献类型：
--
作者：
Xingkai Xu;Lin Han;Yuesi Wang;K. Inubushi
摘要对温带火山岩和热带森林土壤中碳的有效性和代谢产物的差异以及相关的关键影响因素的认识有限。在热带雨林和茶园皆伐后，以及火山岩土壤上发育的3种温带森林（岳桦、云杉、红松与紫椴、水曲柳、蒙古栎混交林）下，采集不同深度的土壤样品，研究土壤微生物生物量碳（MBC）浓度和代谢指标（qCO 2，CO2-C/biomass-C）。土壤微生物量碳浓度和CO2的演变，分别超过7天和21天的培养期，沿着与土壤的主要属性。在土壤全C的基础上，CO2释放和MBC浓度都随着土壤深度的增加而降低。各林分下0 ~ 2.5cm土壤qCO 2均存在一个最大值，培养时间对CO2释放速率无影响，但培养时间对茶园土壤和云杉林土壤MBC浓度和qCO 2有显著影响。热带雨林茶园的转化减少了CO2的排放，增加了土壤中的qCO 2。结果表明，红松阔叶林和热带雨林土壤在20 cm深度以下的微生物量碳（MBC）相对于土壤总碳（TOC）的浓度较高，qCO 2相对较低，说明红松阔叶林和热带雨林土壤微生物群落的碳利用效率高于热带雨林土壤。因子分析和回归分析表明，森林土壤qCO 2的85%的变异可以由土壤的C：N比、水溶性有机碳和交换性铝的含量解释（P < 0.001）。在森林土壤中，特别是在温带火山森林土壤中，qCO 2值随水溶性有机质中Al/C比的增加而降低。土壤交换性Ca、Mg、Al和水溶性有机质C：N比值与土壤微生物量碳的变化有关。因此，土壤微生物量碳浓度和qCO 2是研究温带和热带森林土壤碳有效性和微生物利用效率的有用土壤参数。
Abstract There is limited knowledge about the differences in carbon availability and metabolic quotients in temperate volcanic and tropical forest soils, and associated key influencing factors. Forest soils at various depths were sampled under a tropical rainforest and adjacent tea garden after clear-cutting, and under three temperate forests developed on a volcanic soil (e.g. Betula ermanii and Picea jezoensis, and Pinus koraiensis mainly mixed with Tilia amurensis, Fraxinus mandshurica and Quercus mongolica), to study soil microbial biomass carbon (MBC) concentration and metabolic quotients (qCO2, CO2-C/biomass-C). Soil MBC concentration and CO2 evolution were measured over 7-day and 21-day incubation periods, respectively, along with the main properties of the soils. On the basis of soil total C, both CO2 evolution and MBC concentrations appeared to decrease with increasing soil depth. There was a maximal qCO2 in the 0–2.5 cm soil under each forest stand. Neither incubation period affected the CO2 evolution rates, but incubation period did induce a significant difference in MBC concentration and qCO2 in tea soil and Picea jezoensis forest soil. The conversion of a tropical rainforest to a tea garden reduced the CO2 evolution and increased the qCO2 in soil. Comparing temperate and tropical forests, the results show that both Pinus koraiensis mixed with hardwoods and rainforest soil at less than 20 cm depth had a larger MBC concentration relative to soil total C and a lower qCO2 during both incubation periods, suggesting that microbial communities in both soils were more efficient in carbon use than communities in the other soils. Factor and regression analysis indicated that the 85% variation of the qCO2 in forest soils could be explained by soil properties such as the C:N ratio and the concentration of water soluble organic C and exchangeable Al (P < 0.001). The qCO2 values in forest soils, particularly in temperate volcanic forest soils, decreased with an increasing Al/C ratio in water-soluble organic matter. Soil properties, such as exchangeable Ca, Mg and Al and water-soluble organic C:N ratio, were associated with the variation of MBC. Thus, MBC concentrations and qCO2 of the soils are useful soil parameters for studying soil C availability and microbial utilization efficiency under temperate and tropical forests.