武夷山不同海拔植被土壤微生物量的季节动态及主要影响因子

Seasonal variation and its main affecting factors of soil microbial biomass under different vegetations along an elevation gradient in Wuyi Mountains of China.

土壤微生物量的季节变化在陆地生态系统碳循环方面具有重要作用。为阐明中亚热带武夷山不同海拔梯度带土壤微生物量的季节变化规律及其主要影响因子,选择4种不同海拔梯度的植物群落:常绿阔叶林(EBF,500m)、针叶林(CF,1200m)、亚高山矮林(DF,1800m)和高山草甸(AM,2100m)于2005年6月—2006年6月期间进行了实验研究。结果表明:不同海拔梯度带土壤微生物量均具有明显的季节变化且变化趋势一致,均表现为早春最大,夏季最小;不同海拔梯度带土壤微生物量的季节变化与对应月份的土壤湿度、土壤有效碳均呈显著正相关,而与土壤温度、土壤有机碳、土壤全氮、凋落物输入量等因子相关不显著。土壤有效碳含量、土壤湿度是调控武夷山森林土壤微生物量季节变异的重要生态因子。

Seasonal variation of soil microbial biomass plays an important role in the carbon cycle of terrestrial ecosystem. To understand this variation and its main affecting factors along an elevation gradient in mid-subtropical Wuyi Mountains, four plant communities at different elevation, i.e. , evergreen broadleaf forest at 500 m, coniferous forest at 1200 m, dwarf forest at 1800 m, and alpine meadow at 2100 m were selected as study sites. The study from June 2005 to June 2006 showed that there was an obvious seasonal variation of soil microbial biomass along the elevation gradient, and the variation under the four plant communities had the same trend, being maintained at a high level in early spring but at a low level in summer. Soil microbial biomass had significant correlations with soil available organic carbon and soil moisture, but less correlations with soil temperature, soil total organic carbon and nitrogen, and plant litterfall input, suggesting that soil available organic carbon and soil moisture were the main factors controlling the seasonal variation of soil microbial biomass in the forests of Wuyi Mountains.