不同环境下橡胶凋落叶分解的微生物研究

Comparison of microorganism in rubber leaf-litter decomposition under different environments

凋落物分解过程中的微生物动态对深入了解凋落物分解机理具有重要意义。为了解橡胶凋落叶在不同环境分解过程中的的微生物特征,通过原位网袋法,研究了橡胶凋落物叶在不同调控措施下300和240 d内的分解过程。结果如下:(1)橡胶凋落物分解过程中微生物数量与凋落物残留率及分解环境密切相关,随时间推移,地上组微生物数量呈先上升后下降趋势,地下组微生物数量呈单峰递减趋势。(2)总体来说,整个分解期内,0.07 mm孔径网袋内微生物数量要高于1.00 mm孔径网袋;非肥坑中微生物数量高于肥坑;地下组微生物数量高于地上组。整个分解过程中,细菌数量占绝对优势,其次为放线菌,最后为真菌。(3)相关系分析表明,地上组凋落物分解过程中,细菌数量、微生物总数与分解速率和残留率呈显著相关性,真菌数量与分解速率呈极显著相关,放线菌数量与分解速率和残留率相关性均不显著,说明细菌、真菌是地上组凋落物分解的主要参与者。地下组凋落物分解过程中,各微生物类群数量与残留率均呈显著或极显著相关性,但与分解速率相关性不显著,说明凋落物输入是地下微生物的主要食物来源,而凋落物的分解则更大程度的依赖于微生物、土壤动物和土壤环境的综合作用。

Microorganism plays an irreplaceable role in litter decomposition, and the dynamics of microbial activity in litters is of ecological significance in understanding the mechanism of litter decomposition. Therefore, the microorganisms dynamic characteristics of rubber litter decomposition was studied during 300 days and 240 days by mesh bag method under different control measures in plantations. And the results were as following. （ 1 ） Microbial populations were closely related to litter residues and decomposition environments. The microbial populations has been rising after falling on the ground but directing drop underground by time. （2） Microbial populations in different environments were as follows. 0.07 mm aperture mesh bag 〉 1.00 mm aperture mesh bag, comparison hole 〉 fertile hole, underground group 〉 ground group. During the entire process of decomposition, the quantity of bacteria held absolute superiority, then actinomycetes, finally fungus. （3）Through the correlation analysis, the total number of bacteria, fungi and microbial was significantly associated with the decomposition rate, but there was little correlation to actinomycetes, so it was suggested that fungi and bacteria were the main participants in litter decomposition on the ground. For underground group, the microbial groups were significant or extremely significant correlation with the dry weight of residues, but no significant correlation with decomposition rate, which suggested that litter provided food for underground microbes, and litter decomposition was more dependent on microbes, soil animals and soil environments comprehensive effect.