米槠天然林和桔园土壤微生物群落结构的季节性变化  

Seasonal Variation of Soil Microbial Community Structure in Castanopsis Carlesii Natural Forest and Orange Orchard

作　　者：郑裕雄 曹际玲 杨智杰[1,2] 林成芳[1,2] 黄梦青[1,2] 杨玉盛[1,2] ZHENG Yuxiong;CAO Jiling;YANG Zhijie;LIN Chengfang;HUANG Mengqing;YANG Yusheng(State Key Laboratory for Subtropical Mountain Ecology,Fuzhou 350007,China;College of Geographical Sciences,Fujian Normal University,Fuzhou 350007,China)

机构地区：[1]福建师范大学/湿润亚热带山地生态国家重点实验室培育基地,福建福州350007 [2]福建师范大学地理科学学院,福建福州350007

出　　处：《生态环境学报》2019年第10期1991-1998,共8页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(31670623;31770663)

摘　　要：森林类型的转变是影响生态系统养分循环的重要因素,研究其对土壤微生物群落结构的影响对于通过森林管理措施应对持续加剧的气候变化具有重要的指导意义。利用磷脂脂肪酸(PLFA)技术研究了中亚热带地区米槠天然林(Castanopsis carlesii)和相邻的桔园(Citrus reticulata)土壤微生物群落结构的季节变化特点。结果表明,两种植被类型土壤微生物以细菌为优势类群,分别占微生物总PLFA含量的41.04%和48.01%。主成分分析表明,土壤微生物群落结构差异主要由植被类型和季节变化差异引起。天然林微生物磷脂脂肪酸总量、细菌特征脂肪酸、真菌特征脂肪酸、放线菌特征脂肪酸、革兰氏阳性菌和革兰氏阴性菌特征脂肪酸含量均显著高于桔园。两种植被类型微生物类群特征脂肪酸含量最高值均出现在春季,而天然林最低值出现在冬季,桔园最低值出现在夏季。此外,与天然林相比,桔园的夏、秋和冬季土壤真菌与细菌比(F∶B)、春季革兰氏阴性菌与革兰氏阳性菌比(G^+∶G^-)以及全年环丙烷脂肪酸与其前体脂肪酸比(Cye∶Pre)均呈现不同程度的显著降低,而夏季G^+∶G^-和春夏季顺式异构脂肪酸与反式脂肪酸比(Iso∶Ant)均呈现不同程度的增加。植被类型变化不仅改变土壤微生物群落结构,还影响着微生物抵抗环境变化的能力,不同季节的影响程度存在显著差异。Forest conversion affects the ecosystem nutrient cycling. Understanding the effect of forest conversion on soil microbial community is of great significance for forest management to cope with the increasing climate change. The seasonal variations of soil microbial community structure in Castanopsis carlesii natural forest and adjacent orange orchards were studied by using phospholipid fatty acid(PLFA) technique. The results showed that bacteria was the dominant group of soil microorganisms in the two vegetation types, accounting for 41.04% and 48.01% of the total PLFA, respectively. Principal component analysis showed that the difference in soil microbial community mainly resulted from the different vegetation type and seasonal variation. There were significantly higher amount of total microbial PLFA, bacterial characteristic fatty acid, fungal characteristic fatty acid, actinomycete characteristic fatty acid, Gram-positive bacteria and Gram-negative bacteria characteristic fatty acid in natural forest than those in orange orchard. The highest characteristic fatty acid content occurred in spring for both vegetation types, while the lowest value appeared in winter for natural forest, and in summer for orange orchard. In addition, there were significant decrease for the ratios of fungi to bacteria(F∶B), Gram-negative to Gram-positive bacteria(G^+∶G^-) in spring, and cyclopropane fatty acid to its precursor fatty acid(Cye∶Pre) in summer, autumn and winter in orange orchards compared with natural forests, while the ratio of cis-isomeric fatty acid to trans-fatty acid(Iso∶Ant) increased significantly in spring and summer. Overall, our results suggest that forest conversion not only would change soil microbial community but also would affect the ability of microorganisms to resist environmental alteration, which varies with seasons.

关 键 词：植被类型 磷脂脂肪酸(PLFA) 微生物群落结构 季节动态 

分 类 号：S718.5[农业科学—林学] X17[环境科学与工程—环境科学]