作 者 ：朱万泽,王金锡,张秀艳,李登煜,蔡小虎
期 刊 ：生态学报 2007年 27卷 4期 页码：1386~1396
关键词：季节动态；微生物区系；微生物多样性；湿性常绿阔叶林；华西雨屏区；
Keywords:seasonal dynamic, microbial community, microbial diversity, moist evergreen broad-leaved forest, Rainy Zone of West China,
摘 要 ：采用时空互代的方法，探讨了崇州市鞍子河自然保护区和邛崃市天台山的常绿阔叶林自然恢复过程中土壤微生物数量、组成、区系和多样性变化，结果表明：（1）不同恢复时期土壤微生物数量存在显著性差异，在植被恢复5～40a期间，土壤细菌和放线菌的数量呈增加趋势，以恢复到40a植被土壤微生物总数、细菌和放线菌的数量较高，分别为1.06×106 CFU g-1干土、9.81×105 CFU g-1干土和6.8×104 CFU g-1干土；真菌以100a次生林较高，为9.01×104 CFU g-1干土；植被恢复中细菌占土壤微生物总数的79.06%～93.78%；真菌和放线菌数量分别占4.61%～11.24％和0.52%～15.38%；（2）不同恢复阶段土壤细菌和真菌数量大体上以夏季高，春、秋季较低；放线菌数量为春、秋季较夏季高；（3）植被恢复过程中，土壤微生物群落区系和优势种群组成不同，经鉴定有细菌10个属、真菌7个属、放线菌9个属，细菌以无色细菌属（Achromobater）、棒状杆菌属（Corynebacterium）、短杆菌属（Brevibacterium）和芽孢杆菌属（Bacillus）出现的几率较高；真菌主要是半知菌类和接合菌类，以木霉属（Trichoderma）、腐霉属（Pythium）、青霉属（Penicillium）和犁头霉属（Absidia）分布较为普遍；放线菌9个类群中8个属于链霉菌属（Streptomyces），仅有1个类群属于小单孢菌属（Micromonospora），以白孢类群（Albosporus）、金色类群（Aureus）和灰红紫类群（Griseorubroviolaceus）出现几率为较高；（4）细菌属的Shannon-Wiener指数、Simpson指数以恢复初期、30a生次生林和较原始植被为较高。在植被恢复5～50a期间，真菌和放线菌属的多样性呈波动性增加趋势，到50a达到最高；50a以后，呈下降趋势，表明植被恢复的30～50a土壤环境更适合真菌和放线菌的生长。
Abstract:The Rainy Zone of West China, which is located along the brim of the Sichuan Basin, is a large scale and complicated ecotone and characterized by year-around cloudy and wet climate. There has been an extensive distribution of moist evergreen broad-leaved forest in the rainy zone, but this type of forest had been artificially destroyed because of local concept that evergreen broadleaved forest is “Shaw”. The vegetation in this zone has been effectively recovered in recent years with the execution of “returning sloping cropland to forest" and "natural forest conservation” in our country.
The soil microbial community can have large impacts on plant community dynamics, and the abundance of microbial species in the soil usually is affected by the composition of the plant community. Many studies suggest that the soil microbial community varies with plant community composition, and soil microorganisms can be important drivers of vegetation changes. However, little is known about how soil microbial communities change along a gradient of vegetation succession. In this study, the numbers, composition, microbial flora and diversity of microorganisms were measured using the method of “space-for-time substitution” in different recovery phases of forest at Anzi River Nature Reserve and Qionglai Tiantai National Forest Park. The results indicated that: (1) the quantity of soil microorganisms in different recovery phases of moist evergreen broad-leaved forest showed significant difference (p<0.05). 5 to 40 years after revegetation, the quantity of soil microorganism and bacteria and actinomycetes increased with recovery age and achieved maximum value of 1.06×106 CFU (Coromy Forming Unit) g-1 dry soil, 9.81×105 CFU g-1 dry soil and 6.8×104 CFU g-1 dry soil respectively. The number of soil fungi reached maximum in natural forest (100a) with 9.01×104 CFU g-1dry soil. There was similar composition of soil microbial community in different recovery phases. Soil microbial flora was mainly composed of bacteria, accounting for 79.06%-93.78% of total microorganisms, and fungi for 0.52%-15.38% and actinomycetes for 4.61%-11.24%; (2) number of soil bacteria and fungi in summer were more than that in spring and in autumn. However, numbers of soil actinomycetes in spring and in autumn were more than that in summer. (3) there were different soil microbial flora and various dominant groups during the process of revegetation. There were 10 genuses that belonged to bacteria and 7 genuses to fungi and 9 genuses to actinomycetes according to identification. Among bacteria, the frequency of the presence of Achromobater, Corynebacterium, Brevibacterium and Bacillus were high; the isolated fungi mainly belonged to Deuteromycetes and Zygomycetes, and the distribution of Trichoderma, Pythium, Penicillium and Absidia in the studied plots were very extensive; of 9 actinomycetes genuses, 8 genuses belonged to Streptomyces and the other genus to Micromonospora. Among them, Albosporus, Aureus and Griseorubroviolaceus had higher distribution frequency. (4) there were higher Shannon-Wiener index and Simpson index at the initial stage of revegetation and the secondary forest (30a) as well as the final recovery phases. After revegetation for 5a to 50a, Shannon-Wiener index and Simpson index of fungi and actinomycetes showed an increasing trends in the fluctuating way with the maximum in the secondary forest (50a), and showed downtrend after 50a, which indicated that the soil environment in the recovery process of from 30a to 50a was suitable for growth of fungi and actinomycetes.