南亚热带典型人工林土壤酶活性及微生物多样性研究

发布时间：2018-06-07 22:53

本文选题：土壤酶活性 + 土壤微生物　；参考：《广西大学》2017年硕士论文

【摘要】：土壤作为陆地生态系统的重要组分之一,其内部生态系统结构和功能的变化可以在一定程度上反映其地上植被之间的差异。本文以位于广西凭祥市的中国林业科学研究院热带林业实验中心伏波试验场马尾松、红椎、米老排和火力楠4种南亚热带典型乡土人工纯林以及外来速生桉树人工纯林为研究对象,探讨不同林分类型不同土层(0-20、20-40和0-60 cm)的土壤酶活性、微生物量碳氮和功能多样性的差异,并探究土壤理化性质和土壤微生物量对土壤酶活性的影响;同时比较分析各林分类型土壤表层(0-20 cm)微生物遗传多样性的差异。研究结果对南亚热带红壤丘陵地区植被恢复重建的树种选择以及人工林多目标经营有着重要意义。研究主要结论如下:(1)不同土层的马尾松、红椎、米老排和火力楠人工林的土壤酶活性(脲酶、蛋白酶、酸性磷酸酶、蔗糖酶和纤维素酶)和微生物量碳氮含量均有大于桉树人工林的趋势,且随着土层深度的增加而显著下降(P0.05)。(2)全碳含量与脲酶、酸性磷酸酶和蔗糖酶活性呈显著正相关关系(P0.05);pH与酸性磷酸酶和蔗糖酶活性呈显著正相关关系(P0.05);速效磷含量与脲酶活性存在一定的相关性(P0.05);微生物量碳氮均与蔗糖酶呈显著正相关关系(P0.05)。(3)研究林分土壤微生物碳源利用率最高的时间为108 h。各林分土壤微生物对碳源的利用能力受时间因素的影响显著,并随土层深度的增加而下降。(4)不同土层的马尾松、红椎、米老排和火力楠人工林土壤微生物Shannon功能多样性指数和Simpson功能多样性指数差别各异,但均高于桉树林。糖类、氨基酸类、多聚物类、羧酸类和芳香类碳源是引起不同林分之间土壤微生物功能多样性差异的敏感碳源。(5)4种乡土人工林土壤表层(0-20 cm)的Shannon遗传多样性指数、Simpson遗传多样性指数、丰富度指数和均匀度差异不显著(P0.05),但在数值上均高于桉树林。
[Abstract]:As one of the most important components of terrestrial ecosystem, the change of structure and function of soil ecosystem can reflect the difference of vegetation on the ground to some extent. In this paper, Pinus massoniana, Red vertebra, was used in the Volt-Wave Experimental Center of Tropical Forestry experiment Center, China Academy of Forestry Sciences, Pingxiang City, Guangxi, China. The soil enzyme activities of four typical subtropical native pure forests and exotic fast growing eucalyptus artificial pure forests were studied in different stand types and different soil layers (20-40 and 0-60 cm). The differences of microbial biomass carbon, nitrogen and functional diversity, and the effects of soil physical and chemical properties and soil microbial biomass on soil enzyme activity, and the genetic diversity of soil surface layer (0-20 cm) were compared and analyzed. The results of the study are of great significance to the selection of tree species for vegetation restoration and reconstruction in the subtropical red soil hilly region and the multi-objective management of the plantation. The main results are as follows: (1) soil enzyme activities (urease, protease, acid phosphatase) of Pinus massoniana, Red vertebra, Rhizoma Rhizome and Fructus firewood plantations in different soil layers. Both sucrase and cellulase) and microbial biomass carbon and nitrogen content were higher than those in eucalyptus plantation, and the total carbon content and urease content decreased significantly with the increase of soil depth. There was a significant positive correlation between acid phosphatase and sucrase activity, there was a significant positive correlation between pH and acid phosphatase and sucrase activity, there was a certain correlation between available phosphorus content and urease activity, and microbial biomass carbon and nitrogen were correlated with sucrose. The time of soil microbial carbon use efficiency was 108 h. The ability of soil microbes to use carbon was significantly affected by time factors, and decreased with the increase of soil depth. 4) Pinus massoniana and red vertebrae in different soil layers. The Shannon function diversity index and Simpson function diversity index of soil microorganism were different, but they were higher than those of eucalyptus forest. Carbohydrates, Amino acids, Polymers, Carboxylic acids and aromatic carbon sources are sensitive carbon sources for the difference of soil microbial functional diversity among different stands. The Shannon genetic diversity index (Shannon genetic diversity index) is Simpson. The difference of richness index and evenness was not significant (P 0.05), but higher than that of eucalyptus.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S714.3

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