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林业科学 ›› 2016, Vol. 52 ›› Issue (12): 84-91.doi: 10.11707/j.1001-7488.20161210

• 论文与研究报告 • 上一篇    下一篇

黄土峁状丘陵区不同类型林分土壤微生物功能多样性

翟辉, 张海, 张超, 周旭   

  1. 西北农林科技大学资源环境学院 杨凌 712100
  • 收稿日期:2015-11-30 修回日期:2016-03-29 出版日期:2016-12-25 发布日期:2017-01-16
  • 通讯作者: 张海
  • 基金资助:
    国家农业部科技成果转化项目;陕西省科技攻关项目(2013K01-34);杨凌示范区农业科技示范提升项目(TS-2014-40)。

Soil Microbial Functional Diversity in Different Types of Stands in the Hilly-Gully Regions of Loess Plateau

Zhai Hui, Zhang Hai, Zhang Chao, Zhou Xu   

  1. College of Natural Resources and Environment, Northwest A & F University Yangling 712100
  • Received:2015-11-30 Revised:2016-03-29 Online:2016-12-25 Published:2017-01-16

摘要: [目的] 研究陕西退耕还林中不同类型林分下土壤微生物群落代谢多样性,从微生物的角度对当地典型植被类型做出评价,为该地区植被恢复和培育结构合理、生态功能良好的林分提供科学依据。[方法] 以米脂县境内退耕坡地5种人工林(柠条林、刺槐林、油松林、侧柏林和新疆杨林)为对象,撂荒坡地为对照,采用Biolog-ECO微平板法研究不同类型林分土壤微生物代谢活性(AWCD)、土壤微生物群落代谢多样性指数(Shannon指数、Simpson指数和McIntosh指数)及土壤微生物对不同碳源(糖类、氨基酸类、羧酸类、多聚物类、多酚类和胺类)的利用特征;运用主成分法(PCA)分析不同类型林分土壤微生物的碳源代谢特征。[结果] 5种类型林分土壤微生物活性均显著提高,不同类型林分土壤AWCD值大小依次为:柠条林>刺槐林>油松林>侧柏林>新疆杨林>对照;5种类型林分土壤微生物群落Simpson指数、Shannon指数和McIntosh指数均显著提高,其中柠条林土壤Shannon指数和Simpson指数显著高于其他4种类型林分(P<0.05),而土壤McIntosh指数以刺槐林最大;5种类型林分土壤微生物对糖类、氨基酸类、羧酸类、多聚物类、多酚类以及胺类6类碳源的利用率均高于对照,而不同类型林分土壤微生物对不同碳源的利用率不同。糖类是5种类型林分土壤微生物利用的主要碳源,其次为氨基酸类、羧酸类和多聚物类,而多酚类和胺类利用率较低。PCA分析显示主成分1和主成分2贡献大的碳源分别为20种和17种,在主成分分离中起主要贡献作用的是糖类、氨基酸类和羧酸类。油松林、新疆杨林和对照的土壤微生物群落具有相似的碳源利用特征,而柠条林、刺槐林和侧柏林的土壤微生物群落有各自独特的碳源利用模式,且柠条林分布在PC轴的正方向,表明柠条林土壤微生物群落对碳源的利用能力最强。[结论] 黄土峁状丘陵区坡地人工林较撂荒坡地更有利于提高土壤微生物群落的代谢活性,而种植柠条比其他4种人工林更有利于提高土壤微生物群落的功能多样性。本研究从土壤微生物群落的代谢活性角度为黄土峁状丘陵区退耕还林工程中树种选择和林分培育提供了一定的科学依据。

关键词: 黄土峁状丘陵区, 不同类型林分, 土壤微生物, Biolog, 主成分分析

Abstract: [Objective] In order to evaluate the typical vegetation types used for reforesting formerly cultivated land from the microbial point of view, the main planting tree species of Caragana korshinskii, Robinia pseudoacacia, Pinus tabulaeformis, Platycladus orientalis and Populus alba var. pyramidalis on the sloping land in Mizhi County of Shaanxi province were selected to study the soil microbial metabolic diversity. The purpose of this study was to provide a scientific basis for vegetation restoration and cultivating forests with reasonable structure and favorable ecological function in this area.[Method] The five types of forests were targeted with the nearby abandoned farmland served as the control. Soil samples were collected from all the sloping land. The soil microbial metabolic activity (AWCD), the soil microbial metabolic diversity index (Shannon index, Simpson index and McIntosh index) and the utilization characteristics of soil microbial community to different carbon sources (carbohydrates, amino acids, carboxylic acids, polymer, polyphenols and amines) were studied by using the Biolog-ECO micro-plate technique. The principal component analysis (PCA) method was used to analyze the carbon metabolic characteristics of soil microbial community in the different types of stands.[Result] The soil microbial metabolic activity was significantly increased in the five forests. The AWCD values of soil in the different types of stands followed the order of C. korshinskii > R. pseudoacacia > P. tabulaeformis > P. orientalis> P. alba var. pyramidalis > the abandoned farmland. The soil microbial metabolic activity of C. korshinskii forest was the highest. The Shannon index, Simpson index and McIntosh index of soil microbial community in five types of stands were significantly higher than that in control. Both the Shannon index and Simpson index of C. korshinskii forest were higher than the other four forests (P<0.05). The McIntosh index of soil microbial community of R. pseudoacacia forest was the highest (P<0.05). The utilization rates of carbohydrates, amino acids, carboxylic acids, polymer, polyphenols and amines by soil microbes in the five forests were higher than that in the abandoned farmland, and different carbon sources utilization ability varied among the different forests. The main carbon sources utilized by soil microbes in the five forests were carbohydrates, followed by amino acids, carboxylic acids and polymer, while the utilization rates of polyphenols and amines by soil microbes were very low. PCA analysis indicates that the numbers of carbon sources in relation to PC1 and PC2 are 20 and 17 respectively. Carbohydrates, amino acids and carboxylic acids played a major role in the separation of principal component. The soil microbial community of P. tabulaeformis forest, P. alba var. pyramidalis forest and the abandoned farmland had similar characteristics of carbon sources utilization, while soil microbial community in the other three forests had their unique carbon utilization modes. Moreover, the C. korshinskii forest distributed in the positive direction of PC axis, which demonstrated that the carbon sources utilization ability of soil microbial community in C. korshinskii forest was the best.[Conclusion] The plantations were more beneficial to improve soil microbial metabolic activity than the abandoned farmland in the hilly-gully regions of Loess Plateau. C. korshinskii was better in improving soil metabolic functional diversity than the other studied artificial forests. This study provides to a certain degree a scientific basis for forest species selection and forest cultivation in the project of converting farmland into forest in the hilly-gully regions of Loess Plateau from the aspect of the soil microbial metabolic activity.

Key words: the hilly-gully regions of loess plateau, different types of stand, soil microbes, Biolog, principal component analysis

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