Agricultural Use of Natural Secondary Forest Affects Soil Microorganisms in Hainan Province

PDF HTML阅读 XML下载 导出引用 引用提醒 农业利用对海南省天然次生林土壤微生物的影响 DOI: 10.5846/stxb201310192525 作者: 作者单位: 南京化工职业技术学院,南京师范大学地理科学学院,海南大学农学院,南京师范大学地理科学学院,南京师范大学地理科学学院,南京师范大学地理科学学院,南京师范大学地理科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金资助项目(41271255,41222005); 江苏省高校自然科学研究重大项目(12KJA170001); 江苏省高校优势学科建设工程项目(164320H101) Agricultural use of natural secondary forests affects soil microorganisms in Hainan Province, China Author: Affiliation: Nanjing College of Chemical Technology,School of Geography Science, Nanjing Normal University,Collage of Agriculture, Hainan University,School of Geography Science, Nanjing Normal University,School of Geography Science, Nanjing Normal University,School of Geography Science, Nanjing Normal University,School of Geography Science, Nanjing Normal University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为揭示天然次生林经过长期农业利用后土壤微生物学性质以及土壤养分状况的变异,采集了海南省天然次生林土壤以及由天然次生林经农业开垦转变而成的香蕉、桉树和橡胶林区表层土壤样品,利用磷脂脂肪酸(PLFA)分析、变性梯度凝胶电泳(DGGE)、群落水平生理特征(CLPP)分析等方法探究天然次生林经农业利用对土壤微生物生物量、微生物活性、群落多样性和功能多样性的影响。研究结果显示,天然次生林土壤总磷脂脂肪酸显著高于经农业利用的土壤,分别是香蕉和橡胶林土壤的3倍和2倍。平均颜色变化率(AWCD)以及由PLFA、DGGE和CLPP分析获得的土壤微生物群落多样性和功能多样性均显示出天然次生林高于农业利用的土壤。天然次生林土壤与农业利用土壤的微生物群落结构也存在明显的分异。另外,天然次生林土壤pH值、有机碳、总氮、总磷、速效氮和速效钾含量高于经农业利用的土壤。逐步回归分析显示土壤pH值、有机碳和速效氮是影响土壤微生物生物量、微生物活性、群落多样性和功能多样性的主要因素。研究结果表明,天然次生林经农业利用后,由于种植单一树种和农业管理措施可能造成土壤有机质和养分含量下降,导致土壤酸化,对土壤微生物群落造成负面影响。 Abstract:Natural forests tend to be converted into agricultural lands in developing countries for economic development. In the subtropical regions of China, natural secondary forests are generally converted to banana, rubber, and eucalyptus plantations. Unlike natural forests, agricultural lands are mainly characterized by mono-plantations, tillage, fertilization, and litter removal. These practices may have unfavorable consequences on the soil ecosystem. Moreover, the soil in the subtropical regions of China is classied as Ultisol, which is vulnerable to erosion and degradation under improper soil management. Yet, knowledge about the effects of the conversion of natural forests to agricultural lands on soil quality in these regions remains scarce. Soil microorganisms are critical for organic matter conversion and nutrient cycling, in addition to being sensitive to environmental changes. Thus, soil microbial parameters such as microbial biomass, activity, biodiversity, and composition are considered as reliable indicators of soil quality. To understand the effect of forest conversion to agricultural lands on soil microbial parameters, as well as soil chemical properties, we collected soil samples from a well-conserved natural secondary forest, in addition to transformed banana, eucalyptus, and rubber forests. Phospholipid fatty acid (PLFA) analysis, denaturing gradient gel electrophoresis (DGGE), and community-level physiological profiles (CLPP) were used to investigate various microbial parameters, including microbial biomass, activity, community diversity, and functional diversity. Microbial diversity was expressed as Shannon diversity (H'). Principal component analysis (PCA) was performed to analyze the soil microbial structure based on PLFA, CLPP, and DGGE data. In addition, soil chemical properties were determined, including pH, organic carbon, available nitrogen, total phosphorus, available phosphorus, and available potassium. Stepwise multiple regression analysis was used to determine the main soil properties that influenced soil microbial parameters. The results showed that the natural secondary forest had the highest total PLFA, which was 3 and 2 times higher than that recorded for the banana and rubber forests, respectively. The average color development (AWCD), community diversity, and functional diversity determined from the PLFA, DGGE, and CLPP profiles were also highest in the natural secondary forest. Soil microbial community structure differed between the natural secondary forest and agricultural lands, as well as between the vegetation types. In addition, soil pH, organic carbon, total nitrogen, total phosphorus, available nitrogen, and available potassium were higher in the natural secondary forest compared to the agricultural lands. The stepwise analysis showed that soil pH and available phosphorus affected H' and CLPP values, while organic carbon affected AWCD, H' of fungal DGGE, and fungal biomass values. Total nitrogen and available nitrogen generally affected microbial biomass (total, bacterial, and fungal PLFAs) and community diversity (H' of DGGE and PLFA data). Our results indicate that the conversion of natural secondary forests to agricultural lands leads to soil acidification and a significant decrease in soil organic carbon and nutrient content. Furthermore, conversion decreases microbial biomass, activity, diversity, and functional diversity, causing shifts in soil microbial community structure. The adverse effects of this conversion on soil chemical and microbial properties may be due to the agricultural management practices being followed at local sites. 参考文献 相似文献 引证文献