人为干扰对桂西北喀斯特山地植被多样性及土壤养分分布的影响

发布时间：2018-01-22 00:36

本文关键词： 喀斯特山地草地人为干扰土壤养分植被多样性　出处：《水土保持研究》2016年05期 　论文类型：期刊论文

【摘要】：为促进桂西北喀斯特山地草地生态系统的恢复与重建,在连续3年全面调查的基础上,采用Pearson相关系数法和主成分法研究了人为干扰对喀斯特山地草地植被多样性和土壤养分的影响。结果表明:人为干扰对喀斯特山地草地植被多样性具有明显的影响,其中人为干扰显著降低了植被盖度、地上生物量、丰富度指数和多样性指数(p0.05),对喀斯特山地草地植被均匀度指数和优势度指数没有显著影响(p0.05),说明人为干扰并没有改变物种在生境中的均匀分布和物种发生根本性变化。人为干扰显著增加了土壤容重和pH值(p0.05),降低了土壤含水量和土壤电导率,但4种营养元素(碳、氮、磷、钾)的变化幅度不尽一致,具体表现为人为干扰降低了土壤碳、氮和钾含量,但对土壤磷素并没有显著的影响(p0.05),从降低幅度来看,土壤有效养分降低幅度高于土壤全量养分,由此表明土壤有效养分较土壤全量养分更为敏感。Pearson相关性分析表明,对于人为干扰区和对照区,影响其植被多样性的土壤环境因子不尽一致,其中土壤养分和有效养分在一定程度上起着主导性的影响作用,通过人为干扰区和对照区的相关性系数可知,人为干扰区域和对照区域土壤养分之间均呈极显著正相关,说明土壤系统内部因子处于动态变化和平衡中,在人为干扰下,它们作为相互作用和影响的有机整体表现出统一性和同步性,并没有改变土壤养分因子之间的互作效应,并且土壤全量养分均与其对应的有效养分呈极显著正相关(p0.01),说明其有效养分主要依靠于土壤全量养分。冗余分析的结果显示,对于人为干扰区和对照区,植被与土壤的排序基本没有变化,而人为干扰对土壤养分含量产生了一定的影响,造成二者的RDA排序图不相一致,排序轴可反映喀斯特地区土壤因子的梯度变化特征,表明利用土壤养分作为表征喀斯特山地草地土壤—植被关系的敏感性土壤指示因子是可行的。
[Abstract]:In order to promote the restoration and reconstruction of karst grassland ecosystem in northwest Guangxi, a comprehensive survey was conducted for three consecutive years. Pearson correlation coefficient method and principal component method were used to study the effects of human disturbance on vegetation diversity and soil nutrients in karst grassland. Anthropogenic disturbance has a significant effect on vegetation diversity in karst mountainous grassland. Anthropogenic disturbance significantly reduced vegetation coverage, aboveground biomass, richness index and diversity index (p 0.05). There was no significant effect on the evenness index and dominance index of vegetation in karst mountainous grassland (p0.05). The results showed that anthropogenic interference did not change the uniform distribution of species and the fundamental change of species in habitat, but the anthropogenic interference significantly increased soil bulk density and pH value (p 0.05). Soil water content and soil conductivity were decreased, but the changes of four nutrient elements (carbon, nitrogen, phosphorus, potassium) were not consistent. However, there was no significant effect on soil phosphorus. The decrease of soil available nutrients was higher than that of soil total nutrients. Pearson correlation analysis indicated that the soil available nutrients were more sensitive than the total soil nutrients. Pearson correlation analysis showed that the soil environmental factors affecting the vegetation diversity were different for the anthropogenic disturbance areas and the control areas. Soil nutrients and available nutrients play a leading role to some extent, and the correlation coefficient between artificial disturbance area and control area can be known. There was a significant positive correlation between soil nutrients in anthropogenic disturbance region and control area, which indicated that the internal factors of soil system were in dynamic change and balance, and under artificial disturbance. As an organic whole of interaction and influence, they showed unity and synchronism, and did not change the interaction effect between soil nutrient factors. And the soil total nutrients were significantly positively correlated with their corresponding available nutrients, which indicated that the available nutrients mainly depended on the total soil nutrients. The results of redundancy analysis showed that the available nutrients were mainly dependent on the soil total nutrients. For the artificial disturbance area and the control area, the sequence of vegetation and soil had no change, but the artificial interference had a certain effect on soil nutrient content, resulting in the difference of RDA sequence diagram between them. The sequence axis can reflect the gradient characteristics of soil factors in karst area, which indicates that it is feasible to use soil nutrient as a sensitive soil indicator to characterize the relationship between soil and vegetation in karst mountainous grassland.
【作者单位】：中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;中国科学院环江喀斯特生态系统观测研究站;中国科学院大学;
【基金】：国家林业局林业软科学项目“中国森林旅游产业理论与实践研究”
【分类号】：S158;Q948.1
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