摘要
由人为及自然多种因素的影响造成很多地区人工林地出现衰退现象。本研究选择黄河三角洲不同退化程度的刺槐人工林,对林地土壤酶、养分和微生物及其相关性进行了研究,探讨人工刺槐林退化的原因。结果表明:随着人工刺槐林退化程度加重,土壤脲酶、多酚氧化酶和过氧化物酶活性下降;过氧化氢酶活性则先上升,重度退化林地下降。脲酶与多酚氧化酶和过氧化物酶活性显著相关,过氧化物酶与多酚氧化酶活性显著相关,其他酶之间相关性不显著。土壤养分与土壤酶的变化趋势基本一致,随着林分退化程度加重,有机质、全氮、碱解氮、速效磷含量均呈下降趋势;土壤pH、含盐量随着林分退化程度加重与土壤深度增加而上升,与土壤酶活性的变化趋势相反。土壤酶特别是脲酶活性与土壤养分显著正相关性,与土壤pH和含盐量呈显著负相关。不同退化程度的人工刺槐林地土壤细菌数量最多;真菌和放线菌与细菌变化趋势各不相同,随着退化程度的增加,细菌平均数量表现为未退化>轻度退化>中度退化>重度退化,真菌数量为轻度退化>未退化>中度退化>重度退化,放线菌数量为中度退化>轻度退化>未退化>重度退化。脲酶与细菌、真菌和放线菌数量显著相关,细菌与除过氧化氢酶外的土壤酶活性显著相关,其他酶活性与各类微生物数量相关性不显著。
A great deal of degradation of plantations across the globe are caused by natural and artificial factors.The Yellow River Delta（YRD） is one of China’s three estuarine deltas where plenty protection forests were established in the 1980s to improve local ecological environment.Among the forest plants is Robinia pseudoacacia,covering the largest area as main sand/windbreaker in this region.In recent years,however,much of the R.pseudoacacia plantation has dry-tops and some even wither to death.This has caused significant loss to shelter forest construction and management of salinization in the region.In this paper,R.pseudoacacia plantations with different degradation degrees in the YRD were selected for relational analysis of soil enzymes,nutrients,microbes as a means of exploring the causes of degradation of the plants.The results showed soil urease,polyphenol oxidase and peroxidase activities decreased with the aggravation of R.pseudoacacia plantations degradation.However,hydrogen peroxidase activity presented first increasing and then decreasing tendency.Urease was significantly positively correlated with polyphenol oxidase and peroxidase.Peroxidase was also significantly positively correlated with polyphenol oxidase,but not with the other enzymes.Soil nutrients such as organic matter,total nitrogen,available nitrogen and available phosphorus decreased with increasing degradation degree of R.pseudoacacia plantations.The reverse was the case for soil pH and soil salts.Soil enzymes,especially urease,were significantly positively correlated with soil nutrients and negatively correlated with soil pH and soil salts.Bacteria count was highest in R.pseudoacacia plantation soils with different degradation degrees.With increasing degradation degree of R.pseudoacacia plantation,average soil bacteria count was in the following order： no degradation slight degradation moderate degradation severe degradation.The order for average fungi count was as follows： slight degradation no degradation moderate degradation severe degradation.Then that for actinomycetes was： moderate degradation slight degradation no degradation severe degradation.Urease was highly positively correlated with bacteria and actinomycetes.Bacteria count was highly positively correlated with enzymes,except hydrogen peroxidase.The other enzymes showed no significant correlations with microbial count.
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2012年第11期1478-1483,共6页
Chinese Journal of Eco-Agriculture
基金
国家自然科学基金项目(30970499)资助
关键词
黄河三角洲
刺槐人工林
退化
土壤酶
土壤养分
土壤微生物
相关性分析
Yellow River Delta
Robinia pseudoacacia plantation
Degradation
Soil enzyme
Soil nutrient
Soil microbe
Relational analysis
作者简介
白世红（1964-），女，硕士，教授，主要从事生态、生物统计等教学与科研工作。E-mail：bsh@sdau．edu．cn
通讯作者：马风云（1965-），男，博士，副教授，主要从事生态、生物统计等课程的教学与科研工作。E．mail：sdmfy@sdau．edu．cn
