庆阳市庆城县退耕还林区土壤纤毛虫群落特征

为研究土壤纤毛虫群落对不同退耕模式生态恢复的响应及利用其群落特征来评价退还效果,采用“非淹没培养皿法”、活体观察法和培养直接计数法对甘肃省庆阳市庆城县退耕10年后的多树种混交林(APR)和单一树种经济林(A)以及两个农田对照样地(CK1和CK2)的土壤纤毛虫群落特征进行定性定量研究,同时测定各样地土壤温度、含水量、pH值、电导率、土壤孔隙度、有机质、总氮、总磷、总钾、速效氮、速效磷和速效钾含量,并分析不同退耕还模式下土壤纤毛虫群落特征参数与土壤理化因子间的相关关系。结果为:共鉴定到土壤纤毛虫127种,隶属10纲21目34科52属;退耕样地与农田对照样地土壤纤毛虫物种分布存在明显差异,退耕样地间的物种相似性减小,群落组成复杂化,纤毛虫密度、多样性指数和丰富度指数均显著高于对照(P<0.05),其中混交林物种多样性最高;土壤纤毛虫优势类群由农田样地的肾形目(Colpodida)逐渐过渡为退耕样地的散毛目(Sporadotrichida);相关性分析可知,有机质、总氮、孔隙度和pH是影响土壤纤毛虫群落组成的关键因子,不同退耕模式下土壤纤毛虫群落组成差异较大,表明土壤纤毛虫群落对该地区退耕还林生态恢复工程发生了积极的响应,因此土壤纤毛虫群落特征参数可以作为评价退还效果的重要指标。

Community Characteristics of Soil Ciliates in Forestlands Converted from Cultivated Lands in Qingcheng County,Qingyang City

In this paper we evaluate the returning process of farmland to forest and the response of soil ciliate communities to the ecological restoration.Our aim was to perform an analysis of the characteristics of soil ciliate communities as an important parameter in order to evaluate the returning effect.We utilized non-flooded petri dish method,observations in vivo and directing-culture counting method.This article has a research on the community characteristics of soil ciliates of two different types of forests in this region which include multi-tree mixed forest(APR)and dingle tree economic forest(A),their returning process from farmland to forest along with two farmland contrast(CK1 and CK2).The sites are located in Qingcheng,Qingyang city of Gansu Province.We also investigated the vegetation communities and physic-chemical factors(including soil temperature,soil water content,soil pH,soil electric conductivity,soil porosity,organic matter,soil total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus and available potassium).The results were as follow:A total of 127 species of soil ciliates were identified,belonging to 10 classes,21 orders,34 families and 52 genera.There were significant differences in soil ciliate species distribution between the restored forest plots and the control plots.The species similarity between the returning farmland plots was reduced,and the community composition was complicated.The density,diversity index and richness index of soil ciliates in returning to farmland were significantly higher than those in farmland(P<0.05),of which the species diversity in the mixed forest was the highest.The dominant group of soil ciliates gradually transitioned from the farmland plots Colpodida to the restored forest plots Sporadotrichida.Correlation analysis showed that organic matter,total nitrogen,soil porosity and pH value were the key factors affecting the composition of soil ciliates community.The results showed that the soil ciliates community had a positive response towards the ecological restoration of returning cropland to forest in this area and its characteristic parameters could be used as an ideal index to evaluate the ecological restoration effect.