甘肃天水市退耕还林区土壤纤毛虫群落多样性

Community diversity of soil ciliates in the area of returning farmland to forest in Tianshui City,Gansu

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天水市退耕还林17年的纯种生态林(CH)、纯种经济林(PG)、混交经济林(HJHT)3种典型林地及耕地(GD)的土壤纤毛虫群落多样性进行研究,共鉴定到土壤纤毛虫139种,隶属于9纲20目39科55属.退耕还林后土壤纤毛虫群落多样性显著提高,物种数和平均密度由高到低依次为CH(93种,122.72 ind·g^(-1))>HJHT(85种,120.05 ind·g^(-1))>PG(80种,84.75 ind·g^(-1))>GD(52种,38.65 ind·g^(-1)),C/P系数由高到低依次为GD(0.84)>PG(0.35)>CH(0.31)>HJHT(0.27),优势度指数、多样性指数、丰富度指数和均匀度指数均表现为退耕还林样地大于耕地.纤毛虫优势类群由耕地的肾形目(Colpodida)演替为退耕后的散毛目(Sporadotrichida).生物与环境相关分析(BIOENV)显示,含水量、有机质和总氮是影响土壤纤毛虫群落结构的主要理化因子.退耕还林后土壤纤毛虫群落多样性显著提高,且不同的林地中土壤纤毛虫群落多样性存在差异,种植刺槐的生态林土壤纤毛虫群落多样性最高,种植花椒核桃的混交经济林次之,种植苹果的纯种经济林相对较弱,但林地土壤纤毛虫群落多样性显著高于耕地.

Three sampling sites with different forest types,namely pure ecological forest(CH),pure economic forest(PG),mixed economic forest(HJHT)and cultivated land(GD)in Tianshui City were selected and the community diversity of soil ciliates were studied by using non-flooded petri dish method,observation in vivo and directing-culture counting method.A total of 139 ciliates species were identified,which belonged to 9 classes,20 orders,39 families and 55 genera.The community diversity of soil ciliates increased significantly,the species number and density of soil ciliates from high to low is CH(93 species,122.72 ind·g^(-1))>HJHT(85 species,120.05 ind·g^(-1))>PG(80 species,84.75 ind·g^(-1))>GD(52 species,38.65 ind·g^(-1)),and the C/P indext from high to low is GD(0.84)>PG(0.35)>CH(0.31)>HJHT(0.27).The Simpson index,Shannon-Wiener index,Margalef index and Pielou index showed that sampling sites was larger than cultivated land.The dominant group changed from Colpodida in cultivated land to Sporadotrichida in sampling sites.Water content,organic matter and total-nitrogen are the main influencing soil physic-chemical factors.The community diversity of ciliates in ecological forest was the highest,followed by mixed economic forest,and pure economic forest was weak,but all of them were significantly higher than cultivated land.