汾河水库及河道中优势硅藻生态位的研究

Niche analysis of diatoms in Fenhe river and Fenhe reservoir

采用Levins生态位宽度公式和Petrailis生态位特定重叠指数测定了汾河水库和河道中 5 0个主要硅藻种的生态位宽度和生态位重叠 ,并对生态位宽度和生态位重叠的关系进行了初步探讨 ,结果表明 ,着生硅藻中的原子舟形藻、眼斑小环藻、平卧桥弯藻、尖菱形藻、短小舟形藻、线形曲壳藻、阿尔夫舟形藻等生态位最大 ,浮游硅藻中 ,以具星小环藻、团聚小环藻、眼斑小环藻生态位最宽 ;同时表明 ,生态位宽度大的种与其它种的生态位重叠也较大。生态位重叠表明 ,着生硅藻中 ,生态位重叠普遍偏高 ,河道中 ,清洁水体指示种普通等片藻进攻性最强 ,水库中以α -中污和 β-中污带生物比索曲壳藻进攻性最高。从生态位普遍重叠指数分析 ,浮游硅藻明显小于着生硅藻 ,表明浮游生境下 ,硅藻分化明显 ,着生环境中 。

The niche breadths and overlaps of 50 main diatoms species in the Fenhe river and Fenhe reservoir were measured using the formulas proposed by Levins and Petraitis,and the relationships between niche breadth and niche overlaps were discussed in this paper.The results showed that the niche breadths of Navicula atom,Cyclotella ocellata,Cymbella prostrate,Nitzschia apiculata,Navicula exigua,Achnanthes linearis, and Navicla arvensis in attached diatoms and the Cyclotellastelligera,C.glomerata,and C.ocellale in planktonic diatoms were greater,which was related with their own characteristics and the capability of adaptation to the environment.The niche overlaps among the species with the same or similar environment requirements were greater,while those between the species with broad niche breadth and other species were much greater.In Fenhe river,the aggression of Diatoma vulgare was the strongest,while in the reservoir ,the aggression of Achnanthes biasolettiana was the strongest.