精养池塘水体是一个较为复杂的生态系统,在这个系统内,鱼是能量产出的重要环节,天津市池塘养鱼的养殖模式,多以传统的“生态混养”为主。在该模式中,物质循环及能量转换效率是考察一个生态系统能量循环优劣的重要指标。李思发(1984)、陈一俊(1985)曾对我国南方精养塘的生态状况和能量转换率作过研究。但北方 The intensive pond water body is a more complicated ecosystem. In this system, fish is an important part of energy production. The culture mode of fish ponds in Tianjin is mostly based on the traditional “ecological polyculture”. In this model, material circulation and energy conversion efficiency are important indices for examining the pros and cons of an ecosystem energy cycle. Li Sifu (1984) and Chen Yijun (1985) once studied the ecological status and energy conversion rate of intensive ponds in southern China. But the north