林苇鱼塘留苇密度对螃蟹产量的影响及机理研究

将林带内有芦苇的鱼塘分别设置留苇 0 ,1/4,1/2 ,3/4和 1 0等 5种类型。在林带和芦苇的不同高度 (5种 )、不同时间分别测定了光照度、植物表面温度、气温、水温、风速和水中溶氧含量变化 ,发现林带与不同的留苇密度对鱼塘内环境均有明显的调节作用 ,并存在着明显的差异 ,导致鱼塘内的生物组成有差异 ;鱼塘内不同留苇密度的螃蟹产量差异明显 ,分别为 1/4(74 8 4 0kg/hm2 ) ,1/2 (70 8 0 3kg/hm2 ) ,3/4(6 10 6 5kg/hm2 ) ,1 0 (5 5 3 6 3kg/hm2 ) ,0(5 31 2 2kg/hm2 ) ;单只螃蟹的重量分别为 5 6 6 8g/只 ,5 5 35g/只 ,5 3 4 3g/只 ,5 2 39g/只 ,4 3 37g/只。留苇密度 1/4高产的原因有二 ,一是林苇调节了鱼塘内小环境 ,二是林苇鱼塘内增加了生物的多样性 ,增加了螃蟹饲料源

Study on the regulation of environmental condition by windbreak and reed pond and its action on crab raising in the coastal area

Five models designed included 0,1/4,1/2,3/4 and 1 0 of reed remaining density in the crab raising pool surrounded by windbreak.The survey results showed that there were significant differences of illumination intensity,plant surface temperature and air temperature in the different height of windbreak.There also were significant differences of water surface temperature,wind speed and the content of dissolved oxygen in water in the crab raising pool.Windbreak and reed could regulate the environment condition of the crab raising pool.Different biological composition in the crab raising pool leaded different crab raising produce in the windbreak and reed pond.The produce of crab of 0,1/4,1/2,3/4 and 1 0 of reed density were 748 40,708 03,610 65,553 63 and 531 22 kg/hm 2 respectively.The weights of single crab were 56 68 g(1/4),55 35 g(1/2),53 43 g(3/4),52 39 g(1 0) and 43 37 g(0) respectively.The model of 1/4 for reed remaining density was designed for the highest produce.The high crab produce of model of 1/4 for reed remaining density was attributed to that the windbreak and reed could regulated and optimize the ecological environment in the crab raising pool and biological diversity.