| Wuliangsuhai has evolved into a heavily eutrophic grassy lake.In this paper,aiming at the nutritional value of large submerged plants in Wuliangsuhai Lake and the impact on lake swamping and water quality after winter sinking,a pilot research base was set up in Wuliangsuhai to explore the dynamic relationship between water-grass-fish,from biological manipulation and the recovery mechanism of fishery resources in grass-type lakes is studied in terms of the influence of the serial effect of food chain on water quality.In this paper,the regression equations of plant length and corresponding wet weight and the net growth of submerged plants per unit area of three kinds of submerged plants such as Ophiopogon japonicus,Myriophyllum spicatum,and Valeriana were studied,and different specifications and densities were studiedThe grass carp's feeding rate and feeding intensity of the three submerged plants determined the optimum stocking density and stocking specifications of grass carp in the water area per unit area and its improvement on the water quality of Wuliangsuhai.The test obtained the following results:1.Using the regression equation between plant length and corresponding wet weight,the net growth of each kg of caries,valerian and Myriophyllum spicatum was 0.200 kg,0.290 kg and 0.170 kg,respectively.2.According to the results of this test,when the stocking weight of the stocking grass is about 1 kg,the maximum stocking density of the "grass-fish"quantity balance is 20-23?,respectively,which is 206 tails of caries.328 tails/hm2 of Myriophyllum spicatum,126 tails/hm2 of alfalfa.3.The TN value in the culture area is 0.5 mg/L-0.63 mg/L,and the average concentration of TN in the non-culture area is 0.78 mg/L,which is higher than the total nitrogen concentration in the culture area.4.The TP value in the culture area is 0.04-0.06 mgL,and the average TP concentration in the non-culture area is 0.08 mg/L,which is higher than the TP concentration in the culture area. |
PDF Full Text Request