A 6.2 m thick core of Gucheng Lake sediment provided a 3600 years record of climate change. The contents of the TOC in the core changed from 2.63% to 8.48%, and the δ13C values of organic matter were from - 21.54% to...A 6.2 m thick core of Gucheng Lake sediment provided a 3600 years record of climate change. The contents of the TOC in the core changed from 2.63% to 8.48%, and the δ13C values of organic matter were from - 21.54% to - 27.3%. The TOC/TN ratios indicated that the organic materials in sediments were from lake plankton and land-derived plants.The 2.9-22 m core interval with high TOC/TN ratios, low δ13C values and low contents of TOC indicated a cold climate Stage. The 6.2-5.5 m and 0.4-0.1 m intervals were characterized by low TOC/TN ratios, highδ13C values and high contents of TOC and reflcted temperate climate stages.展开更多
Based on the investigations of bilogical resources on Dec.,1999 in winter Gucheng Lake,Jiangsu Province,the biomass,abundance of zooplankton,hydrophyte as well as compositions and community structures are analysed.Mor...Based on the investigations of bilogical resources on Dec.,1999 in winter Gucheng Lake,Jiangsu Province,the biomass,abundance of zooplankton,hydrophyte as well as compositions and community structures are analysed.Moreover,the changing tendency in 1990-1999 and the culturing capacity of fishery in Gucheng Lake are discussed.Although the water quality of Gucheng Lake belongs to Grade 3 according to national surface water quality standards for drinking water,yet the lake water is under eutrophication gradually,especially in recent years.The potential fishery yields of Gucheng Lake is estimated to be 0.8 million kilogram.Some measures must be taken to prevent the aquatic environment from further deterioration so that the biological resources be protected and utilized in a sustainable way.展开更多
文摘A 6.2 m thick core of Gucheng Lake sediment provided a 3600 years record of climate change. The contents of the TOC in the core changed from 2.63% to 8.48%, and the δ13C values of organic matter were from - 21.54% to - 27.3%. The TOC/TN ratios indicated that the organic materials in sediments were from lake plankton and land-derived plants.The 2.9-22 m core interval with high TOC/TN ratios, low δ13C values and low contents of TOC indicated a cold climate Stage. The 6.2-5.5 m and 0.4-0.1 m intervals were characterized by low TOC/TN ratios, highδ13C values and high contents of TOC and reflcted temperate climate stages.
文摘Based on the investigations of bilogical resources on Dec.,1999 in winter Gucheng Lake,Jiangsu Province,the biomass,abundance of zooplankton,hydrophyte as well as compositions and community structures are analysed.Moreover,the changing tendency in 1990-1999 and the culturing capacity of fishery in Gucheng Lake are discussed.Although the water quality of Gucheng Lake belongs to Grade 3 according to national surface water quality standards for drinking water,yet the lake water is under eutrophication gradually,especially in recent years.The potential fishery yields of Gucheng Lake is estimated to be 0.8 million kilogram.Some measures must be taken to prevent the aquatic environment from further deterioration so that the biological resources be protected and utilized in a sustainable way.
文摘基于水生植物生长影响因子特征,综合考虑光照、营养盐、悬浮物、水动力、温度及底质等因素,初步提出了野外条件下水生植物恢复判别函数;通过对野外环境主要生境因子的耦合数值仿真,首次建立了基于投影寻踪原理的水生植物恢复判别模型;以苦草做为恢复目标种,选择长江中下游地区典型浅水湖泊——高淳固城湖为例,对模型进行了应用,结果表明:固城湖现状生境条件下,可能恢复苦草的水域面积约3.25 km2,占湖泊总面积的10.5%,其中北部湖区与湖心区恢复面积较大,南部湖区也有局部水域适合苦草恢复重建,但面积较小,约0.65 km2.
