长春南湖水生生态系统的能流特征

在作者多年对长春南湖水体进行能量生态学研究的基础上,从生态系统水平进行了能流分析。到达南湖湖面的太阳总辐射为4 969 635.4kJ.m-2.a-1,植物光合作用固定了30 244kJ.m-2.a-1的能量,其效率相当于入射太阳总辐射的0.6%。净初级生产力的15%被植食动物同化。植食动物同化的2 391kJ.m-2.a-1能量,用于呼吸1 467kJ.m-2.a-1,被食肉动物同化445kJ.m-2.a-1,被分解或未利用479kJ.m-2.a-1。食肉动物的总生产力为445kJ.m-2.a-1,呼吸消耗270kJ.m-2.a-1,被分解或未利用175kJ.m-2.a-1。与Cedar Bog湖、银泉(Silver Springs)相比,南湖植食动物对初级生产者的利用效率最低(15.0%),反映了富营养化湖泊的重要特点。应定量研究南湖中被分解和未被利用的部分,进一步揭示某些能流过程的强度与方向。

Energy Flow Characteristics of the Nanhu Lake Aquatic Ecosystem in Changchun

Based on authors’ energy ecology studies on the Nanhu Lake waterbody of Changchun for many years,the energy flow was analyzed on ecosystem level.The total sun radiation striking on the lake surface is 4 969 635.4 kJ·m-2·a-1.The energy fixed by plant photosynthesis is 30 244 kJ·m-2·a-1,which is 0.6% of the total sun radiation.15% of the net primary production is assimilated by herbivores.In the 2 391 kJ·m-2·a-1 of energy assimilated by herbivores,1 467 kJ·m-2·a-1 is respired,445 kJ·m-2·a-1 is assimilated by carnivores,and 479 kJ·m-2·a-1 is decomposed or unused.The total production of carnivores is 445 kJ·m-2·a-1,in which 270 kJ·m-2·a-1 is respired,and 175 kJ·m-2·a-1 is decomposed or unused.Compared with Lake Cedar Bog and Silver Springs,herbivores’ efficiency utilizing primary producers is the lowest in the Nanhu Lake(15.0%),showing the important feature of a eutrophicated lake.The part decomposed or unused in the Nanhu Lake should be quantitatively studied to further reveal the intensity and direction of some energy flows.