Hodkinson I D
Department of Biology, Liverpool Polytechnic, Liverpool.
Environmental Sciences Centre, University of Calgary, Calgary.
Oecologia. 1975 Jun;21(2):131-139. doi: 10.1007/BF00345556.
A beaver pond can be considered an open ecosystem with a number of energy inputs and outputs. The net difference between input and output represents the accumulation of energy within the system. During 1973 input-output parameters were measured independently for one spring fed pond (surface area 736 m) in the Kananaskis Valley, Alberta, Canada. The yearly energy budged indicated that allochthonous energy inputs into the pond were much greater than autochthonous inputs. Of the total yearly energy input 18% was exported, 26% was respired and 56% accumulated in the sediments. This percentage utilization for respiration was low when compared with similar data from the literature for live aquatic ecosystems elsewhere. However the actual annual mean sediment respiration rate of 8.4 ml m hr compared favourably with the figure of 6.1 ml m hr predicted from Hargrave's 1969 respiration equation for benthic communities. This situation suggests that the allochthonous input, while dominant, is highly refractive and rapidly becomes locked up in the sediments. The high photosynthesis-respiration ratio of 0.81 together with the results of earlier litter bag experiments (Hodkinson, 1975) support this conclusion. Thus the beaver pond is a highly accretive heterotrophic ecosystem.
海狸池塘可被视为一个具有多种能量输入和输出的开放生态系统。输入与输出之间的净差值代表了系统内能量的积累。1973年期间，对加拿大艾伯塔省卡纳纳斯基斯山谷的一个由泉水补给的池塘（表面积736平方米）的输入 - 输出参数进行了独立测量。年度能量预算表明，进入该池塘的外源能量输入远大于内源输入。在年度总能量输入中，18% 被输出，26% 用于呼吸，56% 积累在沉积物中。与其他地方水生生态系统的类似文献数据相比，这种用于呼吸的百分比利用率较低。然而，实际年平均沉积物呼吸速率为8.4毫升/平方米·小时，与根据哈格雷夫1969年底栖生物群落呼吸方程预测的6.1毫升/平方米·小时的数值相比更有利。这种情况表明，虽然外源输入占主导地位，但它具有高度难分解性，并且很快就会被锁定在沉积物中。0.81的高光合 - 呼吸比以及早期垃圾袋实验（霍金森，1975年）的结果支持了这一结论。因此，海狸池塘是一个高度积累性的异养生态系统。
