Records of a lake's life in time: the sediments
Records of a lake's life in time: the sediments
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湖泊生命的及时记录：沉积物
作者：
W. Pennington
来自湖泊沉积物岩心分析的证据被用来确定随着时间的推移，导致英国湖区湖泊变化的影响。它们是：1.气候变化，主要记录在微化石组合2.集水区土壤动态--间冰期循环的自然土壤发展及其对水组成的影响，以及人类活动引起的输入扰动。在一系列日益严重的富营养化中，14个湖泊中每个湖泊的现状表明是人类两次改造的结果。第一个是浅水湖的蓄水量显著减少，这是由于在所有湖泊中砍伐和耕种集水区后加速的泥沙堆积速度--这并不影响深水湖的生物。第二个是在过去的120年里，人类和动物的排泄物被引入一些湖泊，这给受影响的湖泊带来了一个更迅速的变化过程，这种变化在浅水湖中更为强烈。
The evidence from analysis of cores from lake sediments is used to identify the influences which, acting through time, have brought about changes in the lakes of the English Lake District. These are: i. climatic changes, recorded mainly in microfossil assemblages ii. soil dynamics on catchments — the natural soil development of an interglacial cycle and its effect on water composition, and iii. perturbations of input resulting from activities of man.The present position of each of 14 lakes in a series of increasing eutrophication is shown to be the result of two processes of modification by man. The first was a significant reduction in volume of the hypolimnion of the shallow lakes, consequent on the accelerated rate of sediment accumulation which followed deforestation and cultivation of catchments in all the lakes — this did not affect the biology of the deep lakes. The second has been the introduction of human and animal wastes into some of the lakes during the last 120 years, which imposed on affected lakes a process of more rapid change which was more intense in the shallow lakes.