THE ECOLOGICAL RELATIONSHIPS OF AQUATIC PLANTS AT LAKE NAIVASHA, KENYA
THE ECOLOGICAL RELATIONSHIPS OF AQUATIC PLANTS AT LAKE NAIVASHA, KENYA
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DOI：
10.1007/bf00014613
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发表时间：
1992-04-10
期刊：
影响因子：
2.6
通讯作者：
HARPER, D
中科院分区：
文献类型：
--
作者：
HARPER, D
奈瓦沙湖水生植物区系的分布和丰度受到两个生态系统一级过程的制约。一个是湖水水位的自然和不可预测的波动，导致水位下降了几个垂直米。另一种是几种外来物种食草性的结果，与扎根的水生植物和浮游植物之间的竞争有关。20世纪60年代和70年代外来引进的影响是到1982年完全消除了湖泊中的沉水植被，主要是通过小龙虾的食草性。自1984年以来，植被逐渐恢复，这与小龙虾种群密度的下降相一致。自1982年以来，浮游植物的浓度逐渐增加，原因是水位下降和用于农业的纸莎草沼泽清除导致营养物质增加。讨论了高水平浮游植物与广泛的滨海杂草床之间的关系。
The distribution and abundance of the aquatic flora of Lake Naivasha has been constrained by two ecosystem-level processes. One is the natural and unpredictable fluctuation of water levels which the lake experiences, resulting in a drawdown zone of several vertical meters. The other is the consequence of herbivory by several alien species, linked with competition between rooted aquatic plants and phytoplankton.The effects of alien introductions in the 1960s and 1970s was to eliminate submerged vegetation from the lake completely by 1982, principally by crayfish herbivory. Vegetation has been progressively returning since 1984 and this return is coincident with a decline in crayfish population density.Concentrations of phytoplankton have progressively increased since 1982 as a result of nutrient increase caused by a decline in water level and papyrus swamp clearance for agriculture. The relationship between high levels of phytoplankton and extensive littoral weed beds is discussed.