Lemly A Dennis, Dimmick John F
Department of Biology, Wake Forest University, 27109, Winston-Salem, North Carolina, USA.
Oecologia. 1982 Sep;54(3):359-369. doi: 10.1007/BF00380005.
The structure and seasonal dynamics of phytoplankton communities in the littoral zone were compared between oligotrophic and eutrophic lakes in the southeastern United States. Differences in diversity and species composition between lakes could be ascribed to long-term variation in nutrients corresponding to trophic status. However, significant within-lake variation could not be accounted for by microstratification of nutrients or other abiotic variables. Local biotic factors, perhaps dominated by the spawning activities of centrarchid fishes, resuspend periphyton and generate tychoplankton which becomes a persistent and integral part of the phytoplankton community in eutrophic systems. The patchy distribution of these biotic factors and resultant tychoplankton may lead to the observed variation. Grazing by herbivorous zooplankton was considered to be the major factor affecting the relative abundance of phytoplankton in the littoral zone, completely overriding the effects of nutrient concentration and biotic interactions between phytoplankton species during spring and summer.The relative importance of tychoplankton and grazing as regulatory factors operates independently of the trophic status or geographical location of a lake, making comparisons of different studies difficult and perhaps meaningless if traditional analyses based only on nutrients and interactions between species of phytoplankton are used. Limnetic as well as littoral components must be considered in future studies of phytoplankton communities in the littoral zone.
在美国东南部，对贫营养湖和富营养湖沿岸带浮游植物群落的结构和季节动态进行了比较。湖泊之间多样性和物种组成的差异可归因于与营养状态相对应的营养物质的长期变化。然而，湖泊内部的显著变化不能用营养物质的微分层或其他非生物变量来解释。当地的生物因素，可能以太阳鱼科鱼类的产卵活动为主导，使周丛生物重新悬浮，并产生 tychoplankton，它成为富营养系统中浮游植物群落的一个持久且不可或缺的部分。这些生物因素和由此产生的tychoplankton的斑块状分布可能导致了观察到的变化。食草性浮游动物的捕食被认为是影响沿岸带浮游植物相对丰度的主要因素，在春季和夏季完全超过了营养物质浓度和浮游植物物种之间生物相互作用的影响。tychoplankton和捕食作为调节因素的相对重要性独立于湖泊的营养状态或地理位置，如果仅使用基于营养物质和浮游植物物种之间相互作用的传统分析方法，会使不同研究之间的比较变得困难，甚至可能毫无意义。在未来对沿岸带浮游植物群落的研究中，必须同时考虑湖沼学和沿岸带的组成部分。
