Phytoplankton associations in a small hypertrophic fishpond in East Hungary during a change from bottom-up to top-down control
Phytoplankton associations in a small hypertrophic fishpond in East Hungary during a change from bottom-up to top-down control
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DOI：
10.1023/a:1003948827254
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发表时间：
2000-04-15
期刊：
影响因子：
2.6
通讯作者：
Padisak, J
中科院分区：
文献类型：
--
作者：
Borics, G;Grigorszky, I;Padisak, J
1992-1995年对匈牙利东部Mezeshegyi-to‘浅水富营养化鱼塘的浮游植物种类组成和丰度进行了研究。池塘呈现出明显的藻类周期性。高多样性浮游植物群落出现在春季和秋季。在冬季，低的多样性值要么与K-战略型物种主导浮游生物的稳定群落状态有关，要么与r-战略型物种的大量繁殖有关。在夏季，稳定的环境导致低多样性、高生物量的浮游植物群落，以圆柱藻为主。此时，圆柱藻的生长条件类似于在连续发酵罐中普遍存在的条件。该物种的压倒性优势持续了四个多月，在此期间，这种浮游植物与热带的浮游植物相似。1993年8月，一种不成功的减少藻类水华的化学处理方法成功地杀死了池塘里的所有鱼类。巨大的鱼群组成了食浮性的鲟鱼。尽管1994年夏季是本世纪最温暖的夏季之一，但预期中的圆柱藻水华未能发育，可能是因为大型浮游动物的捕食压力较大。尽管浮游植物的时空格局主要受自下而上效应的影响，但级联营养相互作用的变化也会对物种组成和生物量产生很大影响。
Phytoplankton species composition and abundance of a shallow hypertrophic fishpond (Mezeshegyi-to', East Hungary) was studied for the period 1992-1995. The pond showed a pronounced algal periodicity. High-diversity phytoplankton assemblages occurred in spring and autumn. During the winter period, low diversity values were related either to stable community states, when K-strategist species dominated the plankton, or to a large bloom of r-strategist species. In summer, the stable environment led to low-diversity, high-biomass phytoplankton assemblages, dominated by Cylindrospermopsis raciborskii. At this time, the growth conditions for Cylindrospermopsis were akin to those prevailing in a continuous fermenter. The overwhelming dominance of this species lasted for more than four months, during which time, the phytoplankton resembled that of one in the tropics. In August, 1993, an unsuccessful chemical treatment for reducing the algal bloom succeeded in killing the pond's entire population of fish. The large fish-stock comprised the planktivorous silver carp. Although the summer of 1994 was one of the warmest summers of this century, the expected Cylindrospermopsis bloom failed to develop probably because of a higher grazing pressure by large zooplankton. In spite of the fact that the temporal and spatial pattern of the phytoplankton is influenced principally by bottom-up effects, changes in cascading trophic interactions may also considerably influence the species composition and biomass.