太湖梅梁湾浮游植物叶绿素a和初级生产力

1998年5月～1999年8月对太湖梅梁湾4站点进行了每季1次、为期1年的初级生产力及相关因子研究，分析了梅梁湾叶绿素a含量和初级生产力的时空分布特征．结果表明，梅梁湾的叶绿素a含量、初级生产力均存在明显的季节变化和空间差异，春、夏季浮游植物叶绿索a含量和初级生产力要比秋、冬季高，空间上位于污染严重的直湖港口6#点叶绿索a含量和初级生产力要高，并大致呈现从湾内向湾口递减的趋势；在春、夏、秋季光照较强时，初级生产力最大指值出现在水下20～50cm处。到冬季垂直差异不明显；10～30℃之间初级生产力基本上随温度的上升而呈指数增加趋势．浮游植物生物现存量与初级生产力存在显著的正相关．营养盐与初级生产力相关性变化很大．光照显著地影响初级生产力的日变化。春、夏季强光作用下表面光抑制现象比较明显．

Chlorophyll a content and primary productivity of phytoplankton in Meiliang Bay of Taihu Lake

Based on the investigations on primary productivity of phytoplankton and related factors at four stations in Meiliang Bay of Taihu Lake from May 1998 to August 1999, this paper studied the distribution of phytoplankton chlorophyll a, its primary productivity, and their relationships with environmental factors. The results showed that there were obvious temporal and spatial differences in chlorophyll a and primary productivity. The high values of chlorophyll a content and primary productivity were recorded in spring and summer. Generally, chlorophyll a content and primary productivity decreased from inner to outer in the bay. The vertical profile of primary productivity showed that the maximum of primary productivity was recorded at 20-50 cm water depth in spring, summer and autumn, while there was no remarkable difference in winter. The primary productivity exponentially increased with water temperature from 10 to 30 degrees C. There was a significant positive correlation between chlorophyll a content and primary productivity. The correlation coefficients between nutrients and primary productivity varied greatly, which presented that nutrient was not the limiting factor for phytoplankton growth. The analysis of P-I curves based on different photosynthesis-irradiance models showed that obvious light inhibition was occurred at surface water in spring and summer.