Analysis on the temporal and spatial distribution of the primary productivity and its influencing factors in Lake Taiping(Reservoir), Anhui Province

Abstract

安徽太平湖是2014年国家列入的重点保护湖泊之一，鉴于其生物本底资料的缺乏，于2012年11月至2014年10月，从上游至下游选取H1、H2、H3、H4、H5共5个样点，采用黑白瓶法对太平湖的初级生产力进行为期2年的调查研究.结果显示，太平湖水柱毛初级生产力、水柱净初级生产力和水柱呼吸量的平均值分别为4.54±6.72、-1.82±7.77和6.50±7.62 g/（m²·d）.时间分布上，水柱毛初级生产力出现3个峰值，分别在2012年11月、2013年5月和2014年7月，呼吸量在2013年7月份出现远高于其他月份的峰值，达到了16.04 g/（m²·d），水柱毛初级生产力季节变化表现为夏季 >秋季 >春季 >冬季.太平湖初级生产力存在显著的空间差异，水平分布上毛初级生产力与呼吸量的水平分布相似，湖心H3样点最小，下游的H4、H5样点较高；垂直分布显示，毛初级生产力主要贡献在表层和1SD层，并沿水深逐渐降低，呼吸量的垂直分布与毛初级生产力不同，最高值出现在1SD和2SD层，各层净初级生产力的值均较小，无明显峰值或谷值.研究表明，太平湖水库水柱的P/R系数小于1，但最高生产力层（表层）的P/R系数大于1.相关分析显示水柱毛初级生产力与温度和湖深呈显著正相关，与其它环境因子相关性不明显.;Lake Taiping in Anhui was one of the protected lakes proposed by China. Given its lack of biological background data, we studied primary productivity of Lake Taiping from November 2012 to October 2014. Five regions from upstream to downstream (H1,H2,H3,H4,H5) were selected for the measurements of the primary productivity with the dark and white bottle method. Results showed that the gross primary productivity, the net primary productivity and the respiratory capacity of a water column in the lake were 4.54±6.72 g/(m²·d), 1.82±7.77 g/(m²·d) and 6.50±7.62 g/(m²·d), respectively. As for the time distribution, the gross primary productivity appeared three peaks, in November 2012, May 2013 and July 2014, respectively. Respiratory capacity was much higher than other months in July 2013, reached 16.04 g/(m²·d). The seasonal variation of gross primary productivity was in the order of summer > autumn > spring > winter. There was a significant spatial difference in primary productivity:in the horizontal distribution, the levels of primary productivity and respiratory capacity distribution similar to that the middle point of H3 obtain minimum, the H4, H5 of downstream at a higher level; in the vertical distribution, the maximum values of the gross primary productivity were obtained in the surface layer and 1 SD layer, and along the water depth decreases gradually. The vertical distribution of respiratory capacity was different from gross primary productivity, the highest in 1 SD and 2 SD layer, and the value of each layer net primary productivity were smaller, and no obvious peak or valley value. This research showed that the coefficient of P/R of phytoplankton of water column was less than 1 in Lake Taiping, while productivity of the highest layer (surface layer) of coefficient of P/R is greater than 1. Correlation analysis showed that the temperature and deep lake were significantly positive correlation with the gross primary productivity of water column, and other environmental factors correlation were not obvious.