Fe限制对小球藻-隆线溞食物链的影响  

Effects of Fe limitation on Chlorella vulgaris-Daphnia carinata food chain

作　　者：成淑君[1] 杜京京[1] 田兴军[1] 

机构地区：[1]南京大学生命科学学院,南京210093

出　　处：《生态学杂志》2014年第7期1940-1945,共6页Chinese Journal of Ecology

基　　金：国家重大水专项(2012ZX07204004-003);中国科学院战略性先导科技专项(XDA 05050204);教育部博士点基金项目(20110091110018)资助

摘　　要：为了研究环境中Fe限制对小球藻-隆线溞食物链的影响,在0～10000 nmol·L-1的范围内设置5个Fe3+浓度梯度培养小球藻(Chlorella vulgaris),22 d后收集藻细胞,然后将收集到的小球藻饲喂隆线溞(Daphnia carinata)14 d,观察小球藻和隆线溞的生长状况。结果表明:Fe3+浓度为0、10、100和1000 nmol·L-1时小球藻的生物密度和叶绿素a的含量都明显低于Fe3+浓度为10000 nmol·L-1时;Fe3+浓度的下降导致小球藻对N的吸收减少,对P的吸收增加;隆线溞的体长和总产幼数随着Fe3+浓度的下降而逐渐降低,当Fe3+浓度为10000 nmol·L-1时,隆线溞最终体长和总产幼数分别为3 mm和93个,而当Fe3+浓度为0 nmol·L-1时,隆线溞最终体长和总产幼数分别为2.6 mm和60个;这说明Fe限制不仅会影响小球藻的生长和其对N、P的吸收,还会抑制以小球藻为食的隆线溞的生长和繁殖。以上结果表明,Fe限制对小球藻-隆线溞食物链的上行效应显著,这有助于进一步了解Fe对淡水浮游动植物的影响。This study aimed to determine the effects of Fe limitation on Chlorella vulgaris- Daphnia carinata food chain. C. vulgaris was cultivated with Fe^3 ＋at five different concentrations between 0- 10000 nmol·L^-1for 22 days. C. vulgaris cells were collected to feed D. carinata for14 days. The growth of C. vulgaris and D. carinata was observed. The results showed that the density and chlorophyll-a content of C. vulgaris were significantly lower at Fe^3 ＋concentrations between 0- 1000 nmol·L^-1than those at Fe^3 ＋concentration of 10000 nmol·L^-1. The decline of Fe^3 ＋concentration resulted in that C. vulgaris absorbed less nitrogen but more phosphorus.The body length and the total number of the cumulative eggs of D. carinata decreased gradually with the declining Fe^3 ＋concentration. The final body length and total newborns of D. carinata were 3 mm and 93 at 10000 nmol·L^-1Fe^3 ＋concentration,while 2. 6 mm and 60 at 0 nmol·L^-1Fe^3 ＋concentration,respectively. It was indicated that Fe limitation had significant effects on the growth of C. vulgaris and its absorption to nitrogen and phosphorus. The growth and reproduction of D. carinata were inhibited under the condition of Fe limitation. These results suggested that the bottom-up effects of Fe limitation on C. vulgaris- D. carinata food chain were significant and this would contribute to exploring the effects of Fe on freshwater phytoplankton and zooplankton.

关 键 词：淡水浮游动物 淡水浮游植物 生长 繁殖 上行效应 

分 类 号：Q178.1[生物学—水生生物学]