【作者】 金晖；

【导师】 王卫民； 曹凑贵；

【作者基本信息】 华中农业大学 ， 渔业， 2009， 硕士

【摘要】 稻田是地球上最重要的人工湿地,也是受人为干扰最大的生态系统,有丰富的生物种群。于2005年6月至8月在华中农业大学试验场,进行了稻、鸭、鱼共育稻田浮游植物群落的研究试验,试验分养鸭组(D)、鱼鸭组(DF)、养鱼组(F)3个试验组,1个对照组(R),每组3个重复,共采样5次,通过对浮游植物的种类、密度、生物量、相似性、多样性、优势度和差异性的分析,研究了稻田浮游植物的群落组成和结构,以及鸭、鱼对浮游植物的群落组成和结构的影响。本次试验共检测到浮游植物38属150个种和亚种,其中裸藻门57个种及亚种,绿藻门46个种及亚种,硅藻门31个种及亚种,蓝藻门13个种及亚种。R组和F组分别检出79个种及亚种和85个种及亚种,D组和DF组分别检出86个种及亚种和100个种及亚种。有鸭组和无鸭组在种类数量和组成上有明显差异,有鸭组种类多于无鸭组,且以裸藻门种类最多;无鸭组则以绿藻门种类最多,有鱼组种类又多于无鱼组。浮游植物的密度5次的平均值DF组最大是4.113×10~6ind/L,其余依次是F组3.418×10~6ind/L,R组1.963×10~6ind/L,D组最小0.651×10~6ind/L。浮游植物的生物量5次平均值DF组17.80mg/L明显高于其他3组,F组9.37mg/L,R组6.99 mg/L,D组最低2.41mg/L。浮游植物的相似性DF组与其他组的相似性较低,R组、D组、F组之间的相似性较高。硅藻门相似性最高,其次是蓝藻门,裸藻门相似性最低。蓝藻门、绿藻门,是DF组与其他组相似性低,R组、D组、F组之间相似性高;硅藻门相似性则是F组与其他3组之间相似性低,R组、D组、DF组之间较高;裸藻门R组与其他3组相似性低,D组、DF组、F组之间相似性高。鸭、鱼的活动对裸藻门相似性影响最大,其次是绿藻门,对硅藻门的影响最小。浮游植物多样性系数平均值DF组最大1.56,其次是D组1.47,R组为1.43,F组最小1.26。鱼、鸭的活动对浮游植物的Margalef多样性系数有一定的影响,鸭的活动增大了浮游植物的Margalef多样性系数,鱼的活动则降低了浮游植物的Margalef多样性系数。浮游植物密度优势度R组、F组主要是小型藻类为优势,D组和DF组第1次、第2次是以小型藻类为优势,后期则是以大型藻类为优势。浮游植物生物量优势度R组从裸藻属、菱形藻属为优势演变成鼓藻属为优势;D组和DF组则是从裸藻属为优势演变成裸藻属和实球藻属为优势;F组优势度初期的第1次、第2次是裸藻属、菱形藻属为优势,第3次、第5次是实球藻属为优势,第4次是鼓藻属为优势。试验结果表明稻田中有鸭有利于大型浮游植物的生长、繁殖,无鸭有利于小型浮游植物的生长、繁殖;有鱼组浮游植物的数量(密度和生物量)多于无鱼组。DF组浮游植物的种类、数量比其他组都高,最适宜浮游植物的生长、繁殖;D组数量比其他组都低,最不适宜于浮游植物的生长、繁殖;稻、鸭、鱼主要是通过改变稻田水体的光照和营养而影响浮游植物的种类和数量。更多还原

【Abstract】 Rice field is the most important artificial wetland on the earth and is the most disturbing ecosystem with abundant biological populations. In the present study, we investigated the constitution of phytoplankton community in the rice field which cultivate ducks and fishes together at Experimental Base of Huazhong Agricultural University from June to August in 2005. The experiment has three test groups and a control group. During the experiment period, we sampled 5 times and analyzed the phytoplankton community through the species composition, density, biomass, similarity index, diversity index and dominance index. The influences of ducks and fishes on phytoplankton community in the rice fields were analyzed.In total, 38 genus and 150 species including subspecies were observed in this experiment, which were composed by 57 species of Euglenophyta, 46 of Chlorophyta, 31 of Bacillariophyta and 13 of Cyanophyta. The group R and The group F had 79 and 85 taxonomic units, respectively. Furthermore, there were 86 and 100 taxonomic units detected in group D and DF, respectively.The maximum average density of total 5 samples of the phytoplankton was 4.113×10~6 ind/L in group DF, followed by group F with 3.418×10~6 ind/L and group R with 1.963×10~6 ind/L, but the minimum was 0.651×10~6 ind/L in group D. Correspondingly, the maximum average biomass of total 5 samples of the phytoplankton was 17.80 mg/L in group DF, significantly higher (P<0.05) than that in the other 3 groups which was 9.37 mg/L in group F and 6.99 mg/L in group R, as well as the lowest of 2.41mg/L in group D.The similarity of the whole phytoplankton community between the group DF and the other 3 groups was less than that among the other 3 groups. The highest similarity was found in Bacillariophyta, followed by Cyanophyta but the lowest in Euglenophyta. The similarity of Cyanophyta was in accordance with the whole phytoplankton community, as well as that of Chlorophyta. The similarity of Bacillariophyta was lower between the group F and the other 3 groups than that among the other 3 groups. The similarity of Euglenophyta was the same as in Bacillariophyta but change to group R. The activities of the ducks and fishes in the rice field had most greatly impact on the similarity of Euglenophyta, secondly on that of Chlorophyta but minimal on Bacillariophyta.The maximum average diversity factor of the phytoplankton was 1.56 in group DF, followed by 1.47 in group D and 1.26 in group R, while the minimum was 1.26 in group D. There were obviously different influences of the activities of ducks and fishes on the Margalef diversity factor of the phytoplankton community. The ducks activities increased the Margalef diversity factor but the fishes’ activities decreased it.The dominant element of the phytoplankton composition in group R and group F was macroscopic algae, the same as in the initial stage of group D and group DF, but the macroscopic algae in the late stage of group D and group DF. The component with the dominant phytoplankton biomass changed from Euglena and Nitzschia to Cosmarium in group R, and from Euglena to Euglena and Pandorina in group D and group DF. The component with the dominant phytoplankton biomass was Euglena and Nitzschia in the first and second sampling in the initial stage in group F, whereas Pandorina in the third and fifth sampling, and Cosmarium in the fourth sampling.The result showed that the cultivating of ducks in the rice fields promoted the growth and reproduction of the macroscopical algae but inhibited that of the microscopical algae. The density and biomass of the phytoplankton in the rice fields cultivating fishes was more than those of the rice fields without fishes. The species and quantity of group DF were so obviously higher than the other three groups that the group DF was the most suitable rice fields for the growth and reproduction of the phytoplankton, while the group D was in the opposite of the group DF. The system that the rice fields cultivating ducks and fishes affected the species and quantity of the phytoplankton in it by changing the illumination and nitrition of the rice fields’ water body.更多还原