帽儿山溪流水生昆虫与环境因子的相关性

Correlation between Aquatic Insects and Environmental Factors in the Maoershan Streams

为进一步分析东北林业大学帽儿山实验林场溪流水生昆虫与环境因子的相关性,于2011年5月、7月、10月、11月,4次野外定点调查,共采集水生昆虫2 962只,隶属于5目、32科、97属、125种;水生昆虫密度为(225±280)ind/m2,生物量为(5.4±5.7)g/m2。运用典范对应分析(CCA)对丰水期(7月)和枯水期(10月)水生昆虫群落组成与14个环境因子的相关性进行了研究。结果表明:丰水期和枯水期水生昆虫群落结构受环境因子影响差异显著(P<0.05);在丰水期,水温、TP、NH4+-N和Chla是影响水生昆虫群落结构的主要环境因子,而枯水期主要受TP、海拔、水温、Chla的影响。从种类水平看,摇蚊幼虫与海拔、Chla呈正相关,与流速呈负相关;大蚊科幼虫与DO呈正相关;E、P、T水生昆虫(E蜉蝣目、P襀翅目、T毛翅目)分布比较集中,并且与Chla呈正相关。通过对不同干扰的水生昆虫群落结构的比较分析表明,溪流中人类季节性漂流对水生昆虫群落结构有显著影响。

To further analyze the correlation between aquatic insects and environmental factors in the streams of Maoershan experimental forestry farm of Northeast Forestry University, four investigations were conducted in May, July, October and November, 2011. Total 2 962 individuals which belong to 125 species of 97 genera in 32 families under 5 orders of aquatic insects were collected. The density of aquatic insects was （225±280） ind/m2, and the biomass was （5.4±5.7） g/m2. The correla- tion between community composition of aquatic insects and 14 environmental factors during both wet season （ on July） and dry season （ on October） was studied, using the Canonical Correspondence A- nalysis （CCA）. The results showed that insect community structure was significantly affected by en- vironmental factors in wet season and dry season. Water temperature, TP, NH4＋-N and Chla were the main environmental factors to affect the aquatic insect community structure in the wet season, and TP, elevation, Chla and water temperature were the main environmental factors in the dry season. The CCA indicted a positive correlation between the distribution of Chironomid larvae and ele-vation and Chla, respectively. However, there was a negative correlation between the distribution of Chironomid larvae and elevation. There was a positive correlation between Tipulidae larvae and dissolved oxygen. The distribution of E, P, T （ E ： Ephemeridae, P ： Perlodidae, T： Tipnlidae） concentrated together, was positively related to Chla. In addition, the analysis of different disturbed degrees indicated that the characteristics of the aquatic insect communities were significantly affected by seasonal drift of tourists.