不同经营模式下山核桃林昆虫群落结构

Insect community structures of Carya cathayensis forests with different management modes in Zhejiang Province

通过分析4种不同经营模式下(荒废野生的山核桃Carya cathayensis林,林下种植植物的山核桃林,传统经营的山核桃林,参照有机化管理的山核桃林)昆虫群落结构的差异,对山核桃林经营模式提出意见与建议。采用马氏网、灯诱和样方调查收集昆虫标本,利用Excel 2013, SPSS 19.0软件对昆虫多样性特征参数、群落稳定性、主分量、群落相似性进行计算和分析。共获得标本22 283号,共计9目84科163种,在物种数上优势类群均为鞘翅目Coleoptera和膜翅目Hymenoptera昆虫,个体数量上优势类群均为同翅目Homoptera和直翅目Orthoptera。从特征性指数看,荒废野生的山核桃林昆虫多样性指数为3.64,均匀度指数为0.74,表现都为最好;林下种植植物的山核桃林昆虫多样性指数为3.12,均匀度指数为0.61,表现次之;马氏网法收集到的昆虫群落中,林下种植植物的山核桃林的昆虫物种数和个体数显著高于其他林(P<0.05),荒废野生和林下种植植物的山核桃林的昆虫多样性指数和均匀度指数差异不显著,但显著高于其他林(P<0.05),传统经营的山核桃林的昆虫优势度指数最高,且显著高于其他林(P<0.05)。从群落结构稳定性上看,参照有机化管理的山核桃林的天敌与害虫种数比值(Sn/Sp)为0.39,表现最好,说明昆虫群落内部食物网的复杂程度及相互制约能力较高;荒废野生的山核桃林的群落物种数和个体数比值(St/Si)为0.04,表现最好,说明昆虫种间数量的相互制约能力较强。主分量分析表明:不同经营模式存在一定差异,昆虫群落变化的主导因素各不相同。相似性分析发现,在度量值为5时,林下种植植物的山核桃林和参照有机化管理的山核桃林的昆虫群落结构接近,荒废野生的山核桃林和传统经营的山核桃林的昆虫群落结构存在差异。荒废野生的山核桃林的昆虫生态结构最稳定,林下种植植物的山核桃林次之。但在实际生产过程中,由于无法荒废山核桃林,因此,林下种植植物的山核桃林经营模式更适合农户,也是未来山核桃林经营模式发展的方向。

To provide opinions and suggestions for management of Carya cathayensis forests, this research analyzed differences in insect communities using four different management modes: Type Ⅰ-a wild C. cathayensis forest, Type Ⅱ-vegetation planted under a C. cathayensis forest, Type Ⅲ-a traditional C. cathayensis forest, and Type Ⅳ-an organically managed C. cathayensis forest. Methods of collecting insect specimens included Malaise trap, light lure, and quadrat survey. Characteristic indexes of diversity, stability of insect community, principal components, and similarity were calculated and analyzed using Excel 2013 and SPSS 19.0 software. Results showed a total of 22 283 insect specimens being collected belonging to 163 species, 84 families, and 9 orders. Coleoptera and Hymenoptera were dominant groups for species numbers;whereas, Homoptera and Orthoptera were dominant groups for individual numbers. For the entire insect community the best performance was with management Type Ⅰ, the wild C. cathayensis forest, with a diversity index of 3.64 and an evenness index of 0.74. For Type Ⅱ, the diversity index was 3.12, and the evenness index was 0.61;this forest management type had good performance. For the insect communities in Malaise traps, the individual number and species number with Type Ⅱ management were significantly higher than the other management types(P<0.05). The diversity index and the evenness index for Type Ⅰ and Type Ⅱ management were not significantly different but were significantly higher than other management types(P<0.05). The dominance index with Type Ⅲ management was significantly higher than other management types(P<0.05). For community structure, the Sn/Spratio for Type Ⅳ management was best with 0.39 meaning that the complexity and mutual restriction ability of the food network in the community was high. The St/Siratio of the wild C. cathayensis forest was best with 0.04 meaning the mutual restriction of species number was stronger. The principal component analysis showed differences for different management modes. Also the dominant factors for changes in the insect communities were different. A similarity analysis found that when the measure was five, insect community structures were similar for Type Ⅱ and Type Ⅳ management. Overall, the ecological structure of the wild C.cathayensis forest(Type Ⅰ management) was most stable followed by Type Ⅱ, and because inefficient use of a C. cathayensis forest was forbidden in the actual production process, the management mode of vegetation planted under a C. cathayensis forest(Type Ⅱ) was recommended for farmers.[Ch, 2 fig. 6 tab. 24 ref.].