Comparative Study on Ground-dwelling Insect Communities between Eucalyptus Plantations and Adjacent Zonal Natural Forests in Yachang, Guangxi

This study investigated ground-dwelling insect communities by using pitfall trap method in the above three forest types in Yachang Orchids Nature Reserve, Guangxi, and unraveled the role of plant communities, stand structure, soil and litter properties involved in the associated mechanisms. The results showed that the ground-dwelling insect diversity in Eucalyptus plantations was significantly lower than that in non-karst natural forests but greater than in karst natural forests. The ground-dwelling insect community composition of Eucalyptus plantations was significantly different from those of karst and non-karst natural forests. Eucalyptus plantations were dominated by Blattidae and Gryllidae; non-karst natural forests were dominated by Gryllidae, Blattellidae, Reduviidae, Drosophilidae and Blattidae; karst natural forests were dominated by Nitidulidae and Drosophilidae. The difference in ground-dwelling insect community composition between Eucalyptus plantations and non-karst natural forests was driven by plant community, seedling density and litter cover, explaining 74.46% of overall dissimilarity in ground-dwelling insect community composition between the two forest types. The difference in ground-dwelling insect community composition between Eucalyptus plantations and karst natural forests was driven by understory tree density, litter cover and litter nitrogen content, explaining 62.27% of overall dissimilarity in ground-dwelling insect community composition between the two forest types. A reduction of understory plants leads to a reduction of ground-dwelling insect diversity in Eucalyptus ecological public forests.