Community diversity of arthropod in monsoon evergreen broad-leaved forest and coniferous and broad-leaf mixed forest in Dinghu Mountain

An investigation of community diversity of arthropod in monsoon evergreen broad-leaved forest and in coniferous and broad-leaf mixed forest were conducted in Dinghu Mountain Biosphere Reserve, Guangdong in May and October 2001. The results showed that average values of arthropod species and individuals in monsoon evergreen broad-leaved forest were significantly higher than those in coniferous and broad-leaf mixed forest in shrub layer in May (because the natural enemies are more and greatly reproduced). In contrast, the values in coniferous and broad-leaf mixed forest were higher than those in monsoon evergreen broad-leaved forest in herb seedling of ground surface in May. The average values of arthropod species and individuals in monsoon evergreen broad-leaved forest were lower than those in coniferous and broad-leaf mixed forest in shrub layer in October, because the pests (Aphis) greatly reproduced, but there was not a significant difference at 0.05 level between the type of forests. In herb seedling, average values of arthropod species and individuals in monsoon evergreen broad-leaved forest were higher than in coniferous and broad-leaf mixed forest in October, there was not a significant difference at 0.05 level between the type of forests too. In the general, between monsoon evergreen broad-leaved forest and coniferous and broad-leaf mixed forest, average values of species and individuals of the pests and natural enemies were similar, there was not a significant difference between the type of forests, unless species and individuals of natural enemies in shrub layer in May and individuals of pests in shrub layer in October. Percentages of natural enemies to total number of species were 27.50%～87.50%, percentages of spider group to total number of species were 18.18%～66.67%, while the percentages of spider group in natural enemy of species were 53.33%～90.91% in all investigation fields. Richness index and Shannon-Weiner index in monsoon evergreen broad-leaved forest were greater than those in coniferous and broad-leaf mixed forest unless in herb seedling in May; in contrast, species concentration index in monsoon evergreen broad-leaved forest was lower than that in coniferous and broad-leaf mixed forest.