Insect community diversity and abundance in diversified pine forests
多样化松林中昆虫群落多样性特征

Massion pine,Pinus massoniana Lamb,and slash pine,Pinus elliottii Engelm,are the main pines in southern China.The insect species composition and community diversity index were examined in six types of pines forests at 15 d interval.The pine forests include: pure pine forest;mixed pine forest with cogon grass,Imperata cylindrical(L.);mixed pine forest with Chinese fir,Cunninghamia lanceolata(Lamb.) Hook;mixed pine forest with tea-oil camellia,Camellia oleifera Abel;mixed pine forest with camphor tree,Cinnamomum camphora(L.) Presl and Formosan sweetgum,Liquidambar formosana Hance;and mixed pine forest with C.oleifera and L.formosana from mason pine forest and slash pine forest.Our results show that there were no significant difference in insect species and abundance between the massion pine forest and the slash pine forest.However,significantly higher community diversity index of total insects and phytophagous group and lower community diversity index of predatory and parasitic natural enemies were observed in slash pine forest.Insect species and abundance,especially the predatory natural enemies,from the mixed forests are significant higher than those from the pure forests.The community diversity indices of total insects,predatory and parasitic natural enemies in the mixed forests were relatively stable during the year,and were significantly higher than those in the pure forests.However,the insect community diversity indices varied among locations and vertical layers of the trees.Significant differences in diversity index of insect community were observed in the direction of the northern and eastern parts of the canopy of the pine trees,but no such differences in the southern and western parts of the tree canopy.Similarly,significant difference in diversity index of insect community occurred on trunk but not on canopy and litter layer of trees.The stability of insect community in the mixed pine forest was discussed.