Diversity of Ground-Dwelling Beetles (Coleoptera) in Larch Plantation with Different Stages of Reforestation in Wolong Natural Reserve, Southwestern China

This paper studied the influences of forest regeneration on the diversity of ground-dwelling beetles (Coleoptera), in taxonomic level of families, in Wolong Natural Reserve (30°45′-31°25′N，102°52′-103°24′E), Southwestern China. Comparisons were conducted among larch plantations of different forest ages, namely, recently planted (5 years old), young (15 years old), mature plantation (45 years old), and natural deciduous broad-leaved forests (ca. 100 years old). Larch plantations were dominated by non-native Larix kaempferi but interspersed with a few native L. mastersian. Pitfall traps were used in the field collections. During the field research, a total of 7 444 beetles were collected, of which, Carabidae accounted for 40.2%, Staphylinidae 38.3%, and Tenebrionidae 6.4%, and these three families were considered as dominant groups. Family richness, diversity and evenness of beetles were significantly higher in three larch plantations than in natural broad-leaved forest; among the three plantations, the highest values were observed in the recently planted whereas the lowest in the young plantation. Contrary to the above three indices, family abundance was higher in natural broad-leaved forest than in three larch plantations; within the three plantations, the lowest value were showed in the recently planted whereas the highest value in the young plantation. Based on the family composition and abundance, ground-dwelling beetles of three larch plantations and the adjacent natural broad-leaved forest could be separated by ordinations of principal coordinate analysis (PCO) and cluster analysis, but beetle assemblages in the mature plantation was similar to both natural forest assemblages and young plantation assembalges. Seasonal dynamics of family abundance were similar among the three plantations, but significantly different from that of the natural broad-leaved forest. However, family richness, diversity and evenness did not show the similar trends. Multiple linear regression analyses showed that the coverage and height (or depth) of canopy layer, herbaceous layer and leaf litter layer were the most important factors in determining the family richness, abundance, diversity; and evenness. Although some similar characteristics in beetle composition were displayed in the mature plantation as well as in the natural broad-leaved forest, our results showed that the composition of ground-dwelling beetles in larch plantations differed obviously from those in the natural deciduous broad-leaved forest at the family level. Finally we concluded that, in an attempt at reforestation by the establishment of plantations, it is necessary to preserve the undisturbed deciduous broad-leaved forest for the purpose of protecting the diversity of ground-dwelling beetles in Wolong Natural Reserve.