PS 27-79 - Land-use and seasonality drive beetle community composition in a semi-deciduous forest in Ghana

Background/Question/Methods

In an Afrotropical region experiencing massive deforestation, interventions revolving around restoration should provide lasting solutions for recovering lost biodiversity as well as reviving the functional roles of biodiversity attributes. A key insect group lost through deforestation but reinstated with restoration interventions is the beetle which has numerous functional and ecological roles for biodiversity and society. Although numerous studies have discussed the effects of pronounced seasonality and land-use changes emanating from mining on beetles elsewhere, the context of Ghana remains scantly understudied. We carried out a comprehensive sampling of ground-dwelling beetle communities in two seasons (dry and wet) spread across four land-use types (restored and natural forests, agroforestry system, and an unrestored former gravel mine) in the semi-deciduous forest zone of Ghana to ascertain if tree communities, vegetation complexity and seasonal differences could support a higher number of beetle assemblages, functional groups and their overall activity-density in a restored post-mine land-use than the surrounding dominant land-use types.

Results/Conclusions

The results of our study revealed striking differences in land-use types in terms of beetle community composition, and activity-density, with most of these differences driven by local habitat conditions as defined by seasonal differences. Taxonomic composition of beetle communities differed significantly between land-use types (F_3,27 = 14.52; p < 0.001) and seasons (F_1,27 = 46.14; p < 0.001). The differences between land-use types did depend on the season (F_3,27 = 10.80; p < 0.001). Most beetle families were well represented in the wet season, except Tenebrionidae, Apionidae and Scotylidae which had higher affinity to the dry season plots. The activity density of beetles was significantly higher in the wet than in the dry season (N = 32, d = 1.29 [95.0%CI 1.81, 0.74], P = 0.000). The average dissimilarity between the dry and wet season plots was 65% and was driven by a higher activity density of Scarabaeidae, Carabidae, Staphylinidae, Hydrophilidae, Histeridae, and Cetonidae in the wet season but a higher activity density of Tenebrionidae and Nitidulidae in the dry season. Our study bridges the knowledge gaps on the effects of land-use management decisions on beetle communities and their dependence on major seasons in an understudied forest zone in Ghana.