Longhorn beetles (Coleoptera : Cerambycidae) have been used to identify sites of high biological diversity and conservation value in cultivated landscapes which are usually composed of heterogeneous mosaics of different land use, but were rarely studied in changing landscapes of humid tropics.
Dr. Meng Lingzeng of Xishuangbanna Tropical Botanical Garden (XTBG) and his colleagues conducted a study in the Naban River valley (ca. 11.000 ha) within the Naban River Watershed National Nature Reserve (NRWNNR) in Xishuangbanna, southern Yunnan province, south-west China (22° 10′ N and 100° 38′ E). The region was dominated by natural rainforest until 30 years ago, but is successively transformed into commercial rubber monoculture plantations since that time.
The objective of the study was to investigate the longhorn beetle species diversity and distribution in that fragmented landscape in relation to land use type and to assess the response of the longhorn beetle guilds to the recent changes in land use. Due to the importance of woody plants as resources for longhorn beetles, the land use types were characterized by their tree species inventory, which largely corresponds with the successional stage of the predominant land use types, including rice field fallows, grassland and shrubland, young and old rubber plantations and natural forest plots.
The overall results on longhorn beetle species richness and abundance in the different habitat types of the study landscape clearly indicated that only one land use type, natural forest, possessed a degree of uniqueness in species diversity. Although young rubber plantations bore the highest longhorn beetle diversity outside forests (half of the total number of longhorn beetle species recorded in total), they can not provide permanent habitats for most of these species, because they develop into closed canopy plantations with less suitable habitat conditions. Therefore, along with an expected expansion of rubber cultivation which largely proceeds at the expense of forest areas, the habitat conditions for longhorn beetles in this region might decrease dramatically in future.
The study entitled “Tree Diversity Mediates the Distribution of Longhorn Beetles (Coleoptera: Cerambycidae) in a Changing Tropical Landscape (Southern Yunnan, SW China)” has been published in PLoS ONE, 8(9): e75481. doi:10.1371/journal.pone.0075481
