Local effects of forest fragmentation on diversity of aquatic insects in tropical forest streams: implications for biological conservation

Abstract

The influence of forest fragmentation (habitat isolation) on biological and ecological diversity of aquatic insects was investigated in streams of fragmented forests in Hulu Gombak (6 streams) and Gunung Angsi (5 streams) and un-fragmented forest of Berembun (6 streams) in peninsular Malaysia. Several environmental parameters including canopy cover, DO, temperature and pH differed significantly among the three catchments (P 0.05). Nestedness pattern that measures the effect of habitat isolation on taxonomic assemblages showed that aquatic insect’s community in un-fragmented forest (Berembun) was less nested (T = 54.4), indicating high diversity compared to highly nested (less diverse) in the two fragmented forests (Hulu Gombak, T = 30.45 and Gunung Angsi, T = 35.45). Taxa similarity in Berembun streams was negatively correlated with the geographical distance among streams (Mantel test, r = − 0.462, P 0.05). We concluded that local habitat conditions were the most important in shaping the aquatic insects community among streams of both unfragmented and fragmented forests.