Impacts of logging and rehabilitation on invertebrate communities in tropical rainforests of northern Borneo

The inclusion of carbon stock enhancements under the REDD+ framework is likely to drive a rapid increase in biosequestration projects that seek to remove carbon from the atmosphere through rehabilitation of degraded rainforests. Concern has recently been expressed, however, that management interventions to increase carbon stocks may conflict with biodiversity conservation. Focusing on a large-scale rainforest rehabilitation project in northern Borneo, we examine the broad impacts of selective logging and subsequent carbon enhancement across a wide range of invertebrate fauna by comparing the abundance of 28 higher-level taxa within two separate rainforest strata (leaf-litter and understorey) across unlogged, naturally-regenerating and rehabilitated forest. We additionally assess changes in functional composition by examining responses of different feeding guilds. Responses of individual taxa to forest management were idiosyncratic but logging resulted in more than a 20% increase in total invertebrate abundance, with fewer than 20% of taxa in either stratum having significantly lower abundance in logged forest. Rehabilitation resulted in a marked reduction in abundance, particularly among leaf-litter detritivores, but overall, there were much smaller differences between unlogged and rehabilitated forest than between unlogged and naturally regenerating forest in both total invertebrate abundance and the abundances of different feeding guilds. This applied to both strata with the exception of understorey herbivores, which were more abundant in rehabilitated forest than elsewhere. These results support previous data for birds suggesting that carbon stock enhancement in these forests has only limited adverse effects on biodiversity, but with some impacts on abundance within particular guilds.