Carabid beetles on an altitudinal gradient: spatial and temporal diversity

Up to 80 percent of the world’s biodiversity occurs in tropical forests. Cloud forests of the eastern Andean slopes of Perú are among regions of highest biodiversity and endemism in the world and are seriously threatened by landscape alterations. Carabid beetles are useful biological indicators because they are highly speciose, are relatively easy to collect, and most species are flightless with low dispersal. Carabid diversity was studied along an altitudinal gradient in the cloud forests of Manu National Park in southeastern Perú. Carabids collected during a one year period yielded 77 morphospecies, of which 60% are expected to be new species. There was a mid-altitude peak in species richness, probably due to overlap of low and high altitude inhabiting species. Number of rare species was negatively correlated with altitude. Seasonality in the cloud forests of southeastern Perú is defined by wet and dry seasons and there was a significantly higher number of species during the rainy season. Species composition was affected primarily by altitude but also exhibited a significant seasonal effect. The present study was the first attempt of a detailed survey of Carabidae diversity along an altitudinal gradient in the cloud forests of southeastern Perú and will be useful as a baseline for future surveys. As climate change intensifies, cloud forests are expected to retreat, with appropriate habitat shifting to higher altitudes and such baseline data will be important for measuring community shifts.