Moth diversity along an elevational gradient in southeast Arizona

The factors that influence biodiversity are the focus of much research in ecology and conservation biology. Our research focuses on moth communities along an elevational transect in the Santa Catalina Mountains in Arizona. The differences in climate along this elevational gradient are correlated with changes in plant communities which shift from desert scrub at low elevation to mixed conifer forest at high elevations. I predicted that, due to their herbivorous nature, moth communities will change as do the plant communities. In addition, the Rapoport-rescue hypothesis predicts that moth diversity will peak at an intermediate elevation due to overlap of species ranges towards the middle of an environmental gradient. To measure moth diversity, blacklight traps were placed at four sites differing in elevation and plant community. Moths have been sorted to morphospecies and identified to family with an initial total of 23,566 moths from 998 morphospecies from all three sampling periods. There are substantial differences in species diversity and community composition at different elevations and across sampling periods. The highest diversity generally appears at middle elevations and appears to be a function of increased overlap with species from high or low elevations. These data help us to gain a better understanding of the vast diversity of insect communities on these mountains and how abiotic and biotic factors might influence their distributions.