Interaction between genetic diversity and temperature stress on life-cycle parameters and genetic variability in midge Chironomus riparius populations

Abstract

The genetic diversity of natural populations and the increase in global temperature are becoming important issues in ecotoxicological research. We investigated the combined effects of 3 different temperature levels and 6 different levels of genetic diversity on the life history parameters of Chironomus riparius. Inbreeding and loss of genetic variation are major threats to small and endangered populations The reduction of fitness due to inbreeding is more severe under stressful environmental conditions. We show that under even a moderate temperature stress, a decrease in genetic variation has important consequences on the fitness of populations. This indicates that the global temperature increase could have serious effects on the distribution and survival of locally distributed or rare species. © Inter-Research 2007.