Ghosts of Habitats Past: Environmental Carry-Over Effects Drive Population Dynamics in Novel Habitat

摘要

The phenotype of adults can be strongly influenced bythe environmental conditions experienced during development. Consequently,variation in habitat quality across space and through timealso leads to differences in the phenotypes of adults. This could createcarry-over effects where differences in the natal habitat quality ofcolonizers influence population dynamics in new habitats. We testedthis hypothesis experimentally by simulating dispersal of Triboliumcastaneum from low- or high-quality natal habitat into new patchesof low- or high-quality habitat. Differences in the natal habitat qualityof colonizers altered population growth trajectories and led to carryingcapacities that differed by up to 63% within a habitat type,indicating that patch dynamics are determined by the interaction ofpast and current habitat quality. Interestingly, even after multiplegenerations, the natal habitat of colonizers determined differencesin adult traits that were related to density-dependent populationregulation. These changes in adult phenotype could at least partiallyexplain why carry-over effects continued to alter population dynamicsfor multiple generations until the end of the experiment. Theseresults highlight the importance of variable habitat quality and carryovereffects for population dynamics.