The ‘natural’ ecosystem components of contemporary landscapes provide services that are vital to humans, including atmospheric maintenance, recharging and natural treatment of human-impacted ground water, and natural recycling of nutrients. Natural ecosystems also provide esthetically and economically important recreational opportunities that are impossible to replicate artificially in more human-dominated ecosystems. Fostering the conservation of natural ecosystems is prudent but requires an understanding of the systems’ ecology. Ultimately conservation biologists aim to develop understanding of the functioning and resilience of natural systems, so that biological diversity can be maintained at all levels through protection of the ecological and evolutionary processes that produced it. Members of PICES work on conservation biology at all levels of biological organization and in a diversity of settings, from the remnant wetlands and forests of Indiana to the rainforests and savannas of Africa and Latin America.