Engaging with novel ecosystems

N ovel ecosystems are assemblages of species that have not co-occurred historically; such ecosystems result directly and indirectly from human activities, are relatively stable, and occupy space alongside existing semi-natural or natural ecosystems in the world's landscapes and seascapes. Although recognized for at least three decades, novel ecosystems have heretofore been overlooked and apparently undervalued by both the scientific and conservation communities. As a consequence, they have also been largely ignored in the policy context. Novel ecosystems currently account for around 40% of the ice-free land on Earth, and probably a similar figure in the marine environment, although less work has been undertaken in the world's coastal seas and oceans in this regard. Such ecosystems are a blind spot in global conservation and restoration priorities as well as in discussions of environmental management and sustainable development. This oversight limits our effectiveness in intervening appropriately in ecosystems that are undergoing rapid environmental changes.