Invasive Plants, Insects, and Diseases in the Forests of the Anthropocene

Invasive species, non-native plants, insects, and diseases can devastate forests. They outcompete native species, replace them in the ecosystem, and even drive keystone forest species to functional extinction. Invasives have negative effects on forest hydrology, carbon storage, and nutrient cycling. The damage caused by invasive species exacerbates the other forest stresses of the Anthropocene: increased human intrusion throughout natural landscapes, the fragmentation of forests, and a changing climate. Warming will open new areas for ecological invasion while the rising concentration of CO2 (carbon dioxide) in the atmosphere gives many invasives an edge over native species. Storms and extreme climatic events are likely to become more frequent, and these events will facilitate the introduction and spread of invasive species. The cumulative effect of these stressors is impaired ecosystems that can no longer provide all the services on which humans rely. Because these changes are not possible without humans to facilitate the introduction and spread of new species, the impact of invasives is a defining element of the Anthropocene.