Modification of Habitat Quality by Non-native Species

Abstract

Non-native species can affect the quality of habitats available to other organisms and, in turn, the ecosystem services they provide or regulate. Although much research to date has focused on the impacts of non-native species on habitats, the links between habitat impacts and the provision or modulation of ecosystem services have remained elusive. This review illustrates two general kinds of non-native species impact on the abiotic conditions and resources available in a habitat: (1) assimilatory-dissimilatory impacts from the uptake and release of energy and materials and (2) physical ecosystem engineering impacts that arise from structural modification of environments caused by species presence and/or activities. Additionally, it distinguishes between physical ecosystem engineering impacts that result from the creation or modification of physical structures per se (e.g., effects on living space) and those that occur because of the interactions of physical structures and different forms of kinetic energy, such as heat or fluid flows (e.g., wind attenuation by trees). Examples are given to illustrate the co-occurrence of multiple impact pathways and their often compound impacts on single habitat attributes. Finally, the habitat-mediated impacts of non-native species on food and raw materials, climate, and tourism and recreation are discussed as examples of cascading impacts on provisioning, regulating, and cultural services, respectively.