Invasion theory as a management tool for increasing native biodiversity in urban ecosystems.
Human activity has altered ecosystems in some places to a point where traditional restoration, ecosystem management and conservation interventions might not be feasible. This is especially true in densely populated urban areas if ongoing stressors are not ameliorated. As a result, different management options are needed for increasing native biodiversity and ecosystem function in novel urban ecosystems. One strategy for increasing biodiversity in urban ecosystems is to employ invasion biology theory to augment the establishment and proliferation of desirable native species. Invasion hypotheses, including fluctuating resources, enemy release, novel weapons, invasional meltdown (facilitation) and propagule pressure, all provide insights into the mechanisms that increase the establishment and spread of populations. These hypotheses point to specific interventions that can be used in urban restoration and management. Synthesis and applications. Viewing invasion mechanisms as a way to increase native biodiversity in novel urban ecosystems provides a useful reframing for assessing possible applications and management interventions for the most difficult-to-restore landscapes. We argue that conservation managers can use and test invasion hypotheses to inform biodiversity management practices in novel landscapes.