Human‐induced land cover change threatens species diversity and ecosystem services. The rapid pace of current change makes predicting species’ declines imperative, but leaves little time for thorough study of all species. One solution is to make generalizations about species’ vulnerability to urbanization based on traits common among studied species in decline. To date, most generalizations about traits associated with species’ declines in response to urbanization are based on presence or abundance, or detailed studies of a few species.

Some communities are susceptible to invasions and some are not. Why? Elton suggested in 1958 that the ability of the community to withstand invading species – its biotic resistance – depends on the number of resident species. Later contributors have emphasized the habitat's ability to support species, as well as the contribution of individual species to the resistance. In this study we use information from 184 introductions of Arctic char into Swedish lakes to study both abiotic and biotic aspects of the resident community's ability to resist introductions.

Global defense spending is $US1753 billion annually or approximately 2.5% of the world GDP. Significant time and resources is spent in training 28 million defense personnel worldwide. Much of this training on land takes place within specifically designated military training areas (MTAs). Globally, the size of the MTA estate is likely to be very large, but just how large is unknown. Our preliminary analyses has identified that MTAs cover at least 1% of the Earth's surface.