Understanding the effects of urbanization on biodiversity patterns is essential to conservation decision making in the urban landscape. The greatest threats to biodiversity in the urban landscape are habitat destruction and invasive species. Understanding the patterns of non-native species spread and the consequences of these invasions is critical for the restoration and management of remnant urban habitats.  These patterns must be examined at the landscape and local scales using current and long-term ecological data. I use examples from the New York Metropolitan region, the most densely populated region in the United States, to assess diversity patterns of plants and use this research to address conservation in the urban landscape.

Results/Conclusions

At the landscape scale, alien species increase with greater urban land cover while native species decrease with urban land cover. These patterns of diversity lead to greater differentiation of communities in the most urban areas which may have important consequences for plant metapopulation dynamics. Over time, species that are successful in the urban landscape are non-native deciduous shrubs and vines with fleshy fruits. Consequences of non-native species at the local scale include reduced forest regeneration and forest herbaceous diversity. Long-term data show that forests in urban landscapes do not maintain native species biodiversity. Preservation of remnant habitats in urbanizing regions is not enough to preserve native biodiversity; active management and restoration is imperative to urban conservation. I will discuss recommendations for conservation and restoration of biodiversity by adapting best management practices for non-native plant species and overabundant wildlife populations. Research on the constraints to biodiversity of urban habitats influences management decisions and provides new models for best management practices that include the human component of urban habitats.