A cultivated environment: exploring the global distribution of plants in gardens, parks and streetscapes
Kendal, D and Williams, NSG and Williams, KJH, A cultivated environment: exploring the global distribution of plants in gardens, parks and streetscapes, Urban Ecosystems, 15 pp. 637-652. ISSN 1083-8155 (2012) [Refereed Article]
Plants cultivated in gardens, parks and streetscapes are becoming increasingly important to peoplesí experience of biological life, and have been the recent focus of research in ecology, invasion biology, human geography and sociology. However patterns of distribution have not previously been explored at a global scale. In this study, global patterns in the distribution of cultivated floras were explored to determine the significance of biophysical and social factors driving species distributions. The taxonomic similarity of 72 published species lists was examined, covering a wide geographic and climatic range and a variety of land uses. Cultivated floras across urban and rural settlements were found to be very different and unsurprisingly to be strongly filtered by temperature. However we found that human behaviour may overcome other physical drivers of plant distribution such as rainfall in some instances. Social factors were also found to be important. Having a different dominant language (a proxy for cultural background) and difference in GDP per person (a proxy for household income) were also related to the dissimilarity of cultivated floras. Differences in both the social and physical environment are related to floristic differences between cities. However, we recognise that other factors identified in the literature but unsuited to meta-analysis, may also influence the composition of cultivated landscapes. These include changes in policy relating to the provision of street and park vegetation, the availability of plants from nurseries and the preferences of influential gardeners and landscape designers. The significance of the relationship between temperature and species composition suggests that cultivated floras are likely to change in response to climate change. The high level of dissimilarity observed between settlements suggests that patterns of potential naturalisation of cultivated plants are likely to be more complex than currently accepted.