Boom-bust economics and vegetation dynamics in a desert city: How strong is the link?

In cities, human activities such as supplemental watering and plantings of ornamental species are thought to decouple vegetation diversity from biophysical processes. Consequently, socioeconomics may arguably be one of the most important factors influencing the pattern and dynamics of vegetation in urban ecosystems. Socioeconomic disturbances, like The Great Recession of 2007 to post-2010, disrupt normal social and economic activity causing changes to the ecology of cities that have yet to be examined. Using the rapidly growing metropolitan area of Phoenix, Arizona, USA, as a case study, we explored the dynamics of residential vegetation diversity from before to after The Great Recession. Our findings linked changing plant community composition and increasing richness with socioeconomics of the housing boom, (from 2000 to 2006) followed by the Great Recession (from 2007 to post-2010). Specifically, we found that the housing market boom-bust episode acted as a socioeconomic driver of overall plant community composition. However, plant species with annual reproduction strategies were instead linked to the previous winter's precipitation and did not respond to socioeconomic disturbance, a behavior expected in native desert plant communities, but not from constructed and managed urban plant communities. This study demonstrates how disturbances to socioeconomic components of ecosystems can result in changes to plant community diversity and dynamics; though, biophysical drivers remain important to short-lived annual species regardless. Undertakings that aim to maintain or increase urban biodiversity for ecosystem services and human well-being need to systematically approach the effects of socioeconomic fluctuations on urban flora. Cross-site comparisons will be key to developing a broader understanding of these coupled dynamics across older and newer, mesic and arid, and growing and shrinking cities.