95th ESA Annual Meeting (August 1 -- 6, 2010)

PS 63-154 - Lots of opportunities: Management of vacant lots as a socio-ecological system

Wednesday, August 4, 2010
Exhibit Hall A, David L Lawrence Convention Center
Yvette Williams, Geography & Environmental Systems, University of Maryland Baltimore County, Baltimore, MD

This dissertation research presents the management of vacant lots as a socio-ecological system which features interactions and feedbacks between ecological systems (e.g., vegetation, soil, water) and social systems (e.g., economic, political, and cultural). In accordance to urban ecological theory, anthropogenic drivers dominate natural drivers of ecological system responses. To illustrate this theory, a continuum of vacant lots in which management is considered the key driver shaping vegetation diversity is proposed. This management continuum consists of highly managed community garden lots, intermediately managed “Clean & Green” lots, and unmanaged vacant lots. Vegetation diversity is defined as relative abundances of life forms (i.e., shrubs, trees, herbaceous plants, vines) using the Raunkiaer classification method. With respect to this proposed continuum, this research hypothesizes that: 1) community gardens should show the highest diversity of vegetation due to human preferences and high levels of management, 3) “Clean & Green” lots should show the lowest diversity of vegetation due to intermediate levels of management, and, finally, 3) unmanaged vacant lots should show a diversity that is intermediate community gardens and “Clean & Green” lots due to no management. A sampling design consisting of eight (8) 1 m2 quadrants with eight (8) ½ m2 quadrants nested within the eight (8) 1m2 quadrants was implemented and percent coverage of life forms for quadrants was recorded for eight (8) vacant lot systems. Two (2) community gardens were inventoried in entirety.

Results/Conclusions      Preliminary findings for this poster presentation focus on the largest lot systems for each vacant lot type in the two neighborhoods. Field observations conditions revealed high variability with respect to the management continuum, with vacant lots showing a range of conditions in terms of trash maintenance, mowing and weeding activities. For the eight (8) vacant lot systems, hemicryptophytes (perennials or biennials with runners) were the most commonly recorded life forms for both unmanaged vacant lots and “Clean & Green” lots while phanerophytes and chamaephytes (trees and shrubs) were more often recorded along the perimeter and/or the rear of these lots.  For community gardens, in addition to hemicryptophytes, cultivated therophytes (annuals) were commonly recorded with fewer recordings of phanerophytes and chamaephytes. Nearly forty (40) percent of the quadrants sampled showed vegetation coverage of fifty percent (50 %). Future analyses will determine the extent to which the vegetation diversity of the management continuum conforms to Grime’s (1973) intermediate disturbance hypothesis.