Suburban Forest Change and Vegetation Water Dynamics in Atlanta, USA
Ecology, Evolution, and Organismal Biology
In the suburban area of northwestern Atlanta, this project tests the hypothesis that tree species composition affects the hydrological response of forest patches and therefore should be considered when assessing the effect of land cover change in the water cycle of suburban areas. In a typical mixed forest fragment a diverse canopy with a rich tree species composition of several deciduous and evergreen tree species was found. The results show a relationship of more than 2:1 water flow under different soil moisture levels, for the broadleaf deciduous (Liquidambar styraciflua L.) compared to the evergreen pine tree species (Pinus taeda L.). The land cover change analysis for the lower Etowah watershed and five counties of northwestern Atlanta from 1992 to 2007 indicates forest cover loss, disturbance within the forest areas, changes from evergreen forest into mixed forest, and localized process of transition from forest towards urbanization. Overall, this research suggests that the water cycle in northern Atlanta may be affected by forest cover decrease, and by changes in the species composition of the forest fragment towards mixed forest.