Effects of parking lot location on size and physiology of four southwestern U.S. landscape trees

Abstract

This study evaluated effects of two parking lot landscape locations on size and physiology of four regionally common landscape tree species. Tree size measurements were made during August 2001 and 2002 and tree gas exchange and leaf chlorophyll concentrations were measured during April and August 2002. Trees were mostly smaller and leaf gas exchange fluxes were lower for Australian bottle tree (Brachychiton populenus Schott & Endl.), Arizona ash (Fraxinus velutina Torr.), and Chinese elm (Ulmus parvifolia Jacq.) located within narrow landscaped medians surrounded by asphalt compared with similarly aged trees in large landscaped areas along the parking lot perimeters. In contrast, parking lot location had no statistical effect on size of Argentine mesquite (Prosopis alba Griebach) except for diameter at breast height, which was significantly less for trees in the landscaped medians in 2002. Leaf chlorophyll concentrations of all trees located in landscaped medians were lower than those of trees within surrounding landscaped perimeter areas except for Australian bottle tree, which had higher significantly leaf chlorophyll concentration during April when located in landscaped medians. Based on these results, Argentine mesquite appears to be the best of these four tree species for use in commercial parking lot landscapes because its growth and physiological function were least affected by parking lot location. © 2005 International Society of Arboriculture.