Effects of root severance by excavation on growth, physiology of two urban tree species

The purpose of this study was to evaluate the effect of two different levels of root severing on tree growth and physiology. In 2004, 48 horsechestnuts (Aesculus hippocastanum) and 48 European limes (Tilia x europaea) were planted in a sandy-loam soil. In June 2009, the following treatments were imposed: 1) roots were severed only at one side of the tree; 2) roots were severed at two opposed sides of the tree; 3) roots were not damaged (control). Stem diameter, shoot growth, leaf gas exchange, chlorophyll fluorescence, and pre-dawn water potential were measured during the following two growing seasons. Results will be discussed in the presentation.