Bepaling van die fisiologiese gesondheid van akkerbome (Quercus robur) in Potchefstroom

Abstract

Trees in an urban setting, such as the exotic Oak trees (Quercus robur L.) in Potchefstroom (North West province, South Africa), provide several ecosystem services on individual tree, street and city level. Since urban trees are very favorable to urban life, it is pivotal to study their health and conserve these trees as long as possible. Quercus robur trees in the historic Oak Avenue in this city have been showing a visual decrease in vitality since 1980, for which the cause is still largely unknown. This study aimed to determine the vitality of a section of the trees in the avenue with different types of land cover by determining visual tree conditions and measuring leaf water potential, proline content, nutrient analysis, chlorophyll content and chlorophyll a fluorescence. Data obtained indicated that the parameters and indicators used to determine tree vitality were beneficial in monitoring plant health; however, this data alone does not account for the health decline of the trees. Though trees with land cover of compacted impervious surface showed lower water potentials, this does not indicate water deficit. Other factors should be considered as the cause of vitality decline in these street trees. Oak trees in the avenue in Potchefstroom should be monitored carefully in the future to ensure successful conservation by scientists, city residents and municipal authorities.