Ornamental Flora and Allergenic Potential in Urban Green Spaces. Comparison in Parks of the Town of Toledo

Abstract

Urban green spaces are important elements providing environmental, social and economic benefits to the population. Nevertheless, allergenicity is not taken into account in selecting species for urban green spaces. In this paper, the Urban Green Zone Allergenicity Index (I_UGZA) has been calculated for the main parks in the town of Toledo . The ultimate purpose of this paper is to assess these spaces’ potential allergenicity and to identify the most important contributors (species) to the index. The results show that elms (family Ulmaceae) are the most abundant trees, whereas plane trees (Platanus orientalis var. acerifolia) and cypresses (family Cupressaceae) are the most relevant contributors to the I_UGZA because of their potential allergenicity. A moderate I_UGZA value (0.3-0.5) was obtained in the three parks with the highest tree density. On the other hand, a low index value (< 0.3) was obtained in the other two parks under consideration, in correspondence with their low tree density and the combination of exotic and native ornamental species. It would advisable when designing new green spaces to combine different species, avoiding large monospecifc surface areas, and to use entomophilous species with low allergenic potential in order to reduce the allergenic risk.