DIVERSITY OF SPONTANEOUS PLANTS IN PUBLIC GARDENS AT ARID ENVIRONMENTS

Abstract

Public gardens are necessary to improve the quality of life, and wellbeing of urban residents. The objective of this study was to inventory the floristic diversity of spontaneous species in three sites representing different public gardens in southwestern Algeria. To document all spontaneous species present, a total of 64 quadrats were established in August 2021. To express differences in diversity between sites, the species richness and biological diversity index were used. A total of 375 individuals, representing 15 families, 29 genera, and 31 species were recorded. The family Asteraceae is represented by the highest number of species (7 species) followed by Amaranthaceae and Poaceae (5 species), whereas, 10 families are represented by one species each. Therophytes (58.06%) and Chamephytes (16.13%) are relatively high life forms of the vegetation spectra. Phytogeographical analysis of the vegetation in the area revealed the forte representation of cosmopolitan elements. The ranges of diversity indices observed in the three sites were: Shannon- Weaver index (2.99-3.86), Evenness index (0.76-0.88) and Sørensen coefficient (53%-61%). The application of principal component analysis to the data characterized the ecological gradients responsible for the distribution of these taxa at the level of the three sites. This study contains important information on spontaneous plants in arid environments, which should be integrated into the priority of plant genetic resources valorization programs.