Urbanization and Plant Diversity in Residential Gardens: a Case Study in Rize, Turkey

Abstract

Abstract Residential gardens serve as vital urban green spaces, offering sanctuaries for urban biodiversity. Our study aimed to investigate the impact of urbanization on the floral diversity of residential gardens in the coastal city of Rize. We classified plant species into native, non-native, and cultivated natural taxa and examined diversity patterns among species with distinct dispersal abilities. Our findings revealed a high frequency of non-native taxa in residential gardens, representing the predominant plant structures. Across 53 sample plots encompassing 150 residential gardens, we recorded 616 species from 120 families. Herbaceous plants accounted for the majority, comprising 74.4% of the total. The Asteraceae family emerged as the most frequently encountered, with 58 different taxa. Commelina communis L. was the most common native plant, while Camellia sinensis L. represented nonnative species, and Brassica oleracea L. var. viridis stood as the cultivated natural taxon. The diversity analyses were elucidated through the utilization of Shannon and Simpson's indices, while the regression analysis examined its variation in relation to the degree of urbanization. Our study exhibited various patterns of plant diversity across different levels of urbanization in the coastal city of Rize. We observed a positive relationship between the degree of urbanization and the diversity of woody plant species. While urbanization generally leads to a decrease in the abundance of herbaceous plant species, it exhibits different patterns in different sections. Through our investigation of the relationship between urbanization and plant diversity in residential gardens, we have gained valuable insights that can guide the development of effective strategies to conserve and sustain this critical biodiversity within urban environments.