Potential for Biodiversity in Shared Residential Yards

Abstract

In urban environments, attention has traditionally been paid to public open spaces. However, private open spaces constitute a significant percentage of the urban area and can thus play a significant role in enhancing biological diversity and facilitating direct interactions between humans and nature within urban settings. According to the 2018 European Union report, 46% of homeowners across Europe live in apartment buildings and yet, most studies that examine the effect of private open spaces on biodiversity focus primarily on yards of single-family housing. The objective of this study is to examine the biodiversity potential offered by shared residential yards focusing exclusively on wild plant species, with the aim of offering planning guidelines that address both the management practices of these lot spaces and their spatial arrangement and qualities. The study was conducted in the city of Givatayim, Israel, in shared residential yards. The basic units (lots and buildings on them) in the city were delineated using a novel approach through a separate characterization of lot sizes and building types, as well as their combination. This process resulted in typologies that cover all residential fabric in the city, allowing systematic sampling. In the spring of 2022, plant surveys were conducted in 56 randomly chosen yards. In these lots, potential open area was measured, and the level of non-maintenance (neglection) was also rated. 74 species of wild plants were found, representing a quarter of all wild plant species in the city. Our results show the combined positive effect of available open space and levels of non-maintenance in these yards on the richness and diversity of wild species. This study highlights the substantial area occupied by residential yards in the city and its role in maintaining biodiversity in urban environments. This study indicates the importance of considering these aspects in architectural and management policies in cities.