Urbanization and Spatial Aggregation Impair Multifunctionality in Urban Vacant Lots

Urban Farm DB summary

A 2026 study of 69 vacant lots in Yokohama, Japan — a city facing potential population decline — quantifying six environmental factors, five ecosystem functions, and the taxonomic and functional diversity and composition of plants, bacteria and fungi, then analysing ecosystem multifunctionality with structural equation modelling, a multiple-threshold approach and generalized linear mixed models. Environmental factors exerted the dominant influence on ecosystem functions, with soil moisture directly enhancing several functions and average multifunctionality. In contrast, spatial aggregation of vacant lots indirectly impaired them, mediated by increased plant richness and altered fungal composition; urbanization affected all ecosystem functions indirectly and had a direct negative effect on average multifunctionality that intensified at higher multifunctionality thresholds. The authors note that dispersed vacant-lot configurations in less urbanized areas may raise multifunctionality while reducing plant diversity, so planning in shrinking cities has to balance biodiversity conservation against multifunctionality. The data show that greening or cultivating vacant lots cannot be treated as simply 'the more the better'.