Comparative Analysis of the Occurrence of Entomopathogenic Fungi in Soils from Flower Strips and Lawns in Urban Space

The changing structure of modern cities intensifies anthropopressure, resulting in the need to create plans for the protection of biodiversity in cities. This can be achieved by establishing lawns and flower strips along the streets and maintaining parks and squares in cities, creating green infrastructure and contributing to sustainable urban development. However, this vegetation also requires protection that is safe for the environment and city residents. Entomopathogenic fungi (EPF) are among the most well-known and effective microorganisms that infect plant pests and conduct the disease process leading to their death. The aim of the study was to conduct a comparative analysis of the generic composition of EPF and determine the density of their colony-forming units (CFUs) in soils from flower strips and lawns located along the main communication routes of the city of Siedlce (Poland). Soil samples collected from two sites and two habitats (a flower strip and a lawn directly adjacent to it)—Site No. 1, Wyszyńskiego Street; Site No. 2, Jagiełły Street—in the spring and autumn of 2021/2022 and 2024. At each site within the habitat, three zones (repeats) were designated, spaced approximately 10–15 m apart. Approximately six samples were collected from each replication, and then a mixed sample was prepared. Four genera of EPF were found in the soil samples: Beauveria, Metarhizium, Cordyceps, and Akanthomyces. The location, habitat type, and season had a significant effect on the diversity of individual genera of fungi and the density of colony-forming units (CFUs) in the studied soils. The dominant types of EPF, forming the most CFUs in the soils from the studied flower strips and the adjacent lawns, were Metarhizium spp. and Beauveria spp. It was found that EPF occurred in higher densities in the soil from the studied habitats (flower strips and lawns) in autumn than in spring. Both of these semi-natural habitats constitute forms of urban greenery that increase biodiversity and provide valuable ecosystem services that support sustainable urban development.