Soil infectivity and arbuscular mycorrhizal fungi communities in four urban green sites in central Argentina

Abstract

Many cities around the globe strive for create and maintain urban forests to improve human health, welfare and more positive interactions towards nature. Frequently, the only available land has compacted and degraded soils with an altered soil biota. Studies are needed to address soilborne fungi biodiversity especially that of arbuscular mycorrhizal fungi (AMF), essential for plant development. Our aim was to evaluate the AMF community composition and soil infectivity in four urban sites with different disturbance levels and management histories (Córdoba, Argentina). In two urban forests (reference and restored) and two parklands (forested and control), indigenous AMF morphospecies, soil compaction and dominant plant cover were determined together with the soil infectivity in a greenhouse experiment. Results indicated that AMF communities were dominated by Funneliformis geosporum, Glomus brohultii and Rhizophagus intraradices which are considered generalists and resilient to harsh environmental conditions. AMF community composition varied greatly between the undisturbed reference site and the more disturbed parklands. The richness, diversity and soil infectivity were higher in both urban forests compared to parklands and was partially related with the greater variety of plant physiognomies (in restored site), the dominance of arboreal cover (in reference site) and the lowest soil compaction compared to parklands. In the restored forest, AMF richness and diversity were higher compared to the parklands and to the control parkland, respectively. The greater subsoil compaction and the higher percentage of herbaceous cover (mainly monospecific lawn) represented the most disturbed conditions as a consequence of trampling and subsequent soil erosion. We concluded that differences existed between urban forests and parklands sites with variable disturbance intensities and management histories, however, the parameters analysed here do not fully describe the effects of local urban conditions in the composition and infectivity status of AMF in the soil, and hence future research approaches are discussed.