北京城市公园常见乔木土壤真菌群落特征及影响因素

The characteristics of soil fungal community and effect factors under common tree species in urban parks of Beijing

快速城市化引起的城市环境污染问题日趋严重,由城市中心到城郊往往呈规律性递变趋势。北京城市公园作为城市绿地主体,不仅是城市居民重要的休闲游憩场所,也能在一定程度上反应环境污染,如土壤重金属污染的作用规律。以北京市这一典型大城市为研究区域,根据不同城市公园的建成时间、所处位置和距离市中心的远近选择六个公园作为研究样点,选取公园常见6种乔木下土壤,通过对土壤重金属含量、土壤理化性质以及土壤真菌群落测定和测序,旨在探讨城市公园植被下土壤真菌群落特征(多样性和群落结构组成)以及影响因素。研究结果表明:北京城市公园乔木下的土壤真菌群落多样性、群落组成以及优势类群受到土壤pH值、土壤养分和水分以及重金属铅的调控。其中公园土壤重金属铅含量增加会降低土壤真菌多样性、显著影响优势类群子囊真菌(占真菌群落73%)以及土壤真菌功能类群病原真菌群落组成。研究揭示了北京城市公园土壤真菌群落特征及调控因素,特别是重金属铅对土壤真菌群落的影响,这对提高城市公园科学管理和环境健康具有积极的应用价值。

Fast urbanization has resulted in serious environmental pollution.The polluted pattern distributed from central city to the country.Urban parks are the major areas for the green spaces in Beijing.Urban parks are not only the important public spaces for the leisure of residents and tourists,but also could response to the environmental pollution,such as soil metal pollution.In this study,we investigated soil fungal community under six common tree species in six urban parks that distributed from central city to the country,aiming to understand the characteristics of fungal community,including diversity and community composition,and the effect factors on fungal community.Soil fungal species,soil heavy mental,soil physical and chemical parameters were measured.The results showed that soil fungal community diversity,composition and dominant species were significantly influenced by soil pH,soil nutrient content,soil water content and Pb content through six parks.Soil fungal diversity was reduced with the increase of heavy metal Pb.Moreover,soil Pb content significantly influenced the dominated family species Basidiomycota,which occupied 73%of the total fungal community species.There was close relationship between community composition of soil pathogen and soil Pb content.It indicates a potential threat to human health from Pb pollution and consequent change in pathogens.Overall,our results provide insight into the importance of soil Pb modifying soil fungal communities in urban parks,increasing our knowledge of soil Pb pollution and being helpful for improving urban park management.