Over the next century, the human population is expected to increase by 2 to 4 billion in urban areas. There has been an emphasis on exploring the benefits of urban plant communities for improvement of air quality, physical activity, social cohesion, and stress reduction in these areas.
New research has demonstrated that the diversity of microbial communities on the leaves of trees is positively correlated with the gradient of urban intensity in highly populated areas. Credit: Pexels
Studies using high genome sequencing have shown that land use type can have an impact on airborne microbial communities, such as those on plants and in trees. It has also been suggested that the surrounding plant microbial community can influence the microbial communities of nearby hospitals, schools, and residences.
According to the authors of a study published in mSystems, understanding the plant microbiome is important for understanding the influence of anthropogenic pressures on the microbial communities of plants and their potential contribution to the urban microbiome.
The authors of this study sampled three study sites located along an urban intensity gradient on the island of Montreal, Canada in July of 2014. The gradient of urban intensity was assessed based on human infrastructures and presence, movements, landscape use, and electric infrastructure. DNA was extracted from the bacterial communities isolated from mature tree leaves and sequenced using whole genome sequencing.
Their results confirmed the findings of previous studies that the microbiomes of rural and urban communities differ significantly. They also found that the bacterial communities found on the leaves of trees in urban communities are significantly different than those found in “natural” environments such as forests.
In addition, they found that conditions linked directly and indirectly to human actions are potential drivers of the changes in the structure of the microbial leaf community. Isolation from other trees also greatly affected leaf microbiome. The authors have concluded that feedback between human activity and plant microbiomes could shape urban microbiomes therefore; affecting human health.