Having a good and healthy natural diversity both in and out of the big urban centers is vital for a lot of “unseen” reasons. Even beyond the direct positive effects of green vegetation and a diverse animal population, there’s also the microbiota diversity we often forget about. Its importance was recently highlighted by a team of scientists led by the University of Adelaide in Australia.
According to the study published in the journal Restoration Ecology, the revegetation of green spaces within cities has the potential of improving the soil microbiota diversity, which can lead to a more biodiverse and natural state with multiple benefits for people as well.
In the study, the scientist looked into the composition of different type of urban green spaces such as parklands, vacant lots, lawns, woodland remnants, vegetated woodlands, and others, all from the City of Playford Council area in South Australia. During this research, they concluded that it’s possible to restore the microbiome of urban green spaces, aka “microbiome rewilding”.
Doing so would mean exposing ourselves to a greater variety of microbiota and thus – help improve and strengthen our immune systems.
Ph.D. Candidate Jacob Mills from the University of Adelaide’s School of Biological Sciences and Environment Institute and lead author of the study explained that, historically, humans used to live in more rural and wild landscapes, which meant we – and our children – were exposed to a richer variety of microbes. Therefore – they used to have much stronger immune systems.
“Urbanisation has radically changed our childhoods. More time spent indoors, poor quality diets and less exposure to wild environments has led to significant increases in non-communicable diseases such as poorer respiratory health,” said Jacob.
“Exposure to biodiverse natural environments carries ecological benefits—green spaces with higher eco-system function give children better exposure to pick things up from soil, for example, there are microbial compounds in soil that reduce stress and anxiety. Put simply, the more diversity in microbiota that children are exposed to the healthier they will grow up,” he followed.
According to the research, woodland remnants and revegetated woodlands also include more plant species native to the region than other green spaces such as lawns and parks. This also means a more diverse microbiota.
“This indicates that the revegetated woodlands soil microbiome had somewhat recovered to its previous more natural biodiverse state,” said Jacob.
“Plant species richness, soil pH and electrical conductivity were the main variables for microbial communities in our study, the more diverse the soil biodiversity the better the eco-system function. Urban spaces low in microbial diversity tend to be more conducive to pathogens and pests, also known as microbial ‘weeds.’ Increasing plant species diversity is important for the structure of microbial communities and increases eco-system function,” he said.
Why does it matter?
All this can seem awfully abstract at first glance but it’s actually very actionable research. According to Mills, the study has implications that can be addressed immediately in urban design plans and urban architecture and councils.
“Our study provides a footing for urban planners and designers to place the environmental microbiome and access to diverse green spaces in their design principles when developing and rejuvenating urban areas.”
“Greater biodiversity comes with the potential to reduce non-communicable disease rates through improved training of our immune systems to fight illness and disease.”
“It could be implemented as a potential preventative health measure, particularly beneficial for lower socio-economic areas and could lessen the burden on our health systems.”
In short, this study is a vital first step toward proving that revegetation improves soil microbial diversity and can create a healthier and biodiverse environment for people. Further studies are also needed and should be coming but even just these results are quite conclusive.
“We hope that this work will inspire further research to understand and measure the impact of microbiome rewilding on human health,” said Jacob.