By HENRY OWINO (Senior Correspondent)
A new research study by a team of scientists says that human activities can change the structure and function of the environment with cascading impacts on human health, a concept known as ‘Planetary Health’.
According to the authors of the new study, published in the journal, One Earth, planting trees and management is involved in many of these chain reactions.
The research team set out to understand does agroforestry the
integrated management of trees, crops and livestock alter microclimates,
hydrology, biogeochemistry and biodiversity for the betterment or detriment of
human health in Sub-Saharan Africa?
Apart from the nutritional benefits of increased fruit consumption from trees
in orchards, homegardens and mixed species’ farm-plots, the ways agroforestry
affects human health are little discussed.
To reach a better understanding, the team of 21 researchers, two from
the London School of Hygiene and Tropical Medicine and the rest from World
Agroforestry (ICRAF) based at research centres throughout the Sub-Saharan
Africa region. Analyzed the ways agroforestry affects food and nutrition
security, the spread of infectious disease, the prevalence of non-communicable
diseases, and human migration.
“The diversity of ways that agroforestry influences human health by changing
the environment was perhaps the most surprising result,” said Todd Rosenstock,
leader of the research team.
“I imagined there would be evidence suggesting that
consuming fruit helps with diet-related health concerns. But we also found work
highlighting the benefits of trees for reducing dust and increasing shade; but
also increasing the abundance of mosquitoes.” He compared.
Despite some increased risks of infectious disease, overall, they found that
increased use of agroforestry could improve a diverse range of pressing health
concerns. The authors argue that outcomes are very much linked to specific
contexts, with the effects on human health determined by ecology, tree species
and tree management.
“Agroforestry includes a wide variety of techniques to manage trees, crops and
livestock together, creating lots of options for farmers, ranchers and
communities to select the right trees for the right places and their objective,”
remarked Roeland Kindt, co-author and senior ecologist with ICRAF.
However, the tremendous number of agroforestry options has led to mixed results
when examining why agroforestry is not more widespread, notwithstanding the
benefits. Reasons found in previous studies range from insecure tenure through
conflict over ownership to lack of appropriate seeds and seedlings.
When asked how agroforestry can be further expanded in scale despite the many
obstacles, co-author Kai Mausch replied: “It is already happening. Countries
across Sub-Saharan Africa are making plans and implementing programs to use
trees to mitigate and adapt to climate change, reverse land degradation and
meet energy needs.
We made great progress in the understanding of the scaling
process of relatively simple agricultural technologies like seeds but also of
complex systems like Agroforestry. However, they remain more difficult to scale
and the evidence is not fully consistent.”
That outlook suggests trees indeed should become more widespread, which would
affect Sub-Saharan African lives and landscapes. While this is a promising
future, the authors caution that using agroforestry to improve planetary health
will require a transdisciplinary and multisectoral effort to turn knowledge
into practical and policy action.