More than 150 years ago Victorian biologist Charles Darwin made a powerful observation: that a mixture of species planted together often grow more strongly than species planted individually.
There is, as yet, no technology that can compete with forests for absorbing and storing atmospheric carbon dioxide. Darwin’s idea of growing lots of different plants together to increase the overall yield is now being explored by leading academics, who research forests and climate change.
Scientists and policymakers from Australia, Canada, Germany, Italy, Nigeria, Pakistan, Sweden, Switzerland, the UK and the US came together recently to discuss if Darwin’s idea provides a way to plant new forests that absorb and store carbon securely.
Happily, following Darwin’s thinking, there is now growing awareness that the best, healthiest forests are ones with the greatest variety of trees - and trees of various ages.
Forests following this model promise to grow two to fourfold more strongly, maximising carbon capture while also maximising resilience to disease outbreaks, climate change and extreme weather.
In mixed forests, each species accesses different sources of nutrients from the others, leading to higher yields overall. And those thicker stems are made mostly of carbon. Mixed forests are also often more resilient to disease by diluting populations of pests and pathogens, organisms that cause disease.
Darwin’s prescient observation is tucked away in chapter four of his 1859 famous book On the Origin of the Species. Yet it is still so outside of the mainstream thinking on forestry that, until now, little major funding has been available to prompt use of this technique.
It has been said that it is impossible to plant a forest, but it should certainly be possible to design a plantation that will blossom into a forest for future generations. We need forests to be a practical, dependable, and just response to our climate and biodiversity crises, and Darwin has shown us the way.