'Grow ecosystems, don't just plant trees!' says new Imperial report on nature

UK policy needs to focus on growing ecosystems, not just planting trees, according to new research from the Hitachi-Imperial Centre.

UK policy needs to focus on increasing the area of diverse forest, incorporating priority species into its environmental plans and designing metrics that reward connected, resilient, self-sustaining ecosystems according to a new briefing note published by the Hitachi-Imperial Centre for Decarbonisation and Natural Climate Solutions and the Imperial Policy Forum. 

The Hitachi-Imperial Centre launched in 2023 and is undertaking a set of joint research projects about decarbonisation and climate repair. The report is its first public output and was launched at a panel event at Imperial. Co-author, Dr Will Pearse, a Reader in Evolutionary Ecology in the Department of Life Sciences, presented its findings and recommendations  based on what is believed to be the world's largest database of how changes in biodviersity affect ecosystem function, with over 220,000 measurements. 

Lessons for businesses and policymakers

 “Carbon sequestration from forests will be much more effective when those forests are biodiverse and UK policy needs to shift from its current focus on counts of, or areas covered by, trees, to increasing the area of diverse forest.” Dr Will Pearse Reader in Evolutionary Ecology, Department of Life Sciences, Imperial College London

Ecosystem functions are the biological, geochemical, and physical processes that take place within an ecosystem, such as the absorption of carbon dioxide by forests. Many of these functions are important for human wellbeing, providing important ecosystem services such as cleaning air, water, and growing food. Drawing on findings from their database, Dr Pearse emphasised that diverse ecosystems capture more carbon.

Further findings from the report were that diverse ecosystems support priority species and are more resilient to environmental change; supporting and sustaining species that provide critical protection from extreme events such as flooding.

A key message from the report was the need to grow urban ecosystems. Maximising the return-on-investment with biodiversity means engaging carefully with urban development. The report recommends that policy makers to raise their ambitions towards growing diverse ecosystems in urban areas so that the critical ecosystem services biodiversity provides can be taken advantage of within urban centres. Planting isolated trees is not enough: we must grow ecosystems within urban areas.

Dr Pearse’s presentation was followed by a discussion with a group of expert panellists, who each provided their own unique perspective on the topic.

Kathryn Brown, Director of Climate Change and Evidence at The Wildlife Trusts, said that there is a lack of recognition of the link between climate and nature: “Government policy doesn't tend to think about [them] together. The new Global Biodiversity Framework has shifted something in government, but we have a problem with how we count carbon, and how we count biodiversity; the approach is often too reductive and that leads to the wrong action being taken. [... ] There is no reason why we shouldn't be focusing on biodiversity as a whole when we think about nature’s role in addressing climate change.”.

Professor James Bullock, Senior Researcher at the UK Centre for Ecology & Hydrology, emphasised the need to consider outcomes other than ecosystem functions when thinking about improving our biodiversity: "Ecosystem services are one key outcome, but not the only outcome we should be focusing on. [...] We also need to move away from specific focus on species to deliver a service, towards creating and restoring a biodiverse world both for all other species and ourselves.”.

Akiko Furuya, Global Ecosystem Protection Specialist at Hitachi Energy,  provided reflections on how businesses might want to approach the issue of biodiversity, especially when their impact might not seem obvious: “The key is to go over the boundary of our control. An industry’s interaction with nature often happens in downstream and upstream ways, for example through the sourcing of products, or consumer use. Businesses therefore need to reflect on how they can collaborate to have impact outside of these boundaries.”.

"Biodiversity and Ecosystem Function: A global analysis of trends" is available to download here

About the Hitachi-Imperial Centre

The Hitachi-Imperial Centre for Decarbonisation and Natural Climate Solutions was established in August 2022 for Hitachi and Imperial to collaborate on fundamental and applied research to drive the transition to net zero pollution. The aim of the Centre is to create novel, cross-domain thinking in the sustainability space to deliver real-world solutions for industry and society.