Scientists have proposed 10 golden rules for tree-planting, which they say must be a top priority for all nations this decade.
Tree planting is a brilliant solution to tackle climate change and protect biodiversity, but the wrong tree in the wrong place can do more harm than good, say experts at the Royal Botanic Gardens, Kew.
The review of research, published in the journal Global Change Biology, found that in some cases, planned tree planting does not increase carbon capture and can have negative effects.
The 10 golden rules are:
Protect existing forests first
Keeping forests in their original state is always preferable; undamaged old forests soak up carbon better and are more resilient to fire, storm and droughts. “Whenever there’s a choice, we stress that halting deforestation and protecting remaining forests must be a priority,” said Prof Alexandre Antonelli, director of science at RGB Kew.
Put local people at the heart of tree-planting projects
Studies show that getting local communities on board is key to the success of tree-planting projects. It is often local people who have most to gain from looking after the forest in the future.
Maximise biodiversity recovery to meet multiple goals
Reforestation should be about several goals, including guarding against climate change, improving conservation and providing economic and cultural benefits.
Select the right area for reforestation
Plant trees in areas that were historically forested but have become degraded, rather than using other natural habitats such as grasslands or wetlands.
Use natural forest regrowth wherever possible
Letting trees grow back naturally can be cheaper and more efficient than planting trees.
Select the right tree species that can maximise biodiversity
Where tree planting is needed, picking the right trees is crucial. Scientists advise a mixture of tree species naturally found in the local area, including some rare species and trees of economic importance, but avoiding trees that might become invasive.
Make sure the trees are resilient to adapt to a changing climate
Use tree seeds that are suitable for the local climate and how that might change in the future.
Plan how to source seeds or trees, working with local people.
Learn by doing
Combine scientific knowledge with local knowledge. Ideally, small-scale trials should take place before planting large numbers of trees.
Make it pay
The sustainability of tree re-planting rests on a source of income for all stakeholders, including the poorest.
Source: BBC Science