probablyasocialecologist:

The focus should not just be on planting huge numbers of trees, but rather on restoring habitats. There are, after all, grasslands and peatlands that store a significant amount of carbon and yet typically have no trees.

A project’s success also depends on planting the right trees in the right place, otherwise the result can be damaging.

“If you plant trees on carbon rich soils like peat, for example, then more carbon will actually be emitted from the soil than you’re gaining from the growth of the trees,” Hardwick said. “So in that case, you’re actually contributing to carbon emissions.”

[…]

The Kew researchers’ golden rules say protecting existing forests should be the number one priority. When it comes to carbon sequestration and biodiversity, new tree plantations can’t beat complex forest ecosystems that have developed over centuries.

Hardwick stresses that any reforestation efforts should also involve local communities and allow them to derive some economic benefit from keeping the trees intact, for example, through sustainable forestry or eco-tourism.

Reforestation projects should aim to replicate what was naturally there before, because tree species will be more likely to survive if they’re already adapted to an area. Hardwick also recommends planting a mix of native species rather than just one variety.

Monocultures are “vulnerable to fire, storm damage, and to pests and diseases, whereas a mix of species will be more stable,” she said. This resilience will become increasingly important in the future, with forests coming under mounting stress from climate change, drought and insect attacks.