Tending seedlings in Indonesia. CIFOR/Ryan Woo

Restoring degraded and deforested landscapes to ecological health is a massive challenge, but ambitious tree-planting initiatives, part of efforts to offset human-generated planet-warming carbon dioxide emissions, could actually be exacerbating the problem.

In a new research paper, scientists with World Agroforestry highlight the risks posed by some large scale tree planting initiatives, proposing 10 principles to support landscapes that increase carbon sequestration and deliver benefits for biodiversity, ecosystem services and sustainable livelihoods.

The research published in Global Change Biology journal details some of the most recent ecological research.

Challenges that the researchers suggest pose risks to effective restoration include targets that are possibly too high, displacement of native biodiversity, a growing number of invasive species, fewer pollinators, less food production due to smaller cropland areas, disrupted water cycles, decreasing levels of carbon stored in aboveground biomass and a reduction in soil organic carbon.

“These negative outcomes are mostly associated with the extensive use of exotic monoculture plantations, rather than restoration approaches that encourage a diverse, carbon‐rich mix of native tree species,” the paper says, stating that only a third of commitments under the Bonn Challenge and other schemes aim to restore natural forests.

Under the Bonn Challenge, countries agreed to restore 150 million hectares by 2020 and 350 million hectares by 2030 as part of the New York Declaration on Forests, which was agreed during U.N. climate talks in 2014.