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Tree seedlings for a reforestation project in Mozambique (symbolic image)
Photo: Nature Picture Library / IMAGO
Mangroves are being planted in Madagascar, and the mountains in Argentina are to be reforested: reforestation projects are considered an important measure against climate change. Billions of euros flow into such projects worldwide. However, they do not always keep what they promise.
In a study in the journal Science, three researchers led by tropical ecologist Kate Parr from the University of Liverpool show that reforestation projects in Africa could destroy valuable ecosystems on a large scale.
The researchers found that countries in sub-Saharan Africa mistakenly want to reforest areas that are savannas or other grasslands. In total, an area the size of France is affected, according to a statement from the university.
Danger to rhinos and wildebeest
“Planting trees in these grasslands can pose a threat to wildlife such as rhinos and wildebeests, as well as to people,” says Parr. In addition, non-native tree species are often used, which further harms ecosystems.
There has been criticism of reforestation projects for a long time. Among other things, they often lead to monocultures of individual plants and not the desired biodiversity. However, so far the problem has not been quantified as precisely as in the present study.
To do this, the researchers examined projects from the Initiative for the “Restoration of African Forest Landscapes,” or AFR100 for short. The Federal Development Ministry is also one of the initiators. 34 countries in sub-Saharan Africa have joined AFR100.
Other continents also affected
The initiative aims to restore ecologically damaged land over a total area of one million square kilometers - almost three times the size of Germany. This should be achieved through planting, natural regeneration and other types of renaturation.
The authors suspect that reforestation of unsuitable areas is also taking place on other continents, for example in India and Brazil. “We urgently need to prevent savannas from being confused with forests,” says Parr.
Sven Günter, an expert in forestry at the Hamburg Thünen Institute, says the study points to an important problem. However, it cannot be deduced from the article that all reforestation measures in Africa are going in the wrong direction. "But he questions projects at the transition zone to savannahs."
Many reforestation projects are based on easy-to-measure parameters such as the number of trees planted as a target for success, says Günter. “It would be more important and more correct to define improved environmental services and improved living conditions for the local population as success factors.”
Problematic definition of forest
Ecologist Manfred Finck from the University of Hamburg considers the UN Food and Agriculture Organization's definition of forest to be particularly problematic. It serves as the basis for many reforestation projects. A forest is therefore an area that the crowns of trees cover at least ten percent.
This ecologically nonsensical definition of forest misdirects funds for restoration, says Günter. "To put it bluntly, every German allotment would meet this criterion."
msk