Regreening: green is not always gold

Abstract

As the upcoming United Nations Biodiversity Conference in Kunming, China, ushers in the UN decade of ecosystem restoration, regreening efforts are sprouting worldwide. Adding vegetation — expedited by new technologies such as EcoFit, which predicts what trees will thrive in a given environment — can salvage highly disturbed habitats, benefiting native species and offsetting climate change. But when aimed at halting desertification, regreening can have a devastating cost for native ecosystems.<p>Great Green Wall initiatives to plant strips of forest to hold back desert expansion are already under way. These will cross vast arid areas such as the Gobi Desert in Asia and the Sahel in Africa, parts of which have not been very green for millions of years.<br></p><p>Regreening in such circumstances could require irrigation for introduced plants that cannot survive otherwise. Native flora adapted to desert conditions would become disadvantaged. Invasive species, pests and pathogens might take over.</p><p>Baseline biodiversity data should be collected before planting in such arid regions, or we risk losing species before their presence is even known to us. Regular environmental assessments will be important to monitor the effects on native ecosystems.</p>