Ecological restoration can curb environmental degradation but little is known about how cost effective the approaches are. Enter an EU-funded team of scientists from the UK and Latin America that investigated the cost-effectiveness of renewing a degraded, or even destroyed, ecosystem through human intervention.

The study's findings are published in the journal Proceedings of the National Academy of Sciences (PNAS). The results are an outcome of the REFORLAN ('Restoration of forest landscapes for biodiversity conservation and rural development in the drylands of Latin America') project, which clinched more than EUR 1.7 million through the 'International cooperation activities' budget line of the EU's Sixth Framework Programme (FP6). REFORLAN identified and promoted approaches for the sustainable management of dryland forest ecosystems.

Countries worldwide are introducing varied, yet costly, approaches to restore ecosystems to their former glory. Despite these formidable efforts, information is lacking about whether the investments being made offer more benefits than financial headaches. Where environmental degradation triggers the most problems is in arid and semi-arid areas that in fact cover almost a third of our planet's land surface, and comprise 50% of the surface area of the world's developing countries.

In their study, the experts found that while these areas are dry they play a huge role in Earth's biodiversity. For instance, varied crops and unique species first emerged in these areas. It should be noted that farmers living in these areas also depend on forest resources to support their livelihoods. But overharvesting, unsustainable land use practices, as well as the expansion of rangeland for livestock and urban settlements have severely affected these critical areas. This degradation has had a huge impact on soil fertility, water availability, the livelihoods of local folk, and biodiversity in general.

The team assessed three restoration approaches and compared them using a simulation model of forest landscapes. They found that ecological restoration of dry forests could be cost-effective with the implementation of 'passive' approaches, as they support the natural process of forest recovery. 'Active' approaches, such as tree planting, may not as effective because they could incur other expenses. Nevertheless, some areas assessed in the study would in fact benefit from active restoration approaches. Researchers from Argentina, Chile and Mexico contributed to the study.