Restoration and repair of Earth's damaged ecosystems
A study published in the Proceedings of the Royal Society B, reviewed more than 400 studies of large-scale disturbances — logging, agriculture, oil spills, dam-building, mining, and aquatic nutrient pollution — and their aftermath. It’s the most comprehensive such review to date.
Given that few ecosystems on the Earth have been unaffected by humans, restoring them holds great promise for stemming the biodiversity crisis and ensuring ecosystem services are provided to humanity. Nonetheless, few studies have documented the recovery of ecosystems globally or the rates at which ecosystems recover. Even fewer have addressed the added benefit of actively restoring ecosystems versus allowing them to recover without human intervention following the cessation of a disturbance. Our meta-analysis of 400 studies worldwide that document recovery from large-scale disturbances, such as oil spills, agriculture and logging, suggests that though ecosystems are progressing towards recovery following disturbances, they rarely recover completely. This result reinforces conservation of intact ecosystems as a key strategy for protecting biodiversity.
Recovery rates slowed down with time since the disturbance ended, suggesting that the final stages of recovery are the most challenging to achieve. Active restoration did not result in faster or more complete recovery than simply ending the disturbances ecosystems face. Our results on the added benefit of restoration must be interpreted cautiously, because few studies directly compared different restoration actions in the same location after the same disturbance. The lack of consistent value added of active restoration following disturbance suggests that passive recovery should be considered as a first option; if recovery is slow, then active restoration actions should be better tailored to overcome specific obstacles to recovery and achieve restoration goals. We call for a more strategic investment of limited restoration resources into innovative collaborative efforts between scientists, local communities and practitioners to develop restoration techniques that are ecologically, economically and socially viable.
Restoration ecology is a rapidly developing science, especially as the Earth has undergone dramatic changes that have brought an even greater need to restore damaged ecosystems. With this need have come international and national pledges to restore ecosystems, such as Aichi Target 15 to restore at least 15% of damaged ecosystems by 2020. Based on our results, we recommend the following steps to achieve these targets. First, the goals of specific restoration projects must be clearly articulated so appropriate methods can be selected and their efficacy in achieving desired outcomes evaluated. Second, passive recovery should be considered as a potentially cost-effective option for ecosystem recovery. Third, if rates of passive recovery are insufficient to achieve project goals, then active restoration strategies should be tailored to the local ecological and socioeconomic conditions; these strategies should ideally be compared to a passive restoration approach to help inform future efforts.
This multi-step approach will require additional and more strategic investment in restoration to provide the innovative developments needed to meet the ambitious goals being set out by international, national and local communities. Large government and industry partnerships with scientists, local communities and stakeholders (such as those that occurred to send astronauts to the moon and those currently proceeding for cancer research) will be critical to achieving these goals.
Further reading : Nature, heal thyself: the lessons of restoration ecology
Source: Jones et al. “Restoration and repair of Earth’s damaged ecosystems.” Proceedings of the Royal Society B, 2018