International Day for Biodiversity
Monday, May 21, 2018
Posted by: Rebecca Shoer
Each year on May 22nd the United Nations celebrates the International Day of Biological Diversity. This year, SER and Wiley are commemorating the occasion with a special virtual issue: “Celebrating 25 Years of Action in Biodiversity.” Over 100 articles from 12 journals are freely available for anyone to read, share, and download, including three from SER’s journal Restoration Ecology.
Bee community responses to a gradient of oak savanna restoration practices
Mitchell C. Lettow, Lars A. Brudvig, Christie A. Bahlai, Jason Gibbs, Robert P. Jean, Douglas A. Landis (2018)
Some restoration projects focus on restoring one component of an ecosystem, which will in turn help restore native plant and animal species. Restoring the flow of a river by removing a dam, for example, benefits all of the species living in that river. Oak savannas in the North American Midwest are a rare and fire-dependent ecosystem, which have been degraded by human development and fire suppression. There’s a significant effort in the Midwest to restore these ecosystems using prescribed burns or removing trees (“thinning”). But restoring oak savannas doesn’t only mean restoring native plants – these ecosystems also need native pollinators to survive. Practitioners therefore have to ask: Which techniques will also bring pollinators back to these restored savannas?
Lettow et al. examined different restoration practices to identify which are the most effective at encouraging pollinator populations. Areas that only used prescribed burns had relatively low numbers of pollinator individuals and species – similar to areas that had not been managed at all – while sites that were both burned and thinned had significantly higher populations and species diversity of pollinators. These findings are extremely valuable for restorationists working in the field and can help ensure that future oak savanna restoration projects bring back the species needed for long-term success.
Biodiversity benefits of vegetation restoration are undermined by livestock grazing
David B. Lindenmayer, Wade Blanchard, Mason Crane, Damian Michael, Chloe Sato (2018)
Restoration projects are rarely considered “finished” – they require long-term monitoring to be sure that the work was both successful and that further work isn’t needed. Unfortunately, many restoration projects are not monitored, which means we have no way of knowing if the ecosystem has truly been restored or has again begun to degrade.
In southeastern Australia, Lindenmayer et al. studied 61 restoration areas to see if they had been managed and monitored effectively. Ranching is an important economic activity in this region, and after restoration plantings were completed, many areas were re-opened to grazing. In some areas, grazing was allowed in a controlled way; in others, grazing was totally unrestricted. Researchers found that any kind of grazing reduced the amount of leaf litter, which in turn reduced the number of bird and reptile species. Other effects on vegetation, like trampling, also reduced the number of bird and reptile species. These results are important for future restoration projects in Australia: it’s essential that restored areas have controlled grazing plans, and that the areas be carefully monitored to ensure that even controlled grazing isn’t negatively affecting restored species.
Recovery of mammal diversity in tropical forests: A functional approach to measuring restoration
Mia A. Derhé, Helen T. Murphy, Noel D. Preece, Michael J. Lawes, Rosa Menéndez (2017)
The way in which we measure the effectiveness of a restoration project is just as important as developing the right techniques (Lettow et al.) and monitoring outcomes (Lindenmayer et al.). What metrics or measurements best define success?
Northeastern Australia is renowned for its biological diversity, especially in the rainforests and wet tropics. These incredible ecosystems are under threat, including the unique mammals that call them home. Restoring these habitats not only helps native species, it also re-creates a functioning ecosystem.
Derhé et al. looked specifically at the response and recovery of small- to medium-sized mammals in restored rainforest areas. It’s not surprising that smaller species can survive in areas that have been degraded – they need less food and physical space to survive. In restored ecosystems, the researchers found that larger mammals started to return as the rainforest grew and matured, while non-rainforest species left. As these species returned, they fulfilled important roles in the ecosystem, like eating fruit and spreading seeds that smaller mammals can’t. Although the total number of species didn’t change, the types of species, and the functions they serve, did. As practitioners and researchers work to restore degraded ecosystems, they can’t measure success only by looking at the number of species – the role that these species play in re-establishing a fully functioning ecosystem is just as important. By combining different indicators, we can get a clear picture of just how effective a restoration project is.
The articles featured in this special issue are free to read, share, and download until July 22nd.