Freshwater ecosystems provide important services to human societies, such as water, food, regulation of hydrological extremes, pollutant attenuation, and carbon sequestration. As…
PLOS ONE has an open Call for Papers on Rewilding & Restoration, with selected submissions to be featured in an upcoming Collection. We hope to feature a diverse range of multidisciplinary and interdiscipinary research, and are especially keen to encourage studies from ecoregions and voices that are underrepresented in the restoration literature.
We asked three of the Guest Editors- Karen Holl, Benis Egoh, and Chris Sandom- to share their thoughts on the past, present, and future of research in rewilding and ecological restoration.
Why is rewilding and restoration an important area of research? How is it relevant to contemporary society and the challenges we face?
KH: Over the past few years there have been a growing number of commitments at the global, national and regional scale to restore ecosystems to conserve biodiversity, sequester carbon, improve water quality and supply, and provide goods and services to people. For example, the United Nations has declared 2021-2030 the Decade on Ecosystem Restoration and the Bonn Challenge aims to get countries to commit to restore 350 million hectares of forest (an area roughly the size of India) by 2030. So there is a dramatic need for ecological and social studies of how to successfully scale up restoration to the large areas proposed.
BE: Restoration is important because it is the only means through which we can recover nature that has been lost. However, it is important that we understand what, how and where we want to restore. One of the biggest challenges is how to measures restoration success. In my opinion, many times we set out to restore with an objective in mind without thinking of the trade-offs and how to measure our success.
CS: We are about to enter the UN’s Decade on Ecosystem Restoration (2021-2030). It has been declared to ‘massively scale up the restoration of degraded and destroyed ecosystems’ to help ‘fight the climate crisis and enhance food security, water supply and biodiversity’. It is an exciting prospect! But, there is a danger this decade will be squandered if restoration practice is not combined with effective rewilding and restoration research. We need this science to improve our understanding of how to increase the probability of rewilding and restoration success across different ecosystems and circumstances. If we can do the science right, we will make restoration more effective and efficient, meaning limited resources can be put to the greatest use in our efforts to meet the big sustainability challenges.
How does your own research fit into this theme?
KH: For the past 25 years, I have studied how to restore forests, primarily in Latin America, and a range of ecosystems in California and worked with practitioners on how to implement the results of this work. I hope that the papers in this Collection will provide additional insights and case studies that complement my recent Primer of Ecological Restoration book and that I can use in teaching.
BE: In my research, I investigate the trade-offs and benefits from restoration and how we can plan to minimise these trade-offs- where should we be restoring to get the biggest benefits while minimizing cost?
CS: My research is focused on rewilding, in particular, trophic rewilding. I want to understand how reintroducing large mammals can help ecosystems restore and maintain themselves. I typically look at how carnivores influence herbivores, herbivores influence vegetation structure, and how this effects ecosystem functioning and the delivery of ecosystem services like mitigating climate change. I do my best to cover multiple spatial and temporal scales, covering local field projects, such as the Knepp rewilding project, to global macroecological research and looking at snapshot comparisons in the present to palaeoecology that spans millennia.
What trends or exciting advances have you seen in your field recently?
KH: There is increasing recognition of the importance of socioeconomic considerations. The scale of studies is also slowly increasing, which is important. There is increasing recognition that we are restoring in a time of rapid global change and that our restoration approaches need to reflect this reality.
BE: The most exciting advances to me is the research around financing restoration and how a variety of sectors including insurance companies are coming on board to fund restoration measures. Beneficiaries of restoration projects are starting to understand the benefit they get from nature through research on ecosystem services. Also, our research on planning restoration to achieve multiple benefits moves away from traditional ad-hoc restoration. However, implementation of restoration plans is still very low because restoration is mostly opportunistic.
CS: Two papers I’ve really enjoyed this year are “The megabiota are disproportionately important for biosphere functioning” by Brian Enquist and colleagues and “Trophic rewilding revives biotic resistance to shrub invasion” (paywall) by Jennifer Guyton and colleagues. The first provides a theoretical underpinning for the importance of ‘megabiota’ – the largest plants and animals – for driving biosphere scale processes like ecosystem total biomass, resource flows and fertility using metabolic scaling theory. The second reports that in Gorongosa National Park, Mozambique, a decade of large ungulate population recovery has reversed the expansion of an invasive woody species, which had established after the megafauna had been massively reduced in the preceding decades. I think these papers offer important advances in the theory and empirical evidence supporting trophic rewilding.
How does interdisciplinarity contribute to progress in this area of research?
KH: Restoration ecology is an inherently interdisciplinary field. Even if we knew everything about the science of the physical and ecological processes needed to restore ecosystems, which we don’t, success of ecological restoration projects depends critically on engaging stakeholders throughout the process, from planning to implementation to maintenance and monitoring. We need good examples of projects that have succeeded in addressing legal, economic, and social considerations to result in ecological restoration projects that last beyond the first few years.
BE: Successful restoration requires information on land suitability from soil scientists, cost of restoration from an economic perspective, type of species and habitat requirement from ecologists, consideration of the social aspect and careful planning to maximize benefits. Interdisciplinarity is therefore at the center of research in restoration.
CS: Interdisciplinary research is absolutely essential in rewilding and restoration. While the practices of rewilding and restoration seem to be focused on ecology, the factors governing success or failure are typically more about people. As a result, we need social scientists, psychologists, economists, researchers across the humanities as well as practitioners and indigenous and local knowledge to develop and implement innovative rewilding and restoration science.
What advice would you give to a student keen to work in this area of research?
KH: I tell my students to get training in both the natural and social sciences. It is important thing to get hands on experience working on restoration projects to understand the constraints and opportunities of on-the-ground projects and to collaborate with practitioners on designing research questions that are both scientifically rigorous and will help improve restoration efforts.
BE: This is an exciting area of research with a variety of directions that can be pursued.
CS: Think big and get creative. Rewilding and restoration are systems science. They are all about understanding how all the parts of nature, including people, fit together and function. You need to think about the system as a whole, and how whatever it is you are researching fits into that bigger picture. You need to address the question: what are the potential cascading effects of any particular rewilding or restoration action? Because nature is a complex system it is dynamic and chaotic, so you need to be comfortable with uncertainty and work in probabilities. Also, we still have a lot to learn so get creative and embrace diversity in thinking and practice. It is an exciting and challenging field to work in, it makes it very rewarding!