Improving Ecosystems through Rewilding
Dec 9th, 2013 | By Ross Primmer | Category: Environmental Management, FavoritesRewilding is a method of restoring the increased functionality of ecosystems through the re-introduction of flora and fauna into areas where they may once have existed but are not currently present. The concept aims to work with natural processes to restore a more self-sustaining ecosystem that is less reliant on people for continued inputs or management.
The concept was recently explored in the book Feral by George Monbiot. Feral defines the concept of rewilding, provides example case studies of successful rewilding projects, and suggests how the concept might be applied as a future management technique for protected areas in both the United Kingdom and globally.
Benefits of Rewilding
Rewilding offers an alternative method for managing protected sites and open areas. When successful, rewilding can improve biodiversity and produce ecosystems that have enhanced ability to adapt to environmental change. Although a complex issue, rewilding has the potential to offer a more financially viable way to manage land when compared to other more traditional management methods.
Keystone Species
A fundamental element of rewilding is the re-introduction of what are known as keystone species; these being species that perform functions considered essential for the maintenance of an ecosystem. Increased scientific understanding of the interaction between species and, in particular, the effects that keystone species have on the environment is fundamental to the concept of rewilding. The aim of reintroducing keystone species is to re-establish ecological niches that enhance the ecosystem’s ability to regulate itself (e.g. through the predator/ prey relationship). In turn, the re-establishment of ecological niches encourages increased species diversity, and natural regulation requires less intensive management by people.
Land Management
This self-regulation is an important consideration as external factors such as climate change are increasingly modifying natural environments. For example, studies in the United Kingdom have shown that in the last 30 years migratory bird species are increasingly overwintering in more northerly latitudes. ([1]) Rewilding may offer a more flexible approach that allows natural processes to find their own way in the face of environmental change.
At present many protected sites require active land management for the maintenance of specific environmental conditions. In the UK, heathland is actively burnt, as it has been for centuries, to prevent habitat succession to oak woodland. Often these methods bear the legacy of traditional farming techniques and by their very nature require an on-going commitment to maintain the flora and fauna of interest.
In addition, farming on marginal land in the UK (e.g. hill farming) is becoming increasingly uneconomic and has for many years been heavily reliant on subsidies from the EU. Between 1992 and 2002, the annual income of farmers in the Peak District National Park fell by approximately 75%. Without subsidies, farms struggle to achieve a positive income. ([2]) Rewilding offers an alternate way to manage the land that could reduce reliance on such payments in the future.
Even in the best of circumstances, the financial, commercial, and economic pros and cons of rewilding form a complex web that must be carefully thought out before proceeding with a course of action. One thing that is clear: successful rewilding must be done in conjunction with land owners and tenants to generate maximum benefit. The continued generation of income from the land is essential for the maintenance of livelihoods, but income generated after rewilding may be achieved through diversification into other industries such as tourism.
Case Studies
Two successful rewilding projects are described below.
1. Re-introduction of wolves in Yellowstone National Park
In the United States, the wolf was considered to be extinct from Yellowstone National Park by the mid-1930s, but it was reintroduced in 1995. Studies indicate that following the reintroduction of wolves, both vegetation cover and height has increased in the park due to the wolves’ increased predation of elk ([3]). In addition, elk behaviour has changed. Herds are now more mobile and avoid areas where they may be vulnerable to predation, which has reduced the intensity of grazing (3). This has resulted in a number of benefits to other species such as
- beaver through improved habitat (3)
- grizzly bear through improved food availability ([4])
- birds of prey through increased carrion associated with wolf kills ([5]).
Benefits to the physical environment have also been recorded including reduced erosion of river and stream banks ([6]).
2. Re-introduction of beavers in Scotland
Beaver dam construction is known to have a wide range of positive and negative impacts on river systems. Pools created by dams may support increased populations of invertebrates and provide refuge for fish species during periods of low river flow. However, dams may also present obstacles to migratory fish species and cause a localised reduction in water quality ([7]). Overall, beavers are considered to have a net positive effect on river systems ([8]).
In 2009 beavers were reintroduced into river systems in the Knapdale Forest, Argyll, Scotland. The aim of this project was to establish the viability of the reintroduction of beavers in the UK from scientific, economic and cultural perspectives ([9]). Interestingly the beavers are already a tourist attraction and an asset to the local economy ([10]).
Challenges of Rewilding
Despite the many potential benefits, rewilding also presents a range of challenges. Typical obstacles include:
- Stakeholder Conflict – Reintroduction of keystone species can cause conflict with landowners and other stakeholders. Reintroduction of top predators may cause safety concerns with the public and conflict with groups such as game hunters or livestock owners. Public misconceptions present challenges that must be overcome for a rewilding project to be successful. For example, in Scotland landowners initially expressed concerns that reintroduced herbivorous beaver would prey upon commercially important populations of wild salmon.
- Uncertain Outcomes – The outcomes of rewilding are uncertain. This ultimately could result in a species of particular interest being marginalised or lost from a site due to competition. Such change also presents a problem within the EU regulatory framework for designated sites that identify areas of conservation importance by “qualifying interest features.” Qualifying interest features are a set of pre-defined characteristics used to identify specific species and habitats of interest in a designated site. Compliance with the regulations requires the maintenance of habitat or species population at a set level. In short, if the species or habitats within a designated site change it may lose its designated status.
- Invasive Species – Rewilding may also present increased opportunities for non-native species to become established. Natural processes may not be able to regulate populations of invasive species, which may in turn out-compete native species and result in reduced species diversity. In the UK the establishment of rhododendron in oak woodlands is an existing problem. A native of the Himalayas, rhododendron supports no native insect species in the UK ([11]) and inhibits the growth of native plant species through by blocking light from reaching the woodland floor ([12]).
- Land Requirements – Large areas of land may be required for the full benefits of rewilding schemes to be realised. This may result in changes to existing landscapes such as moorland and upland grassland, which have specific economic and cultural values and environmental characteristics. Such interactions are complex and subject to significant debate. In the UK areas of managed upland heath support a range of species that might not necessarily be supported if the land was allowed to revert to a more natural state. Moorland areas also have their own specific cultural and economic values that could be affected by rewilding.
Summary
Rewilding is a management technique that can enhance the biodiversity of designated sites, reduce the need for human management, and offer improved resistance to environmental changes such as climate change. It may also offer an alternate method of income generation for land owners and tenants, especially those who generate little income from their existing farming activities. However, it must be said that defining economic benefits is complicated.
In the EU there are challenges in terms of the existing regulatory framework for designated sites, and opposition from stakeholders will always be an important factor. Effective stakeholder engagement will be as important as scientific considerations for the successful implementation of future rewilding projects in the UK and beyond.
About the Author
Ross Primmer is a consultant in the London, U.K. office of Environmental Resources Management (ERM), where he specializes in environmental impact assessment planning and sustainability. Ross has an MSc in Coastal and Marine Resources Management from the University of Portsmouth, a BSc in Environmental Science from the University of East Anglia, and is an associate member of the Institute of Environmental Management and Assessment (IEMA).
Photograph: Yellowstone Park by Michael Bittner, Winchester, U.S.A.
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Footnotes
([1])Lehikoinen, A., Jaatinen, K., Vähätalo, A. V., Clausen, P., Crowe, O., Deceuninck, B., Hearn, R., Holt, C. A., Hornman, M., Keller, V., Nilsson, L., Langendoen, T., Tománková, I., Wahl, J. and Fox, A. D. (2013), Rapid climate driven shifts in wintering distributions of three common waterbird species. Global Change Biology
([2]) Peak District Rural Deprivation Forum (2004). Hard Times, A Research Report into hill farming and farming families in the Peak District. Available Online: http://www.scribd.com/doc/52830806/Hard-Times-A-research-report-into-hill-farming-and-farming-families-in-the-Peak-District
([3]) Ripple, W.J. Beschta, R.L. (2012). Tropic Cascades in Yellowstone: The first 15 years after wolf reintroduction. Biological Conservation 145 pp 205-213.
([4]) Ripple, W.J. Beschta, R.L. Fortin, J.K. Robbins, C.T. (2013). Trophic cascades from wolves to grizzly bears in Yellowstone. Journal of Animal Ecology
([6]) Wolf, E.C. Cooper, D.J. Thompson-Hobbs, N. (2007). Hydrologic Regime and Herbivory Stabilise an Alternative State in Yellowstone National Park. Ecological Applications 17 pp 1572-1587.
([7]) Kemp, P.S., Worthington, T.A. & Langford, T.E.L. 2010. A critical review of the effects of beavers upon fish and fish stocks. Scottish Natural Heritage Commissioned Report No. 349.
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