Depopulation has led to abandonment of less fertile agricultural lands throughout Europe. Portugal, with its declining population, is a prime example. In the Côa Valley, the abandonment of farmland has been turned into an opportunity for rewilding efforts to create new wilderness. Already the valley has seen the return of many endangered species, such as the wolf and Iberian lynx. The Côa Valley in Portugal is our first area of focus in a new series which will highlight the benefits of depopulation for rewilding efforts in Europe.

By Pernilla Hansson

Several countries in Europe have achieved stable or declining human populations through accomplishments in health care, education, and changing norms, which have lowered fertility rates. Partly as a result, rural depopulation and farmland abandonment are powerful trends across the continent. Between 1970 and 2010, approximately 15% of European farmlands went out of production¹, primarily less productive land such as grazed mountainous areas.

Rural abandonment is often seen as negative, being the product of diminishing livelihoods in the countryside, while continued traditional farming is often believed to play a key role in maintaining an open, highly bio-diverse landscape. These factors have prompted efforts to keep rural populations on an economically unprofitable and often socially declining countryside. The EU provides large environmental subsidies to compensate farmers who are struggling on less productive lands, as well as smaller incentives for farmers to use their lands more sustainably.² However, the subsidies do not effectively target the reasons for rural land abandonment³, and rural abandonment is projected to continue despite EU subsidies.²

In fact, smaller populations and fewer hectares under agricultural production are good things, at least from the perspective of other species. The underlying assumption that perpetual human intervention is needed to retain high biodiversity is false³; while it is true that some species benefit from semi-open, traditionally managed farmland, the overall biodiversity of many areas can be higher on more natural lands, especially if the areas are large. The benefits of traditional agriculture keeping the landscape open can also be provided through other means, such as restoration through wild grazers. So instead of spending money on ineffective compensation measures keeping people in unprofitable situations on the countryside, rural depopulation should be seen as an opportunity for nature to recover, especially in Europe, which today hosts the least amount of wilderness of any continent.¹ This is where the concept of rewilding comes in.

Rewilding aims to restore a dynamic ecological succession in areas that humans have abandoned, by building networks of wild species that together form resilient and self-sustaining ecosystems. This can sometimes be done passively, by allowing nature to recover by its own means, but the process can be slow and assumes that the critical native species still persist in the area or can recolonize from nearby. This is not always the case, especially when landscapes are species-poor or fragmented. The process can therefore be sped up by relocating species into the rewilding area. These species may have previously existed in the area but become locally extinct, or they may have been chosen to fill an ecological role that is currently missing from the ecosystem. The restoration of landscapes has been highlighted as an important goal via the 15^th Aichi Biodiversity Target of the Convention on Biological Diversity, in which 123 sovereign states agreed to restore at least 15% of degraded habitats by this year, 2020.⁴ Abandoned farmland has specifically been identified as contributing significant numbers of restoration sites for rewilding.

In Europe, one of the key players in these endeavours is the umbrella organisation Rewilding Europe.

Rewilding Europe has numerous projects throughout the continent, including a flagship project located in north-eastern Portugal in the Côa Valley. Portugal’s population has been declining since 2009, with fertility rates around 1.37 in 2017.⁵ The region in which the project is located has experienced some of the highest rural abandonment rates in Europe⁶, with the population decreasing since the 1990s.⁷ The decline is likely to continue in the future, with Portugal’s population projected to decline from 10.2 million to 6.9 million by 2100 under a continuation of status quo fertility and net migration level.⁸ Like many other European countries, population density is high in Portugal, and both ecosystems and people can benefit from a so-called depopulation dividend.

When people move out and domestic animals stop grazing, landscapes can become covered in dense undergrowth or scrub. This not only leads to the loss of many species that require open landscapes, but can also lead to increased fire frequency.⁷ The north-eastern part of Portugal already faces large wildfires due to its seasonally dry climate and the presence of coniferous production forests which were planted to replace abandoned farmland in the past.⁹ One of the goals of Rewilding Europe’s Côa Valley project is to reintroduce large wild herbivores to create a mosaic of grasslands between forest patches. Not only do these grasslands act as firebreaks against the frequent fires, but they also create open environments for species threatened by scrub overgrowth. The core area of the rewilding project, the Faia Brava Reserve, is intended to be fully rewilded as a self-regulating ecosystem not dependent on intensive human intervention, while the areas surrounding it may allow for some sustainable use. Reintroduction of wild horses and bovids to the core area has led to the desired mosaic of grasslands in the region, and the success in mitigating wildfires is evident by the Faia Brava Reserve being spared from recent forest fires in north-eastern Portugal.¹⁰

The cattle released into the reserve also play an important role in the Tauros breeding programme, which is trying to recreate a breed of wild cow similar to the extinct Auroch. Aurochs were wild European cattle that were vital for keeping landscapes open¹¹. Due to human expansion and persecution, they were displaced and hunted to extinction centuries ago. Our modern-day cattle were domesticated from the Auroch, which is how the Tauros programme was conceived. Some breeds of cows retain more similarities to the wild Auroch, and an ambitious breeding programme hopes to create a new wild bovine similar to its extinct ancestor. Full success will involve not just recreating the wild cattle, but integrating them into semi-natural landscapes and restoring some of the ecological interactions they took part in centuries ago. Not an easy task, but definitely worthwhile!

Since the creation of the Côa Valley rewilding area in 2011, the area’s wildlife has started to recover. The populations of rabbit and red-legged partridge have increased, both of which are important prey to the Iberian lynx, an endangered species native to the Iberian Peninsula. A recovery of the lynx population on the peninsula has been facilitated by breeding centres in southern Spain and Portugal. Other endangered animals are also reappearing in the rewilding area, such as the wolf and Iberian imperial eagle, which had almost disappeared due to human activities. Wolves, as top predators, are important to the region. They currently live in highly isolated populations, which is one of the problems that the project is trying to amend. The areas where roe deer and red deer roam have expanded in the Côa Valley, and they are both important prey species for the wolves. Continued human population decrease will open up more land for wilderness. Ultimately, the Côa Valley project’s aim is to recreate core rewilded areas similar to the Faia Brava Reserve along the valley, to provide a stepping stone pattern of smaller wild areas and reduce the isolation of populations of wild animals and plants.

The Côa Valley project also involves people that still live in the area, changing the nature of commerce in the region to centre around sustainable agricultural production and ecotourism. Rewilding Europe aims to show how rewilding can be economically viable, to make it a more readily accepted alternative on less viable agricultural lands, as compared to subsidies and tree plantations, monocultures that reduce biodiversity and are susceptible to pest species.

Rewilding in the Côa Valley has been successful for both humans and animals, boasting a mosaic landscape with many different environments for different species. Its success shows that farmland abandonment is an opportunity for nature to reclaim some of the land humans occupied long ago. With restoration and rewilding efforts, the landscape can, over time, become a self-sustaining ecosystem with high biodiversity values. Although the final report on the Aichi Targets is yet to be completed, it seems as if we are far from reaching the goal of 15% restoration of degraded areas.^4,12 If we want the future to allow for more thriving wild nature, depopulation and rewilding will play key roles in ensuring space for other species, as they have in the Côa Valley.

References:

1. Navarro LM. Rewilding abandoned landscapes in Europe: Biodiversity impact and contribution to human well-being. University of Lisbon, Department of animal biology (Doctorial thesis) 2014.
2. Merckx T, Pereira HM. Reshaping agri-environmental subsidies: From marginal farming to large-scale rewilding. Basic and Applied Ecology. 2015 Mar;16(2): 95-103.
3. Navarro LM, Pereira HM. Rewilding abandoned landscapes in Europe. In: Navarro LM, Pereira HM, eds. Rewilding European Landscapes. Cham: Springer International Publishing; 2015. p. 3-23.
4. Secretariat of the Convention on Biological Diversity. Global Biodiversity Outlook 4. Montréal (QC); 2014. 155 p. https://www.cbd.int/gbo/gbo4/publication/gbo4-en.pdf
5. Family Indicators [Internet]. OECD Social and Welfare Statistics (database). Accessed February 12, 2020. Available from: https://doi.org/10.1787/efd30a09-en
6. Rewilding Europe. Western Iberia [Internet]. Nijmegen; Rewilding Europe; Accessed February 12, 2020. Available from: https://rewildingeurope.com/areas/western-iberia/.
7. Almeida AC. Rural abandonment and landscape evolution in the Central Region of Portugal. In: Jones G, Leimgruber W, Nel E, eds. Issues in Geographical marginality: Papers presented during the Commission Meetings 2001-2004. Demographic problems. Grahamstown: Rhodes University; 2007. p. 53-63.
8. Cafaro P, Dérer P. Policy-based Population Projections for the European Union: A Complementary Approach. Comparative Population Studies. 2019 Oct;44: 171-200.
9. Benayas JMR, Bullock JM. Vegetation Restoration and Other Actions to Enhance Wildlife in European Agricultural Landscapes. In: Navarro LM, Pereira HM, eds. Rewilding European Landscapes. Cham: Springer International Publishing; 2015, p. 127-142
10. Allen D, Schepers F. Rewilding Europe: Annual Review 2018. Nijmegen (NL): DPN Rikken Print; 2019. p. 64-65. https://www.rewildingeurope.com/wp-content/uploads/publications/rewilding-europe-annual-review-2018/index.html#
11. van Vuure C. Retracing the Aurochs: History, Morphology & Ecology of an Extinct Wild Ox. Sofia and Moscow: Pensoft Publishers; 2005. 431 p.
12. Birdlife International, Conservation International, RSPB, Nature Conservancy, WWF. Convention on Biological Diversity: Progress report towards the Aichi biodiversity targets. Cancun (MX); 2017. 8 p. https://thought-leadership-production.s3.amazonaws.com/2016/12/07/15/33/12/1119cbd0-b781-4c44-b2b6-cc686af6e8f1/CBD-Aichi-Targets-Progress-Dec2016.pdf