Farmland Abandonment as Opportunity for Wilderness Expansion
Farmland abandonment in Europe is a result of the economic and social changes at national, continental and global levels. Abandonment happens especially in areas where land productivity is not sufficiently high to sustain an adequate income for
Fig. 2.3 Farmland abandonment in Europe projected for the year 2040 by the Dyna-CLUE model based on four VOLANTE scenarios. We indicate in how many of the four scenarios land abandonment is found significant across the continent
farmers, even with the support of subsidies (Rey Benayas et al. 2007, see Chap. 1). These land-use changes raise challenges in terms of lifestyles, social structure and biodiversity (Munroe et al. 2013). Thus, predicting these changes has received considerable importance in recent research. We map the areas in Europe where farmland abandonment is projected to take place based on the Dyna-CLUE model (Verburg and Overmars 2009) (Fig. 2.3). For the projections of the social and economic drivers driving farmland abandonment, we used four VOLANTE scenarios describing different development paths towards the year 2040 (Paterson et al. 2012). These scenarios are loosely based on the Special Report on Emission Scenarios (SRES) of the Inter-governmental Panel on Climate Change (Nakicenovic et al. 2000) and they cover the range of socio-economic conditions across the axes of regionalization versus globalization, and willingness versus reluctance against sustainable lifestyle changes at the societal level. We indicate here in how many of the four scenarios land abandonment is found significant across Europe (Fig. 2.3).
How will farmland abandonment affect wilderness value? The answer to this question depends on where farmland abandonment takes place. Many areas of abandonment can be found around mountainous regions such as the Apennines, the Massif Central, the Carpathians, the Balkans, areas of higher altitude and lower productivity that have already experienced abandonment in the past decades (Fig. 2.3). These areas have a low density of human population and a low level of infrastructure development. As the human density will decrease even more, the use of artificial light will decrease as well, but the physical infrastructures will withstand for longer than the outmigration of people albeit with lower intensity of use. Spurred by the already existing infrastructure, many abandonment areas might also see a surge in tourism, biofuels cultivation and renewable energy industries, replacing the agricultural activities (Laiolo and Tella 2006).
From an ecological point of view, farmland abandonment will directly lead to a decrease in harvested PP as grazing and cultivation are projected to drop. This will increase the resources available to wild populations and ecosystems, and vegetation cover will evolve towards a more natural state (Rey Benayas et al. 2007). Previous studies have showed that increased availability of biomass and reduced presence of humans lead to growing numbers of wild herbivores in south Asia (Madhusudan 2004). The recovery of ecosystems to a wilderness state depends on rebuilding natural trophic cascades and networks that are both resilient to natural disturbances and able to sustain key ecosystem functions. In these networks, megafauna and apex predators have a fundamental role, especially in the depleted conditions of the current European biota (Schmitz 2006; Sekercioglu 2006; Johnson 2009; Ritchie and Johnson 2009). For the natural recovery of ecosystems and the return of these species, the presence of source populations is paramount and adjacency to existing core wilderness areas will be a key driver (see Chaps. 4, 8).
We explore the chances for a natural recovery of European fauna by mapping the distribution of megafauna (Fig. 2.4). The results are encouraging for many areas of future agricultural abandonment: megafauna richness is high in the adjacent areas and many wild populations have already begun to recover, especially in the case of mammals (Enserink and Vogel 2006). In the case of birds, the literature reports significant changes in the community patterns due to abandonment, especially negative effects on populations of farmland birds with narrow habitat preferences (Sirami et al. 2008). The correlation between the number of mammal species and the percentage of projected abandoned area in a grid cell is ρ = 0.14 ( p < 0.001) whereas for bird species it is negative at ρ = − 0.15 ( p < 0.001). Thus megafauna mammal species might be in a better position to take advantage of the new resources and space made available by farmland abandonment. We did not consider here the possible spatial autocorrelation of the data because we were interested only in the spatial coincidence between abandonment and megafauna.
However, some of the future abandoned areas have been affected by invasive species, fire suppression practices, and missing trophic links during thousands of years of human use (Proença et al. 2010; Wehn et al. 2011). Thus abandonment may not be sufficient to return these areas to a vegetation close to PNV in a short term without management actions (see Chap. 8). But even in these areas the abandonment will have immediate positive effects on wildlife by reducing human disturbance, increasing landscape connectivity, and releasing ecological processes from human control and thus increasing the wilderness value of the land (see Chap. 1).
Aplet et al. (2000) describe the two dimensional space defined by the axes of freedom and naturalness as a framework for wilderness management. Freedom is understood as the absence of human control over ecological processes (i.e selfwilled) while naturalness is the degree to which ecosystems are close to an accepted ecological benchmark. Such a framework is readily usable for mapping the tradeoffs related to human management in areas affected by invasive and exotic species, thus increasing naturalness but decreasing freedom (Landres et al. 2000; Sydoriak et al. 2000), but also the current views on rewilding as some advocate for serious management commitments in order to achieve a certain perception of wilderness (Donlan et al. 2006). However, we consider that the ultimate aim of rewilding is not to recreate some image of pre-human ecosystems, but to facilitate new, selfregulating systems that appear naturally out of the current conditions. A realistic expectation is that in the absence of human management, the new rewilded areas will form novel ecosystems that share elements with the pre-human past but also integrate current factors. Minimum human management and this new wilderness of natural and self-sustaining ecosystems should be the goal of rewilding.