Across Europe, centuries of interactions between low-intensity human activities, such as extensive small-scale farming, and the surrounding environment have created what we now call “cultural landscapes”, which provide important ecosystem services and often support a rich biodiversity. However, since the second half of the 20th century several countries have witnessed large-scale social changes that have led to modifications in these landscape dynamics. There is growing evidence that this can also entail an impact to biodiversity, as the intermediate disturbance that can benefit species is lost or replaced by more disruptive activities (such as intensive vs. extensive farming: MacDonald 2000).
These same dynamics may be a leading factor in the disappearance of the yellow-bellied toad Bombina pachypus from peninsular Italy (Figure 1). The species has declined in the last thirty years and is now listed as Endangered by the IUCN. However, the causes of this decline are still unclear: in Liguria, northern Italy, habitat loss is believed to be the main driver, with recent systematic monitoring for the amphibian fungal disease chytridiomycosis failing to detect signs of this devastating pathogen (Canessa et al, in press).
Figure 1. The Apennine Yellow-bellied toad Bombina pachypus (photo: A. Arillo)
In natural sites, flooding and desiccation are natural processes, and where they continue the species still occurs in relatively large numbers. On the other hand, in artificial sites disturbance is provided by traditional management (cleaning and dredging) (Figure 2): after land parcels or traditional practices are abandoned, sites degrade rapidly and become unsuitable. Significantly, in our study all artificial sites that had been abandoned by farmers immediately prior to or after 2005 did not host toad populations when we re-sampled them. Artificial sites that were still maintained (and therefore disturbed) were still occupied by the species.
Figure 2. The transition between a maintained artificial water body (left) and an abandoned one unsuitable for yellow-bellied toads (right) can occur within a few years (photos: S. Canessa)
The conservation of culture and biodiversity needs is deeply connected in many parts of Europe: this requires an approach that is somewhat contradictive of the usual point of view of human activities as inherently negative. However, where large scale processes such as land abandonment are involved, they may be difficult to reverse by conservation funding alone. However, where traditional practices are still widespread, it is imperative that social and environmental planning should take into account the impacts on biodiversity that the abandonment of such practices may entail.
Canessa, S.a, Oneto, F.b, Ottonello, D.b, Arillo, A.b and Salvidio, S.b (2013). Land abandonment may reduce disturbance and affect the breeding sites of an endangered amphibian in northern Italy. Oryx, 47(2): 280-287
a ARC Centre of Excellence for Environmental Decisions, School of Botany, University of Melbourne, 3010 Victoria, Australia
b Dipartimento di Scienze della Terra, dell’Ambiente e della Vita, University of Genoa, Genoa, Italy
Canessa, S., Martel, A. and Pasmans, F. (in press). No detection of chytrid in first systematic screening of Bombina variegata pachypus (Anura: Bombinatoridae) in Liguria, northern Italy. Acta Herpetologica.
MacDonald, D., Crabtree, J.R., Wiesinger, G., Dax, T., Stamou, N., Fleury, P., Gutierrez-Lazpita, J. and Gibon, A. (2000) Agricultural abandonment in mountain areas of Europe: environmental consequences and policy response. Journal of Environmental Management, 59: 47-69.
Warren, S.D. , Büttner, R. (2008): Relationship of endangered amphibians to landscape disturbance. The Journal of Wildlife Management 72: 738-744.
Contributed by Stefano Canessa, ARC Centre of Excellence for Environmental Decisions, School of Botany, University of Melbourne, 3010 Victoria, Australia
Personal blog: http://www.canessas.wordpress.com