Long-term societal trends which include decreasing population in structurally poorer regions and changes in agricultural policies
have been leading to land abandonment in various regions of Europe. One of the consequences of this development includes spontaneous
forest regeneration of formerly open-land habitats with likely significant effects on plant and animal diversity. We assess
potential effects of agricultural decline in Switzerland (41,000 km
2) and potential impacts on the spatial distribution of seven open-land species (insects, reptile, birds) under land-use change
scenarios: (1) a business-as-usual scenario that extrapolates trends observed during the last 15 years into the future, (2)
a liberalisation scenario with limited regulation, and (3) a lowered agricultural production scenario fostering conservation.
All scenarios were developed in collaboration with socio-economists. Results show that spontaneous reforestation is potentially
minor in the lowlands since combinations of socio-economic (better accessibility), topographic (less steep slopes), and climatic
factors (longer growing seasons) favour agricultural use and make land abandonment less likely. Land abandonment, spontaneous
reforestation, and subsequent loss of open-land, however, are potentially pronounced in mountainous areas except where tourism
is a major source of income. Here, socio-economic and natural conditions for cultivation are more difficult, leading to higher
abandonment and thus reforestation likelihood. Evaluations for open-land species core habitats indicate pronounced spatial
segregation of expected landscape change. Habitat losses (up to 59%) are observed throughout the country, particularly at
high elevation sites in the Northern Alps. Habitat gains under the lowered agricultural production scenario range between
12 and 41% and are primarily observed for the Plateau and the Northern Alps.
Keywords Agricultural decline - Habitat suitability maps - Species habitat distribution modelling - Scenarios of land use change - Switzerland