Environmental and land use determinants of grassland patch diversity in the western and eastern Alps under agro-pastoral abandonment

Abstract

Agro-pastoral decline in European mountain areas has recently caused changes to traditional landscapes with negative consequences on semi-natural grassland conservation and the associated biodiversity and ecosystem services. In the Italian Alps, grassland patches enclosed in a forest matrix are progressively disappearing. Two alpine valleys (Pesio and Pejo), having similar land-use history, were chosen as representative of management conditions of western and eastern Italian Alps, respectively. This study aims at interpreting the effect of abandonment on grassland patch plant diversity, considering land cover changes of the last 60 years, and assessing the role of ecological, topographic, management and landscape configuration on current grassland species richness. The total area of grassland patches has declined by 54% and 91% at Pesio and at Pejo, respectively. Actual grassland patch species richness was mostly influenced by ecological factors, such as quantity of light, soil moisture and reaction, then by topographic features, especially slope, and finally by management intensity. Landscape factors exerted a slightly significant effect on plant diversity. In the two valleys, differences on management practices were detected. Even though in the western valley the conservation of several grazing activities contributed to slow down the process of patch reduction, many species-rich grasslands were generally under-grazed. Conversely, in the eastern valley, despite a denser road network, the stronger decline of grassland patch extension was linked to the hay making decline. At the same time, overuse of grassland patches near farms reduced plant species richness. As a conclusion, plant species richness was weakly related to the area of grassland patches and current and historical landscape configuration were of relatively lower importance than ecological, topographic and management factors, when evaluated at patch-level.

A biodiversity-friendly rotational grazing system enhancing flower-visiting insect assemblages while maintaining animal and grassland productivity

“…After several millennia of land management, agro-pastoral systems have contributed to create a wide variety of semi-natural habitats, often characterised by high biodiversity levels (Orlandi et al, 2016).…”

Balancing Economic Development and Environmental Conservation for a New Governance of Alpine Areas

“…However, nowadays, the Alpine environment is affected in particular by the phenomenon of abandonment of traditional activities over large areas, often accompanied by severe depopulation. The ensuing transformation of the landscape, tied up in particular to the rapid and often irreversible loss of open spaces, is already showing negative effects for the conservation of biodiversity [37][38][39][40][41][42]. In fact cultural landscapes in the Alps have long provided diversified habitats for numerous species, some of which are now endangered.…”

“…In many valleys, moreover, the rapid advance of forest is leading to an extensive homogenization of landscape and a loss of scenic view. This has a negative impact on summer tourism [37][38][39][40][41][42]. Other possible negative implications of abandonment are those connected to the protective functions of the forests: forests that over the centuries have been altered by Man, nowadays need forms of management tailor-made to guarantee their stability, functionality, and a capacity for natural regeneration.…”

Plant species selection by sheep in semi-natural dry grasslands extensively grazed in the south-western Italian Alps

“…After World War II, the decline in labour and in the number of stocked animals in human mountain habitats of Italy, such as semi-natural grasslands, favoured shrub and tree encroachment and led to a loss in plant and animal diversity (Falcucci et al 2007;Lonati et al 2014;Orlandi et al 2016) and to a decrease in the yield and nutritive value of forage (Freléchoux et al 2007). …”