Low-Intensity Agricultural Landscapes in Transylvania Support High Butterfly Diversity: Implications for Conservation

Abstract

European farmland biodiversity is declining due to land use changes towards agricultural intensification or abandonment. Some Eastern European farming systems have sustained traditional forms of use, resulting in high levels of biodiversity. However, global markets and international policies now imply rapid and major changes to these systems. To effectively protect farmland biodiversity, understanding landscape features which underpin species diversity is crucial. Focusing on butterflies, we addressed this question for a cultural-historic landscape in Southern Transylvania, Romania. Following a natural experiment, we randomly selected 120 survey sites in farmland, 60 each in grassland and arable land. We surveyed butterfly species richness and abundance by walking transects with four repeats in summer 2012. We analysed species composition using Detrended Correspondence Analysis. We modelled species richness, richness of functional groups, and abundance of selected species in response to topography, woody vegetation cover and heterogeneity at three spatial scales, using generalised linear mixed effects models. Species composition widely overlapped in grassland and arable land. Composition changed along gradients of heterogeneity at local and context scales, and of woody vegetation cover at context and landscape scales. The effect of local heterogeneity on species richness was positive in arable land, but negative in grassland. Plant species richness, and structural and topographic conditions at multiple scales explained species richness, richness of functional groups and species abundances. Our study revealed high conservation value of both grassland and arable land in low-intensity Eastern European farmland. Besides grassland, also heterogeneous arable land provides important habitat for butterflies. While butterfly diversity in arable land benefits from heterogeneity by small-scale structures, grasslands should be protected from fragmentation to provide sufficiently large areas for butterflies. These findings have important implications for EU agricultural and conservation policy. Most importantly, conservation management needs to consider entire landscapes, and implement appropriate measures at multiple spatial scales.

High cover of forest increases the abundance of most grassland butterflies in boreal farmland

“…Correspondence: Marjaana Toivonen,Finnish Environment Institute,Natural Environment Centre,P.O. Box 140, Conservation of grassland butterflies requires preservation of grassland habitats combined with a landscape approach (Bergman et al, 2004;Dover & Settele, 2009;Berg et al, 2011;Ellis et al, 2011;€ Ockinger et al, 2012a;Loos et al, 2014). While semi-natural grasslands have become scarce and isolated, butterflies may find complementary and supplementary resources in other open habitats, for example in road verges, fallows, power-line corridors, and forest clear-cuts (Berg et al, 2011;Blixt et al, 2015;Toivonen et al, 2016;Viljur & Teder, 2016).…”

Linking occurrence and changes in local abundance of farmland bird species to landscape composition and land-use changes

“…intensification of agriculture in productive areas and abandonment of farmland in less productive areas, is widespread in Europe and is causing farmland biodiversity to decline (Robinson and Sutherland, 2002). Farmland butterflies, birds and many other taxa associated with traditional low intensity farming have suffered from this polarization of agriculture (Chamberlain et al, 2000;Stoate et al, 2001;Wretenberg et al, 2006;Baldi et al, 2013;Loos et al, 2014). Most studies of farmland biodiversity declines and its relationships to landscape structure and farming practices are "snapshot" studies, i.e.…”

Land management impacts on European butterflies of conservation concern: a review

“…During the twentieth century, mechanisation in both agriculture and forestry brought the era of intensive land use (Young et al 2005;Wrbka et al 2008;Korösi et al 2014), and the traditional land use practices were no longer economically viable (Konvicka et al 2005;Henle et al 2008). Consequently, the land became either intensively used or abandoned, which led to population declines in numerous butterfly species (Dover et al 2010;Horák et al 2013;Loos et al 2014).…”

“…These types of management imitate the traditional way of meadow use (Saarinen and Jantunen 2005;Loos et al 2014). D'Aniello et al (2011), who compared the effects of grazing and mowing for meadow butterflies, found that grazing is generally more effective in maximising the number of butterfly species occurring in meadows; however, low intensity mosaic mowing provides almost equally positive results.…”