Individual study: Vascular plant and Orthoptera diversity in relation to Alpine grassland management and landscape composition, southern Trento Province, Italy
Marini L., Fontana P., Scotton M. & Klimek S. (2008) Vascular plant and Orthoptera diversity in relation to grassland management and landscape composition in the European Alps. Journal of Applied Ecology, 45, 361-370
In the European Alps, agricultural intensification has led to loss and fragmentation of semi-natural habitats e.g. herb- and invertebrate-rich alpine meadows. The aim of this study was to determine the effects of grassland management and landscape composition on local diversity patterns of vascular plants and orthopterans (grasshoppers and crickets) in Italian Alpine hay meadows.
Study sites: The study was carried out in 2006 in the districts of Low Valsugana, High Valsugana and Val Lagarina (601-1,273 m a.s.l.), southern Trento Province, north-east Italy. Forty-five hay meadows were selected to provide a range of management practices and different landscape composition (i.e. varying urban, grassland and forest elements).
Hay meadow management: Three groups of management regimes (15 fields each) were defined by the amount of nitrogen (N) fertilizer applied and cutting frequency:
i) extensive - no fertilizer or very low level N application (< 25 kg N/ha/yr), cutting once in July;
ii) low intensive - N application < 100 kg N/ha/year; cut twice (June and August);
iii) intensive - N application < 300 kg N/ha/year; cut twice (June and August).
Plant and orthopteran diversity: Vascular plant diversity was estimated once before the first cut and once before the second cut. Orthoptera were sampled over two summer visits (19-27 July and 23-29 August) i.e. during the periods of maximum activity and density.
Vascular plant and Orthoptera diversity were affected primarily by grassland management rather than landscape context. Unsurprisingly, extensive meadow management was best for conserving high species richness. Plant communities of the intensively managed meadows were typically dominated by a few nitrogen-demanding and competitively aggressive ruderals and grasses. In each of the management types the following were recorded: extensive - 161 plant species (77 exclusively; species richness 37 spp./100 m²); low intensive - 89 (four exclusively; 30 spp./100 m²), and intensive - 92 (nine exclusively; 21 spp./100 m²).
In intensively-managed meadows Orthopteran communities were depauperate comprising a few abundant Caelifera (e.g. meadow grasshopper Chorthippus parallelus), whilst crickets (Ensifera) had very low densities: extensive meadows - 36 species found (10 exclusively; 12 spp./400 m²); low intensive 25 (five exclusively; 10 spp./400 m²); and intensive 19 (two exclusively; seven spp./400 m²).
Plant diversity patterns were not significantly related to any of the landscape composition variables measured; a high proportion of urban elements and grassland in the surrounding landscape (radius 500 m) negatively affected Orthoptera species richness.
Note: The compilation and addition of this summary was funded by the Journal of Applied Ecology (BES). If using or referring to this published study, please read and quote the original paper, this can be viewed at: http://www3.interscience.wiley.com/cgi-bin/fulltext/119392050/PDFSTART