Agricultural management, vegetation traits and landscape drive orthopteran and butterfly diversity in a grassland–forest mosaic: a multi‐scale approach

Abstract

Abstract. 1. Most ecological processes at the population and community level act on multiple spatial scales. We identified the influence of grassland management, vegetation traits and landscape on orthopteran and butterfly diversity in 44 meadows located in a forest‐dominated region in the Italian Alps. The meadows were sampled in landscapes characterised by different proportions of woody vegetation and grasslands quantified at 11 spatial scales (95–3000 m). 2. We applied a multi‐scale approach to investigate the scale‐dependent effects of landscape. Then, we built generalised linear models (Poisson and log‐link function) to test simultaneously vegetation traits and landscape variables on insect species richness. 3. High fertilisation and cutting frequency created tall, species‐poor plant communities. This change reduced orthopteran diversity by providing an unsuitable sward structure, and butterfly diversity by creating disturbed plant communities with low species richness and abundance of flowering forbs and host plants. 4. The proportion of woody vegetation had a strong positive effect on the richness of both groups at the smallest spatial scale (95 m), indicating the importance of undisturbed vegetation in the surrounding of mown meadows. The effect tended to disappear with increasing spatial extent. 5. A multi‐scale approach was necessary to identify the effects of landscape factors in this study system. Conservation measures should endorse the maintenance of species‐rich, sparse and short plant communities by reducing organic fertilisation and cutting frequency. However, these schemes should also promote the presence of undisturbed woody vegetation in the immediate surrounding landscape or at least should prevent the complete mowing of large areas.

Orthoptera assemblages of beech stand plots during early succession stages after clearcutting -

“…The number of Ensifera species did not manifest relevant changes during the first and the second year. This result is consistent with the result obtained by Marini et al (2009a) for meadow succession. We contributed to the evidence that in the first two years of the forest colonisation process, Caelifera have a higher indicator value than Ensifera.…”

“…This species was not found yet to occur in closed canopy beech forests (Kulfan et al 2011, own unpublished results). In the second year of the clearcut succession, the typical indicator species was well-flying P. falcata (typical of high herbs and shrubs) recorded also by Marini et al (2009a), Fartmann et al (2012) in early and intermediate succession stages of grasslands. In the second year, typical was also higher abundance in terricolous C. vagans (preferring light forests and bare ground) characteristic of deforested plots (Hochkirch et al 2008).…”

“…Several orthopteran species have been recognised as suitable bioindicators of habitat changes (Marini et al 2008;Fabriciusová et al 2011;Fartmann et al 2012). Progressive encroachment of grassland habitats causes a reduction in the species number in Caelifera (Marini et al 2009a) while in newformed clearcuts in coniferous and mixed forests Caelifera are dominant (Laussmann 1993;Jenni et al 2007). Ensifera are mostly associated with woody plants (Detzel 1998;Ingrisch, Köhler 1998), however, the new clearcuts exhibited only a few species in the first years (Laussmann 1993;Jenni et al 2007).…”

Effects of habitat and landscape features on grassland Orthoptera on floodplains in the lower reaches of the Tisza River Basin

“…Further, intermediate dispersers were excluded from the analyses, as they are often the species whose classifi cation is uncertain (cf. Marini et al, 2009a;2012). The mean number of ovarioles is a rough measure of the reproductive potential of females (Reinhardt et al, 2005) and is generally coded into three categories: low (< 10), intermediate (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) and high (> 25) (cf.…”

“…The effect of landscape composition on assemblages of Orthoptera is often scale-dependent (e.g. Marini et al, 2009a), thus we also aimed to determine the appropriate spatial scale for assessing the amount of grassland habitat. As species with different life history traits often need different environmental conditions, the effects on species richness of various life-history traits were tested separately.…”