Olga Tzortzakaki

Greece is a European hotspot for Orthoptera (378 species), yet it has been scarcely explored. We investigated the distribution and habitat preferences of the species of two endemic Orthoptera genera, Parnassiana and Oropodisma, in the montane ecosystems of central Greece. We conducted field surveys from 2021 to 2024 in 174 sites across seven mountains. The species of both genera preferred habitats above 1500 m, with species-specific preferences for microhabitat parameters: Parnassiana species favored moderate slopes with dense shrub cover, while Oropodisma species favored substrates with intermediate stone cover and relatively high vegetation cover. Species distribution models estimated the area of suitable habitat for Parnassiana to be at 5 km² and Oropodisma at 3.28 km². The Normalized Difference Vegetation Index (NDVI) and potential evapotranspiration were the key environmental drivers of the habitat suitability for both genera. Generalized regression models showed that altitude positively influenced Parnassiana population density, peaking at 2200 m, whereas rock and soil cover negatively impacted Oropodisma population densities. The results emphasize the critical role of montane habitats in sustaining these species and provide essential data for future research and conservation strategies.

This study deals with the future of the traditional agroforestry systems (TAFSs) in the northern Mediterranean Basin. Important productive systems, such as ancient non-irrigated olive groves and extensive silvopastoral systems, from subalpine grasslands to coastal landscapes, are being irreversibly degraded, threatening the bio-cultural heritage of the Mediterranean region, an area recognized as a global biodiversity hotspot. In the midst of the global biodiversity and climate crisis, immediate actions are proposed for the protection and conservation management of TAFSs, within a new EU policy framework. Having the TAFSs of Greece in the spotlight of this analysis, a four-step approach was used in order to review the value of agroforestry in terms of (a) biodiversity (birds, mammals, invertebrates and soil biota), (b) agroforestry landscapes, such as traditional olive groves on terraces and valonia silvopastoral systems, (c) ecosystem services, especially concerning cultural values, and (d) the modern threats to traditional agroforestry. Through this research, problems are highlighted and European policy priorities are defined. Our conclusion is that there is an immediate need to revise the European Union rural, forestry, and environmental policies in the Mediterranean region, following the provisions of the new EU Nature Restoration Law, in order to revive agroforestry landscapes and make them productive and sustainable again for the benefit of rural economies, local communities, and biodiversity, especially in marginal Mediterranean mountainous and island areas, where depopulation and susceptibility to wildfires are major threats.

Aim: Anthropogenic‐driven biodiversity loss can impact ecosystem stability. However, most studies have only evaluated the diversity–stability relationship at the local scale and we do not fully understand which factors stabilize animal populations and communities across scales. Here, we investigate the role of species dispersal ability, climate, spatial distance and different facets of biodiversity on the stability of butterfly populations and communities across multiple spatial scales.Location: Primarily Western Europe.Time Period: 2005–2016.Major Taxa Studied: Butterflies (Rhopalocera) of Europe.Methods: We assembled a continent‐wide database of European butterflies' abundance and used Structural Equation Modelling to evaluate the direct and indirect effects of multiple stabilizing mechanisms. In parallel, we tested the effect of dispersal ability on the stability at multiple spatial scales, using a butterfly mobility index as an indicator of dispersal capacity.Results: Regional stability strongly reflected local stability, which in turn was driven by both taxonomic and functional α‐diversity. Spatial asynchrony was also important for regional stability and it was driven by both functional β‐diversity and metapopulation asynchrony, which in turn increased with spatial distance among communities. We observed a positive effect of temperature on functional α‐diversity and on local stability, whereas precipitation negatively influenced local diversity. Finally, spatial asynchrony contributed more to the regional stability of less mobile species compared to highly mobile ones, indicating that both extrinsic and intrinsic determinants of connectivity impact regional stability indirectly.Main Conclusions: Our results demonstrate the importance of local and regional processes for regional stability. However, the relative contribution of spatial asynchrony and metapopulation asynchrony increases with connectivity loss, especially for less mobile species, indicating that landscape management should be tailored depending on the dispersal capacity of organisms. Both local biodiversity loss and regional biotic homogenization destabilize metacommunities, with potential implications for the reliable provision of ecosystem functions.

Greece is a European hotspot for Orthoptera (378 species), yet it has been scarcely explored. We investigated the diversity patterns of Orthoptera and the ecological mechanisms shaping them by sampling 15 sites (30 plots of 1ha) across five habitats in Mount Mitsikeli, a Natura 2000 site. The mountain is deemed rich (0.4 species/km²), hosting 34 species, including a species of European interest (Paracaloptenus caloptenoides). The grassy openings in the beech–fir forest and rural mosaics were found to be important habitats for Orthoptera, while the mountain grasslands were poorer but hosted a greater abundance of grasshoppers. The three main environmental factors shaping diversity patterns (with an explained variance of 51.34%) were grass height, the cover of woody vegetation and the cover of bare ground. Beta diversity was high (with a Bray–Curtis of index 0.45 among habitats). Species turnover prevailed among all sites and within agricultural land, beech–fir forest and Mediterranean scrub, while nested patterns prevailed within mountain grasslands and mixed thermophilous forest. Conservation actions should target sites in ecosystems driven by species turnover, but primarily the most species-rich sites are driven by nestedness. Such actions should include the implementation of biodiversity-inclusive grazing schemes to hamper forest encroachment and the restoration of mountain grassland quality from cattle overgrazing.

Many hirundine species construct their nests by carrying mud particles from adjacent areas. This study aimed to investigate for the first time the materials that mud-nesting hirundines choose for nest construction from a mineralogical and sedimentological perspective. For this purpose, we sampled nests of three sympatric species, namely the Barn Swallow (Hirundo rustica), the Red-rumped Swallow (Cecropis daurica) and the House Martin (Delichon urbicum), from southeastern Europe. Our results showed that all species tend to use clay minerals as a cement and especially smectite and illite and if these minerals are not present in the adjacent area, they use halloysite, kaolinite or chlorite. The amounts of clay minerals in the nests are generally low indicating that the studied species can accurately identify the properties of the nesting materials. Most of the non clay minerals that they use are the common, easily accessible colourless or white minerals with low specific gravity values such as quartz, feldspars and calcite. Grain size distribution analysis revealed that the amount of clay sized grains in the mud nests of all three species is relatively low, while the amount of larger grain particles decreases when the size of the non clay minerals is small. The Red-rumped Swallow showed an increasing preference for larger grain size particles and quartz, the Barn Swallow for finer grain size particles and calcite, and the preferences of the House Martin are in between the other two species. The three hirundine species present different nest building strategies and depending on the nest architecture, each of them seems to show preference for specific minerals and specific grain sizes.