Abstract
To understand how diversity is distributed in space is a fundamental aim for optimizing future species and community conservation. We examined in parallel species richness and beta diversity ...components of nine taxonomic groups along a finite space, represented by pastured grasslands along an elevational gradient. Beta diversity, which is assumed to bridge local alpha diversity to regional gamma diversity was partitioned into the two components turnover and nestedness and analyzed at two levels: from the lowest elevation to all other elevations, and between neighboring elevations. Species richness of vascular plants, butterflies, beetles, spiders and earthworms showed a hump-shaped relationship with increasing elevation, while it decreased linearly for grasshoppers and ants, but increased for lichens and bryophytes. For most of the groups, turnover increased with increasing elevational distance along the gradient while nestedness decreased. With regard to step-wise beta diversity, rates of turnover or nestedness did not change notably between neighboring steps for the majority of groups. Our results support the assumption that species communities occupying the same habitat significantly change along elevation, however transition seems to happen continuously and is not detectable between neighboring steps. Our findings, rather than delineating levels of major diversity losses, indicate that conservation actions targeting at a preventive protection for species and their environment in mountainous regions require the consideration of entire spatial settings.
Since the end of the nineteenth century, socio-economic changes have greatly altered the Central European landscape and the structural and functional quality of habitats. Urban sprawl areas have ...appeared, a reduction of multiple forest uses has resulted in the densification of forests and agricultural land use has changed fundamentally through specialisation and intensification. Many of these changes affect biodiversity. To determine the important drivers of spatio-temporal dynamics of the population of 28 game species, we first considered a total of 130 potential explanatory variables. Second, we aggregated the main drivers of single-species models for habitat guilds. Third, we evaluated the results to aid in the development and implementation of mitigation measures for different ecoregions. We used harvest data as a surrogate for population density from 1875 to 2014 in South Tyrol, Italy. In generalised linear models, we used environmental characteristics such as climate, landscape diversity and structures, land cover, hunting, wildlife diseases, competition and predation, land-use type, and intensity (including pesticide use) as explanatory variables to predict the spatio-temporal dynamics of game species. The important drivers are land use and management changes (intensification in the agriculturally favourable areas, extensification or abandonment in the unfavourable areas) as well as associated changes in the landscape features, diversity and structure, and hunting management. Climatic variables, interspecific competition and diseases only play a subordinate role. The dynamics of the habitat guilds and their drivers provide concrete indications for measures to maintain or improve the habitat quality for the investigated species. Particularly important are transfer payments to ensure extensive agricultural use, increasingly through the takeover of personnel costs, but also for the installation of an independent body that monitors and evaluates the effectiveness of the measures.
The severe biodiversity decline in European agricultural landscapes demands a specific evaluation of the various land-use practices. Many butterflies in Europe, as an important ecological indicator ...and pollinator taxon, require human interventions to sustain their populations in cultivated landscapes. However, land-use changes and management intensification are currently responsible for their decline. In this study, we compare butterfly communities occurring on 93 sites in seven widely distributed land-use types, viz. extensive meadows and pastures, semi-intensive meadows, vineyards, arable land, settlements and apple orchards. We recorded a high butterfly diversity in supposedly high nature-conservation value (HNV) grasslands (extensive meadows and pastures). All other land-use types showed significantly lower diversity, with decreasing diversity from semi-intensive meadows to apple orchards. Moreover, functional traits uncovered a general trend: extensive grasslands supported communities of more specialized and sedentary species whilst all other non-HNV land-use types showed communities characterized by mobile generalists. Community composition was driven by the land-use type and explained by plant-based indicator values for nutrients and light and temperature variables. Important life-history traits further correlated with site variables confirming the shift from specialists to generalists along increasing land-use intensity gradients and the effect of the thermal environment on phenological traits. We found supporting evidence for the effectiveness of regional Agri-Environmental Measures for butterfly conservation in European cultural landscapes and for the European conservation schemes to focus at least partly on the preservation of HNV grasslands with extensive management. Furthermore, we clearly show the poor ecological state of butterfly communities in more disturbed land-use types (including urban areas) and propose adopting measures to improve butterflies’ conservation in these environments.
Understanding the effects of landscape composition and configuration, climate, and topography on bird diversity is necessary to identify distribution drivers, potential impacts of land use changes, ...and future conservation strategies. We surveyed bird communities in a study area located in the Central Alps (Autonomous Province of South Tyrol, northeast Italy), by means of point counts and investigated taxonomic and functional diversity at two spatial scales along gradients of land use/land cover (LULC) intensity and elevation. We also explored how environmental variables influence bird traits and red-list categories. Models combining drivers of different types were highly supported, pointing towards synergetic effects of different types of environmental variables on bird communities. The model containing only LULC compositional variables was the most supported one among the single-group models: LULC composition plays a crucial role in shaping local biodiversity and hence bird communities, even across broad landscape gradients. Particularly relevant were wetlands, open habitats, agricultural mosaics made up of small habitat patches and settlements, ecotonal and structural elements in agricultural settings, and continuous forests. To conserve bird diversity in the Alps, planning and management practices promoting and maintaining small fields, structural elements, and a mosaic of different LULC types should be supported, while preserving continuous forests at the same time. Additionally, pastures, extensively used meadows, and wetlands are key to conservation. These strategies might mitigate the impacts of global change on bird diversity in the Alps and in other European mountain areas.
Traditionally managed mountain grasslands are declining as a result of abandonment or intensification of management. Based on a common chronosequence approach we investigated species compositions of ...16 taxonomic groups on traditionally managed dry pastures, fertilized and irrigated hay meadows, and abandoned grasslands (larch forests). We included faunal above- and below-ground biodiversity as well as species traits (mainly rarity and habitat specificity) in our analyses. The larch forests showed the highest species number (345 species), with slightly less species in pastures (290 species) and much less in hay meadows (163 species). The proportion of rare species was highest in the pastures and lowest in hay meadows. Similar patterns were found for specialist species, i.e. species with a high habitat specificity. After abandonment, larch forests harbor a higher number of pasture species than hay meadows. These overall trends were mainly supported by spiders and vascular plants. Lichens, bryophytes and carabid beetles showed partly contrasting trends. These findings stress the importance to include a wide range of taxonomic groups in conservation studies. All in all, both abandonment and intensification had similar negative impacts on biodiversity in our study, underlining the high conservation value of Inner-Alpine dry pastures.
The global decline of biodiversity has affected European forests, involving many tree species and forest-dwelling threatened animals. An integrated approach linking forest structure and multi-taxon ...diversity is increasingly needed to maintain the multifunctionality of forest ecosystems. We investigated the relationship between forest structure, deadwood elements, canopy attributes, and tree-related microhabitats on bat and bird communities in the north-eastern Italian Alps. We collected forest attributes, bats, and bird data on 40 forest plots encompassing the diversity of forest types. To assess the different contributions of each forest attribute variables we performed a two-step statistical analysis using generalised and linear models, including bat and bird taxonomical and functional diversity indices as response variables. Our findings reveal that bats and birds respond differently to variation in forest structural characteristics. Specifically, bat species richness was higher in forests with both higher standing tree and lying deadwood volume. The Shannon diversity index for bird community was higher in forests with high volumes of coarse lying deadwood and stumps. Moreover, plots with mature trees, gaps, and heterogeneous diameter distribution fostered the presence of generalist species of bats and birds, while the abundance of tree-related microhabitats was not significant for these two taxa. This study demonstrates that the optimal habitat conditions for bats and birds in Alpine forests are multifaceted. Promoting distinctive elements within forest stands and a complex forest structure through adaptations in forest management interventions would enhance the conservation of multi-taxon forest biodiversity.
•Forest structure and deadwood elements relates to bats and birds in the Italian Alps.•Bat richness was higher with both higher standing tree and lying deadwood volume.•Bird community was more diverse with high volumes of logs and stumps.•Promoting a complex forest structure sustains a multi-taxon forest biodiversity.
Understanding the main drivers of biodiversity loss in Europe's agricultural landscapes has been a research priority in the last decades. One of the most important factors promoting biodiversity in ...farmed landscapes is habitat heterogeneity, which has often proved crucial for avian species and communities. Birds are highly sensitive to environmental changes and make use of a broad range of ecological niches, thus being exceptionally sensitive to the loss of habitat heterogeneity. Remote sensing data are particularly suited to quantify habitat heterogeneity at fine scales over relatively large extents, allowing to consider how different measures of heterogeneity may affect biotic communities at a regional scale. Here, we used airborne LiDAR (Light Detection And Ranging) and satellite multispectral data to derive vegetation canopy height and primary productivity for 118 sites in complex agricultural landscapes in a region in the Central Alps. We computed different bird diversity indices and classified bird species into guilds according to specific traits to analyse the relationship between avian communities and different facets of habitat heterogeneity. Results confirmed that habitat heterogeneity is essential in shaping rich and diverse bird communities, and it is particularly important for several farmland birds. By comparing the effects of canopy height, primary productivity, and specific vegetation features (e.g., cover of grassland, shrub, and tree layers), we showed how different habitat characteristics as well as landscape heterogeneity affected bird richness, diversity, functional entropy, and trait patterns. Landscape and height heterogeneity, estimated by NDVI and LiDAR Rao's Q indices, strongly influenced all response variables, for example, high NDVI values promoted species diversity and ground-understory nesters, and shrub layer was important for ground-understory nesters and forest specialists. Finally, we provide recommendations for conservation practices and mitigation measures to improve bird diversity in agricultural landscapes.
•Community composition of other taxa changed consistently with bird communities and indicator species within farmlands.•Efficiency of different bird indices as bioindicators varied across landscapes ...and taxa.•Species richness, number of threatened and farmland birds were most selected indices.•14 different indicator species were found for grasslands and crops.•European serin and Alpine accentor were the most selected indicator species.
Biodiversity loss is a global issue, particularly in mountain regions, where land-use/land-cover and climate change dramatically impact on species and communities. Sound ecological research and up-to-date information on biodiversity are needed to support conservation efforts. However, this information is often difficult and costly to obtain. Therefore, bioindicators serve as surrogates to provide information on the entire biocenosis. Birds are considered excellent bioindicators as they occupy different ecological niches and trait spaces.
We present a study about the efficiency of birds as bioindicators for the diversity of other taxa in a mountain region in the Central Alps. We surveyed bird communities at 115 sites across a gradient of different grasslands and crops and compared them with the diversity of other taxa (bats, butterflies, grasshoppers, arachnids, and vascular plants). We aimed to identify indicator bird species for grasslands and crops, to assess cross-community concordance between birds and other taxa, and to model the efficiency of bird indices and indicator species as bioindicators of the diversity across habitat types and taxa.
We identified indicator bird species for different grassland and crop types and found that efficiency of bird indices and single species varied for habitat types and taxa. We highlight the importance of using carefully selected bioindicators in biodiversity monitoring and conservation planning, and the need for an integrated and interdisciplinary approach for biodiversity research. Moreover, by looking at a combination of different indices we can gain a more comprehensive understanding of ecosystem functioning. We also provide a framework for the use of bird-based monitoring programs and bird-derived indices to guide biodiversity conservation, and emphasise the importance of incorporating different bioindicators into biodiversity research and monitoring to provide a more comprehensive understanding of ecological biodiversity patterns and trends.
The greater noctule bat,
Nyctalus lasiopterus
(Schreber, 1780), is one of the rarest bat species in Europe. Data on its distribution in the central and western parts of the continent are largely ...lacking. For the first time,
N. lasiopterus
was observed in South Tyrol (Northern Italy) using bat detectors in the summer of 2016 and in the following years until 2021. The five sites where the species was detected are located in a limited area of the Adige Valley, which is characterised by low elevation and a mild climate. Multiple recordings indicated a continuous summer presence of
N. lasiopterus
on the southern side of the Alps
.
Additionally, we present insights on echolocation and species identification, including statistically significant differences in the call metrics of
N. lasiopterus
compared to
Tadarida teniotis
. These results are important at a European level given that data is lacking on the populations of
N. lasiopterus
in Europe outside the Mediterranean.
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