•Impacts of the EU’s CAP instruments, production intensity and landscape characteristics on farmland birds were analysed.•Areas with high direct payment support were negatively associated with ...farmland bird diversity.•Farmland bird diversity was highest in a diversely cropped farmland with <25 % of woody vegetation.•Open grasslands in Natura 2000 sites with low stocking density supported the highest diversity of grassland specialists.•AES and “Greening” measures had a weak effect on bird diversity, possibly due to ineffective implementation.
The paper investigates the relative influence of landscape characteristics, production intensity and the EU’s Common agricultural policy interventions on the diversity of farmland birds. For this purpose, data from the Farmland Bird Monitoring Scheme in Slovenia and high spatial resolution data from the national agricultural databases in the period 2008–2019 were analysed with the Boosted Regression Trees (BRT). The diversity of farmland birds was found to be highest in open, diversely cropped and extensively to moderately intensively managed landscapes in Natura 2000 sites where farm holdings were allocated a low average amount of both direct payments and payments for agri-environmental measures (AEM) and organic farming (OF). Furthermore, the highest diversity of the subgroup of grassland specialists was associated with very open and extensively managed grassland landscapes with low stocking density (<0.7 LU/ha). By contrast, the diversity of habitat generalists was highest in heterogeneous landscapes with a high diversity of land-use types, measured at the broader spatial scale. Areas with a higher allocation of direct payments and payments for AEM and OF were associated with lower farmland bird diversity, whereas high diversity was found in Natura 2000 sites and in some areas with natural constraints (LFA). Agri-environmental measures and the “Greening” measures had a negligible relative influence on bird diversity, possibly due to ineffective implementation and low uptake by beneficiaries.
The intensification of production, particularly in the beef and dairy sectors, which has been supported by the Common agricultural policy direct payments, and forest succession in marginal areas were identified as the potential key drivers of the recent farmland biodiversity loss in Slovenia. The future CAP income support schemes should be redesigned to ensure at least neutral if not positive overall effects on farmland biodiversity by gradual phasing-out of references to (historic) production levels, increased conditionality and more effective voluntary agri-environmental measures.
We studied the effects of different land uses on conservation value and bird diversity in a Northern Adriatic karstic landscape. Our research area was situated in SW Slovenia and was covered with dry ...pastures and meadows in different stages of forest sucession and with different grazing intensities. We surveyed birds in 2007 and 2012 using the line transect method, with 50.4 km being covered each year. In the analysis we divided the survey transects into 200 m tiles which were used as statistical units in the analysis. We then modelled conservation value, bird diversity and bird abundances with different land uses; we used boosted regression trees as a modelling tool. Canonical correspondence analysis showed that a distinct group of birds occurred on tiles with higher grazing intensity. The species in this group also had significantly higher abundances in 2012 than in 2007. Forest succession was the most important predictor of SPA conservation value (Special Protected Areas according to the Directive on the conservation of wild birds of the European Union) and had negative effect on it; grazing intensity had a unimodal positive influence on conservation value and was most beneficial at low intensity. The model for the European conservation value showed a rather low predictive power. Farmland bird diversity was also negatively affected by forest and positively by grazing intensity. For the four Natura 2000 species—protected species in the SPA Kras (Woodlark
Lullula arborea
, Red-backed Shrike
Lanius collurio
, Corn Bunting
Emberiza calandra
and Skylark
Alauda arvensis
), forest cover also had a negative effect. Grazing intensity had a positive effect for Woodlark, Red-backed Shrike and Skylark. The highest SPA conservation value and farmland bird diversity could therefore be achieved in a landscape with as low a forest succession as possible and grazing present but at low intensity. We recommend inclusion of appropriate measures in the agri-environment schemes (CAP pillar II) of Rural Development Programmes of the countries in the region with similar areas. The payments should be sufficiently stimulative to reopen the large areas subject to forest encroachment in the Northern Adriatic hinterland.
•Patch diversity was smaller on consolidated sites, with arable fields prevailing.•Bird diversity and abundance of most species were higher on non-consolidated sites.•Only Eurasian Skylark and Common ...Stonechat were more abundant on consolidated sites.•Land consolidation negatively affects birds’ European conservation value.•Land consolidation should not be performed at Natura 2000 sites.
Land consolidation can negatively affect biodiversity, as it is usually followed by the expansion of arable land, a decrease in crop and land cover diversity, and an increase in the application of agrochemicals. The aim of our study was to compare the species’ composition and abundance of farmland birds, as well as habitat structure, on consolidated and non-consolidated sites in Goričko, NE Slovenia. Habitat diversity was much lower on consolidated sites compared to non-consolidated ones, with arable fields and associated habitats (e.g. grass field margins, field tracks) prevailing on the former. Non-consolidated sites held higher proportions of different types of meadows, hedgerows, solitary trees, succession and traditional orchards. Farmland bird diversity and the abundance of a majority of farmland bird species were higher on non-consolidated sites. The only two exceptions to this were the Eurasian Skylark and the Common Stonechat, which were more abundant on consolidated sites. Both of the species suffered population declines at Goričko in the period 1997–2016, bringing into question the suitability of intensively managed arable fields as their breeding and foraging habitat. Individual species’ regression analysis revealed that the most influential positive explanatory variable for the presence of Red-backed Shrike, Tree Sparrow and Common Whitethroat was non-consolidated, extensively managed mosaic landscape, whereas for the Yellowhammer this explanatory variable was superseded only by forest islands without traditional orchards. Land consolidation, as performed in Slovenia, negatively affects farmland bird diversity and its European conservation value, which is why it should not be performed on Natura 2000 sites, designated for nature conservation.
Identifying climate refugia is key to effective biodiversity conservation under a changing climate, especially for mountain‐specialist species adapted to cold conditions and highly threatened by ...climate warming. We combined species distribution models (SDMs) with climate forecasts to identify climate refugia for high‐elevation bird species (Lagopus muta, Anthus spinoletta, Prunella collaris, Montifringilla nivalis) in the European Alps, where the ecological effects of climate changes are particularly evident and predicted to intensify. We considered future (2041–2070) conditions (SSP585 scenario, four climate models) and identified three types of refugia: (1) in‐situ refugia potentially suitable under both current and future climate conditions, ex‐situ refugia suitable (2) only in the future according to all future conditions, or (3) under at least three out of four future conditions. SDMs were based on a very large, high‐resolution occurrence dataset (2901–12,601 independent records for each species) collected by citizen scientists. SDMs were fitted using different algorithms, balancing statistical accuracy, ecological realism and predictive/extrapolation ability. We selected the most reliable ones based on consistency between training and testing data and extrapolation over distant areas. Future predictions revealed that all species (with the partial exception of A. spinoletta) will undergo a range contraction towards higher elevations, losing 17%–59% of their current range (larger losses in L. muta). We identified ~15,000 km2 of the Alpine region as in‐situ refugia for at least three species, of which 44% are currently designated as protected areas (PAs; 18%–66% among countries). Our findings highlight the usefulness of spatially accurate data collected by citizen scientists, and the importance of model testing by extrapolating over independent areas. Climate refugia, which are only partly included within the current PAs system, should be priority sites for the conservation of Alpine high‐elevation species and habitats, where habitat degradation/alteration by human activities should be prevented to ensure future suitability for alpine species.
By combining distribution models (based on a large, high‐resolution dataset, and balancing statistical accuracy, ecological realism, and predictive/extrapolation ability) with climate forecasts, this study identified climate refugia for high‐elevation bird species (Lagopus muta, Anthus spinoletta, Prunella collaris, Montifringilla nivalis) in the European Alps, considering both in‐situ refugia (suitable now and in the future) and ex‐situ refugia (suitable only in the future). Most species will undergo a marked contraction towards higher elevations. In‐situ refugia for at least three species cover ~15,000 km2 of the Alpine region (44% included within protected areas) and represent priority sites for the conservation of high‐elevation species and habitats.
Declines in European bird populations are reported for decades but the direct effect of major anthropogenic pressures on such declines remains unquantified. Causal relationships between pressures and ...bird population responses are difficult to identify as pressures interact at different spatial scales and responses vary among species. Here, we uncover direct relationships between population time-series of 170 common bird species, monitored at more than 20,000 sites in 28 European countries, over 37 y, and four widespread anthropogenic pressures: agricultural intensification, change in forest cover, urbanisation and temperature change over the last decades. We quantify the influence of each pressure on population time-series and its importance relative to other pressures, and we identify traits of most affected species. We find that agricultural intensification, in particular pesticides and fertiliser use, is the main pressure for most bird population declines, especially for invertebrate feeders. Responses to changes in forest cover, urbanisation and temperature are more species-specific. Specifically, forest cover is associated with a positive effect and growing urbanisation with a negative effect on population dynamics, while temperature change has an effect on the dynamics of a large number of bird populations, the magnitude and direction of which depend on species' thermal preferences. Our results not only confirm the pervasive and strong effects of anthropogenic pressures on common breeding birds, but quantify the relative strength of these effects stressing the urgent need for transformative changes in the way of inhabiting the world in European countries, if bird populations shall have a chance of recovering.
1.Intermittent karst lakes are important for forming wetland habitats in otherwise dry karstic landscapes. With characteristic water regimes they are unable to retain water owing to their underground ...drainage system.
2.Many Dinaric intermittent karst lakes (karst poljes) have gone through severe human disturbances in the past, aimed at fluctuating water levels in karst poljes. These measures had the goal of achieving either permanent dry agricultural land or permanent lakes for various purposes. Usually dams were built for water storage to achieve these goals.
3.This research aimed to determine the population responses of bird species that are important for conservation, to water level changes on Cerknica Lake (Slovenia), a large Dinaric intermittent karst lake, to inform effective conservation for such systems.
4.Water level and vegetation were strong drivers of waterbird diversity and abundance, based on analysis using canonical correspondence analysis and boosted regression trees.
5.Water level was critical for the conservation of important bird species. Water and reed specialists (e.g. water rail Rallus aquaticus) require management of refugia in wetlands to create mosaics of water and reedbeds. The formation of nature reserves, quiet zones and habitat restoration is needed for these specialist species. In these areas, mowing should be limited or not present at all.
6.Measures dealing with land‐use change and connectivity between habitats, for instance agri‐environmental measures, are more appropriate for rare bird species with wider niche breadths (but still narrower than generalists), e.g. skylark (Alauda arvensis) and linnet (Linaria cannabina).
Maximizing the area under biodiversity‐related conservation measures is a main target of the European Union (EU) Biodiversity Strategy to 2020. We analyzed whether agrienvironmental schemes (AES) ...within EU common agricultural policy, special protected areas for birds (SPAs), and Annex I designation within EU Birds Directive had an effect on bird population changes using monitoring data from 39 farmland bird species from 1981 to 2012 at EU scale. Populations of resident and short‐distance migrants were larger with increasing SPAs and AES coverage, while Annex I species had higher population growth rates with increasing SPAs, indicating that SPAs may contribute to the protection of mainly target species and species spending most of their life cycle in the EU. Because farmland birds are in decline and the negative relationship of agricultural intensification with their population growth rates was evident during the implementation of AES and SPAs, EU policies seem to generally attenuate the declines of farmland bird populations, but not to reverse them.
Farmland birds in the European Union have declined by 57% in the past 35 years, raising the need for efficient, large-scale conservation measures to halt and reverse their negative trends. The ...Eurasian Scops Owl Otus scops is an indicator of extensively managed agricultural landscapes, typical of areas of high biodiversity. Its breeding biology is poorly known, but central to understanding the drivers of its marked decline in different European countries, including Slovenia. We used GPS-loggers to study home range size and habitat use of breeding individuals in NE Slovenia. Kernel home ranges (95%) of three females were estimated and their habitat use was analysed by spatial logistic regression models with Moran's Eigenvectors. Individual home range sizes ranged from 2.2 to 48.2 ha. In general, the females preferred to forage close to their nests. One female had a much larger home range than the other two, because of her exploitation of presumably highly profitable foraging grounds far away from her nest. In a mosaic of different agricultural habitats, the females showed a clear preference for extensively managed areas, such as hedges, meadows, abandoned vineyards and traditional orchards. Based on our findings several conservation measures are proposed, aimed at enhancing insect diversity and abundance as well as prey accessibility.
Interspecific interactions are crucial in determining species occurrence and community assembly. Understanding these interactions is thus essential for correctly predicting species' responses to ...climate change. We focussed on an avian forest guild of four hole‐nesting species with differing sensitivities to climate that show a range of well‐understood reciprocal interactions, including facilitation, competition and predation. We modelled the potential distributions of black woodpecker and boreal, tawny and Ural owl, and tested whether the spatial patterns of the more widespread species (excluding Ural owl) were shaped by interspecific interactions. We then modelled the potential future distributions of all four species, evaluating how the predicted changes will alter the overlap between the species' ranges, and hence the spatial outcomes of interactions. Forest cover/type and climate were important determinants of habitat suitability for all species. Field data analysed with N‐mixture models revealed effects of interspecific interactions on current species abundance, especially in boreal owl (positive effects of black woodpecker, negative effects of tawny owl). Climate change will impact the assemblage both at species and guild levels, as the potential area of range overlap, relevant for species interactions, will change in both proportion and extent in the future. Boreal owl, the most climate‐sensitive species in the guild, will retreat, and the range overlap with its main predator, tawny owl, will increase in the remaining suitable area: climate change will thus impact on boreal owl both directly and indirectly. Climate change will cause the geographical alteration or disruption of species interaction networks, with different consequences for the species belonging to the guild and a likely spatial increase of competition and/or intraguild predation. Our work shows significant interactions and important potential changes in the overlap of areas suitable for the interacting species, which reinforce the importance of including relevant biotic interactions in predictive climate change models for increasing forecast accuracy.
Interspecific interactions are crucial in determining species occurrence and community assembly. This study analysed the distributions of four species, which are affected by reciprocal interactions and will be impacted by climate change. The latter will impact the assemblage both at species and guild levels, as the potential area of range overlap, relevant for species interactions, will change in both proportion and extent in the future, causing the geographical alteration or disruption of species interaction networks. Relevant biotic interactions should be included in predictive climate change models for increasing forecast accuracy.
This paper assesses the effects of agricultural payments on changes in farmland bird diversity in Slovenia. Diversity was measured by Shannon index, while the impacts were estimated with the ...first-difference estimator on panel data for municipalities with and without special protection areas for birds. The effects of agricultural payments on farmland biodiversity require that the balance of financial instruments be taken into account when the agricultural policy is being drafted. The effects of payments in municipalities with and without special protection areas indicate the need to consider the landscape perspective and adapt schemes to landscape type while preparing the national agricultural policy.
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