Types Of Semi-natural Habitats Research Articles

How seasonality, semi-natural habitat cover and compositional landscape heterogeneity affect pollen collection and development of Apis mellifera colonies in Mediterranean agro-sylvo-pastoral systems

ContextThe reduction in the abundance and diversity of flowering plant species, mainly due to landscape alteration and consequent habitat loss, negatively affects honey bee populations and is the main driver of their decline. To safeguard pollination service and food security, we need to know how landscape characteristics affect the availability of pollen sources and consequently colony performance across seasons.ObjectivesWe therefore here explore how seasonality, percentage of semi-natural habitat cover and compositional landscape heterogeneity affect the abundance, richness, diversity and composition of pollen collected by honey bees and the development of their colonies in a Mediterranean area where agro-sylvo-pastoral systems are widely spread.MethodsFor the purpose of our study, pollen samples were collected over a year from colonies of Apis mellifera placed in four sampling sites selected across a gradient of landscape heterogeneity and where semi-natural habitats were predominant at various levels within an agro-sylvo-pastoral zone. Simultaneously, the extension of the sealed brood of the same colonies was periodically evaluated.ResultsWe found that the amount of pollen collected by honey bees was positively correlated with the percentage of semi-natural habitat cover and that increasing habitat diversity at the landscape level had a significant positive effect on the richness and diversity of pollen collected by honey bees. In addition, season significantly affected the amount, diversity and composition of pollen collected by honey bees. Furthermore, bee colony growth was positively correlated with richness, diversity and amount of pollen collected by honey bees.ConclusionOur study highlights the importance of an abundant and diverse pollen diet for honey bee colony development, which in agro-sylvo-pastoral systems seems to be ensured by a heterogeneous landscape dominated by different types of semi-natural habitats.

Both long-term grasslands and crop diversity are needed to limit pest and weed infestations in agricultural landscapes.

Increasing landscape heterogeneity has been suggested to be an important strategy to strengthen natural pest control in crops, especially through enhancing the amount of seminatural habitats. Increasing crop diversity is also a promising strategy to complement or replace seminatural habitat when seminatural habitat is scarce. However, their relative or possibly interactive effects on pest and weed infestation remain poorly investigated, and the role of different types of seminatural habitats has been understudied. Using an extensive sampling effort in 974 arable fields across 7 y, we evaluated the separate and interactive effects of crop diversity (seven arable crop types) and the amount of four types of seminatural habitats (meadows, hay, forests, and hedgerows) in the landscape on pest and weed control. Meadows and crop diversity, respectively, supported insect pest and weed control services in agricultural landscapes through a complementarity effect. Crop diversity increased weed seed predation rate (by 16%) and reduced weed infestation (by 6%), whereas long-term grasslands (to a much higher degree than hay or woody habitats) increased insect pest predation rates (by 23%) and reduced pest infestation (by 19%) in most arable crops. Our results demonstrate that diversification of the agricultural landscape requires long-term grasslands as well as improved crop diversity to ensure the delivery of efficient pest and weed control services.

Increase in breeding bird abundance and diversity with semi-natural habitat in vineyard landscapes.

Agricultural expansion and intensification are major threats to biodiversity, and even some once common farmland bird species are now endangered. Wine-growing landscapes are intensively managed but can still be an attractive habitat for a wide range of species. However, only few bird species breed within vineyards and thus, semi-natural habitat types like hedges, woodland patches and grasslands are crucial for bird populations. We investigated how birds breeding in wine-growing areas are influenced by the surrounding landscape at three spatial scales: territories, sampling transects and landscapes. In the German wine growing region Palatinate, sixteen landscapes with a radius of 500 m were chosen spanning a gradient in the cover of semi-natural habitat. Bird territories were mapped along three transects of 500 m length in each landscape. We found 300 territories of 33 bird species. Positive effects of semi-natural habitat cover on birds were strongest at the transect scale, with almost proportional increase of species and territory numbers with the cover of semi-natural habitat. Most bird species selected territories that contained more semi-natural habitat than the landscape-wide average of 13.5%, but e.g. woodlark and linnet showed an opposite preference. In addition, the birds' community composition was influenced by the composition of the surrounding landscape. Most species were associated with semi-natural habitat types or built-up areas while vineyards had hardly any species associated with them. Our results suggest that in wine-growing landscapes, the decline in farmland birds can be reversed by the re-establishment of hedges, trees, woodland patches, traditional orchards and grassland areas. However, as preferences at the territory scale were species-specific, there is no uniform best solution for bird conservation in viticultural landscapes. Thus, landscape development should always be accompanied by experts that take the demands of existing and potential breeding birds into account.

Agricultural land-use and landscape composition: Response of wild bee species in relation to their characteristic traits

In the past centuries, farmland has undergone a fundamental transformation through changed farming practices, such as the use of agrochemicals and advanced machine processing. Particularly since the 1970s, agriculturally driven land-use change has caused destruction of natural and semi-natural habitats, and as a consequence, severe loss of biodiversity. Hence, identifying landscape patterns and habitats that enhance species richness, and detecting species and traits that are most vulnerable to intensive land-use are prerequisites for conservation. To evaluate the effects of agricultural land-use and landscape composition on wild bees, we investigated 340 cross-transects in 34 test areas in the main agricultural regions of Austria within the framework of the biodiversity monitoring program BINATS. Using multivariate models (GLM, DCA), wild bees and potential explanatory parameters (e.g. Shannon landscape diversity index, plant diversity, flower cover) were documented, and their interrelationships analyzed. We found strong negative effects of increased agricultural land cover on species richness, abundance and functional richness. Species richness was positively correlated with an increasing area of semi-natural elements (e.g. extensive grassland, hedgerows, fallows) and the number of different habitat types, while wild bee abundance was best explained by the presence of semi-natural habitats and flower cover. Colletidae were significantly associated with the area of semi-natural elements, and were especially sensitive to agricultural intensification. Many species from communities that are present in complex landscapes disappeared in intensively managed farmland, and the majority of species decreased in response to simplified landscapes. A few species, however, even benefited. Our results emphasize the importance of diverse semi-natural elements and high regional flower cover within farmland for maintaining and enhancing species richness and abundance, and for promoting a positive spillover effect of pollinators to the surrounding agricultural landscape. Especially members of the family Colletidae, with a high proportion of specialized species, will benefit from diverse semi-natural habitat types. Given the unique importance of wild bees as pollinators of wildflowers and crops, it is crucial to improve and expand agri-environmental schemes to combat ongoing biodiversity loss in farmland.

Different semi-natural habitat types provide complementary nesting resources for wild bees

Semi-natural habitats provide refuge for pollinating insects such as wild bees. Different types of semi-natural habitat can provide complementary floral resources throughout the year, but it is uncertain to what extent different semi-natural habitat types provide nesting habitat for wild bees. In this study, nesting resources for wild bees and nest-searching bees were surveyed visually in three different types of semi-natural habitat (i.e., hollow roads, tree rows, and forest edges). The composition of nesting resources for wild bees varied across the three types of semi-natural habitat. We also identified clear indicators of nesting resources within the different habitat types. We conclude that different types of semi-natural habitat provide varying and complementary nesting resources for wild bees. This study further highlights the importance of semi-natural habitat for pollinator conservation and emphasizes the need for further research to increase our understanding how different wild bee species use different habitat types for nesting.

The effect of semi-natural habitat types on epigaeic arthropods: Isolate habitats make critical contribution to biodiversity in agricultural landscape

Semi-natural habitats in agricultural landscapes vary greatly in shape and vegetation characteristics. They can appear either as relatively large patches of several hectares or as narrow bands (less than 1 m wide) between fields and roads and between fields. Semi-natural habitats support biodiversity and associated ecosystem services on farmland, thereby contributing to sustainable agriculture.However, the effects of different semi-natural habitat types on the polytrophic level of epigaeic arthropods are still unclear. In this study, we classified semi-natural habitats into five types. (1) woody areal (WA), (2) woody line (WL), (3) herbaceous areal (HA), (4) herbaceous line (HL) and (5) isolate habitat (IH). We aimed to explore differences in epigaeic arthropod community composition in five different semi-natural habitats and the effects of different semi-natural habitats and different sampling locations on epigaeic arthropod activity-density and diversity. The results showed that epigaeic arthropod communities show significant differences, not only between farmland and semi-natural habitats, but also between different types of semi-natural habitats. Isolate habitats have the highest activity-density of epigaeic arthropods and Linear herbaceous maintain the highest epigaeic arthropod diversity. We also found in this study, both the activity-density and diversity of epigaeic arthropods showed edge-biased distribution. It may be possible to promote sustainable agricultural ecosystems by understanding the effect of semi-natural habitats on epigaeic arthropods, which is conducive to improving the quality of the agricultural ecological environment.

Perennial woodlands benefit parasitoid diversity, but annual flowering fallows enhance parasitism of wheat aphids in an agricultural landscape

Agriculture intensification poses serious threats to natural enemy biodiversity and associated ecological services. The conservation or reestablishment of semi-natural habitats is used to counteract negative effects of agriculture intensification on natural enemies. Understanding specific functions of different habitats for natural enemies from a landscape perspective is an important step needed for the development of sustainable agriculture. Here, focusing on parasitoids of wheat aphids, we examined effects of the proportion and connectivity of two main semi-natural habitats (woodlands and fallows) present in landscapes, measured within circular buffer radii of 0.5, 1.0, 1.5, and 2.0 km around sampling sites, on parasitoid (mummy) density, biodiversity (Shannon diversity) and associated services (parasitism rate) in 35 wheat fields. We also compared local vegetation communities of these two semi-natural habitats to test whether plant characteristics can shed light on the potential mechanisms driving parasitoids responses to different landscape habitats. We found that the parasitoid diversity was much higher in landscapes dominated by woodlands, while fallows in the landscape promoted parasitoid density and parasitism. Woodlands connectivity at larger scales (such as 1.5 or 2.0 km) displayed positive effects on parasitoid activities, fallows connectivity at the smaller scale (0.5 km) had a positive effect on the hyperparasitism rate. In terms of vegetation characteristics, fallows provided more flowering plants and floral resources, while woodlands suffered less disturbance across years. Local vegetation composition of the semi-natural habitats indeed help explain their different effects on parasitoids at larger landscape scales. We suggested that future research should investigate the role of different types of semi-natural habitats. Conservation management should combine different habitats, such as perennial and annual habitats, to promote the functional complementarity for beneficial organisms. Based on results from local vegetation survey, we also suggested native flowering plants such as Capsella bursa-pastoris L., Lagopsis supina Steph., and Calystegia hederacea Wall. in fallows could be used as functional plants to conserve wheat aphid parasitoids.

Conservation potential of semi-natural habitats for birds in intensively-used agricultural landscapes

Agricultural intensification resulted in substantial loss of farmland biodiversity. Semi-natural habitats may be viewed as potential buffers of these adverse impacts, but a rigorous assessment of their capacity for supporting farmland biodiversity is lacking. In this study, we explored conservation potential of two different types of semi-natural habitats for birds in intensively-used agricultural landscapes – farmland hedges (i.e., linear strips of shrubby and tree vegetation) and open scrubland (i.e., scattered shrubs and abandoned orchards). Specifically, we tested whether the abundance and species richness of birds differ between these habitats considering various species traits, such as habitat affinity (i.e., forest, farmland and urban species), diet specialization (i.e., animal eaters, plant eaters, and omnivores) and conservation status (Species of European Conservation Concern). We found that open scrubland hosted on average 37.9 bird species and 122.6 individuals per 1 km2 of the transect, whereas farmland hedges hosted only 19 species and 61.8 individuals per 1 km2 of the transect. However, results have substantially changed if we considered the area of suitable habitat into account. More specifically, open scrubland hosted more bird species and individuals when we considered open habitat species and the area of open habitats, whereas farmland hedges had higher species diversity and individuals of woodland bird species when we considered the area of woodland habitats. Similarly, analyses of habitat affiliations of individual species corresponded to the whole-community patterns; and revealed that several woodland bird species were mainly associated with farmland hedges (e.g., Chaffinch Fringilla coelebs, Common Nightingale Luscinia megarhynchos and Blackcap Sylvia atricapilla), whereas the open scrubland was preferred by open habitat bird species (e.g., Corn Bunting Emberiza calandra, Quail Coturnix coturnix and Skylark Alauda arvensis). These results demonstrate that semi-natural habitats, both open scrubland and farmland hedges, have large potential for promotion and conservation of bird communities within intensively used agricultural landscapes, as both may have represented suitable habitats for species with different ecological requirements. Therefore, management measures focused on the enlargement of the area of these habitats, in combination with suitable management (e.g., regulating the progress of natural succession in open scrubland; increasing structural diversity of existing farmland hedges), may substantially contribute to bird conservation within agricultural landscapes.

Wooded Semi-Natural Habitats Complement Permanent Grasslands in Supporting Wild Bee Diversity in Agricultural Landscapes.

Simple SummaryLoss of semi-natural habitats in agricultural landscapes negatively affects wild bees. These pollinators are, however, very important in agricultural landscapes as they enable the pollination of crops and wild plants. The aim of this study was thus to understand the respective roles of different wooded and herbaceous habitats in their ability to support a diversity of wild bees. We first found that wild bee communities differed between wooded and herbaceous habitats, some bee species being found in one type of habitat and not in the other. We also showed that wooded semi-natural habitats provide some species of pollen preferred by the bees. Finally, we found that in wooded habitats there are some interactions between plant and bee species that do not happen in permanent grasslands. However, the latter also plays an important role in the diversity of bees and plants, and these wooded and herbaceous habitats complement each other. Overall, our results underline the importance of maintaining a diversity of semi-natural habitats in agricultural landscapes to maintain a diversity of wild bees and thus promote the pollination of wild plants and crops.Loss of semi-natural habitats (SNH) in agricultural landscapes affects wild bees, often negatively. However, how bee communities respond varies and is still unclear. To date, few studies have used precise descriptors to understand these effects. Our aim was to understand the respective and complementary influences of different wooded and herbaceous habitats on wild bee communities. We selected thirty 500-m radius landscapes on a gradient of a percentage of wooded SNH in south-western France. At each landscape, we sampled wild bees in spring 2016 and plants in spring 2015 and 2016 at the forest edge, in a hedgerow, and in a permanent grassland. Pollen carried by the most abundant bee species was collected and identified. Using beta diversity indices, we showed that wild bee community composition differs between the three SNH types, and especially between herbaceous and wooded SNH. Based on Jacobs’ selection index, we showed that pollen of some plant species recorded in wooded SNH are preferentially selected by wild bees. Studying the impact of the loss of each SNH type on the global bee-pollen interaction network, we found that wooded SNH contributed to its resilience, enabling specific plant–bee interactions. Overall, our results underline the non-negligible contribution of wooded SNH to the diversity of wild bees in agricultural landscapes, and thus the importance of maintaining different types of SNH.

Does the urban heat island determine the distribution of Fallopia taxa in cities? – preliminary study from Wrocław (Central Europe)

Among the invasive plant species found in Europe and North America, particular attention is paid to the Fallopia (Reynoutria) genus: Fallopia japonica, Fallopia sachalinensis and the hybrid created as a result of their crossing - Fallopia × bohemica. Many works describe the extraordinary expansiveness of knotweeds, in anthropogenic habitats, especially in large cities, the representatives from the Fallopia genus are already a permanent element of the local flora. The specific ecological properties of the cities can favour the expansion of Fallopia genus. The goal of this work was to answering the question - is there a relationship between the spread of knotweeds in the city and the local climatic conditions in the form of the so-called urban heat island? The field work was carried out in Wroclaw, which is the fifth largest city in Poland, with an area of 292.82 km2 . The study showed that despite the potentially broad thermal amplitude, Fallopia japonica prefers the areas in the city with the highest temperature. The invasion of this species proceeds most intensively in the warmest regions of the city. Similar tendencies are observed in the case of the interspecies hybrid - Fallopia × bohemica. The third taxon - Fallopia sachalinensis - clearly prefers slightly colder parts of the city. It is worth noting that representatives of the Fallopia genus do not appear in the coldest parts of Wroclaw. This is quite puzzling, because in these city areas, there are some types of semi-natural habitats which the invasive knotweeds usually willingly occupy. The preliminary study shown that in the urban ecosystem, the thermal factor influences the spread of the Fallopia genus. Research in this area regarding the all Fallopia taxa will continue.

Data on the bumblebee assemblages (Apidae: Bombus spp.) lives in lands under agri-environment commitment

The goal of agri-environmental schemes (AES) and greening programs are protecting and increasing biodiversity in agricultural lands. The evaluation of effectiveness of AES needs further investigations. For the purpose of investigations, species and species groups should be selected which can indicate the effects of changes in landscape use on biodiversity. Bumblebees are good indicators for this purpose.
 The role of bumblebees in pollination is well studied but in the case of different crops, much less detailed data are available. In 2018, bumblebee assemblages of 44 sites belonged to 8 different agricultural and semi-natural habitat types were studied in the surroundings of Sajószöged, Tiszaújváros and Derecske.
 This study provides new distribution data of 8 bumblebee species in three 10×10 km UTM cells covering the sampling area. According to our results, the alfalfa and red clover fields and semi-natural grasslands has more species rich and abundant bumblebee assemblages than different crop fields (sunflower, oilseed radish and vegetable morrow) and can help protect bumblebee assemblages of agricultural lands. Based on the collected distribution and abundance data, the role of the bumblebees in pollination of the studied crops should be re-evaluated.

The potential of different semi-natural habitats to sustain pollinators and natural enemies in European agricultural landscapes

Semi-natural habitats (SNH) are vital to sustain pollinators and natural enemies, and the ecosystem services they provide in agroecosystems. However, little is known about the relative importance of different SNH types and their vegetation traits for pollinators and natural enemies. Yet, such knowledge is essential for effective habitat management to promote both functional arthropod groups and associated multiple ecosystem services. We quantified vegetation traits and abundances of pollinators (bees) and natural enemies (predatory flies and parasitic wasps) in 217 SNH differing in type (woody or herbaceous) and shape (linear or areal habitats), for edge and interior locations within each SNH patch with respect to adjacent crops, across 62 agricultural landscapes in four European countries. Pollinators and natural enemies responded distinctively to major SNH types and within-habitat location of SNH: abundance of natural enemies (predatory flies and parasitic wasps) was higher along woody habitat edges than herbaceous SNH or the interior of woody habitats. In contrast, bee abundances, especially of honey bees, were generally higher in areal herbaceous compared to woody SNH. Abundances of both wild bees and managed honey bees were lowest for the interior sampling location in areal woody habitats. These findings reflected divergent key vegetation traits driving pollinator and natural enemy abundances across SNH: bee pollinators increased with herbaceous plant cover and were well predicted by SNH type and the floral abundance of identified key plant trait groups. In contrast, floral abundances of these plant groups were poor predictors of the studied natural enemies, which were better predicted by SNH type and sampling location within SNH. Our findings stress the need to move beyond the simplistic pooling of SNH types and highlight the importance of considering their vegetation traits to more reliably predict pollinators and natural enemies in agroecosystems. They suggest that the floral abundance of key groups of flowering plants is crucial for habitat management to promote bee pollinators, while vegetation-structural traits appear more important for predatory flies and parasitoids. The distinct importance of different SNH types and associated vegetation traits for pollinators and natural enemies calls for agroecosystem management ensuring diverse SNH with complementary vegetation traits to concomitantly foster pollination and pest control services.

Military land use and the impact on landscape: A study of land use history on Danish Defence sites

Counting for as much as 6% of Earth’s terrestrial surface, military land use constitutes an important share of human land use. Yet, only few studies analyse the general impact of military land use on landscape and biodiversity. This article presents a countrywide study of land use, land use change and biodiversity content on all Danish defence sites larger than 10 ha, comprising roughly 40,000 ha or 1% of the Danish terrestrial area. Based on interpretation of historical maps, land use history was analysed for the period from the 1870′s to the present. Furthermore, available national data were applied to assess present land use and biodiversity content within and in the surrounding of defence sites. The historical analysis revealed six typical trajectories of land use change. In terms of total area, the two most important were conservation of open, semi-natural habitat types (47%) and change from agriculture to open, semi-natural habitat types (34%). Results also show, that for sites characterised by these two land use change trajectories, present proportions of open semi-natural habitats as well as biodiversity contents are significantly higher within the sites compared to their surroundings. It is concluded that military land use in most cases had a significant beneficial impact on present day land cover composition and biodiversity.

A new method for jointly assessing effects of climate change and nitrogen deposition on habitats

Climate change and nitrogen (N) deposition are among the most important drivers of biodiversity change at a global scale. Although commonly considered separately in applied research, conservation, and policy development, both empirical evidence and modelling studies indicate that these two stressors may act synergistically and trigger a more pronounced biodiversity loss than each of them alone. Interactive effects thus need to be considered in biodiversity conservation. In this study, we propose a new method for jointly assessing risk from both stressors to habitats by combining climate envelope modelling and the evaluation of exceedance of empirical critical loads for eutrophication through N deposition. Based on this approach we can calculate a combined risk metric, which is the scaled exceedance of the N critical load and climatic thresholds in the three-dimensional space of N deposition, temperature, and water limitation. We use a habitat map to project this risk metric for 34 EUNIS habitat types across Austria. Resulting risk maps indicated that about 16 % of the area of these natural and semi-natural habitat types is currently at risk from either N exceedance, drought or warming. Using combinations of future climatic (RCP2.5 and RCP8.5) and N deposition (business as usual, current legislation and maximum feasible reduction) scenarios, we predict that the area at risk might increase to up to 19% until 2050, with risk from N-deposition decreasing and risk from climate change increasing. Combined impacts of both stressors affect only up to 2% of the entire evaluated area, but are much more frequent in particular habitat types such as oligotrophic bogs and subalpine to alpine grasslands. We conclude that this method provides a useful screening procedure to identify and compare areas and habitats under combined risk from both stressors and to thus support prioritization and decision making in biodiversity conservation.

Both woody and herbaceous semi-natural habitats are essential for spider overwintering in European farmland

Semi-natural habitats (SNH) support biodiversity and associated ecosystem services on farmland, thereby contributing to sustainable agriculture. However, little is known about the specific suitability of different types of SNH as overwintering habitat for predatory arthropods, despite the crucial role of such knowledge for conservation biological control. We used ground photoeclectors to sample spiders in 65 habitats comprising crop fields and four major SNH types (herbaceous areal, herbaceous linear, woody areal, woody linear) across two study regions in Switzerland and Germany to identify the most important overwintering habitats for spiders. Spider emergence started in February and over half of the individuals of the most common spiders had already emerged by late April. SNH supported on average 146% higher species richness and 194% higher densities of spiders than crop fields. Woody and herbaceous SNH supported distinct spider communities, with individual species exhibiting marked preferences for either woody or herbaceous SNH. Habitat shape (areal or linear) had no significant effects on spider overwintering. Woody SNH hosted more species, whereas herbaceous SNH had higher densities of agrobiont species (i.e. species known to reach high densities in crops in the growing season). Given the higher number of overwintering agrobionts in herbaceous SNH, this habitat type has potential to promote pest control by spill-over of spiders into nearby crops early in the season. In contrast, woody SNH seem to be more important for the conservation of diverse spider communities that are highly distinct from those inhabiting open land. Hence, creating and preserving a variety of SNH is key to provide suitable overwintering sites for species in agricultural landscapes.

Overwintering of pollen beetles and their predators in oilseed rape and semi-natural habitats

Semi-natural habitats (SNH) maintain high levels of biodiversity and ecosystem functioning within agroecosystems. While management recommendations for SNH to promote biodiversity and optimize natural pest control, have mostly focused on improving food resources for predators, overwintering conditions have hitherto received less attention. The success of conservation biological control is often hampered by a lack of knowledge on how different habitats and their associated traits drive the overwintering of both, crop pests and their natural enemies. Moreover, there are concerns that SNH may act as reservoirs for crop pests.We investigated the overwintering of pollen beetles (Meligethes spp.) and their predators (predatory ground beetles) across 40 habitats of all major types of SNH as well as 8 winter oilseed rape (WOSR) fields, to identify the importance of type and key traits of habitats. Overwintering of pollen beetles was higher in WOSR fields (7 individuals per 0.25 m2) and forest edges (4) compared to flower strips (2) or forest interiors (1). Similarly, overwintering of predatory ground beetles was higher in forest edges and WOSR fields (11 and 10 individuals, respectively) than in flower strips, meadows or hedgerows (4, 4 and 2 individuals). The predator-prey ratio (number of predatory ground beetles / number of pollen beetles) was higher in forest edges than in flower strips, meadows or hedgerows, and intermediate in WOSR fields. Pollen beetle numbers were negatively associated with increasing litter cover and positively with increasing bare soil, while predatory ground beetles were positively associated with soil bulk density and bare soil cover. The proportion of SNH at the landscape level (1 km radius) did not affect overwintering pollen beetles, predatory ground beetles or predator-prey ratio.We conclude that WOSR fields, rather than SNH are the major overwintering habitat and source of spring colonisation of WOSR by pollen beetles. Forest edges promote predatory ground beetles rather than pollen beetle populations according to their disproportionally high value of overwintering individuals. Agri-environmental measures to promote predatory ground beetles rather than pollen beetles should promote overwintering habitats with compact soils and high litter cover.

Identifying Habitat Type Conservation Priorities under the Habitats Directive: Application to Two Italian Biogeographical Regions

The ongoing biodiversity crisis necessitates greater efforts to ensure the adequate conservation of critical habitat types. Even though the identification of protected areas is still required in Europe, conservation efforts are now focusing on management requirements for protected areas and habitat types. Establishing effective management approaches is important for the conservation of the natural and semi-natural habitat types that are identified under the Habitats Directive framework. In this study, we propose a methodology for determining priorities in the conservation management of habitat types based on readily available data. This method relies on four simple criteria to rank habitat types, which includes: conservation condition, biodiversity value, pressure factor, and the cover relevance of habitat types (indicating regional responsibility in terms of area covered). After ranking the habitat types based on the sum of the scores given to all of the criteria, the 25% top-ranking habitat types were prioritized. The pressure factors are analyzed using cluster analysis to better convey information regarding the management needs of groups of habitat types. This prioritization method was tested in habitat types occurring within the Italian Alpine and Continental biogeographical regions. From this analysis, forests, bogs and fens, and dry grasslands were identified as conservation priorities for the Alpine region; meanwhile, a wider variety of habitat types were identified for the Continental region. Important pressure factors were identified (e.g., roads and motorways) for these two biogeographical regions of Italy, which could be used to suggest specific conservation measures. The proposed approach represents a transparent and reliable method for outlining habitat-type priorities based on conservation, biodiversity, pressure, and cover factors, which can be applied to identifying conservation measures that can help achieve biodiversity targets.

A pan-European model of landscape potential to support natural pest control services

Pest control by natural enemies (natural pest control) is an important regulating ecosystem service with significant implications for the sustainability of agro-ecosystems. The presence of semi-natural habitats and landscape heterogeneity are key determinants of the delivery of this service. However, to date, synthetic and consistent indicators at large scales are lacking. We developed a pan-European, spatially-explicit model to map and assess the landscape potential to sustain natural pest control. The model considers landscape composition in terms of semi-natural habitats types, abundance, spatial configuration and distance from the focal field. It combines recent high-resolution geospatial layers with empirical results from extensive field surveys measuring the specific contribution of different semi-natural habitats to support insects flying enemies providing natural pest control. The resulting maps facilitate a comparison of the relative biological control potential of different areas and show that currently a large proportion of high-productive agricultural areas in Europe has low potential. The obtained indicator can inform the formulation of policies and planning strategies aimed at increasing biodiversity and ecosystem services and can be used to assess trade-offs between different services. Potential fields of application include the Common Agricultural Policy and the EU Biodiversity Strategy, in particular the implementation of Green Infrastructure.

Use of long-term data to evaluate loss and endangerment status of Natura 2000 habitats and effects of protected areas.

Habitat loss is a key driver of biodiversity loss. However, hardly any long-term time series analyses of habitat loss are available above the local scale for finer-level habitat categories. We analysed, from a long-term perspective, the habitat specificity of habitat-area loss, the change in trends in habitat loss since 1989 (dissolution of the communist state), and the impact of protected areas on habitat loss in Hungary. We studied 20 seminatural habitat types in 5000 randomly selected localities over 7 periods from 1783 to 2013 based on historical maps, archival and recent aerial photos and satellite imagery, botanical descriptions, and field data. We developed a method for estimating habitat types based on information transfer between historical sources (i.e., information from a source was used to interpret or enrich information from another source). Trends in habitat loss over time were habitat specific. We identified 7 types of habitat loss over time regarding functional form: linear, exponential, linear and exponential, delayed, minimum, maximum, and disappearance. Most habitats had continuous loss from period to period. After 1986 the average annual rates of habitat loss increased, but the trend reversed after 2002. Nature conservation measures significantly affected habitat loss; net loss was halted, albeit only inside protected areas. When calculating the degree of endangerment based on short-term data (52 years), we classified only 1 habitat as critically endangered, but based on long-term data (230 years), this increased to 7 (including habitat that no longer existed). Hungary will probably reach the global Convention on Biological Diversity Target 5 but will probably not achieve the EU Biodiversity Strategy target of halting habitat loss by 2020. Long-term trend data were highly useful when we examined recent habitat-loss data in a wider context. Our method could be applied effectively in other countries to augment shorter-term data sets on trends in habitat area.

Landscape complexity promotes hoverflies across different types of semi‐natural habitats in farmland

Abstract Semi‐natural habitats (SNH) provide essential resources for many organisms in agricultural landscapes and can increase biodiversity at the local and landscape scale. For the management of ecosystem services, it is crucial to understand how local characteristics of SNH and the surrounding landscape complexity affect beneficial species. We investigated this for hoverflies (Diptera: Syrphidae)—an important functional group providing both pest control and pollination services—in a total of 138 SNH within 35 agricultural landscapes in Switzerland and Germany. SNH differed in type (woody, herbaceous), shape (areal, linear) and availability of food resources (floral resources and aphids). They were located along a gradient of landscape complexity (1%–75% SNH in a 1 km radius). In total, 9,030 hoverflies belonging to 89 species were collected. In both countries, hoverfly community composition was mainly driven by SNH type and SNH shape, in addition to landscape complexity in Switzerland. Species richness of hoverflies increased with additional SNH at the landscape scale. However, the ubiquitous and dominant aphidophagous species Episyrphus balteatus was indifferent to landscape composition. Species richness of total and aphidophagous hoverflies was higher in woody than in herbaceous SNH. Hoverfly species richness was similar in linear and areal SNH, but non‐aphidophagous hoverflies were more vulnerable to landscape simplification in linear than areal SNH. Effects of the SNH type partly differed between the two countries. In Germany, the dominant aphidophagous species E. balteatus preferred woody over herbaceous SNH, while no such difference was found in Switzerland. Overall, local richness and abundance of floral resources were poor predictors for hoverfly abundance, richness or community composition. Synthesis and applications. Hoverfly species richness and community composition in semi‐natural habitats (SNH) were mainly driven by the SNH type and landscape complexity. Conservation and restoration of complex agricultural landscapes with a high proportion of different SNH types is therefore key for the conservation of hoverfly diversity, and thus likely to promote pest control and pollination services provided by them. Thereby, local improvement of SNH to promote hoverflies has to consider regional differences in habitat characteristics.