International audience | A range of policy initiatives have been promoted in recent years to address the decline of bee populations in Europe and North America. Among these has been the establishment of flower-rich habitat within or around intensively farmed landscapes to increase the availability of pollen and nectar resources. The composition of these habitats depends on location and compatibility, with adjacent cropping systems, but they often consist of fields planted with temporary flowering cover crops, field borders with perennial or annual flowering species, hedgerows comprising prolifically flowering shrubs, and grass buffer strips (used to manage erosion and nutrient runoff) which are supplemented with dicotyledonous flower species. While the primary objective of such measures is to increase the ecological fitness of pollinator populations through enhanced larval and adult nutrition, such strategies also provide secondary benefits to the farm and the surrounding landscape. Specifically, the conservation of pollinator habitat can enhance overall biodiversity and the ecosystem services it provides (including pest population reduction), protect soil and water quality by mitigating runoff and protecting against soil erosion, and enhance rural aesthetics. Incorporating these secondary benefits into decision making processes is likely to help stakeholders to assess the trade-offs implicit in supplying ecosystem services. (C) 2012 Elsevier B.V. All rights reserved.

1. Alterations in land use and biological invasions are two major components of global change that threaten biodiversity. There is high concern about their impact on pollinators and the pollination services they provide. However, the growing literature shows different, even contradictory results. 2. We present a global meta-analysis of 58 publications reporting 143 studies (37 on landscape alteration and 21 on biological invasions) to assess the extent to which these components affect pollinators, and whether taxonomic and ecosystem-type differences in pollinator responses occur. We also quantified which component of landscape alteration had the largest effect on pollinators and assessed whether animal invasions differ from plant invasions in their effect on native pollinators. 3. Habitat alteration and invasions affected pollinators to the same magnitude by decreasing visitation rates. Vertebrates in altered landscapes and insects (excluding bees) in invaded areas were the most affected pollinator taxa. 4. Pollinator abundance was more reduced in altered forest ecosystems than in altered grasslands; while the reverse pattern was found for pollinator richness. However, the response of pollinators to invasions was independent of ecosystem type. 5. Disturbance of the surrounding matrix was more important in decreasing pollinator visitation rates than fragment size. 6. Invasive animals seemed to have a more consistent negative effect on visitation rates than invasive plants. 7. Synthesis. Our study highlights that different components of global change have similar negative outcomes on pollination patterns, but that responses of pollinators vary among taxa and ecosystem types, as well as the attributes of landscape alteration considered and whether the invader is an animal or a plant. | Funding was provided by STEP (244090-STEP-CP-FP) of the EU 7FP, the Spanish Ministerio de Ciencia e Innovacion project MONTES (CSD2008-00040) and a PhD fellowship (JAE-Predoc) to AMC. | Peer reviewed

A coastal grassland was used as a model system to examine how grazing management, un-grazed (for six years), rabbit grazed or fully grazed (ponies 0.2ha⁻¹, cattle 0.05ha⁻¹ and rabbits 45ha⁻¹), affected biodiversity and ecosystem service provision, by measuring an extensive suite of biophysical variables as proxies for ecosystem services. For ‘supporting services’, nutrient cycling was greatest in un-grazed grassland but primary productivity did not differ. The ‘provisioning service’ of food production was only provided by fully grazed grassland. For grazing effects on ‘regulating services’ total carbon (C) stock did not differ and effects on pest regulating invertebrates and pollinator abundance were variable. The potential for flood control was considered greatest in the un-grazed grassland; with faster water infiltration than in the fully grazed grassland. The ‘cultural service’ of environmental appreciation was considered higher in fully grazed grassland due to significantly greater plant species richness, more forb species and more forbs flowering than in un-grazed grassland.

Mainstreaming ecosystem services in EU decision making processes requires a solid conceptual and methodological framework for mapping and assessing ecosystem services that serve the multiple objectives addressed by policies. The PRESS-2 study (PEER Research on EcoSystem Services Phase 2) provides such an analytical framework which enables the operationalization of the present scientific knowledge base of environmental data and models for application by the EU and Member States for mapping and assessment of ecosystem services. This study is structured along three strands of work: policy and scenario analysis, mapping and valuation. Linking maps of ecosystem services supply to monetary valuation allows an analysis of the expected impact of policy measures on benefits derived from ecosystem services. The first case study looks at water purification and demonstrates the three-step assessment cycle, investigating the impacts of agricultural and water policy scenarios on the capacity of ecosystems to purify water and on the benefits that are derived from improved water quality at different spatial scales. In general, the conclusion is that greening the CAP, would improve water quality and increase the benefits to society as measured via monetary valuation. Yet, reduction rates differed between the different levels (EU and basin scale) suggesting that the assessment of policy measures is scale-dependent, which, in turn, justifies our multi-scale assessment approach. The second case study (recreation) presents evidence that millions of people visited forests several times per year and they expressed their willingness to pay to continue doing so. The visitor statistics that are used in this study confirm the usefulness of the ROS approach (Recreation Opportunity Spectrum) to identify areas in terms of their accessibility and potential to provide recreation services. In addition, PRESS-2 presents a spatial analysis of city population density and green urban areas. The third case study regards pollination. Pollination services offered by insects such as wild bees and bumblebees are essential to maintain crop production, in particular of fruits and vegetables. PRESS-2 demonstrates that the coverage and resolution of current datasets are already sufficient to map the potential of ecosystems to provide this ecosystem service. However, future research should contribute to better ecological observations of key pollinator species to include important drivers of pollinators abundance in modelling and mapping approaches. Europe has ambitious biodiversity and ecosystem services targets. Much of the ambition incorporated in the targets rests on the premise that ecosystem services are dependent on biodiversity for which there is indeed a substantial amount of evidence. Achieving biodiversity targets requires prioritizing investments and making them cost effective based on a sound knowledge base and assessment methods, which PRESS has contributed to. Our approaches show that the inclusion of the ecosystem services concept into policies would allow a systematic review of the consequences of policy measures for services beyond conventional environmental assessments. In order to be able to react and adapt to new circumstances, consequences of policies must be continuously monitored and flexible in design. Therefore, it is necessary to quantify goals and determine baseline levels describing what the situation was before the measure against which progress is verifiable. However, research is only one element of the necessary efforts to restore natural ecosystems and to preserve biodiversity in Europe. Therefore, the PRESS-2 team reiterates the conclusion of the first report and calls for a broad collaboration of all stakeholders involved, including researchers, policy makers, stakeholder groups and citizens, in an integrated ecosystem services approach. | v | ok

As costs for mineral fertilizers rise, legume-based leys are recognised as a potential alternative nitrogen source for crops. Here we demonstrate that including species-rich legume-based leys in the rotation helps to maximize synergies between agricultural productivity and other ecosystem services. By using functionally diverse plant species mixtures these services can be optimised and fine-tuned to regional and farm-specific needs. Field experiments run over three years at multiple locations showed that the stability of ley performance was greater in multi-species mixtures than in legume monocultures. In addition, mixing different legume species in the ley helps to suppress both early and late weeds. Further, combining complementary phenologies of different legume species extended forage availability for key pollinator species. Finally, widening the range of legume species increases opportunities to build short term leys into rotations on conventional farms via cover cropping or undersowing.

Early successional landscapes along or adjacent to infrastructure installations have been highlighted as potential pollinator conservation zones that provide environmental benefits and ameliorate some of the negative impacts of wildland conversion. Habitat development and management initiatives in this field are active, but vetted support for particular techniques and strategies is lacking and technical information is diffuse. We reviewed the current scientific and technical literature relating to right-of-way and roadside management to produce an overview. Surveys and comparative studies dominate the literature, with limited manipulative experimentation and limited tests of best management practices. Local floristic diversity is shown to be a determinant of butterfly, bee, and fly patterns but data is almost entirely lacking on vertebrate pollinators. The degree to which these linear landscape corridors can promote movement and connectivity is also not well addressed, yet there is a focus in the conservation community to promote migrations and movement. Contrasting results are reported for the impact of disturbance regimes associated with management (mowing and herbicide use), and there is also only minimal attention given to the potential negative impacts that are experienced by pollinators on rights-of-way. Even with the limited literary accounts of pollinator management in these landscapes we believe infrastructure landscapes can provide substantial benefits to pollinator species and ecosystem services and encourage further management-based investigations.   Please find supplementary files to this article in the menu on the left side.

Urbanization is a widespread and rapidly growing threat to biodiversity, therefore we need a predictive understanding of its effects on species and ecosystem processes. In this paper we study the impact of urbanization on a guild of nectar-feeding birds in a biodiversity hotspot at the Cape of Africa. The guild of four bird species provides important ecosystem services by pollinating 320 plant species in the Cape Floral Region. Functional diversity within the guild is related to differences in bill length. The long-billed Malachite Sunbird (Nectarinia famosa) plays an irreplaceable role as the exclusive pollinator of plant species with long nectar tubes. We analyzed the composition of the guild in suburban gardens of Cape Town along a gradient of increasing distance from the nearest natural habitat. Urbanization reduces the functional diversity of the nectarivore guild. Malachite Sunbirds did not penetrate more than 1 km into the city, whereas only the short-billed Southern Double-collared Sunbirds (Cinnyris chalybea) occurred throughout the urbanization gradient. The lack of data precludes conclusions regarding the detailed responses of Orange-breasted Sunbirds (Anthobaphes violacea) and Sugarbirds (Promerops cafer), however their absence across the entire gradient is suggestive of high sensitivity. The functional diversity of this guild of pollinators can potentially be restored, but the pros and cons of this conservation action need to be considered.

Zumkier U. <em>Impacts of the invasive alien Heracleum mantegazzianum on native plant-pollinator interactions</em>. Bielefeld: Universität; 2012. | Pollination is one of the most essential ecosystems services, it is crucial to the reproduction of most flowering plants, and plays an important role in crop production. This fundamental ecosystem service is threatened by the ongoing global change, which includes climatic change, changes in land use, and the introduction and spread of alien species. Alien plants may have a negative impact on native plants when they compete for pollination services. Effects of competi- tion for pollinators may have an impact on the quantity as well as the quality of pollination. The quantity of pollination adresses the number of visits a plant receives, while the quality of pollina- tion describes the number of transferred pollen grains. The complex interactions of these factors determines the outcome of seed set for a plant. Ultimately, a negtive affection of these compo- nents may lead to a reduction of plant fitness. The fact that alien plants often have large showy inflorescences as they were commonly introduced as ornamentals makes them potentially supe- rior competitors. Alien plants have been shown to affect the quantity as well as the quality of co- flowering native species. Furthermore, it has to be taken into consideration that species do not interact in a vacuum, plants and pollinators form a mutualistic interaction network. While there is evidence that alien plants are well-integrated into interaction networks, there is still a demand to know if this integration translates into effects on the quality of pollination and reproductive success of a community of co-flowering plants. Aim of this thesis was to scrutinize the impacts of the alien invasive plant Heracleum mantegaz- zianum on native plant-pollinator systems. Due to its tall growth and large compound inflores- cences H. mantegazzianum definitively has the potential to affect the pollination of native plants. In order to find out about the pollinators of the invader a field study was conducted, which included observation of flowers and measurements of pollinator efficiency. The same measure- ments were made for the native closely related Heracleum sphondylium in order to detect an overlap of pollinator faunas. An experimental garden setup was used in order to determine the effect of the invader on insect visitation and set seed of an array of co-flowering plants. Addi- tionally, I used a network approach to explore the impact of H. mantegazzianum on two- and one-mode network parameters. Furthermore, the transport of alien pollen was quantified and network parameters of networks based on visitation, interaction and pollen transfer were com- pared. Results show that the large inflorescences of the invader were highly attractive to a broad range of insects, yet there were just a few insects truly important pollinators, most of all the honeybee Apis mellifera. There was low potential for competition between the two Heracleum-species, yet the invader might have a potential to influence native plant-pollinator interactions due to its association with the super-generalist A. mellifera. However, results of the experimental garden revealed that visitation rates of co-flowering plants were (although statistically non-significant) generally enhanced, and the effect on seed set was neutral. H. mantegazzianum was found not only to be well integrated, but dominant in invaded visitation networks. Nevertheless, in com- bination with the results for seed set it was concluded that the impact of the invader was not detrimental to the invaded plant-pollinator system. Additionally, I could show that, while flower visitors of H. mantegazzianum were less constant than on other plants and there were plant-to- plant interactions for all co-flowering plants, still little alien pollen was transferred. Neverthe- less, there was a potentially competitive effect of conspecific pollen loss depending on the plant species. Network analysis showed that the alien plant was only dominant in terms of visitation but not in terms of interspecific pollen potentially transferred. This highlights that both, the quantity and the quality component, need to be assessed to create an adequate estimate on the impact of an invader on plant-pollinator systems.