The biodiversity consequences of killing Ecological Focus Areas

After the December 2012 Council proposed amendments, the vote of the agricultural committee of the European Parliament (COMAGRI) on January 24 2013 de facto kills any hope of deriving serious biodiversity benefit from the CAP reform. The COMAGRI amendments are particularly fatal to the Ecological Focus Area (EFA) measure, which is now nearly ‘as dead as a dodo’. The fact that the COMAGRI amendments largely restate the Agricultural Council’s draft position on the EFA leaves little hope for future debates between the Parliament and the Council. The conclusions of the European Council on February 8, 2013 can be seen as the burial of the EFA.
Many economists and think tanks doubted that the combination of Pillar 1 payments and green requirements was the most cost-efficient way to promote biodiversity and were not enthusiastic about the EFA idea. It is now time for them to realize that while Pillar 2 payments will be cut, Pillar 1 payments will be maintained but without any serious biodiversity requirement.
How the EFA proposal has been neutered
Both the Agricultural Council’s decision and the COMAGRI vote relax many greening aspects of the Pillar 1 payments proposed by the Commission (1). The Commission wanted to condition all direct payments in respect to the conditions laid out for the Green Payment, so that there would be some cross-compliance between the different layers of payments (2). The COMAGRI vote removed all potential links between getting the Basic Payment and complying with the requirements of EFA, permanent pasture preservation and crop rotation, echoing the draft position of the Council in December 2012. Any prospect of a leverage effect between the Green Payment and other payments is now history. At the same time, environmental requirements of the Basic Payment tended to be relaxed compared to the current situation (for a comparison of the different positions and amendments see this post).
The Green Payment is now clearly optional. In addition, the conditions to obtain the Green Payment have themselves been neutered by the various amendments of the Commission’s text proposed by both the COMAGRI and the Agricultural Council. These amendments look like technicalities, but in practice, they water down considerably the EFA requirements (3). With the COMAGRI amendments, permanent crops would be removed from the EFA constraint; some elements that are not part of the arable land could be counted against the requirement; land planted with nitrogen fixing crops would be part of the EFA; EFAs could be used for production provided that no chemical input were used. Farms below the size of 10 hectares would be exempted from the obligation of EFAs; rather than imposing that EFA cover 7% “of their eligible hectares as defined in Article 25(2), excluding areas under permanent grassland” to obtain the Green Payment as stated in the Commission proposal, the COMAGRI voted for 3% obligation, with a move to 5% in from 2016 (4). The COMAGRI also included some possibilities for Member States to implement 3% EFA at the regional level, which could help in building adjacent EFAs but might also lead to count as EFAs some fallows that exist “naturally” in some particular areas. Definitions of some technical terms were also extended by COMAGRI amendments, all of them involving a relaxation of the requirements.
Many of the COMAGRI amendments on EFAs converge with the stocktaking of the Agricultural Council in December 2012, as summarized in the conclusion of the Cyprus presidency. Agricultural ministers also proposed to broaden the definition of EFAs; to leave Member states with latitude to define which areas should be considered for ecological focus in their territory; to exempt farms smaller than 15 hectares from EFA requirements; to consider that some farms de facto meet the requirement, provided that they dedicate 70% of their land surface to grazing or herbaceous production; to remove permanent crops and leguminous crops from areas subject to the EFA requirement; and to allow Member States to implement half of the EFA requirement through collective actions undertaken at a different geographical level in order to obtain adjacent ecological focus areas.
Equally important are the flexibility provisions (Member States can substitute environmental certification schemes for one or more of the greening measures) and ‘green by definition’ equivalence (all farmers enrolled in agri-environment measures are automatically eligible for the green payment) in the COMAGRI amendments and in the Cyprus presidency conclusions, which considerably weaken the Commission’s original proposals.
So, what is left of the EFAs?
When it drafted the 7% EFA requirement proposal, the Commission estimated that at least 3% of the land on almost any farm qualifies as EFA, once existing buffer strips, field borders and field sections where tractors can hardly access were all taken into account. Therefore, one can safely consider that there is no longer any serious practical requirement left for the farmer after the adoption of the COMAGRI provisions on EFAs.
The COMAGRI vote could theoretically be modified in plenary session in March 2013, but given that the few MEPs who have some expertise on CAP issues sit in the COMAGRI it is hard to imagine that the Parliament as a whole will inverse the COMAGRI decisions on technical issues. It will more likely focus on CAP budgetary issues. In any case, the blow to the EFAs will likely be fatal since the positions taken by Agricultural ministers in December 2012, i.e. more or less the same as the COMAGRI amendments, were largely endorsed by the Heads of States (5). Indeed, the conclusion of the European Council on February 8 2013 states that

“The requirement to have an ecological focus area on each agricultural holding will be implemented in ways that do not require the land in question to be taken out of production(…)”

This can be viewed as the final nail in the coffin for EFAs.
The EFA section of the October 2011 Commission’s proposal had a frosty reception by farmers’ organizations. Opposition from the COPA-COGECA was very strong. Many economists also criticized the design of the EFA proposal. Some questioned the impact of a ‘one size fits all’ measure when benefits and compliance costs are heterogeneous. Most economists actually support greater focus of CAP funds on the environment and the provision of public goods, but few have sympathy for the Pillar 1 approach. This explains why the farm lobby attacks against the EFAs have not been seriously opposed by academics and think tanks. Even the environmental NGOs were critical, arguing that scattering of the protected EFAs would limit the benefits for those species that require a more concentrated habitat. Sadly, the Council and the COMAGRI leave everybody with the worst of all worlds, i.e. large Pillar 1 payments without (serious) EFA requirements.
What is the damage to biodiversity?
Fostering biodiversity is tricky. In ecology, few scientific results hold independently of local conditions and species. Population dynamics depend on multiple factors, face complex non-linearities, path dependency and tipping points. The relation between agricultural production and biodiversity indicators can be highly convex (so that a limited intensity of agriculture already results in large biodiversity losses, e.g. type a in the figure below) or concave (in which case low impact on biodiversity is maintained until high levels of intensity, e.g. type b). Some species, especially farmland specialists, also need some degree of agricultural activity to maintain their habitats but suffer from high levels of intensification (e.g. type c). The consequences of sparing some land for biodiversity conservation as originally proposed in the case of EFAs are therefore very different across situations. The much debated issue of whether land sharing à la EU is more efficient than land sparing à la US for protecting biodiversity clearly depends on the shape of the so called density dependence function: land sharing, such as conservation reserves or national parks, will be better adapted to an a-type than to a c-type or b–type function in the figure below, where farmers can more easily be put in charge of the provision of biodiversity services. The shape of these functions is strongly dependent on the community considered and shifting from an a-type to a c-type function is likely to depend on whether native species or farmland species are considered (see reference [34] below for example).

Obviously, the lack of robust results with a general scope does not help the cause for shallow measures such as EFAs. A group of French researchers surveyed the scientific literature and debated the results in an attempt to shed light on the potential benefits of EFAs. These discussions shed some light on the ecological benefits that one may have expected from the measure originally proposed by the Commission.
In short, in addition to the few impact assessments of the proposed EFAs, there are two main bodies of literature that can help us assess the potential benefits of EFAs in terms of biodiversity. The first one is the evaluation of Agri-Environmental Schemes (AES) that have had some ecological focus components, including environmental set-aside. The second one is the Swiss experience with Ecological Compensation Areas (ECAs). ECAs show some similarity with the proposed EFAs, including the requirement that 7% of agricultural land under conservation programs receives a series of payments, even though the many supplementary agri-environmental measures available to a Swiss farmer make it difficult to isolate the ECA effect. Below, I will mainly summarize the synthesis done by Valentine Guéneau from AgroParisTech, and contributions by Rodolphe Sabatier from INRA and Felix Teillard from the Muséum National d’Histoire Naturelle in internal seminars of the group. The bracketed numbers refer to the references found at the end of the document, for those who would like to explore the issue further.
The potential impacts of EFAs on plant biodiversity
Regarding plant biodiversity, not all scientific results converge. Works based on the AES experience lead to rather pessimistic conclusions regarding the ability of such schemes, particularly in areas characterized by some intensive agriculture [25]. However, a series of results based on the Swiss experience lead to much more optimistic conclusions, showing that the ECAs are characterized by much more diverse flora [6, 30, 26, 27]. It seems that fertilizer and pesticide reduction on the ECAs are part of the explanation, suggesting that other measures, such as organic farming could also do the job as well as EFAs. Restrictions on mowing also seem to play an important role. The ECAs also help limiting the expansion of some of the most invasive plants, thanks to more competition from a broader range of local varieties [29]. Overall, the literature on the Swiss ECA experience suggests that EFAs would have had a positive effect on plant biodiversity. This form of biodiversity has a positive impact on animal and insect species, since plants participate in their habitat and alimentation.
The potential impacts of EFAs on arthropods
There is convergence of results on the fact that ECAs have a positive effect on pollinating insects [1, 2, 29, 26], with visible effects on the reproduction of some crops that require pollination. However, this impact becomes rapidly limited with increased distance from the the ECAs. The smallest pollinators, which play a crucial role in addition to bees do not travel far, suggesting that the scattering of the EFAs feared by environmentalists would not be completely negative for this particular ecological service [1, 29]. Again, as limitation of chemicals and late mowing play an important role in maintaining the greater population of pollinating insects, ECAs are perhaps not the crucial factor per se [1,6,7]. But unless some other form of protected habitat is found, EFAs appear to be beneficial in this area.
Arthropods that play an important role in controlling pests (e.g. ladybirds, bugs) are highly favoured by the presence of hedges, grass strips and other linear landscape elements, and they need habitats and food but also some protection during harvests [11]. The impact of a large population of arthropods on the whole agricultural production is significant [2]. They notably help to reduce the use of insecticides. The impact of EFAs on other arthropods such as spiders and beetles is more ambiguous [2, 31, 26]. The structure of the vegetation and the type of habitat seem more determinative than the ECAs per se. The diversity of these populations would benefit from sowing some particular types of plants such as lucerne or alfalfa and from adopting some particular harvesting and mowing techniques [32, 26].
Overall, while there is limited evidence of the potential impact on spiders and beetles, EFAs could greatly improve the services provided by arthropods in terms of pollination and pest control.
The potential impacts of EFAs on mammals
Small mammals are more abundant in ECAs than in other areas in Switzerland. The density of soil cover plays an important role and thick grass strips and large unploughed field borders have a significant impact on mammal populations, as does connectivity with hedges and existing natural habitats (woods, bushes). On the other hand, ploughing and manure spreading have a strongly negative impact, and if they are allowed on EFAs, the positive impact on mammals could be reduced significantly [5, 3]. It is noteworthy that EFAs could also contribute to an increase in the population of some small mammals that are seen as undesirable by farmers, such as voles (Microtus is the latin name, campagnols in French). It is also noteworthy that while a larger population of small mammals has an indirect but important impact on the population of their predators (larger mammals and birds of prey), this relation is not linear and depends on the presence of particular habitats. Larger mammals also benefit from habitats such as EFAs, but they are often subject to threshold effects. In any case, the literature that could help assess the impact of EFAs is limited.
The potential impacts of EFAs on birds
There is evidence of a sharp decrease in farmland bird populations in the EU, particularly in areas of intensive agriculture (6). Studies have shown that particular types of EFAs could have a large positive impact on some bird species. This is typically the case of hedges that provide shelter from predators and habitats for reproduction and nesting [21]. However, like for larger mammals, the effect of EFAs depends greatly on the presence of other elements of natural habitats, such as proximity of afforested areas, orchards or wild vegetation. The positive impact of more rodents on the population of predators is larger when a mosaic of dense vegetation and arable crops is present. Many species depend on a diversity of complementary habitats [36]. Habitat diversity is necessary for owls and buzzards, for example to be able to hunt and reproduce [4, 3]. This illustrates the key importance of the ecological complementation process [35] for mobile species such as birds and mammals, if different resources, including shelter and food, are provided. The Swiss experience in Aargau County suggests that the ECAs have had a significant and positive impact on bird populations, but a variety of agri-environmental measures have resulted in a high percentage of diverse ecological areas and a larger share of the total surface under ecological conservation [30]. For lower levels such as the one proposed by the Commission for the EFAs, the impact seems much smaller [10].
Due to the variety of habitats needed and the complex dynamics of each species, one cannot draw a general conclusion on the effect of EFAs on bird populations. However, the positive impact of EFAs on some species appears significant.
Endangered species
For those species of birds and mammals that are already experiencing a strong decline, various assessments suggest that AES have had a very limited impact [14, 6]. The literature suggests that the EFAs proposed by the Commission are hardly up to the task of protecting species that are red listed as threatened.
The potential impacts of different types of EFAs
The Swiss experience provides some interesting results regarding the biodiversity impacts of different types of ECAs. Pastures managed in a way that restricts early harvests with very low or no fertilizer and chemicals have clearly significant benefits on arthropods, including the pollinating ones [1,2,26]. However, the impact on many bird populations depends on the connectivity with other forms of habitats, which refers to other types of EFAs such as hedges or orchards, and the thickness and continuity of hedges [10, 11, 15]. Linear elements of the landscape, such as grass strips, hedges and field borders play an important role for small mammals, birds and insects [3, 5, 11, 15, 20, 21]. Synergy with some agricultural techniques and productions (alfalfa, lucerne) has also been demonstrated [32, 28]. Wild flower strips are also particularly useful for the population of pollinating insects and birds [17, 10]. Fallows have a significant impact on the diversity of plants, birds, insects and spiders [12, 16]. But interactions with the proximity of other forms of habitat are important, especially for the colonization of fallows and meadows (the metapopulation effect) as well as for species relying on a diversity of habitat (the complementation effect).
Ecological continuity between EFAs and with semi-natural habitats plays a large role on the biodiversity impact of such measures [1]. Connecting EFAs is essential for some arthropods. Linear connectivity of habitats is necessary for the mobility of small mammals [19, 8,15, 33]. More generally, without such connectivity, it is difficult to have a balanced rate of colonization and extinction, and the probability of disappearance of a species in the area is high [24]. The negative side is that corridors make it possible for invasive species to disseminate more rapidly (dissemination of invasive plants has been favored in the corridors on the side of motorways, for example).
Heterogeneity within a given EFA, such as a grass strip or hedge, is important for certain species such as hares, for example. The synergy with the adjacent non-agricultural landscape is complex: Within close proximity to a semi-natural habitat (wood patch, pond, etc.) the marginal effect of an EFA can be small. However, in many cases, connectivity with such areas strongly reinforces the impact of the EFA [8, 18]. Similar synergies can be observed when EFAs are implemented on or close to low input agricultural systems [24, 27]. In particular, the combination of EFAs and a reduction in fertilizers can limit production losses; noting that the measures taken to foster biodiversity tend to be more successful when agricultural techniques are already rather extensive.
Although landscape heterogeneity sustains metapopulation dynamics and favors resource complementarity and habitat diversity, some authors recently emphasized that some specialist species benefit from the homogeneity of their habitat [38, 39]. This suggests that ECAs could be used to promote both landscape heterogeneity (e.g. hedges, field margins) and habitat homogeneity (e.g. meadows, set-asides), according to conservation priorities.
In conclusion
There is a lot of debate over the ability of the EFAs proposed by the Commission to have an effective impact on biodiversity. A rate of 7% EFA as proposed by the Commission would clearly have an economic cost, even though in practice it would only lead to return of about 3% of arable land into areas which protect biodiversity. The results presented above do not show that the benefits of the EFAs exceed their cost. Nor do they question the fact that there were much cheaper ways to foster biodiversity than to provide a huge amount of money to farmers (Pillar 1 payments) and impose some requirements on them, as many observers such as Louis Mahé or Alan Matthews have argued. The conclusions drawn from the survey of the scientific literature regarding the potential effect of EFAs are mixed. Biodiversity is complex and the determinants are numerous. EFAs would play a very limited role for some species such as large mammals, and there is little hope to see a significant impact on endangered species whose populations have already greatly declined.
But the survey unambiguously shows the potential positive impact on several forms of biodiversity, including some that provide economically important ecosystem services such as pollination and pest control. The evaluation of linkages between agricultural techniques and biodiversity published by the Institut National de la Recherche Agronomique in 2009 (in French) concludes that Switzerland is the only country in Western Europe which has seen a noteworthy deceleration in the decline of biodiversity (see Table 4.3.3). The conditionality of direct payments to ECAs has played an important role in attaining this result. The Swiss experience also shows that the benefits of a 7% EFA could be expanded if other measures were taken to increase the connectivity of habitats and the heterogeneity of landscapes, and if more incentives were offered to ensure that the EFA will include higher impact measures such as flower strips and hedges.
The various amendments adopted by COMAGRI reduce the actual constraint of the EFAs to basically nothing when compared with the current situation. This not only means that the bulk of direct payments will not be subject to the EFA requirements, but also that getting the Green Component of the direct payments should be more or less automatic for most farmers. Hence, the debate on whether Pillar 1 payments conditioned to EFAs are a more expensive than more focused payments to achieve biodiversity now seems out of date: Europeans will have to pay for Pillar 1 subsidies but with no serious biodiversity gain in return.
One can admit that more impact assessment would be needed to further assess the costs and benefits of the measure. But scientific uncertainty has seemed to be used as an excuse for the COMAGRI to empty the Commission’s proposal of any biodiversity content. The current rates of decline of biodiversity as observed on bird and insect populations are scary. To take a typical ‘common’ farmland bird such as the linet (Carduelis, linote in French), the current population is only 29% of what it was twenty years ago, according to French STOC data [37]. The decline is also dramatic for once common birds such as the skylark (Alauda arvensis or alouette in French), or the common quail. And the decline rate is much higher for most emblematic and threatened farmland bird species. Data show that it is in agricultural areas that bird populations decline most. In exchange for some €280 billion of direct payments proposed by the February Council under Pillar 1 (the European Parliament wants more), some effort might have been asked to farmers to protect the skylark. Both the COMAGRI and the Council seem to have decided otherwise.
(1) For the definition of the EFAs and the other requirements proposed by the Commission to obtain the green payments see the IIEA paper by A. Matthews.
(2) Although the drafting of the October 2011 proposal was ambiguous on this aspect, Commissioner Ciolos was rather clear on this point in a meeting we had with him on November 9 2011.
(3) The COMAGRI amendments can be found here. On EFAs, see in particular amendment #65. The comparison of the Agricultural Council conclusions (Cyprus presidency conclusions) and the COMAGRI amendments was made easy by A. Matthews in his table . While the various amendments are highly technical, Alan Matthews’ table for Article 29 makes it clear that most of them relax the EFAs requirements. Note that the IEEP also provides a short summary of the COMAGRI amendments here.
(4) In the COMAGRI amendments, EFAs would be weighted on the basis of their ecological significance. Weighting coefficients should be drawn up by member states and approved by the Commission. By the end of March 2017, the Commission would have to present an evaluation report and if necessary a legislative proposal to further increase the percentage to 7%. This proposal, if tabled, would be subject to approval by both the European Parliament and the Council.
(5) The European Council conclusions can be found here (see article 65 on the EFAs). See also the Article 17 of the Agricultural Council declarations that support the idea that Member States could offer their farmers the possibility to fulfil greening requirements through alternative measures.
(6) At the EU level, data from the European Environment Agency show that the common farmland bird population has decreased by 50% between 1980 and 2010. After a slowdown in the decline due in particular to the period when setting land aside was mandatory, the fall in population seems to have resumed. In countries where detailed bird abundance data are available, the decline in the farmland bird population is still steeper over the recent period than in both the EEA and Birdlife Europe aggregate data for the whole EU. See in particular [37] and the results of the STOC survey in France, showing that farmland birds have declined steadily between 2005 and 2009.
Acknowledgements: In addition to Valentine Guéneau’s collaboration, I benefited from discussions with Louis-Pascal Mahé, Alan Matthews, Rodolphe Sabatier, Félix Teillard, Jane Stewart but the ideas expressed here do not necessarily reflect their point of view. Thanks to them and to the MOBILIS project (Fondation pour la Recherche sur la Biodiversité) for supporting the brainstorming on EFAs.
Scientific papers quoted
[1] Albrecht, M., Duelli, P., Müller, C., Kleijn, D., And Schmid, B. The Swiss Agri-Environment Scheme Enhances Pollinator Diversity And Plant Reproductive Success In Nearby Intensively Managed Farmland. Journal of Applied Ecology 44, 4 (2007), 813–822.
[2] Albrecht, M., Schmid, B., Obrist, M. K., Schüpbach, B., Kleijn, D., And Duelli, P. Effects of Ecological Compensation Meadows on Arthropod Diversity In Adjacent Intensively Managed Grassland. Biological Conservation 143 (2010), 642–649.
[3] Arlettaz, R., Hl, M. K., Almasi, B., Roulin, A., And Schaub, M. Wildflower Areas Within Revitalized Agricultural Matrices Boost Small Mammal Populations But Not Breeding Barn Owls. Journal Ornithologique 151 (2009), 553–564.
[4] Aschwanden, J., Birrer, S., And Jenni, L. Are Ecological Compensation Areas Attractive Hunting Sites For Common Kestrels (Falco Tinnunuculus) And Long-Eared Owls (Asio Otus)? Journal Ornithologique 146 (2005), 279–286.
[5] Aschwanden, J., Holzgang, O., And Jenni, L. Importance Of Ecological Compensation Areas For Small Mammals In Intensively Farmed Areas. Wildlife Biology 13 (2007), 150–158.
[6] Aviron, S., Nitsch, H., Jeanneret, P., Buholzer, S., Luka, H., Pfiffner, L., Pozzi, S., Schüpbach, B., Walter, T., And Herzog, F. Ecological Cross Compliance Promotes Farmland Biodiversity In Switzerland. Frontiersinecology And The Environment 7 (2009).
[7] Batàry, P., Bàldi, A. B., Sàrospataki, M., Kohler, F., Verhulst, J., Knop, E., Herzog, F., And Kleijn, D. Effect of Conservation Management on Bees And Insect-Pollinated Grassland Plant Communities In Three European Countries. Agriculture, Ecosystems & Environment 136 (2010), 35–39.
[8] Baum, K. A., Haynes, K. J., Dillemuth, F. P., And Cronin, J. T. The Matrix Enhances The Effectiveness of Corridors And Stepping Stones. Ecology 85 (2004), 2671–2676.
[9] Benton, T. G., Vickery, J. A., And Wilson, J. D. Farmland Biodiversity: Is Habitat Heterogeneity The Key? Trends In Ecology & Evolution 18 (2003), 182–188.
[10] Birrer, S., Spiess, M., Herzog, F., Jenny, M., Kohli, L., And Lugrin, B. The Swiss Agri-Environment Scheme Promotes Farmland Birds: But Only Moderately. Journal Ornithologique 148 Supplément 2 (2007), 295–303.
[11] Burgio, G., Ferrari, R., Pozzati, M., And Boriani, L. The Role Of Ecological Compensation Areas On Predator Populations: An Analysis on Biodiversity And Phenology of Coccinellidae (Coleoptera) on Non-Crop Plants Within Hedgerows In Northern Italy. Bulletin Of Insectology 57 (2004), 1–10.
[12] Buskirk, J. V., And Willi, Y. Enhancement of Farmland Biodiversity Within Set-Aside Land. Conservation Biology 18 (2004), 987–994.
[13] Carvell, C., Meek, W. R., Pywell, R. F., Goulson, D., And Nowakowski, M. Comparing The Efficacy of Agri-Environment Schemes To Enhance Bumble Bee Abundance And Diversity On Arable Field Margins. Journal of Applied Ecology 44, 1 (2007), 29–40.
[14] David Kleijn, ., Baquero, R. A., Clough, Y., Diaz, M., De Esteban, J., Fernandez, F., Gabriel, D., Herzog, F., Holzschuh, A., Jãhl, R., Knop, E., Kruess, A., Marshall, E. J. P., Steffan-Dewenter, I., Tscharntke, T., Verhulst, J., West, T. M., And Yela, J. L. Mixed Biodiversity Benefits Of Agri-Environment Schemes In Five European Countries. Ecology Letters 9, 3 (2006), 243–254.
[15] Davies, Z. G., And Pullin, A. Are Hedgerows Effective Corridors Between Fragments Of Woodland Habitat? An Evidence Based Approach. Lanscape Ecology 22 (2007), 333–351.
[16] Decourtye, A., Lecompte, P., Pierre, J., Chauzat, M.-P., And Thiebeau, P. Introduction De Jachères Florales En Zones De Grandes Cultures : Comment Mieux Concilier Agriculture, Biodiversité Et Apiculture ? Courrier De L’environnement De L’inra 54 (2007).
[17] Decourtye, A., Mader, E., And Desneux, N. Landscape Enhancement Of Floral Resources For Honey Bees In Agro-Ecosystems. Apidologie 41 (2010), 264–277.
[18] Donald, P. F., And Evans, A. D. Habitat Connectivity And Matrix Restoration: The Wider Implications Of Agri-Environment Schemes. Journal Of Applied Ecology 43, 2 (2006), 209–218.
[19] Duss, M., Meichtry-Stier, K. S., Pasinelli, G., Baur, B., And Birrer, S. La Mise En Réseau Des Surfaces Ecologiques Favorise Les Sauterelles. Recherche Agronomique Suisse 3 (2012), 4–11.
[20] Hannon, L. E., And Sisk, T. D. Hedgerows In An Agri-Natural Landscape: Potential Habitat Value For Native Bees. Biological Conservation 142, 10 (2009), 2140 – 2154.
[21] Hinsley, S., And Bellamy, P. The Influence Of Hedge Structure, Management And Landscape Context on The Value of Hedgerows To Birds: A Review. Journal of Environmental Management 60, 1 (2000), 33 – 49.
[22] Jeanneret, P., Schã¼Pbach, B., Pfiffner, L., Herzog, F., And Walter, T. The Swiss Agri-Environmental Programme And Its Effects on Selected Biodiversity Indicators. Journal For Nature Conservation 11, 3 (2003), 213 – 220.
[23] Kleijn, D., Kohler, F., Baldi, A., Batàry, P., Concepciòn, E. D., Clough, Y., D?Àz, M., Gabriel, D., Holzschuh, A., Knop, E., Kovàcs, A., Marshall, E. J. P., Tscharntke, T., And Verhulst, J. On The Relationship Between Farmland Biodiversity And Land-Use Intensity In Europe. Proceedings of The Royal Society 276 (2008), 903–909.
[24] Kleijn, D., Rundloöf, M., Scheper, J., Smith, H. G., And Tscharntke, T. Does Conservation on Farmland Contribute to Halting The Biodiversity Decline? Trends In Ecology & Evolution 26 (2011), 474–481.
[25] Kleijn, D., And Sutherland, W. J. How Effective Are European Agri-Environment Schemes In Conserving And Promoting Biodiversity? Journal Of Applied Ecology 40 (2003), 947–969.
[26] Knop, E., Kleijn, D., Herzog, F., And Schmid, B. Effectiveness Of The Swiss Agri-Environment Scheme In Promoting Biodiversity. Journal Of Applied Ecology 43 (2006), 120–127.
[27] Kohler, F., Verhulst, Knop, E., Herzog, F., And Kleijn, D. Indirect Effects of Grassland Extensification Schemes on Pollinators In Two Contrasting European Countries. Biological Conservation 135 (2007), 302–307.
[28] Musters, C., Van Alebeek, F., Geers, R., Korevaar, H., Visser, A., And De Snoo, G. Development of Biodiversity In Field Margins Recently Taken Out of Production And Adjacent Ditch Banks In Arable Areas. Agriculture, Ecosystems & Environment 129 (2009), 131–139.
[29] Ricketts, T. H., Regetz, J., Steffan-Dewenter, I., Cunningham, S. A., Kremen, C., Bogdanski, A., Gemmill-Herren, B., Greenleaf, S. S., Klein, A. M., Mayfield, M. M., Morandin, L. A., Ochieng, A., And Viana, B. F. Landscape Effects On Crop Pollination Services: Are There General Patterns? Ecology Letters 11 (2008), 499–515.
[30] Roth, T., Amrhein, V., Peter, B., And Weber, D. A Swiss Agri-Environment Scheme Effectively Enhances Species Richness For Some Taxa Over Time. Agriculture, Ecosytem & Environment 3148 (2008).
[31] Schmidt-Entling, M. H., And Döbeli, J. Sown Wildflower Areas To Enhance Spiders In Arable Fields. Agriculture, Ecosystems &Amp; Environment 133, 12 (2009), 19 – 22.
[32] Woodcock, B. A., Potts, S. G., Pilgrim, E., Ramsay, A. J., Tscheulin, T., Parkinson, A., Smith, R. E. N., Gundrey, A. L., Brown, V. K., And Tallowin, J. R. The Potential of Grass Field Margin Management For Enhancing Beetle Diversity In Intensive Livestock Farms. Journal of Applied Ecology 44 (2007), 60–69.
[33] Zellweger-Fischer, J., Kéry, M., And Pasinelli, G. Population Trends Of Brown Hares In Switzerland: The Role of Land-Use And Ecological Compensation Areas. Biological Conservation 144 (2011), 1364–1373.
[34] Steffan Dewenter et al. (2007),Tradeoffs between income, biodiversity, and ecosystem functioning during tropical rainforest conversion and agroforestry intensification, PNAS, 104:12 4973-4978.
[35] Dunning, J. B., Danielson, B. J. & Pulliam, H. R. (1992) Ecological Processes That Affect Populations In Complex Landscapes. Oikos, 65, 169-175.
[36] Brotons, L., Wolff, A., Paulus, G. & Martin, J. L. (2005) Effect of adjacent agricultural
habitat on the distribution of passerines in natural grasslands. Biological Conservation, 124, 407-414.
[37] Jiguet F., Devictor V., Julliard R, Couvet D. French citizens monitoring ordinary birds provide tools for conservation and ecological sciences. Acta Oecologica, 2011.
[38] Báldi, A. & Batáry, P. (2011). Spatial heterogeneity and farmland birds : di?erent perspectives in Western and Eastern Europe. Ibis, pp. 875-876.
[39] Batáry, P., Fischer, J., Báldi, A., Crist, T.O. & Tscharntke, T. (2011). Does habitat heterogeneity increase farmland biodiversity? Frontiers in Ecology and the Environment, 9, 152-153.

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