Agri-environment Scheme Options Research Articles

Improving the evidence base for delivery of public goods from public money in agri-environment schemes

There is growing interest around the world in more effectively linking public payments to the provision of public goods from agriculture. However, published evidence syntheses suggest mixed, weak or uncertain evidence for many agri-environment scheme options. To inform any future “public money for public goods” based policy, further synthesis work is needed to assess the evidence-base for the full range of interventions currently funded under agri-environment schemes. Further empirical research and trials should then focus on interventions for which there is mixed or limited evidence. Furthermore, to ensure the data collected is comparable and can be synthesised effectively, it is necessary to reach agreement on essential variables and methods that can be prioritised by those conducting research and monitoring. Future policy could then prioritise public money for the public goods that can most reliably be delivered, offering better value for taxpayers and improving the provision of ecosystem services from agricultural landscapes.

Improving the evidence base for delivery of public goods from public money in agri-environment schemes

There is growing interest around the world in more effectively linking public payments to the provision of public goods from agriculture. However, published evidence syntheses suggest mixed, weak or uncertain evidence for many agri-environment scheme options. To inform any future “public money for public goods” based policy, further synthesis work is needed to assess the evidence-base for the full range of interventions currently funded under agri-environment schemes. Further empirical research and trials should then focus on interventions for which there is mixed or limited evidence. Furthermore, to ensure the data collected is comparable and can be synthesised effectively, it is necessary to reach agreement on essential variables and methods that can be prioritised by those conducting research and monitoring. Future policy could then prioritise public money for the public goods that can most reliably be delivered, offering better value for taxpayers and improving the provision of ecosystem services from agricultural landscapes.

The effects of a decade of agri‐environment intervention in a lowland farm landscape on population trends of birds and butterflies

Abstract Declines in farmland biodiversity remain evident despite over three decades of research and implementation of agri‐environment schemes (AES). Although positive effects of AES are often demonstrated locally or in the short term, studies exploring longer term trends in biodiversity often show contradictory results. Evidence for the potential of AES to drive beneficial changes in populations remains sparse, especially for mobile taxa such as birds and butterflies. We analysed the abundance of 12 widespread bird and 9 butterfly species from a 10‐year study of AES intervention in a farmland landscape in southern England. We compared estimates of annual population growth rates from our study landscape with rates derived from large‐scale national monitoring schemes in equivalent landscapes without substantial AES. Species trends in our study landscape were frequently stable or increasing, in contrast to concurrent declining trends in equivalent landscapes without AES. These differences were significant for total abundance of granivorous species and for chaffinch Fringilla coelebs, blue tit Cyanistes caeruleus and great tit Parus major individually. For butterflies, differences in trends were significantly more positive for gatekeeper Pyronia tithonus and green‐veined white Pieris napi, while small white P. rapae showed a trend that was significantly more negative in our study landscape. Synthesis and applications. Our results demonstrate that, for some bird and butterfly species, the higher abundances associated with areas of AES uptake within a typical commercial farmland landscape can co‐occur with positive or stable population trends over long time scales and that these trends can show significant differences from those in equivalent landscapes without substantial AES interventions. Our results suggest that previously observed inconsistencies in AES benefits may in part reflect a lack of long‐term studies with accurate data on AES uptake and quality (i.e. successful implementation and management). Our results, thus, affirm the importance of delivering and monitoring high‐quality AES options if the design and implementation of the next generation of AES is to achieve significant benefits for biodiversity.

Designing a survey to monitor multi-scale impacts of agri-environment schemes on mobile taxa

Agri-environment schemes (AES) are key mechanisms to deliver conservation policy, and include management to provide resources for target taxa. Mobile species may move to areas where resources are increased, without this necessarily having an effect across the wider countryside or on populations over time. Most assessments of AES efficacy have been at small spatial scales, over short timescales, and shown varying results. We developed a survey design based on orthogonal gradients of AES management at local and landscape scales, which will enable the response of several taxa to be monitored. An evidence review of management effects on butterflies, birds and pollinating insects provided data to score AES options. Predicted gradients were calculated using AES uptake, weighted by the evidence scores. Predicted AES gradients for each taxon correlated strongly, and with the average gradient across taxa, supporting the co-location of surveys across different taxa.Nine 1 × 1 km survey squares were selected in each of four regional blocks with broadly homogenous background habitat characteristics. Squares in each block covered orthogonal contrasts across the range of AES gradients at local and landscape scales. This allows the effects of AES on species at each scale, and the interaction between scales, to be tested. AES options and broad habitats were mapped in field surveys, to verify predicted gradients which were based on AES option uptake data. The verified AES gradient had a strong positive relationship with the predicted gradient. AES gradients were broadly independent of background habitat within each block, likely allowing AES effects to be distinguished from potential effects of other habitat variables. Surveys of several mobile taxa are ongoing.This design will allow mobile taxa responses to AES to be tested in the surrounding countryside, as well as on land under AES management, and potentially in terms of population change over time. The design developed here provides a novel, pseudo-experimental approach for assessing the response of mobile species to gradients of management at two spatial scales. A similar design process could be applied in other regions that require a standardized approach to monitoring the impacts of management interventions on target taxa at landscape scales, if equivalent spatial data are available.

Improving the evidence base for delivery of public goods from public money in agri-environment schemes

There is growing interest around the world in more effectively linking public payments to the provision of public goods from agriculture. However, published evidence syntheses suggest mixed, weak or uncertain evidence for many agri-environment scheme options. To inform any future “public money for public goods” based policy, further synthesis work is needed to assess the evidence-base for the full range of interventions currently funded under agri-environment schemes. Further empirical research and trials should then focus on interventions for which there is mixed or limited evidence. Furthermore, to ensure the data collected is comparable and can be synthesised effectively, it is necessary to reach agreement on essential variables and methods that can be prioritised by those conducting research and monitoring. Future policy could then prioritise public money for the public goods that can most reliably be delivered, offering better value for taxpayers and improving the provision of ecosystem services from agricultural landscapes.

Agri-environmental measures and the breeding ecology of a declining farmland bird

Agricultural intensification is a key cause of the population declines shown by many farmland bird species across Europe. Changes in land management through agri-environment schemes (AES) are frequently cited as the best tool to reverse these trends, to date however they have received mixed support. This study tested whether AES options in England that provide winter seed food or insect-rich foraging during the breeding season, were associated with improved breeding performance in tree sparrow, Passer montanus, and/or the formation of larger breeding colonies. Breeding attempts (n=428) representing 210 pairs of tree sparrow comprising 22 colonies were compared in Wiltshire, England in 2013 and 2014. The area of margin AES, an insect-rich habitat, was positively correlated with fledgling success per breeding attempt and per breeding pair. Colony size increased with increasing wild bird seed mix AES area, a winter seed food resource, but this option negatively affected hatching success and the number of fledglings produced per breeding attempt. The observed association between colony size and this habitat was expected given that wild bird seed mixtures provide important seed food resources for granivorous birds during winter. The negative correlation with fledgling success, on the other hand, requires further investigation to determine whether this relationship relates to a lack of invertebrate and seed food during the breeding period. These results highlight the importance of providing a suite of AES habitats that are appropriately located to deliver both overwintering and breeding requirements of target, declining farmland birds.

Using fledged brood counts of hedgerow birds to assess the effect of summer agri-environment scheme options

A key aim of many European agri-environment schemes (AES) is to improve biodiversity on farmland. In recent years, several countries have been looking at long term trends in the spring adult population size of a target group of farmland birds as an indicator of this. The overall trend in these indicators is however not upwards. While this might suggest we need to look at the design and deployment of habitat management options within schemes, there is an increasing view that we also need to refine and improve our indicators, or the way we monitor them.Relating spring adult bird population size to AES options is problematic not least because of the time lag between the deployment of those designed to enhance bird breeding success in summer, and the spring surveys the following year. At the other end of the scale detailed studies of breeding success in farmland birds have practical/cost restraints. We argue that to understand the impact on farmland birds of particular summer options within AESs we need to be able to estimate the breeding success of local bird populations quickly and cheaply. This would enable us to relate particular AES options to the breeding performance of the birds actually using them.Complementing a previous study of woodland birds, we assess the likelihood of encountering fledged broods of hedgerow nesting bird species during transect surveys without finding nests, and then apply a simple mark-recapture analysis technique to provide an index of breeding success for those species. Following spring adult assessments, counts of fledged broods were undertaken four times a week during April, May, June and July, in four 2.5km hedgerow transects, at four sites in southern England in 2010. Mean daily detection probabilities of fledged broods of 16 common hedgerow birds were calculated from these counts using the software Presence. For 15 out of these 16 species these detection probabilities were sufficiently high for a programme of fledged brood surveys, involving just two or three visits per week from mid-May to mid-July, to provide a useful estimate of breeding success.The survey technique and associated analyses make certain assumptions when providing estimates of breeding success and these are discussed. Little is known about initial dispersal in passerine fledglings and a study in hedgerows may be useful here. However our pilot study suggests that the method could have application as a relatively easily derived productivity index for hedgerow birds, and hence an additional method available to study the impact of certain AES options on indicator species, or for research studies.

Stakeholder perceptions of the effectiveness and efficiency of agri-environment schemes in enhancing pollinators on farmland

In parts of the northern hemisphere, many pollinator species are in decline, with potential adverse implications for pollination and the ecosystem service of food production. It is therefore important to understand how habitats primarily orientated towards food production can be managed in an efficient way to enhance pollinator populations for current and future food security. In Europe, agri-environment schemes are a well-established method for promoting nature conservation on farmland. Some previous studies indicate that certain agri-environment schemes may be beneficial to pollinator populations by promoting increased floristic diversity in agricultural habitats. However, there has been no analysis of the efficiency or cost-effectiveness of these interventions. We used an online survey to evaluate the perceptions of growers in England following the Conservation Grade environmentally-sensitive farming protocol, regarding the effectiveness of different agri-environment scheme options in enhancing pollinators on their farms and the costs of implementation. Options within the agri-environment schemes that were perceived as most effective in enhancing pollinators were those related to improving floristic diversity of field headlands and enhancing or restoring semi-natural grassland. However, these options were not generally the most efficient, due to their high cost. Hedgerow management interventions were shown to be the most efficient, despite being perceived as relatively ineffective, due to the low costs of these options. We have therefore found that there is often a mis-match between effectiveness and efficiency of interventions for enhancing pollinators. Trade-offs are likely to be necessary when making decisions on implementing interventions, and farm size as well other local differences should be taken into account in this decision-making process.

Influence of agri-environment scheme options on territory settlement by Yellowhammer (Emberiza citronella) and Corn Bunting (Emberiza calandra)

Conserving farmland birds is a key objective for agri-environment schemes (AES) across Europe, with a number of management options aimed at providing invertebrate food and nesting habitats. We analysed territory settlement by two widespread but declining farmland buntings with contrasting nesting requirements: the Yellowhammer Emberiza citrinella, a boundary-nesting species, and the Corn Bunting Emberiza calandra, a ground-nesting species. The study was conducted on farms participating in the English Higher Level Stewardship scheme to test whether territory settlement is influenced by the provision of key arable AES options. Both species settled preferentially in localities containing sown arable field margins, while Corn Bunting also settled in localities containing nectar flower mixtures. These preferences are likely to reflect foraging rather than nesting habitat requirements. Yellowhammer selected territories containing hedgerows under AES management, which are nesting rather than foraging habitat but may also provide food. Uptake by land owners of several AES options likely to provide limiting resources for farmland birds was very low, and because uptake at the landscape scale is also low, wider-scale population level benefits are likely to be constrained. However, this is one of few studies demonstrating selection of widely applied arable AES options by breeding farmland birds.

Biodiversity at the farm scale: A novel credit point system

Farmland biodiversity has often been assessed, but seldom at the farm scale, although it is ultimately the farm level at which decisions are taken. Therefore, a credit point system (CPS) was developed based on 32 options known to enhance farmland biodiversity. It was verified whether the resulting CPS score and farm-scale biodiversity are correlated considering four indicator groups (plants, grasshoppers, butterflies and birds) on 133 farms in the Swiss lowland. We further compared the suitability of the CPS score in reflecting farm-scale biodiversity to three alternative habitat measures, i.e. the amount of ecological compensation areas (ECAs, i.e. agri-environment scheme options), ECAs with a high ecological quality and valuable semi-natural elements (SNEs).Species richness and density of plants, grasshoppers, butterflies and birds were analysed, for ‘all species’, stenotopic farmland species and ‘red-listed’ species within each group, resulting in 19 biodiversity measures (dependent variables). Basic models were built, first without, then by including a range of environmental variables and compared to models expanded by the CPS score or one of the three habitat measures (ECAs, high-quality ECAs or SNEs). For each of the 19 biodiversity measures, the CPS score and the three habitat measures were ranked by how much their inclusion improved the basic model, to determine which measure best captured biodiversity at the farm scale.We demonstrate that the CPS score reflects farm-scale biodiversity. For 13 out of 19 biodiversity measures, models including the CPS score performed better than those without. The CPS score was found to be the most suitable predictor for a fast and efficient assessment of farm-scale biodiversity, which makes it suitable for use in large scale agri-environment schemes.

Synergies between site protection and agri‐environment schemes for the conservation of waders on lowland wet grasslands

Two conservation strategies have been put in place in Europe to address precipitous population declines of wading birds that breed on lowland wet grasslands. These are site protection and agri‐environment schemes (AESs) and the two are rarely compared, or their synergy assessed. Increasingly, efforts to recover populations of previously widespread species follow a landscape‐scale approach whereby habitat improvement takes place at key sites through partially overlapping protected area management and AESs. To investigate whether site protection and AESs improve the conservation status of breeding waders and how these interact, we partially repeated a 2002 survey of breeding waders on protected areas (nature reserves and Sites of Special Scientific Interest) and sites with wader‐specific AES options in England in 2009 and 2010. We then assessed the individual and combined effects of these delivery mechanisms on field occupancy, breeding density and population change of four species of declining wader (Northern Lapwing Vanellus vanellus, Common Snipe Gallinago gallinago, Eurasian Curlew Arquata numenius and Common Redshank Tringa totanus). Although results for Curlew differed from the other species, in general field occupancy was positively influenced by conservation delivery mechanisms, with the highest occupancy and breeding densities on land where site protection was combined with wader‐specific AES options. Field occupancy varied between different types of AES, with higher occupancy associated with higher‐level options in fields, particularly those on nature reserves. Outside nature reserves, the history of AES management did not influence wader populations, but within nature reserves and on fields that gained AES management between 2002 and 2009–2010, populations of Curlew and Snipe were more likely to have persisted and population change in Snipe and Lapwing was more positive. We conclude that the conservation of breeding waders will be most effective when site protection and AES management are combined on the same land. Using limited AES money to support management for breeding waders on, around and between the existing network of protected sites will protect remaining populations while presenting opportunities for population expansion in future.

Impact of landscape improvement by agri-environment scheme options on densities of characteristic farmland bird species and brown hare (Lepus europaeus)

Causes for farmland bird declines are well studied, but on landscape level agri-environment schemes (AES) often show limited gains for biodiversity. We analysed population trends of nine farmland bird species and the brown hare in a Swiss arable landscape. Further, we focused on the impact of the quantity and quality of different ecological compensation area (ECA) options on densities of the study species, as well as on the extent of ECAs required on arable farmland to stop population declines of typical farmland species. Densities of bird species and hare counts were positively correlated with the quantity of ECAs and semi-natural habitat. However, effects of ECA options on birds and hares are species specific. The quantities of wildflower areas and semi-natural habitat strongly enhanced bird and hare numbers. The quality of the ECA options was also important, as densities were positively related to the amount of meadows of high ecological quality, but not to the amount of meadows of low ecological quality. To attain target densities, the required proportion of high-quality AES options and semi-natural habitat has to be at least 14%. This study provides evidence that intensively managed arable farmland can be improved for bird diversity and hare density by the Swiss AES. The amount of AES options of high ecological quality is of major relevance for nature conservation. We estimate that the amount of high-quality options and semi-natural habitats in the Swiss arable lowland must be four times higher than today's area to halt and reverse population declines of farmland species.

Should We Stay or Should We Go Now? What Happens to Small Mammals When Grass is Mown, and the Implications for Birds of Prey

With some raptors showing widespread declines, management of grassland to enhance access to their small mammal prey may be an important conservation tool. Many small mammal species prefer long grass as a habitat that offers protection from predation, and past studies on the consequences of grass cutting to small mammals have yielded mixed results. Using live trapping, we show that although mowing grass causes a rapid decline in small mammal captures, a small proportion of captures (20%–27%) still occurred in patches of mown grass immediately after cutting. This proportion more than halved again when the cut grass that was initially left in situ was removed. We conclude that some small mammals may remain in mown areas provided some form of cover — i.e. the cut grass — is present. These findings are discussed in light of agri-environment scheme options (e.g. grass margins) that could be improved to benefit birds of prey.

Population trends of brown hares in Switzerland: The role of land-use and ecological compensation areas

Over the last decades, agricultural land-use practices have been intensified throughout Europe. As a consequence of the resulting loss of habitat heterogeneity, numerous species associated with traditional farmland have undergone severe population declines. To mitigate the negative effects of intensive agriculture on farmland biodiversity, agri-environment schemes (AES) have been adopted in various European countries since the early 1990s. The effects of AES have been evaluated for different taxa, but rarely for larger mammals like the brown hare ( Lepus europaeus), a characteristic species of traditional open farmland. Using spotlight counts from 58 brown hare monitoring study sites over 17 years, we analysed the effects of land-use and several agri-environment scheme options on brown hare density in the Swiss lowland. We used open-population binomial mixture models to jointly model abundance and detection probability, thereby accounting for imperfect detection of hares. Mean observed counts of brown hares in Switzerland from 1992 to 2008 suggested a slight decline followed by a recovery in arable study sites, whereas a sustained decline was apparent in grassland sites. Mean detection probability ranged widely from year to year (arable: 0.33–0.70; grassland: 0.21–0.80). When accounting for imperfect detection, a population recovery was apparent in both land-use types, although hare densities remained at low levels compared to other European countries. The amount of extensively managed hay meadows seemed to have a positive effect on brown hare abundance both in arable and grassland sites. Hedgerows were also positively related to hare density, although only in arable study sites. The amount of set-asides/wildflower strips and brown hare density were related neither in arable nor in grassland sites. This result was probably caused by the fairly low percentages of this AES option in our study sites. Habitat improvements by means of AES indicate some positive effects on brown hare populations in Switzerland, but the quantity and quality of AES must still be increased. Combined with a binomial mixture model correcting for imperfect detection, spotlight counts are an effective tool for estimating population trends, especially for large-scale and long-term surveys like the Swiss brown hare monitoring.

Habitat preference and mobility of Polia bombycina: are non-tailored agri-environment schemes any good for a rare and localised species?

General agri-environment schemes (AES) have been shown to benefit widespread species, but there is little information on the extent to which rare, more localised, species may also benefit. We tested whether AES options aimed at increasing general biodiversity also benefit a highly endangered moth, Poliabombycina, without species-specific tailoring. We assessed effects on its abundance of two AES options, wide field margins and hedgerow trees, using light traps at the landscape-scale and for mark-release-recapture at the farm-scale. We hypothesized that abundance would be highest at wide field margins and at hedgerow trees, and that if hedgerow trees conferred a positive effect, individuals would be more likely to follow hedgerows than crossing exposed fields while on the move. The results showed that significantly more individuals were captured at sites with a hedgerow tree. Numbers were also higher at wide margins, but this was not statistically significant, and no individuals were caught at field centres. Our study suggests that general options within appropriately designed and implemented AES aimed at increasing overall biodiversity in intensive agricultural landscapes have the potential to not only benefit common, widespread habitat generalists, but some rare and more endangered species as well. P. bombycina serves as an example of how general AES options, existing and novel ones alike, might cater for the needs of rare and localised species. As the precise ecological requirements of most invertebrate species remain unknown, we urge scientists and governments to address the challenge to research and design truly general AES, which options should be able to deliver not only for widespread species but also for the less-widespread counterpart of farmland biodiversity.

The conservation of arable plants on cereal field margins: An assessment of new agri-environment scheme options in England, UK

Agri-environment (AE) schemes aim to arrest declines in arable biodiversity through cereal field margin management options. We evaluated the effectiveness of uncropped cultivated margins (UCM), spring fallow (SF) and cropped conservation headlands with (CH) or without fertiliser inputs (CH(NF)) in sustaining plant species diversity and rare species, in England, UK. Sampling was stratified at 1 m, 3 m and 5 m from the edge of the margin and in eight regions to assess environmental influences on species composition. Species diversity, including rare species, was highest on UCM, followed by SF and CH(NF) margins. Diversity was generally lower on cropped margins due to competition from the crop. Fertilised CH margins were the least diverse option and were similar to cereal crop controls. Species diversity was greatest at the edge of all except UCM margins and there was a strong latitudinal decline in overall diversity and rare species. AE management accounted for more variation in species composition than habitat context, physical/climatic variables, soil properties or region. At cropped sites, there was overlap between margin type and other variables but soil properties explained less variation. At uncropped sites, management and physical/climate variables explained most variation but soil properties were more important than at cropped sites. These findings confirm that AE schemes are effective in conserving arable plants, including rare species, across a variety of landscape types. More precise geographical targeting, improved control of competitive species and research on the habitat requirements of rare species will improve the overall efficacy of schemes in the future.