Agri-environment Schemes Research Articles

Do agri-environment measures help improve environmental and economic efficiency? Evidence from Bavarian dairy farmers

AbstractThis study presents an innovative empirical application to the assessment of agri-environment measures on environmental and economic efficiency. Using a multi-equation representation with desirable technology and its accompanying undesirable by-production technology, we investigate the effects of agri-environment measures on farm-level environmental and economic efficiency. A combination of propensity score matching and a difference-in-difference approach is used to estimate the policy effect. The application focuses on a balanced sample of Bavarian dairy farms surveyed between 2013 and 2018. Results suggest that agri-environment schemes do not alter farms’ economic efficiency, whereas environmental efficiency does not seem to be stimulated by schemes participation.

The contrasting response of cavity‐nesting bees, wasps and their natural enemies to biodiversity conservation measures

Abstract The implementation of agri‐environmental schemes (AES) is a major tool to sustain biodiversity and ecosystem services in European agricultural landscapes. The benefit of different types and features of novel biodiversity measures needs to be assessed in order to successfully conserve insect communities in agroecosystems. We set up trap nests in 3 × 3 km landscapes in Germany, in which farmers implemented different novel biodiversity measures. We tested the effect of different features of the closest three biodiversity measures (i.e. distance to measures, measures' area, measures' quality) and of the proximity to forest and oilseed rape and of landscape connectivity on the abundance and species richness of cavity‐nesting bees, wasps and their natural enemies. We found total cavity‐nesting insect abundances to increase with measures' quality and to decline with increasing distance to oilseed rape and forest. Parasitism and mortality rates declined with edge density. Cavity‐nesting bees were not affected by biodiversity measures. Total wasp and herbivore‐predating wasp abundances increased in proximity to biodiversity measures. The abundance and species richness of all wasps, natural enemies and spider‐predating wasps declined with increasing distance to forest. Cavity‐nesting wasps benefit from biodiversity measures, while effects on solitary bees might only be detectable after several years after measure establishment. The proximity to forest is a major factor promoting insects as forest edges provide food, nesting sites and shelter. We emphasise the need for long‐term insect monitoring and an increasing focus of future AES on the creation of nesting habitats for effective insect conservation.

Floral enhancement of arable field margins increases moth abundance and diversity

Moth populations have declined across large parts of north-western Europe since the mid-20th century due, in part, to agricultural intensification. Agri-environment schemes (AES) are widely implemented across Europe to protect biodiversity in agricultural landscapes. Grass field margins enriched with wildflowers typically out-perform grass-only margins in terms of increasing insect abundance and diversity. However, the effect of wildflower enrichment on moths remains largely unstudied. Here, the relative importance of larval hostplants and nectar resources for adult moths within AES field margins are investigated. Two treatments and a control were compared: (i) a plain grass mix, the control, (ii) a grass mix enriched with only moth-pollinated flowers, and (iii) a grass mix enriched with 13 wildflower species. Abundance, species richness and Shannon diversity were up to 1.4, 1.8 and 3.5 times higher, respectively, in the wildflower treatment compared to plain grass. The difference in diversity between treatments became greater in the second year. There was no difference in total abundance, richness or diversity between the plain grass treatment and grass enriched with moth-pollinated flowers. The increase in abundance and diversity in the wildflower treatment was due primarily to the provision of larval hostplants, with nectar provision playing a smaller role. The relative abundance of species whose larval hostplants included sown wildflowers increased in the second year, suggesting colonisation of the new habitat.Implications for insect conservation.We show that, at the farm scale, moth diversity can be greatly enhanced and abundance moderately enhanced by sowing diverse wildflower margins, providing these insects with both larval hostplants and floral resources, compared to grass-only margins.

A window into land managers’ preferences for new forms of agri-environmental schemes: Evidence from a post-Brexit analysis

Securing the provision of environmental public goods from agriculture is central to addressing the critical challenge of ensuring global food security while halting ecosystem degradation. Agri-environment schemes (AES) are considered to have a key role to play in supporting the transition to more sustainable ways of producing food. Existing evidence suggests that farmers are generally willing to enrol in AES for the delivery of environmental features, but robust policy support requires further exploration of land managers’ preferences and how these interplay with contract features to achieve higher environmental targets. We undertook a discrete choice experiment with land managers in post-Brexit UK, with what can be considered a ‘benchmark’ sample of younger AES-inclined land managers. This provides a window into the future of the UK farming landscape, but also, given the revision of the European Union’s Common Agricultural Policy and other international discussions, it also provides insights into land managers’ preferences for new contract features more widely. Our results suggest that (such type of) land managers are likely to be receptive to a transition to result-based, collaborative schemes supporting landscape-wide interventions in alignment with net zero agendas. These interventions could be done in exchange for levels of compensation similar to current levels. While this raises promise, our results also emphasize challenges, particularly to attract those less generally AES-prone land managers. Payments levels probably need to remain close to the current ones (not lower), farmers’ awareness and support for net-zero agendas need to be reinforced and more interaction between land managers and policy makers will be needed.

Varying response of breeding waders to experimental manipulation of their habitat and predators

Many ground-nesting bird species including waders are of conservation concern across Europe. Population declines of Eurasian Curlew Numenius arquata (hereafter Curlew), a globally Near-threatened wader, exemplify this and are driven by low breeding success due to predation, and loss and degradation of breeding habitat. We tested whether the combined delivery of vegetation management and lethal control of Red Foxes Vulpes vulpes and Carrion Crows Corvus corone and Hooded Crows C. cornix improved Curlew nesting success and breeding abundance across UK study sites over five years. On trial sites, vegetation management improved habitat condition and Curlew distributions shifted towards managed areas. However, changes in predator abundances, Curlew nesting success and Curlew breeding abundance did not differ between trial and reference sites. Northern Lapwing Vanellus vanellus numbers increased on trial sites and decreased on reference sites, whilst Common Snipe Gallinago gallinago numbers showed no treatment response. Some of these outcomes were associated with additional environmental variables added to Treatment:Year terms in three-way interactions (changes in fox abundance associated with abundance of non-native gamebirds; changes in Crow abundance associated with gamebirds and woodland area; changes in Curlew nesting success associated with crow abundance), highlighting that outcomes depend on site-specific contexts, and consistent responses to interventions cannot be assumed. The difficulty in increasing Curlew nesting success likely relates to underlying mesopredator densities in the UK, which are known to be high in a European context. Our results suggest that a model of delivery like this study, including management of predators using lethal control, at comparable intensities, is highly unlikely to be effective for Curlew or Snipe within agri-environment schemes, but could be for Northern Lapwing. To make progress on wader recovery it is imperative to understand the underlying drivers of high mesopredator densities and address these through landscape-scale intervention and policy changes.

Exploring farmers’ perspectives on collective action: a case study on co-operation in Dutch agri-environment schemes

To improve the ecological effectiveness of agri-environment-climate measures (AECM), collective approaches to co-ordinate AECM beyond the farm level have emerged, which are characterised by different levels of co-operation between individual farmers. As participation is voluntary, understanding farmers’ perspectives on collective action in the context of these economic incentive instruments is crucial to improve existing or design novel approaches. We conducted a Q study on farmers’ viewpoints on collective AECM in the Netherlands, where all AECM have to be realised jointly since 2016. Our results reveal three dominant views on collective AECM: a collective-oriented, a business-oriented and an environment-oriented perspective. Clear preferences for the collective approach show that even in cultures with strong values of independence joint action is possible, as farmers’ autonomy can be strengthened through co-operation. Considering different perspectives on collective approaches within the institutional design can help to develop more targeted, and thus successful, incentives.

Wild plants in hedgerows and weeds in crop fields are important floral resources for wild flower-visiting insects, independently of the presence of intercrops

The availability of diverse floral resources is crucial for the maintenance of pollinating insects and the pollination service they provide in agricultural landscapes. Ensuring plant diversity is thus essential for the maintenance and even restoration of pollinator communities. Many studies have highlighted the beneficial effects for pollinating insects of the floral resources provided either by uncultivated plants in agroecological infrastructures such as hedgerows and in crop fields, or by the addition of cultivated flowers through intercropping. However, the role of these different co-occurring vegetation types in providing floral resources to wild flower-visiting insects remains unexplored simultaneously, especially regarding their potential interacting effects. Using a paired design sampling approach, we investigated the contribution of floral resources provided by hedgerows, weeds in crop fields, and legumes intercropped with winter cereals, and their interacting effects, to the abundance of different groups of wild flower-visiting insects, plant-insect interactions and insect preferences. Our results show that the abundance of most groups of floral visitors were enhanced by the cover or species richness of floral resources provided by hedgerows or by weeds in crop fields. Interactions between uncultivated plants and insects were driven by the presence of some particular ‘preferred’ plant species offering either abundant, accessible or high-quality floral resources. By contrast, abundance of floral visitors was not enhanced by the addition of legume flowers through intercropping. The positive effects of flowering wild plants in hedgerows and crop fields remained mostly unchanged in the presence of intercrops, because of the limited contribution of legumes in providing attractive floral resources to floral visitors. Our results highlight the critical role of floral resources provided by weeds in crop fields for diverse flower-visiting insects, in addition to the floral resources provided by hedgerows. We recommend that agri-environment schemes should promote a wide diversity of floral resources at field margins through the retention of existing semi-natural elements or the sowing of wildflower mixtures. More importantly, our study encourages the seeking of alternative forms of weed management, which support a trade-off between the maintenance of pollinating insects and pollination service provision on the one hand, and crop yields and incomes for farmers on the other.

The role of rice farmers’ attitude and trust in government in decision-making for participating in a climate-related agri-environmental scheme

Excessive use of synthetic fertilizer has been proven to be an important cause of greenhouse gas emissions and water pollution in many Asian countries. This article aims to provide a better understanding of rice farmers’ preferences for a chemical fertilizer reduction scheme (CFRS) by integrating economic and psychometric factors. A survey of 292 farmers was conducted in Taiwan. The results show that farmers using more chemical fertilizers have a negative attitude towards implementing SAP and less trust in government and would prefer a higher entry payment over an eco-label. On the other hand, farmers using less chemical fertilizer prefer to receive an eco-label rather than incentive payments. Our findings indicate that an eco-label and higher entry payment could overcome the psychological factors that hinder farmers’ engagement. This study provides policymakers with insights into farmers’ decision-making, which could lead to chemical fertilizer reduction, thereby mitigating climate change.

Conservation measures or hotspots of disease transmission? Agri-environment schemes can reduce disease prevalence in pollinator communities.

Insects are under pressure from agricultural intensification. To protect pollinators, conservation measures such as the EU agri-environment schemes (AES) promote planting wildflowers along fields. However, this can potentially alter disease ecology by serving as transmission hubs or by diluting infections. We tested this by measuring plant-pollinator interactions and virus infections (DWV-A, DWV-B and ABPV) across pollinator communities in agricultural landscapes over a year. AES had a direct effect on DWV-B, reducing prevalence and load in honeybees, with a tentative general dilution effect on load in early summer. DWV-A prevalence was reduced both under AES and with increasing niche overlap between competent hosts, likely via a dilution effect. By contrast, AES had no impact on ABPV, its prevalence driven by the proportion of bumblebees in the community. Epidemiological differences were also reflected in the virus phylogenies, with DWV-B showing recent rapid expansion, while DWV-A and ABPV showed slower growth rates and geographical population structure. Phylogenies indicate that all three viruses freely circulate across their host populations. Our study illustrates how complex interactions between environmental, ecological and evolutionary factors may influence wildlife disease dynamics. Supporting pollinator nutrition can mitigate the transmission of important bee diseases, providing an unexpected boost to pollinator conservation. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.

Comparing the cost-effectiveness of delivering environmental benefits through subsidies to farmers vs land purchase

Action to address biodiversity declines and climate change must be taken on farmland which covers half of all habitable land on Earth. European governments have predominantly invested in agri-environment schemes (AES) which pay farmers to change their management to the benefit of the environment. We conducted the first UK-based comparison of the cost-effectiveness of this approach with an alternative strategy of land purchase where organisations are contracted to manage government-owned land for nature. We took a novel approach to estimating the costs of paying farmers in an AES to create and manage habitat using results from a choice experiment conducted amongst 118 arable farmers in England. We estimated the costs of land purchase, and its subsequent management, based on the literature. Given equal annual spend, we estimated the benefit delivered by each strategy for a suite of environmental outcomes (bullfinches, lapwings, yellowhammers and climate mitigation) and explored how relative cost-effectiveness varied with budget, discount rate and timescale. We found AES were more cost-effective if budgets for environmental policies do not increase and where the environmental outcome is expected to decline rapidly without action in the next 50 years. However, if budgets were to increase considerably to reflect the scale of the biodiversity and climate crises, land purchase would deliver more biodiversity and climate mitigation in the longer term. The cost-effectiveness of the land-purchase strategy was sensitive to fluctuations in land prices which presents a challenge to policymaking which also must consider the impacts on farming communities of large-scale changes in land ownership.

Optimizing agri-environment schemes for cost-effectiveness, fairness or both?

AbstractWe investigate empirically trade-offs between improving the cost-effectiveness of an agri-environment scheme (AES) and its distributional impacts, applying the criteria of equality (equal payments), equity (equal producer surplus), and the Rawlsian maximin criterion (here understood as maximizing the producer surplus in the poorest region). Using an ecological-economic modelling procedure, we simulate an existing grassland AES in Saxony, Germany and design two cost-effective alternatives—one AES with spatially homogeneous payments and one with regionally differentiated payments—and compare the distributional impacts of the three schemes. For spatially homogeneous payments, we find a trade-off between cost-effectiveness and equality but not equity and the Rawlsian maximin criterion. This suggests that cost-effectiveness improvements do not necessarily go against distributional concerns. However, the substantial cost-effectiveness improvements that can be achieved with regionally differentiated AES come at the expense of distributional setbacks according to all applied fairness criteria.

Nitrogen balance is a predictor of farm business performance in the English Farm Business Survey

Global environmental sustainability and food security are fundamental societal issues, and most crop production relies upon inputs from organic or inorganic nitrogen sources. Previous research in the Global North has demonstrated a typical over application of nitrogen across global agriculture with substantial negative impacts on the environment. The objective of this work was to draw on English Farm Business Survey (FBS) data of non-organic General Cropping and Cereal farms to explore the relationship between farm gate nitrogen balance, fertilizer application advice and farm business performance. A mixed effects generalized modeling approach was used to partition the variance into random (such as year, or farm ID) and fixed effects (those of interest). Whilst the financial performance of farm businesses is subject to high variance and multiple drivers, a negative relationship was detected between business performance and farm gate nitrogen balance, we demonstrate that nitrogen lost to the environment of >60 kg per hectare is associated with a significant negative impact on farm performance. Supplier-provided fertilizer advice was also associated with reduced farm performance. These results imply a positive effect on farm performance of enhancing on-farm understanding of crop nutrient requirements through the provision of accredited fertilizer advice. Within the stated bounds our model demonstrates good predictivity on randomly subsetted data, and is presented as a tool for use in scenario modeling of interventions such as agri-environment schemes, Natural Capital and Ecosystems Assessment, and the UN Sustainable Development Goals.

Hedgerows have contrasting effects on pollinators and natural enemies and limited spillover effects on apple production

Agricultural intensification has resulted in a decline in insect biodiversity and threatens the provision of valuable ecosystem services. Agri-environment schemes (AESs) have been implemented in an effort to conserve biodiversity on farmland and increase agricultural sustainability, but their effectiveness can vary widely. To better determine which factors influence AES effectiveness, the relative roles of local habitat features, habitat quality, and landscape context need to be further explored. The aim of this study was to determine the most important factors influencing field margin AES effectiveness in commercial apple orchards, in terms of arthropod biodiversity conservation and ecosystem service provision. We surveyed wild bees and aphid natural enemies in field margins and apple trees in 20 orchards, ten bordered by hedgerow field margins (an AES) and ten with herbaceous field margins (no hedgerows present, not an AES). We considered field margin floral resources and the cover of semi-natural habitat in the surrounding landscape as indicators of local habitat quality and landscape context, respectively. We furthermore quantified pollination and pest control as measures of ecosystem service delivery and the relationship between arthropod communities and apple yield (initial and final fruit set) and quality. We found that hedgerow presence strongly predicted both pollinator and natural enemy communities and that these relationships were more pronounced than those with local habitat quality and landscape context. Hedgerows were negatively related to wild bee richness and abundance within the orchard, and positively related to natural enemy richness and abundance at the field margin but not within the orchard. We found no relationships between local and landscape factors and ecosystem service delivery, and no relationship between wild bee communities and apple yield, suggesting that apple is not pollen limited in our study system. There was, however, a negative relationship between natural enemy richness and initial fruit set. We conclude that annually cut hedgerows can benefit the conservation of natural enemies, but have limited arthropod-mediated private benefits for apple production, and likely need to be supplemented with additional local habitat resources for the conservation of wild bees. Our findings indicate that local habitat factors can strongly influence biodiversity regardless of landscape context, but that AESs likely need to be designed with separate biodiversity and ecosystem service targets, and specific taxonomic groups, in mind.

The importance of landscape heterogeneity and vegetation structure for the conservation of the Ortolan Bunting Emberiza hortulana

Summary Over the last decades, European farmland birds have strongly declined, mainly driven by agricultural intensification. The Ortolan Bunting Emberiza hortulana has suffered one of the most severe declines among farmland specialists. In order to maintain viable populations of the species in the long run, there is a vital need for evidence-based conservation measures. The main goal of this study was to detect the key drivers of breeding-territory selection and mating success of the species in an agricultural landscape in central Europe. We found that the landscape structure within the territories of Ortolan Bunting breeding pairs strongly varied from the overall habitat availability in the study area on both the territory and home-range scales. However, the environmental conditions also differed between the territories of breeding pairs and those of unpaired males. While landscape structure played an important role in breeding-territory selection, it had only weak effects on mating success. In contrast, crop type and vegetation height at potential nesting sites were important drivers of mating success. Overall, our study revealed that Ortolan Bunting has very complex breeding-habitat requirements. Only heterogeneous agricultural landscapes where (1) suitable song posts, (2) appropriate nesting sites, and (3) sufficient foraging habitats occur in close proximity are suitable for breeding. According to the findings of our study, agri-environmental schemes should primarily facilitate low-intensity farming practices that promote landscape heterogeneity, provide suitable nesting sites, and sustain a high abundance of invertebrate prey in farmlands.

Collaborative agri-environmental governance in the Netherlands: a novel institutional arrangement to bridge social-ecological dynamics

The theoretical benefits of collaborative landscape-scale approaches to agri-environmental land management have been widely discussed. However, there is little empirical study of the practical governance mechanisms through which such collaborative management may be realized. In 2016, an innovative collaborative agri-environmental scheme was established in the Netherlands. In this scheme, “agricultural collectives”—i.e., groups of farmers organized as certified conservation organizations—are collectively responsible for the implementation of agri-environmental policies at the local level. With a focus on the Dutch model’s multi-level governance dimensions, this article examines how devolving important aspects of decision making on agri-environmental management to the level of a collective body of farmers shapes the implementation of agri-environmental policies on the ground. Based on new empirical data, we highlight the important roles of agricultural collectives in balancing trade-offs between ecological and social targets when setting environmental objectives, coordinating landscape-scale management, and contracting individual farmers. At the same time, the local embeddedness of agricultural collectives and close interpersonal ties can give rise to new governance risks that need to be considered, including goal divergence between the collectives and public bodies, as well as cases of prioritization of social interests over ecological interests in agri-environmental management. As we argue, combining governance through agricultural collectives with a high level of transparency regarding contracting decisions, as well as enhancing the inclusivity of the scheme through new funding opportunities for agri-environmental management, can optimize the benefits of these collectives.

A novel farmland wildflower seed mix attracts a greater abundance and richness of pollinating insects than standard mixes

Abstract Wildflower strips are a popular agri‐environment scheme (AES) implemented on farmland to provide forage for insect pollinators. The standard seed mixtures were often formulated without a clear evidence base, and subsequent field trials to assess their attractiveness to insects are commonly carried out at low taxonomic resolution (e.g., pooling all ‘solitary’ bees). We created two novel wildflower mixes: a wild bee mix based on primary research (WB) and one on literature‐based evidence (LT). We trialled our novel mixes against two standard AES wildflower mixes: a Fabaceae‐heavy mix (FAB); a diverse wildflower mix (WF); plus a fallow plot (control). Our aim was to determine which mix attracted the highest overall insect pollinator abundance and highest species richness for wild bees. Our WB mix attracted both the highest number of total insect visitors, and the highest wild bee abundance and richness. WB attracted significantly more bumblebees (abundance and richness) than the typical low diversity, Fabaceae‐heavy mix (FAB); and significantly greater solitary bee abundance, than all other treatments. Only 11 ‘key’ wildflower species were required to cater to all wild bee species recorded during the study, eight of which were sown species. Taraxacum officinale agg., Cirsium vulgare, Daucus carota and Geranium pyrenaicum received the highest numbers of wild bee species visits. In conclusion, we suggest a novel wildflower seed mix based on primary research has the potential to provide more attractive forage for both wild bees and other insect pollinators compared to current AES mixes.

Complementary effects of biodiversity and ecosystem services on spatial targeting for agri-environment payments

Landscape multi-functionality is often valued by scientists and appreciated by citizens. In agro-ecosystems this often translates into policy that aims to protect biodiversity through conservation incentives, sometimes spatially targeted to decrease the impact of productive activities. Incentive schemes that aim at protecting a range of other benefits, are still rare. Resources are often limited and spatial heterogeneity can be high, so there is a need to investigate whether efficient schemes could be designed through the targeting of areas that offer both high biodiversity and ecosystem services. Using Scotland’s agricultural landscapes, we build on previous work to investigate whether there is spatial coincidence between species richness of species targeted by agri-environment schemes and four key ecosystem services, namely nutrient retention, carbon sequestration, pollination and prevention of soil erosion. We used models of the distribution of these ecosystem services and the distribution of 83 species of conservation value and relevant to lowland grasslands and croplands. Through spatial analysis we showed that complementarity depends on scale and that, at the landscape scale, it would be possible to define a zonation that encompasses areas that offer relatively higher levels biodiversity and ecosystem services. Conservation incentives schemes could become more inclusive and more efficient if they targeted the identified areas.

Key Habitat Factors of Breeding Birds in Agricultural Hedgerow Landscapes in East-Fryslân, the Netherlands, in European Perspective – Ecological Evaluation and Relation to Agri-Environmental Schemes

Modern agricultural landscapes suffer heavily from biodiversity loss. To counter this loss, it is important to understand the key factors that affect biodiversity in these landscapes. We studied the relationships between breeding birds and the habitat characteristics of the small-scale hedgerow landscapes of East-Fryslân, The Netherlands, a typical agricultural landscape that is under pressure from upscaling and habitat degradation. We questioned whether our findings collaborate the results of hedgerow studies from other countries. We also analysed whether agri-environmental schemes were effective for breeding birds. In this study, breeding birds and fifteen habitat factors were surveyed along 170 transects in two different regions in East-Fryslân in 2018. 37 bird species were identified, of which 19 were woodland species, 18 shrub species and 7 hedgerow specialists. We found five habitat characteristics to be key factors for breeding bird numbers. Four of these factors were intrinsic factors of the hedges (i.e. shrub cover, cover of brambles and nettles, crown width, hedge width at the base) and one spatial factor (i.e. number of hedge corners within a 150-m radius, corresponding to hedge intersections). Four key factors were the same for the two regions, but effect sizes differed between factors and species groups. As proxies for habitat volume (amount of habitat), the intrinsic key factors for hedgerow breeding birds in East-Fryslân correspond to those found in Britain and Eastern Europe, despite considerable differences in botanical composition, structure and management of the hedges. In contrast to studies on British hedges, we found mainly quantitative key factors and only one qualitative factor (cover of brambles and nettles). We found one spatial key factor (hedge intersections) and no correlation of bird numbers with density of hedges in the vicinity. We discuss the ecology of the key factors with respect to food provisioning and breeding. We also conclude that agri-environmental schemes favour key habitat factors and through this shrub birds. Implications of our findings are that traditional management favours breeding birds, but also that management should partly be extensified.

Spiders indicate delivery of an agri-environment scheme at multiple diversity levels

Agri-environment schemes (AES) are expected to counteract the negative impacts of intensive agriculture on biodiversity. These schemes were specifically designed to target farmland biodiversity and included, for instance, ecological focus areas (EFAs). In Switzerland, in order to qualify for direct payments, farmers must manage 7% or more of their land as biodiversity promotion areas (BPAs). BPAs encompass extensively managed and low intensity hay meadows, fallows (wildflower strips), traditional orchards with high-stem trees and hedgerows. Evaluation of AES delivery for biodiversity is of crucial importance but must be performed across several years and considering the various components of species diversity to avoid incomplete or wrong conclusions. From a complex study design comprising 478 fields in three regions and sampling over 7 years with four sampling times, spider assemblages of BPA habitats were compared to corresponding conventionally managed fields. A battery of investigations was performed including alpha- and beta-diversity analysis, multivariate dispersion, indicator species and species specificity to understand what BPAs deliver for spiders in the habitat scale and farming landscape. Results showed that alpha-diversity (average number of species) was usually higher in BPA habitats than in conventionally managed fields but the species composition (beta-diversity) had more power to perceive AES impact. Furthermore, the various environmental conditions of BPAs in the farming landscape led to highly diverse spider assemblages (multivariate dispersion) emphasizing that not only the agricultural management plays a role in determining species diversity but the environmental heterogeneity. Indicator (and rare) species were mostly found in woody BPAs (hedges and high-stem tree orchards) revealing the high importance of these BPA habitats for spider conservation. At regional scale, BPA hedges contributed most to the regional diversity of spiders in grassland and mixed regions while BPA meadows and wildflower strip BPAs were first delivering in the region of arable crops. Recommendations highlight the role of the woody habitats and of the environmental heterogeneity in the farming landscape as well as of regional planning to make AES effective.

Meeting tree planting targets on the UK's path to net-zero: A review of lessons learnt from 100 years of land use policies

The UK government has pledged to achieve net-zero greenhouse gas emissions by 2050. Ambitious targets have been set to plant nearly a million hectares of new woodland in the UK by 2050 to meet these net-zero commitments. More than 70% of UK’s land is used for agricultural production and to meet these targets the Climate Change Committee has estimated that by 2050 approximately 21% of agricultural land will be required for tree planting, agroforestry and the extension of farm hedges. Achieving this creates a potential conflict between land for food production and land for carbon sequestration. However, trees and woodlands, when integrated into farming systems, can be multifunctional and play a significant role in helping farmers adapt and become more resilient in the face of climate change.Over the last 100 years numerous government policies and incentive schemes have endeavoured to encourage more tree planting activities amongst farmers and landowners with varying degrees of success. This paper reviews the role of policy in determining the presence of trees in the UK’s agricultural landscape over the past 100 years. We quantify the current extent of woodland and tree cover and aim to put the UK’s net-zero tree planting targets in the context of historical agricultural land use patterns. We evaluate drivers behind the current extent of trees, woodland and agroforestry on UK farms and identify key elements of success in current and previous policies and incentive schemes to help inform future policy mechanisms for the UK to meet its tree planting targets.Farmers are increasingly under pressure to deliver a wide range of environmental goals as well as producing food. The effectiveness of financial incentives to influence tree planting is dependent on the pre-existing interest and values of the farmer or landowner and grants alone may not be sufficient to encourage farmers to plant trees. Scheme complexity, bureaucracy and insufficient payment rates are barriers to the success of woodland grants and agri-environment schemes. Simplicity is important to encourage uptake, however oversimplification of schemes can lead to unintended consequences. Advice and guidance are key elements in the successful adoption of any new land management methods. A key to future progress will be scheme flexibility to enable farmers to choose to plant trees where it best suits local conditions, to align policy tools with farmer values and to ensure that farmers and landowners have the knowledge and support to make these decisions.