Hedgerow Management Research Articles

Delineating the spatial drivers of agri-environment scheme adoption at field and farm levels

Agri-environment schemes (AES), introduced by the EU Common Agricultural Policy (CAP), aim to compensate land owners for implementing environmentally-friendly practices. Whilst literature has examined their effectiveness and how farmer characteristics govern AES adoption, there is a lack of knowledge about the spatial drivers of AES, particularly structural, biophysical and landscape factors in the UK. Using the Humber region as a case study, this paper explores how the uptake of Countryside Stewardship options has varied from 2016 to 2021. It also examines 2500 farms from the field- and farm-level data of 2019 to better understand what type of land British farmers are adopting AES on. Logistic regression analysis is used to identify the factors (including farm and landscape characteristics, designated sites and land quality) that best explain overall AES adoption, as well as specific scheme adoption, at the field- and farm-level. Our analysis reveals that ‘buffer strips’, ‘hedgerow management’, ‘permanent grassland’, and ‘winter bird food’ are the most commonly adopted schemes of 2019. AES are generally adopted on larger fields and farms that feature marginalised, unproductive and vulnerable land, except for ‘buffer strips’ which showed a larger tendency to appear on fields with more profitable, higher quality land. This study, therefore, supports the notion that AES are generally placed on lower quality land and that large proportions of agricultural land owners are not effectively targeted. With the expected loss of direct payments to farmers in the UK as a result of the Department for Environment, Food & Rural Affairs (DEFRA) post-Brexit re-evaluation of rural policy, these results call for the Sustainable Farming Incentive (SFI) to be made more accessible and inclusive to a broader diversity of farmers.

Biomass carbon stocks and stock changes in managed hedgerows

Landscape features, such as hedgerows, can play a role in enhancing terrestrial carbon (C) sinks, especially in North-western Europe, where they form a large part of the agricultural landscape. To date, there are few studies relating aerial imagery to ground-truthed biomass measurements and relating changes in biomass to hedgerow management. This study sought to develop relationships between measured biomass of hedgerows and digital elevation model (DEM) data from drones and aircraft. Furthermore, changes in hedgerow above-ground and below-ground biomass stocks were assessed using a systematic grid sample, DEM data and developed volume-biomass regression models. The developed inventory framework was then applied to a pilot study area of 419,701 ha in Ireland.Robust relationships were developed relating DEM data to volume and above-ground biomass. Model equations were also developed linking above-ground and below-ground biomass. However, these were less robust due to the confounding impacts of hedgerow management intensity, hedgerow type and dominant species. Above-ground biomass density was linearly correlated with hedge volume. Wider, less intensively managed, irregular hedges exhibit a higher biomass stocks per km, when compared to regular, more intensively managed hedgerows. When the models were extrapolated to the county level, hedgerow biomass C pools for Co Wexford and Waterford are suggested to be a net emission of −0.3 tC ha−1 year−1 due to hedgerow removals and management. Flailing or coppicing of hedgerows, in particular irregular profile hedgerows, had the largest impact on the biomass C balance in the pilot study area. Re-introduction of traditional management practices such as layering and increasing the allowable hedgerow width in areas qualifying for farm payments could be considered with the aim of increasing the maximum sink potential of established hedgerows.

Harnessing practitioner knowledge to inform the conservation of a protected species, the hazel dormouse Muscardinus avellanarius

Abstract Conservation decisions are typically constrained by the availability of published evidence. Practitioners and non‐academic experts often possess additional knowledge, including about the practical plausibility of conservation actions, which may lead to more effective planning and outcomes. However, practitioner knowledge is rarely considered during formal evidence syntheses. Alongside a formal literature review, we conducted 26 interviews involving 38 conservation professionals to elicit their knowledge of the conservation of a protected and declining species in England, the hazel dormouse Muscardinus avellanarius. Practitioners and non‐academic experts provided additional insights about dormouse ecology and conservation, beyond those synthesized from the published literature, though we found few contradictions between these different information sources. Instead, practitioner knowledge helped to verify, clarify and expand upon evidence from empirical studies. In general, practitioners emphasized that dormice are far more adaptable than traditionally perceived, with thriving populations found in hedgerows, scrub, road verges and railway verges, rather than solely within broadleaf woodlands. Proposed opportunities for restoring dormouse populations included improving hedgerow management, creating new woodlands, bringing existing woodlands back into management, setting aside unproductive land and improving habitat connectivity. However, participants emphasized the need for landscape‐scale approaches, accounting for the impacts of climate change, and better surveying and monitoring. Key practical considerations included overcoming time and financial constraints, providing better advice, knowledge and training, changing attitudes of land owners and managers and balancing other demands such as agricultural productivity and the requirements of other species. Despite the insights they provided, participants highlighted many remaining knowledge gaps. These included uncertainties arising from the published literature, as well as scarcely studied topics that are of major practical importance, namely the effectiveness of dormouse mitigation measures in planning and development, and the impacts of anthropogenic disturbance and pollution on dormice. Our findings improve the evidence base for restoring hazel dormouse populations and for further empirical evidence gathering. More generally, the study highlights how practitioner knowledge can help both to supplement traditional published evidence and to better frame conservation programmes, which may lead to more successful outcomes.

The Great British Hedgerow Survey

In 2013, when the dormouse reintroduction protocol was revised, a national hedge survey methodology was available. This survey enabled individual hedge quality to be assessed and from that, it was possible to quantify the quality of landscape links between reintroduction sites. There was an opportunity to build on this survey so that it could be used more widely and have more useful outcomes. The People's Trust for Endangered Species (PTES) acquired the existing data from the national (DEFRA) survey and started to develop a survey methodology that would be compatible with it, be simple to use, provide a report on the existing state of the hedgerow and give management advice on how to maintain the hedgerow in good condition. As part of the survey development, posters were designed. One of these asks: ‘What have hedgerows ever done for us’, to demonstrate the benefit of hedgerows in the landscape. The other shows ‘The hedgerow management cycle’ to highlight the dynamic nature of hedgerow condition. There are two different hedgerow surveys available, each with a slightly different focus and outcomes. Healthy Hedgerows is a rapid hedgerow survey designed for landowners that want to create a hedge management plan. The Great British Hedgerow Survey generates more detailed feedback on hedgerow health and offers management advice. It is particularly suited to volunteer groups. This talk will discuss the development of the surveys and their part in hedgerow protection in the UK in the future.

Hedgerow Management Cycle

Hedgerows are as dynamic as the plants that make them, which means it would be fighting a losing battle if we tried to keep them the same size and shape forever. Instead, work out where the hedge is on the management cycle and work according to that. The ultimate goal in hedge management it to create a thick, dense hedgerow. These are the hedges that are most beneficial to landowners as well as for nature. When we cut hedges at the same point year after year, it will produce fewer flowers and fruits for wildlife, it will lose its lower branches and the hedge will become tall and at risk of invasion, opening up gaps and eventually even failure. Trimming to a slightly higher and wider point each year will help prevent this, and the hedge can be re-shaped when needed. However the hedge is managed each year, at some time the lower parts of the hedge vegetation will become thin and the hedge will need more dramatic action like laying or even coppicing. This only needs to be done every 40+ years to keep the hedge healthy and valuable for our wildlife. This is shown in more detail on the hedgerow management cycle plan.

Diversity of small terrestrial mammals under different organic farming management in Mediterranean and Continental agriculture ecosystems

Diversity of small terrestrial mammals under different organic farming management in Mediterranean and Continental agriculture ecosystems

The Political Ecology of Hedgerows and Their Relationship to Agroecology and Food Sovereignty in the UK

Hedgerows can make an important contribution to agroecological transitions and to an overall contribution to multifunctional agro-ecosystems with multiple benefits for biodiversity, climate change mitigation, soil health, human health, well-being, and livelihoods. Where such agroecological transition assumes the form of political agroecology, this can underpin transformation of the farming system towards food sovereignty. Current mismanagement of hedgerows is constraining the optimum delivery of ecosystem services by these important features of the British landscape. This mismanagement is, moreover, an integral part of a (capitalist) productivist degradation of the countryside that is contributing to the delivery of ecosystem disservices and is, therefore, antithetical to the adoption of agroecological production practises. Being contrary to the requirements of political agroecology, it is similarly antithetical to the requirements of food sovereignty. In response, this paper outlines what appears to be required, in policy and political terms, for the adoption of an agroecological and food sovereignty framework enabling the sustainable management of hedgerows and maximising their potential for ecosystem services delivery.

Effects of hedgerow enhancement as a net zero strategy on farmland biodiversity: a rapid review

In order to mitigate the effects of climate change, the UK government has set a target of achieving net zero greenhouse gas (GHG) emissions by 2050. Agricultural GHG emissions in 2017 were 45.6 million tonnes of carbon dioxide equivalent (CO2e; 10% of UK total GHG emissions). Farmland hedgerows are a carbon sink, storing carbon in the vegetation and soils beneath them, and thus increasing hedgerow length by 40% has been proposed in the UK to help meet net zero targets. However, the full impact of this expansion on farm biodiversity is yet to be evaluated in a net zero context. This paper critically synthesises the literature on the biodiversity implications of hedgerow planting and management on arable farms in the UK as a rapid review with policy recommendations. Eight peer-reviewed articles were reviewed, with the overall scientific evidence suggesting a positive influence of hedgerow management on farmland biodiversity, particularly coppicing and hedgelaying, although other boundary features, e.g. field margins and green lanes, may be additive to net zero hedgerow policy as they often supported higher abundances and richness of species. Only one paper found hedgerow age effects on biodiversity, with no significant effects found. Key policy implications are that further research is required, particularly on the effect of hedgerow age on biodiversity, as well as mammalian and avian responses to hedgerow planting and management, in order to fully evaluate hedgerow expansion impacts on biodiversity.

Effects of hedgerow enhancement as a net zero strategy on farmland biodiversity: a rapid review

In order to mitigate the effects of climate change, the UK government has set a target of achieving net zero greenhouse gas (GHG) emissions by 2050. Agricultural GHG emissions in 2017 were 45.6 million tonnes of carbon dioxide equivalent (CO2e; 10% of UK total GHG emissions). Farmland hedgerows are a carbon sink, storing carbon in the vegetation and soils beneath them, and thus increasing hedgerow length by 40% has been proposed in the UK to help meet net zero targets. However, the full impact of this expansion on farm biodiversity is yet to be evaluated in a net zero context. This paper critically synthesises the literature on the biodiversity implications of hedgerow planting and management on arable farms in the UK as a rapid review with policy recommendations. Eight peer-reviewed articles were reviewed, with the overall scientific evidence suggesting a positive influence of hedgerow management on farmland biodiversity, particularly coppicing and hedgelaying, although other boundary features, e.g. field margins and green lanes, may be additive to net zero hedgerow policy as they often supported higher abundances and richness of species. Only one paper found hedgerow age effects on biodiversity, with no significant effects found. Key policy implications are that further research is required, particularly on the effect of hedgerow age on biodiversity, as well as mammalian and avian responses to hedgerow planting and management, in order to fully evaluate hedgerow expansion impacts on biodiversity.

Making hedgerows pay their way: the economics of harvesting field boundary hedges for bioenergy

Existing landscape features, such as field boundary hedgerows, can contribute to food, fodder, material, and energy production for an EU bio-based circular economy. Recent trials undertaken by the project team in the UK demonstrated that hedgerows can be managed to produce woodfuel of a quality that meets industry standards. However, to be attractive to farmers, woodfuel production from hedgerows must be profitable. This paper uses the FarmSAFE model to undertake a financial assessment with data generated from these trials. The net present value of a standard hedgerow management method (flailing every 2 years) was compared with those from alternative hedgerow management scenarios for woodfuel production over a 60 year time horizon. Using data from the hedgerow trials, the results showed that coppicing hedgerows for woodfuel production could provide a profit to the farmer. The sale of woodchips into an off-farm market was found to be profitable if harvesting with tree shears (medium scale harvesting capacity) or a Bracke felling head (large scale harvesting capacity), but chainsaw harvesting (small scale harvesting capacity) was unprofitable. When considering the use of woodchips on farm to replace purchased woodchip or heating oil, the financial benefit to the farmer increased. Sensitivity analyses showed that the use of medium scale machinery (tree shears) made the hedgerow enterprise most resilient to changes in prices, grants, and costs. This scale of machinery is appropriate for local energy production whilst also being affordable to farmers and local contractors.

Drivers of songbird territory density in the boundaries of a lowland arable farm

Conventional farming in the UK has had adverse effects on farmland biodiversity, particularly during post-war intensification of agriculture. Efforts have been made in the reversal of these effects, with much of the literature reporting a mixture of findings. At a localised scale, these efforts have been noticeable with RSPB Hope Farm observing a 200% increase in bird territory numbers from 2000 to 2012, achieved with the wide implementation of agri-environment schemes (AES) on the farm. We aimed to investigate the spatio-temporal drivers of territory density in four hedgerow specialist bird species using a thirteen year (2000–2012) dataset of hedgerow management, in-field cropping and field boundary habitat records. Territory maps were used to calculate territory counts for each hedgerow across the time period. Generalised Linear Mixed Models were used to model territory counts for each habitat variable. These findings demonstrate that for Emberiza citrinella, Carduelis cannabina and Sylvia communis, presence of oilseed rape (OSR) is a strong predictor of higher territory numbers, leading to a doubling in territory density compared to absence of OSR. However, tree presence in hedgerows was a negative predictor of territory numbers for these species. Opposing trends were observed for Carduelis chloris, which exhibited significantly greater territory numbers in roadside hedgerows, hedges with trees and when adjacent fields were not sown with a main crop. Management of hedges was a weak predictor of S. communis territories. This demonstrates that crop type, AES features, tree presence and location of hedgerows are drivers of farmland bird territory numbers. These findings validate the usefulness of more sustainable, wildlife-friendly farming under previous CAP rules and have important implications for post-Brexit farming policy, such as the Agriculture Bill.

Quantified Benefits of Cultivating Day-Lily (Hemerocallis citrina) Hedgerows over Multiple Years on Sloped Red-Soil Farmland, Southern China

Planting hedgerows is an effective measure for increasing soil and water conservation on sloped farmland, although the comprehensive and dynamic changes in benefits across the life span of the hedgerow are not fully understood. To expand our understanding in this area, day-lily (Hemerocallis citrina) was selected to research the effect of hedgerows built on sloped red-soil farmland in southern China. In situ observations of runoff and soil loss from 2012 to 2018 were recorded in triplicate for two treatments: (1) conventional downslope-ridge tillage (CT) and (2) hedgerow intercropping with downslope-ridge tillage (HT). Micro-topography, soil nutrient content, and crop yield changes in the study plots were recorded. Hedgerows began intercepting runoff and soil loss simultaneously from the second year after they were planted, reducing annual surface runoff (35–66%) and annual erosive sediment (32–87%). As hedgerows became established, they provided increasing positive effects on soil and water conservation. However, those beneficial effects were gradually obscured by changes in micro-topography. The presence of the hedgerow had no obvious influence on soil total nutrient contents under this experimental condition. On average, planting the hedgerow reduced peanut yield by 21% but reduced rapeseed yield only by 2%. Compared with CT treatment, the average economic output of HT treatment after reaching the hedge’s initial production was 1.52 times greater, showing a quadratic trend and reaching a maximum about 4 years after construction by regression. These findings indicate that hedgerow management could be optimized according to the desired beneficial soil and water conservation or crop yield characteristics in different developmental phases.

Apple farming systems – current initiatives and some prospective views on how to improve sustainability

Apple cultivation has evolved tremendously in past decades. Both apple productivity and aesthetic quality of the fruit have been strongly improved resulting from genetic improvement, optimization of tree training and pruning, and orchard design and management. However, these improvements were also done at the expense of an increasing dependence on external inputs such as water, fertilizers and synthetic pesticides. This dependence is now questioned because of the generated environmental pollutions and health issues. In the last decades, an increasing amount of initiatives have been developed that open the way towards more sustainable apple production systems. Concepts as well as on-station and on-farm works are developed in various contexts such as 'integrated fruit production', 'organic farming' and 'agroecology' with the objectives to increase biological regulations of pests and diseases and/or to improve soil fertility. All together results point out the importance of diversifying resources and habitats for beneficial arthropods in the orchard and its vicinity to foster ecosystem services related to pest suppression and to adopt cultural practices enhancing soil fertility. They also indicate some practical guidelines consisting in a better management of grass alleys and lining hedgerows within and around the orchard, respectively. From a more prospective view and taking inspiration from tropical fruit-tree based agroforestry, these works suggest that combining apple trees with other herbaceous and woody plants with various uses (soft fruit, aromatic plants, etc.) opens to more resilient agroecosystems, possibly mitigating climate change. These works also enlarge our vision of the current apple orchard towards a multiproduction system including apple among other productions. From the 'plant science' point of view the idea to grow apple in agroecosystems challenges current knowledge of the plasticity of the apple tree physiology and architecture, and agronomic performance, in response to interactions with neighbouring plants. It also stimulates necessary collaborations with other research fields such as socio-economics, for example on how the grower may handle those complex agroecosystems, optimize labour and valorize production.

Hedgerow management experiment relevant to agri-environment schemes: cutting regime impacts species richness of basal flora and Ellenberg indicator profiles

Hedgerow plant communities, including herbaceous species growing in the hedge base, are important conservation indicators of hedgerow habitat condition. The effects of management have the potential to alter the species richness and composition of hedgerow plant communities, but this has not previously been tested experimentally. A novel field experiment was used to test the effects of hedgerow management on hedgerow basal flora. Hedgerow cutting treatments, including relaxed cutting regimes funded under agri-environment schemes, were applied in replicated blocks at four sites in lowland UK. After 6 years of experimental cutting treatments the hedgerow plant communities were surveyed, both directly under the woody hedgerow vegetation and immediately adjacent to the hedges. For hedgerow plots cut in autumn, a reduced intensity cutting regime (incremental cutting) resulted in an average reduction of one species and a small shift towards plants typical of less fertile conditions, compared to cutting back to a standard height and width. Hedgerow plots cut in late winter had a plant community typical of slightly shadier conditions, compared with those cut in autumn. Hedgerow cutting management can thus alter the richness and composition of plant communities, over relatively short timescales. These results are discussed in the context of longer term trends in hedgerow plant communities across northern Europe, and conservation management funded under agri-environment schemes.

Managing hedgerows for nocturnal wildlife: Do bats and their insect prey benefit from targeted agri‐environment schemes?

AbstractMitigating the detrimental impacts of intensive farming on biodiversity requires the implementation of cost‐effective conservation actions. Targeted agri‐environment schemes (AESs) to enhance populations of threatened species inhabiting farmland have been proposed for this purpose, yet their effectiveness for nocturnal wildlife remains unknown.We assessed whether hedgerow management prescribed by targeted AESs to improve habitat conditions for the greater horseshoe bat (Rhinolophus ferrumequinum) in England may positively influence the species, the entire bat assemblage and the insect prey of bats. We specifically investigated the responses of bats (occurrence, activity and species richness) and insects (biomass, abundance and diversity) to time since last trimming (from 1 up to 10 years). We explored the mechanisms underlying the effects of AES via changes in trimming regime on bats. Moreover, we investigated the effects of landscape context on bats as we expected that highly mobile species would benefit further from landscape‐scale management.Bat species richness significantly increased with time since last trimming. Three bat taxa of major conservation concern in Western Europe substantially benefited from the targeted prescription, namelyR. ferrumequinum,Rhinolophus hipposiderosandPlecotusspp. Insect family richness and dipteran abundance were also significantly greater at hedgerows that were untrimmed for at least 3 years. The activity of more common bat species (i.e. pipistrelle bats) was not influenced by time since last trimming.Changes in trimming regime strongly affected hedgerow height which directly and indirectly (by increasing prey abundance) influenced bat occurrence, activity and species richness along hedgerows.The activity of highly mobile bat species was mainly associated with a range of landscape attributes. The amount of semi‐natural grassland within 0.5 km of the sampling sites positively influencedR. ferrumequinumwhile the presence of urban areas negatively affected light‐sensitive bat species.Synthesis and applications.The implementation of targeted agri‐environment schemes can include effective measures to enhance bats and their insect prey in farmland. Although we highlight the success of current prescriptions on hedgerow management, we suggest that their effectiveness can easily be optimized by encouraging farmers to keep hedgerows untrimmed for longer periods (>3 up to 10 years). We also highlight that a multi‐scale management approach is required to successfully promote bats in farmland.

Qualitative and Quantitative Analysis of Hedgerows in Urban Areas

The research aimed to analyze the maintenance, composition, pruning, planting aspects and architectural elements on urban hedgerows. This study was carried out in an area of Imbiribeira, Recife, PE, Brazil, during six months. The survey was conducted in an area of 30 city blocks (37.024 hectares). The application of the questionnaire was directed to people residing, working, or owning real estate that contained hedgerows. Maintenance (person with the responsibility of pruning and maintenance of the hedge and types of maintenance performed on the hedges); Plant species aspects (species used were classified into groups of plant species: arboreal, shrub, herbaceous and climbing plants); Composition (homogeneous or heterogeneous); Pruning (maintenance or topiary); Planting aspects (planting alignment, spacing rhythm and dimensions of the hedge). In the study area, 30 blocks were sampled, where the presence of hedgerows was observed in 18 of them. The people responsible for the maintenance and management of hedgerows were mostly non-professional workers. The practice of watering hedgerows was found in 95.24% of the visited properties. The use fertilizer was found in 28.57% of the cases and only 4.76% of the properties use pesticide products due to phytosanitary problems. Most of the hedgerows had a homogeneous composition. Topiary pruning is the most practiced treatment on the hedgerows, with a frequency of 82.28% in the study area. The quincux planting with no definite spacing rhythm was the most found. The most observed Planting Alignment in the study area was in line. The most observed Spacing Rhythm was the one with no rhythm of planting. Although hedgerows are widely used in urban and rural areas, studies on their maintenance, composition, structure, ecological importance and relevance to biodiversity conservation are scarce.

Moth responses to sympathetic hedgerow management in temperate farmland

Hedgerows provide valuable habitats and corridors for many species in farmland, yet a lack of appropriate management may threaten their benefits to biodiversity. Although agri-environment scheme (AES) prescriptions on hedgerow management have the potential to reverse the detrimental effect of over-trimming on wildlife, their effectiveness has rarely been addressed. The aims of the study were to (i) assess moth responses to trimming regimes; and (ii) investigate the influence of the surrounding landscape on moth assemblages. We specifically tested the effectiveness of the trimming regime recommended by the targeted AES that was implemented on farms near greater horseshoe bat (Rhinolophus ferrumequinum) colonies since it represented the most sympathetic hedgerow management option among English AES options. We sampled adult micro- and macro-moths along 64 hedgerows located within 20 English farms using light traps, and classified moths into two guilds reflecting their larval food preferences, namely grass/herb- and shrub/tree-feeders. Our results suggest that reducing trimming has a positive impact on macro-moth species richness as well as on shrub/tree-feeder abundance and species richness. It also benefited four moth species that are significantly declining in Britain. Furthermore, while the proportion of woodland at a large spatial scale (3.0 km radius around the sampling sites) was positively associated with the abundance of macro-moths and grass/herb-feeders, woodland connectivity had a positive effect on the species richness of grass/herb- and shrub/tree-feeders at large and medium (1.5 km radius) scales, respectively. Both the abundance and species richness of macro-moths and the abundance of shrub/tree-feeders were negatively affected by the presence of arable fields adjacent to hedgerows. Overall, these findings reveal the wider biodiversity benefits of targeted AESs focusing on habitat improvement for R. ferrumequinum, and the importance of woodland in the wider landscape. We therefore strongly recommend implementing a multi-scale management approach (i.e. from field to landscape) through the use of adequate AES prescriptions to conserve moths in agricultural landscapes.

The Relative Effects of Local and Landscape Characteristics of Hedgerows on Bats

The role of hedgerows in maintaining biodiversity in areas of intensive agriculture is well known, particularly for bats. However, few studies have addressed the importance of the intrinsic characteristics of hedgerows for bats and disentangled the relative effects of local and landscape characteristics of hedgerows on bat activity. In an acoustic survey, we assessed bat activity by recording bat calls using detectors and manually verified all calls using spectrogram analysis. The parameters used to determine local hedgerow structures were the length of the line of trees, of shrub hedgerows, of wooded hedgerows without shrubs and of hedgerows including the three strata (tree, shrub and herb) at a local scale. We assessed the influence of hedgerow structure and on bat activity with an approach considering both species and community, comparing two different scales, the local and the landscape. We highlighted the importance of hedgerow characteristics for bats on both the local and landscape scales even though responses differ between species and spatial scales. We found that the presence of trees in hedgerows exerts a generally positive influence on bat activity and that hedgerows with the three strata had lower bat activity than hedgerows with trees. In our study, some bats seemed to prefer agricultural landscapes dominated by wooded hedgerows and, on the local scale, hedgerows that include trees with little diversified among strata, except for gleaning species. Our study shows that in terms of hedgerow management, conservation efforts must be designed and undertaken on both the local and landscape scales.

Experimental evidence for optimal hedgerow cutting regimes for Brown hairstreak butterflies

Abstract The Brown hairstreak butterfly has declined in range and abundance over the past 50 years, leading to designated conservation status in several European countries including England and Wales. The Brown hairstreak's decline has been linked to changes in hedgerow management, based on mortality of eggs over winter and female oviposition preferences. We assessed Brown hairstreak egg abundance in late winter over 4 years in response to hedgerow management treatments to manipulate the frequency, timing, and the intensity of trimming (reduced intensity resulting in an annual increase of approximately 10 cm in hedge height and width), using a field experiment with a randomised block design. Hedgerow plots cut every year to a standard height and width had the lowest Brown hairstreak egg abundance; this is the most common hedgerow management outside agri‐environment schemes (AES). Cutting hedgerow plots at a reduced intensity nearly doubled the number of surviving eggs in late winter. Plots cut at a reduced frequency in autumn (once every 3 years), which forms part of current English AES, had 1.3 times more eggs than those cut annually. Current AES management prescriptions are likely to benefit the Brown hairstreak, but its requirements need to be balanced with those of other taxa in relation to the timing of hedgerow cutting. Cutting hedges at a reduced intensity has previously been shown to benefit the wider Lepidoptera community as well as Brown hairstreak butterflies. Reduced intensity cutting does not currently form part of AES hedgerow prescriptions, but could be considered for inclusion in future schemes.

Bayesian inferences of arthropod movements between hedgerows and orchards

Hedgerows are agro-ecological infrastructures that are assumed to enhance biodiversity in an agro-ecosystem and the control of crop pests. However, local movements of arthropod predators from hedgerows to crops remain poorly understood. In this research, these movements were analysed in eleven commercial apple orchards over two weeks in the spring of 2014. Predators were indirectly marked by spraying ovalbumin on the hedgerows. Canopy and ground predators were captured using beating and pitfall traps, respectively, in both the orchards and the hedgerows, and individuals marked by ovalbumin were detected using ELISAs. Approximately 20% of the 1272 captured predators were identified as marked. Movements between the orchards and the hedgerows of the most abundant predator taxa (Forficula auricularia, Chrysoperla sp., Philodromus spp., Cheiracanthium mildei, and Nebria brevicollis) and of four guilds (ground spiders, ground beetles, canopy spiders and canopy insects) captured across the eleven locations were estimated using a Bayesian model. On one hand, canopy insects and ground spiders were less likely to stay in the hedgerows than were the canopy spiders and ground beetles. On the other hand, the canopy spiders and ground beetles were less likely to stay in the orchard than were the canopy insects and ground spiders. However, there were exceptions within these groups: F. auricularia and N. brevicollis exhibited a high probability of staying in the hedgerow and in the orchard, respectively. Overall, these results demonstrate the frequent movements that occurred between the orchard and the adjacent hedgerow in a diverse range of predator taxa. The probabilities of movement were further affected by the characteristics of the orchard for most taxa. Therefore, agro-environmental measures that focus on hedgerow management require consideration of the local arthropod predator communities and their characteristics to enhance pest control in apple orchards.