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Conventional arable cropping with annual crops established by ploughing and harrowing degrades larger soil aggregates that contribute to storing soil organic carbon (SOC). The urgent need to increase SOC content of arable soils to improve their functioning and sequester atmospheric CO2 has motivated studies into the effects of reintroducing leys into long-term conventional arable fields. However, effects of short-term leys on total SOC accumulation have been equivocal. As soil aggregation may be important for carbon storage, we investigated the effects of arable-to-ley conversion on cambisol soil after three years of ley, on concentrations and stocks of SOC, nitrogen and their distributions in different sized water-stable aggregates. These values were benchmarked against soil from beneath hedgerow margins. SOC stocks (0–7 cm depth) rose from 20.3 to 22.6 Mg ha−1 in the arable-to-ley conversion, compared to 30 Mg ha−1 in hedgerows, but this 2.3 Mg ha−1 difference (or 0.77 Mg C ha−1 yr−1) was not significant). However, the proportion of large macroaggregates (> 2000 μm) increased 5.4-fold in the arable-to-ley conversion, recovering to similar abundance as hedgerow soils, driving near parallel increases in SOC and nitrogen within large macroaggregates (5.1 and 5.7-fold respectively). The total SOC (0–7 cm depth) stored in large macroaggregates increased from 2.0 to 9.6 Mg ha−1 in the arable-to-ley conversion, which no longer differed significantly from the 12.1 Mg ha−1 under hedgerows. The carbon therefore accumulated three times faster, at 2.53 Mg C ha−1 yr−1, in the large macroaggregates compared to the bulk soil. These findings highlight the value of monitoring large macroaggregate-bound SOC as a key early indicator of shifts in soil quality in response to change in field management, and the benefits of leys in soil aggregation, carbon accumulation, and soil functioning, providing justification for fiscal incentives that encourage wider use of leys in arable rotations.

The increasing input of anthropogenically-derived nitrogen (N) to ecosystems raises a crucial question: how do N inputs modify the soil microbial stability, and thus affect crop productivity? Soils from an 8-year rice-wheat rotation experiment with increasing N-input rates were subjected to drying–rewetting (DW) cycles for investigating the resistance and resilience of soil functions, in terms of abundances of genes (potential functions) and activities of enzymes (quantifiable functions), to this stress, and particularly the contribution of resistance and resilience on crop production was evaluated. Although the DW cycles had a stronger effect compared to N fertilization level, the N input was also important in explaining the variation in the resistance and resilience of functional genes and the activities of enzymes involved in C, N and P cycling. Crop yields benefited from both of high resistance and high resilience of soil microbial functions, though the resistance and resilience of soil enzyme activities exhibited a stronger contribution to crop yields compared to the functional genes and the overall contribution strength was conditioned by N input levels. In addition to the well-known direct contribution of N fertilization on crop yields, N input plays an indirect role on crop production via conditioning the resistance and resilience of soil functions in response to repeated DW cycles.

Intensification of agriculture has led to major losses of hedgerows and field margins worldwide. Soil sample extraction, in situ time series of soil moisture, temperature and soil water quality analyses, annual earthworm sampling and arbuscular mycorrhizal (AM) fungi sampling enabled comparison of soil functions between typical hedgerows, grass field margins, pasture and arable (mainly winter wheat) fields in a temperate, lowland setting. Mean bulk density (upper 50 cm), surface compaction and soil moisture content were significantly lower while organic matter content and porewater dissolved organic carbon concentrations were significantly greater in hedgerow soils, than margins or fields. Mean nitrate and phosphate concentrations were three and ten times larger, respectively, in soil solutions under hedgerows than arable fields while ammonium concentrations were least in arable fields. Saturated hydraulic conductivity was significantly greater under hedgerows (median = 102 mm hr−1) where it took an average of one hour longer for soils to reach maximum moisture content following rainfall, than adjacent arable (median = 3 mm hr−1) or pasture fields and margins (median = 27 mm hr−1). Hedgerow soils had a greater proportion of flow through micropores and less macropore flow than other soils. The pasture and margin soils had the largest proportion of macropore flow (>85%) and more (and larger) anecic earthworm species, such as Lumbricus terrestris which produce vertical burrows. Earthworm density, biomass and diversity were greater in pasture and margin soils, followed by hedgerow soils, and tended to be lowest in arable soils. For both total and AM fungi, hedgerow soils hosted a distinct and heterogeneous soil community, margin and pasture communities were diverse but clustered together, and arable communities formed a distinct cluster, with low inter-sample variation and significantly lowest AM fungal richness. The findings demonstrate that soils under hedgerows, which should be conserved, can provide important functions on farmland including storing organic carbon, promoting infiltration and storing runoff, increasing earthworm diversity and hosting distinct AM communities.

Nitrogen contributes to plant defense responses by the regulation of plant primary metabolism during plant-pathogen interactions. Based on biochemical, physiological, bioinformatic and transcriptome approaches, we investigated how different nitrogen forms (ammonium vs. nitrate) regulate the physiological response of cucumber (Cucumis sativus) to Fusarium oxysporum f. sp. cucumerinum (FOC) infection. The metabolic profile revealed that nitrate-grown plants accumulated more organic acids, while ammonium-grown plants accumulated more amino acids; FOC infection significantly increased levels of both amino acids and organic acids in the roots of ammonium-grown plants. Transcriptome analysis showed that genes related to carbon metabolism were mostly up-regulated in plants grown with nitrate, whereas in ammonium-grown plants the up-regulated genes were mostly those that were related to primary nitrogen metabolism. Root FOC colonization and disease incidence were positively correlated with levels of root amino acids and negatively correlated with levels of root organic acids. In conclusion, organic acid metabolism and expression of related genes increased under nitrate, whereas ammonium increased the level of amino acids and expression of related genes; these altered levels of organic acids and amino acids resulted in different tolerances to FOC infection depending on the nitrogen forms supplied.

The study of ecosystem processes over multiple scales of space and time is often best achieved by using comparable data from multiple sites. Yet long term ecological observatories have often developed their own data collection protocols. Here we address this problem by proposing a set of ecological protocols suitable for widespread adoption by the ecological community. 2. Scientists from the European ecological research community prioritised terrestrial ecosystem parameters that could benefit from a more consistent approach to data collection within the resources available at most long term ecological observatories. Parameters for which standard methods are in widespread use, or for which methods are evolving rapidly, were not selected. 3. Protocols were developed by domain experts, building on existing methods where possible, and refined through a process of field testing and training. They address above-ground plant biomass; decomposition; land use and management; leaf area index; soil mesofaunal diversity; soil C and N stocks, and greenhouse gas emissions from soils. These complement existing methods to provide a complete assessment of ecological integrity. 4. These protocols offer integrated approaches to ecological data collection that are low cost and are starting to be used across the European Long Term Ecological Research community.

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.

Intensive arable cropping depletes soil organic carbon and earthworms, leading to loss of macropores, and impaired hydrological functioning, constraining crop yields and exacerbating impacts of droughts and floods that are increasing with climate change. Grass and legume mixes traditionally grown in arable rotations (leys), are widely considered to regenerate soil functions, but there is surprisingly limited evidence of their effects on soil properties, resilience to rainfall extremes, and crop yields. Using topsoil monoliths taken from four intensively cropped arable fields, 19 month-old grass-clover ley strips in these fields, and from 3 adjacent permanent grasslands, effects on soil properties, and wheat yield in response to four-weeks of flood, drought, or ambient rain, during the stem elongation period were evaluated. Compared to arable soil, leys increased earthworm numbers, infiltration rates, macropore flow and saturated hydraulic conductivity, and reduced compaction (bulk density) resulting in improved wheat yields by 42–95 % under flood and ambient conditions. The leys showed incomplete recovery compared to permanent grassland soil, with modest gains in soil organic carbon, total nitrogen, water-holding capacity, and grain yield under drought, that were not significantly different (P > 0.05) to the arable controls. Overall, grass-clover leys regenerate earthworm populations and reverse structural degradation of intensively cultivated arable soil, facilitating adoption of no-tillage cropping to break out of the cycle of tillage-driven soil degradation. The substantial improvements in hydrological functioning by leys will help to deliver reduced flood and water pollution risks, potentially justifying payments for these ecosystem services, especially as over longer periods, leys increase soil carbon sequestration.

Sustainable intensification is a process by which agricultural productivity is enhanced whilst also creating environmental and social benefits. We aimed to identify practices likely to deliver sustainable intensification, currently available for UK farms but not yet widely adopted. We compiled a list of 18 farm management practices with the greatest potential to deliver sustainable intensification in the UK, following a well-developed stepwise methodology for identifying priority solutions, using a group decision-making technique with key agricultural experts. The list of priority management practices can provide the focal point of efforts to achieve sustainable intensification of agriculture, as the UK develops post-Brexit agricultural policy, and pursues the second Sustainable Development Goal, which aims to end hunger and promote sustainable agriculture. The practices largely reflect a technological, production-focused view of sustainable intensification, including for example, precision farming and animal health diagnostics, with less emphasis on the social and environmental aspects of sustainability. However, they do reflect an integrated approach to farming, covering many different aspects, from business organization and planning, to soil and crop management, to landscape and nature conservation. For a subset of ten of the priority practices, we gathered data on the level of existing uptake in English and Welsh farms through a stratified survey in seven focal regions. We find substantial existing uptake of most of the priority practices, indicating that UK farming is an innovative sector. The data identify two specific practices for which uptake is relatively low, but which some UK farmers find appealing and would consider adopting. These practices are: prediction of pest and disease outbreaks, especially for livestock farms; staff training on environmental issues, especially on arable farms.

Understanding the trade‐offs between yield, ecosystem services, and other societal benefits is a fundamental prerequisite for the sustainable intensification of agriculture. Here, we develop and test an holistic approach to assessing farm performance across production, social, financial, and environmental dimensions. A longlist of potential indicators was reduced to a smaller subset of Headline Indicators, covering financial performance, levels of food production (standardized in terms of energy content), social characteristics of the farmer (including age, level of education, and degree of business cooperation), hours worked on the farm and provision of public access, and environmental quality (including impacts on climate regulation and water quality). A new index for biodiversity was created and validated, based on land use and management. Data were collected from 59 English and Welsh farms, using a questionnaire structured to be similar to the UK Farm Business Survey. Data were analyzed per farm and per unit area. The main overall variation in Headline Indicators was due to positive relationships between production, profitability and predicted levels of nitrate and GHG emissions, while social variables and biodiversity were generally unrelated to production. Cereal production was associated with relatively low levels of GHG emissions per unit of food production. There were strong differences in indicator profiles between farm types. Such metrics have value in helping understand how best to drive sustainable intensification, especially as it should involve reducing the pollution footprint of food production.

Agricultural intensification has significantly increased yields and fed growing populations across the planet, but has also led to considerable environmental degradation. In response an alternative process of ‘Sustainable Intensification’ (SI), whereby food production increases while environmental impacts are reduced, has been advocated as necessary, if not sufficient, for delivering food and environmental security. However, the extent to which SI has begun, the main drivers of SI, and the degree to which degradation is simply ‘offshored’ are uncertain. In this study we assess agroecosystem services in England and two contrasting sub-regions, majority-arable Eastern England and majority-pastoral South-Western England, since 1950 by analysing ecosystem service metrics and developing a simple system dynamics model. We find that rapid agricultural intensification drove significant environmental degradation in England in the early 1980s, but that most ecosystem services except farmland biodiversity began to recover after 2000, primarily due to reduced livestock and fertiliser usage decoupling from high yields. This partially follows the trajectory of an Environmental Kuznets Curve, with yields and GDP growth decoupling from environmental degradation above ~£17,000 per capita per annum. Together, these trends suggest that SI has begun in England. However, the lack of recovery in farmland biodiversity, and the reduction in UK food self-sufficiency resulting in some agricultural impacts being ‘offshored’, represent major negative trade-offs. Maintaining yields and restoring biodiversity while also addressing climate change, offshored degradation, and post-Brexit subsidy changes will require significant further SI in the future.

As a result of the complexity of agri-food systems, popularly-supported ‘win-win’ solutions rarely result in wholly satisfactory outcomes. We draw on documented cases of the introduction of agricultural input subsidies; the intensification of livestock production; and the development of genetically modified crop varieties as examples of agri-food systems in which there are multiple interconnected sustainability priorities and inevitable conflicts. Generic or narrowly conceived goals may not fully reflect the multiple and conflicting dimensions of sustainability that are relevant to such cases. There is a need to advance established multiple-win agendas, such as sustainable intensification and climate smart agriculture, to more fully reflect this complexity. We propose the use of the sustainability space concept for defining and monitoring sustainability priorities that might become the basis for effective management of complex systems. We further outline the challenge of defining and monitoring these priorities, which will require carefully designed, interdisciplinary and participatory research agendas.

A diverse range of response options was evaluated in terms of their utility for sustaining ecosystem services in the UK. Robustness of response options was investigated by applying a ‘stress-testing’ method which evaluated expected performance against combined scenarios of socioeconomic and climate change. Based upon stakeholder feedback, a reference scenario representing current trends in climate and socioeconomic drivers (‘business-as-usual’) was used as a dynamic baseline against which to compare results of other scenarios. The robustness of response options was evaluated by their utility in different environmental and social contexts as represented by the scenarios, and linked to their adaptability to adjust to changing conditions. Key findings demonstrate that adaptability becomes increasingly valuable as the magnitude and rate of future change diverges from current trends. Stress-testing also revealed that individual responses in isolation are unlikely to be robust meaning there are advantages from integrating cohesive combinations (bundles) of response options to maximise their individual strengths and compensate for weaknesses. This identifies a role for both top-down and bottom-up responses, including regulation, spatial targeting, incentives and partnership initiatives, and their use in combination through integrated assessment and planning consistent with the adoption of an Ecosystem Approach. Stress-testing approaches can have an important role in future-proofing policy appraisals but important knowledge gaps remain, especially for cultural and supporting ecosystem services. Finally, barriers and enablers to the implementation of more integrated long-term adaptive responses were identified drawing on the ‘4 Is’ (Institutions, Information, Incentives, Identity) conceptual framework. This highlighted the crucial but usually understated role of identity in promoting ownership and uptake of responses.

Geogenic and anthropogenic activities can leads to agriculture soil pollution and land degradation. Many cost-effective and environment friendly strategies are applied to improve soil fertility, reduce soil pollution and human health risks caused by consumption of metals contaminated vegetables. In this study we evaluate the effects of rice husk biochar (RHB), biochar from corn cob (CCB) and biochar from peanut shells (PNB) on the bioavailability of potentially toxic elements (PTEs) in soil, its bioaccumulation and antioxidant enzymes activities in Lactuca sativa L. plants. RHB, CCB and PNB amendments significantly (P ≤ 0.05) increased Lactuca sativa L. biomass production (39%, 65% and 100%) as well as soil fertility. Amendments of PNB, RHB and CCB significantly (P ≤ 0.05) increased soil available phosphorous (P), cation exchange capacity (CEC), pH, total nitrogen (TN), total carbon (TC) and dissolved organic carbon (DOC) concentration, but markedly reduced bioavailable concentrations of cadmium (Cd) (31%, 20% and 22%) arsenic (As) (33%, 22% and 27%), and lead (Pb) (46%, 24% and 32%). In addition, CCB and PNB amendments significantly (P ≤ 0.01) decreased the shoot accumulation of Pb, Cd and As, while RHB amendment increased the shoot accumulations of nickel (Ni) and chromium (Cr). The reduction in PTEs accumulation may be linked with increased sorption of PTEs by biochars. Furthermore, amendments of CCB and PNB significantly (P ≤ 0.05) suppressed the activities of SOD (53% and 69%), POD (22%, 31%) but stimulated (38% and 31%) with amendment of RHB. However, RHB, CCB and PNB amendments significantly (P ≤ 0.05) suppressed the activity of CAT (21%, 41% and 48%) in Lactuca sativa L. plants. PNB was the most effective soil amendment as compared with RHB and CCB. However, to fully elucidate the effects of the tested biochars, long-term field trails are needed.

The extent to which conversion to organic farming influenced habitat diversity within less favored areas (LFAs) was determined. Similar numbers of conventional (not converted) (n = 16), recent converts ( 5 years; n = 16) were surveyed. Each holding was characterized in terms of habitat classes using a rapid ground survey. Conversion to organic farming had little effect on overall habitat diversity. This could be linked to the physical challenges of farming in LFAs limiting management options. The results highlight the need for a separate evidence base for the development of policies relating to farming and biodiversity in marginal areas.

Several influential reports have suggested that one of the most appropriate responses to expected food shortages and ongoing environmental degradation is sustainable intensification, i.e. the increase of food production with at worst no increase in environmental harm, and ideally environmental benefit. Here we sought evidence of sustainable intensification among British farmers by selecting innovative arable, dairy, mixed and upland farms and analysing their own data on yields, inputs and land use and management for 2006 and 2011. The evidence was obtained by interview, and was interpreted in terms of the ecosystem services of food production (GJ ha−1, where area took into account estimated area to grow any imported animal feeds), regulation of climate, air and water quality (modelled emissions of GHGs (CO2e ha−1), ammonia (kg ha−1) and nitrate loss (kg ha−1)) and biodiversity (using an index based on the presence of habitats and management). Several farms have increased both food production and other ecosystem services over this time by increasing yields, using resources more efficiently and/or enhancing biodiversity, and sometimes by reducing livestock numbers and increasing cropping. The motivation has been to improve farm profitability through increasing food production, reducing input costs and accessing public payments through agri-environment schemes and generating renewable energy. Such sustainable intensification was not achieved by farmers who increased meat or milk yields. Sustainable intensification can be achieved when the correct drivers are in place to influence the actions of individual farmers. Also, it is possible to indicate sustainable intensification by using a small number of high-level indicators derived from data that farmers already hold, though such an approach may not capture the impacts of farmer innovative practices.

Several recent influential reports (for example, Royal Society, 2009; Foresight, 2011) have suggested that, in response to expected food shortages and ongoing environmental degradation, a policy of sustainable intensification of agriculture should be pursued. Such a policy would involve producing more food without expanding the area under cultivation and without adverse environmental impact. This is in many respects a new way of approaching food production, which will require scientific innovation and technology adoption, but also an appropriate policy framework to elicit an appropriate response in appropriate locations to secure other ecosystem services (Godfray et al, 2010).

Here, we review the delivery of ecosystem services from Enclosed Farmland in the UK, and explore how the expected demands for ecosystem services might be met in the future. Most Enclosed Farmland is managed for agriculture; the UK is 60% self-sufficient in foods. Pollinators are in serious decline, but little is known of trends of predators of crop pests. Effects of agriculture on water quality and climate regulation are negative but improving; GHG emissions fell by 20% between 1990 and 2008. Recent declines in numbers of some farmland birds and in plant species richness have been halted, though not reversed. Enclosed Farmland provides considerable leisure and cultural value. Effective delivery of multiple ecosystem services requires improved understanding of how ecosystem services are generated, and of their economics and governance. Food production can be integrated with the delivery of other ecosystem services by promoting a diversity of farming systems and allocating land to different ecosystem services according to its suitability. Approaches include, minimising negative environmental impacts of food production through technology; mitigating environmental harm by managing areas for environmental benefit, from patches within fields to much larger areas; and developing markets and regulations for environmental protection.

Sustainable intensification is a concept of growing importance, yet it is in danger of becoming scientifically obsolete because of the diversity of meanings it has acquired. To avoid this, it is important to consider the various scales on which it can aid progress towards feeding human populations while also protecting our environment.

The US beef industry is a major contributor of greenhouse gases and is commonly regarded as unsustainable at current levels. A new study models a system in which sustainability could be increased by subsistence on grass and agricultural by-products, prompting the question, ‘what are the limits of sustainable livestock production in the US’?

There is a consensus that globally we need more food, from roughly the same areas of land, with an improved delivery of ecosystem services. The challenge, therefore, is to simultaneously raise yields, increase the efficiency with which inputs are used and reduce the negative environmental effects of food production, a process termed as ‘sustainable intensification’ (Foresight, 2011). This certainly sounds like intensification, but will it be enough, and is it necessarily sustainable? Increasingly, sustainability is being considered in the context of delivery of ecosystem services, both now and in the future. The evidence from the UK shows that current agricultural practices tend to be negatively correlated with most other ecosystem services, that is, as yields increase, services such as the provision of clean water, regulation of water quantities and greenhouse gases and levels of cultural value and biodiversity tend to go down (Firbank et al., 2011). The relationships are not always linear; there are situations in which some agricultural production can enhance some ecosystem services (e.g. grazing of grassland nature reserves enhances biodiversity outcomes), and also it is possible to enhance non-agricultural ecosystem services without significant loss of yield, for example, by controlling diffuse pollution. So Figure 1a is a conceptual model describing the contemporary relationship between the delivery of agricultural production (i.e. traded goods, such as food and fibre) and non-agricultural ecosystem services (for which market systems are largely absent or underdeveloped).

1. There is an urgent need to accurately model how environmental change affects the wide-scale functioning of ecosystems, but advances are hindered by a lack of knowledge of how trophic levels are linked across space. It is unclear which theoretical approach to take to improve modelling of such interactions, but evidence is gathering that linking species responses to their functional traits can increase understanding of ecosystem dynamics. Currently, there are no quantitative studies testing how this approach might improve models of multiple, trophically interacting species, at wide spatial scales. 2. Arable weeds play a foundational role in linking food webs, providing resources for many taxa, including carabid beetles that feed on their seeds and weed-associated invertebrate prey. Here, we model associations between weeds and carabids across farmland in Great Britain (GB), to test the hypothesis that wide-scale trophic links between these groups are structured by their species functional traits. 3. A network of c. 250 arable fields, covering four crops and most lowland areas of GB, was sampled for weed, carabid and invertebrate taxa over 3 years. Data sets of these groups were closely matched in time and space, and each contained numerous species with a range of eco-physiological traits. The consistency of trophic linkages between multiple taxa sharing functional traits was tested within multivariate and log-linear models. 4. Robust links were established between the functional traits of taxa and their trophic interactions. Autumn-germinating, small-seeded weeds were associated with smaller, spring-breeding carabids, more specialised in seed feeding, whereas spring-germinating, large-seeded weeds were associated with a range of larger, autumn-breeding omnivorous carabids. These relationships were strong and dynamic, being independent of changes in invertebrate food resources and consistent across sample dates, crops and regions of GB. 5. We conclude that, in at least one system of interacting taxa, functional traits can be used to predict consistent, wide-scale trophic links. This conceptual approach is useful for assessing how perturbations affecting lower trophic levels are ramified throughout ecosystems and could be used to assess how environmental change affects a wider range of secondary consumers.

1. Understanding the wide-scale processes controlling communities across multiple sites is a foremost challenge of modern ecology. Here, data from a nation-wide network of field sites are used to describe the metacommunity dynamics of arable carabid beetles. This is done by modelling how communities are structured at a local level, by changes in the environment of the sampled fields and, at a regional level, by fitting spatial parameters describing latitudinal and longitudinal gradients. 2. Local and regional processes demonstrated independent and significant capacities for structuring communities. Within the local environment, crop type was found to be the primary determinant of carabid community composition. The regional component included a strong response to a longitudinal gradient, with significant increases in diversity in an east-to-west direction. 3. Carabid metacommunities seem to be structured by a combination of species sorting dynamics, operating at two different, but equally important, spatial scales. At a local scale, species are sorted along a resource gradient determined by crop type. At a wider spatial scale species appear to be sorted along a longitudinal gradient. 4. Nation-wide trends in communities coincided with known gradients of increased homogeneity of habitat mosaics and agricultural intensification. However, more work is required to understand fully how communities are controlled by the interaction of crops with changes in landscape structure at different spatial scales. 5. We conclude that crop type is a powerful determinant of carabid biodiversity, but that it cannot be considered in isolation from other components of the landscape for optimal conservation policy.

International audience; Agricultural intensification is best considered as the level of human appropriation of terrestrial net primary production. The global value is set to increase from 30%, increasing pressures on biodiversity. The pressures can be classified in terms of spatial scale, i.e. land cover, landscape management and crop management. Different lowland agricultural landscapes in Great Britain show differences among these pressures when habitat diversity and nutrient surplus are used as indicators. Eutrophication of plants was correlated to N surplus, and species richness of plants correlated with broad habitat diversity. Bird species diversity only correlated with habitat diversity when the diversity of different agricultural habitats was taken into account. The pressures of agricultural change may be reduced by minimizing loss of large habitats, minimizing permanent loss of agricultural land, maintaining habitat diversity in agricultural landscapes in order to provide ecosystem services, and minimizing pollution from nutrients and pesticides from the crops themselves. While these pressures could potentially be quantified using an internationally consistent set of indicators, their impacts would need to be assessed using a much larger number of locally applicable biodiversity indicators.

Ecosystem carbon (C) fluxes in terrestrial ecosystems are affected by varying environmental conditions (e.g. soil heterogeneity and the weather) and land management. However, the interactions between soil respiration (Rs) and net ecosystem exchange (NEE) and their spatio-temporal dependence on environmental conditions and land management at field scale is not well understood. We performed repeated C flux measurement at 21 sites during the 2013 growing season in a temperate upland grassland in Germany, which was fertilized and cut three times according to the agricultural practice typical of the region. Repeated measurements included determination of NEE, Rs, leaf area index (LAI), meteorological conditions as well as physical and chemical soil properties. Temporal variability of Rs was controlled by air temperature, while LAI influenced the temporal variability of NEE. The three grass cuts reduced LAI and affected NEE markedly. More than 50% of NEE variability was explained by defoliation at field scale. Additionally, soil heterogeneity affected NEE, but to a lower extent (>30%), while Rs remained unaffected. We conclude that grassland management (i.e. repeated defoliation) and soil heterogeneity affects the spatio-temporal variability of NEE at field scale.

1 We investigated the role of non-native species (neophytes) in common British plant communities using botanical data from two stratified random surveys carried out in 1990 and 1998. 2 We found that from 16 851 plots surveyed in 1998 there were 123 non-native species found mostly in arable, tall grass/herb and fertile grassland habitats. Invasive non-native species, e.g. Fallopia japonica, Impatiens glandulifera and Rhododendron ponticum, were uncommon in this survey. 3 Between 1990 and 1998 the total number of non-native species increased but the mean number of species per sample plot decreased. The mean cover of non-natives increased from 1.2% to 1.9%. 4 There were positive spatial and temporal relationships between non-native and native species diversity. However, there was a weak negative relationship between changes in non-native cover and native diversity. 5 The species composition and ecological traits of communities containing non-natives were very different from those that did not contain them. 6 In the British countryside non-native species were mainly found in habitats with anthropogenic associations, high fertility, high number of ruderal species and high diversity. There is also an indication that successional shifts where competitive invasive species dominate involve non-native species. 7 National-scale changes in plant community composition are likely to be closely correlated with external land-use impacts. Changes such as eutrophication, nitrogen deposition and increased fertility in infertile habitats are likely to benefit both native and non-native invasive species; however, currently these trends benefit native species much more often than non-natives. 8 Non-native species are known to have significant effects on native species at local scales in many countries; however, at the landscape scale in Great Britain they are best considered as symptoms of disturbance and land-use change rather than a direct threat to biodiversity.

1. In temperate farmed landscapes conservation policies increasingly emphasize large-scale reductions in land-use intensity. Yet despite a managed reversion to more favourable abiotic conditions, depleted regional species pools may prevent the re-assembly of target communities. 2. Using national-scale survey data recorded across Great Britain in 1998, we investigated the extent to which grassland indicator plant species persisted on potential refuge habitats across a spatial gradient of intensive land cover in lowland 1-km squares. These habitats comprised road verges, field boundaries, watercourse banks and small biotope fragments. Intensive land cover comprised built land, arable and improved grassland. 3. The rate of reduction in indicator species richness across the intensive land cover gradient was significantly lower in all potential refuge features than in surrounding fields and larger areas of habitat. 4. The best refuge locations were watercourse banks and small biotopes. In both cases, indicator species richness was higher than adjacent fields at the lowest intensive land cover and stayed higher as intensive land cover increased. 5. However, as intensive land cover increased, plant traits associated with higher nutrient availability were more prominently represented among indicator species. 6. Although richer assemblages of indicator species persisted on refuge features, population sizes are likely to be small, because of species-area effects, and also vulnerable to nutrient surpluses and reduced or inappropriate disturbance. 7. Synthesis and applications. Across the British lowlands, linear landscape features and small habitat fragments can provide limited safe havens for unimproved grassland plant species. However, the identity of refuge features and their species richness and composition are likely to vary with local conditions. Three activities are therefore paramount in assessing their role in larger scale extensification schemes: (i) development of rapid ways of assessing the plant diversity and distribution of refuge features in local areas; (ii) quantification of the risks posed to the viability of residual source populations through implementation of different options for incorporating them into extensification schemes; (iii) maximization of scheme performance by targeting landscapes with sufficient residual diversity to enable increases in population size of the target species in the medium term.

Analysis of detailed data on habitat turnover derived from the Countryside Survey of Great Britain indicates that some types of habitat conversion can be predicted. We report that parcels of semi-natural grassland were more likely to have been converted to intensive agriculture if they were large, had a high nutrient status and were in the proximity of land that has already been intensified; three variables indicating an environmental potential for intensification. Most of the conversions predicted by the models were observed (high specificity) but a substantial number of conversions were not predicted (low sensitivity), indicating that the models could be refined by integrating additional information. We suggest that the ecological and spatial characteristics of individual parcels of semi-natural habitats and their surrounding land use should be used as a basis to assess the risk of biodiversity loss in dynamic agricultural landscapes.

The conservation and management of biodiversity requires accurate, repeatable and cost-effective monitoring techniques. In this study, a simple and rapid methodology was employed to measure the quality of different habitats for butterfly species on 10 arable farms in lowland Britain. This habitat monitoring was seven times more rapid than the traditional species-based butterfly monitoring. Data on butterfly abundance were combined with the information gathered on habitat quality at five of the farms using stepwise regression. These models had a consistently high degree of explanatory power for the summary variables of total butterfly abundance and species richness, and the functional groupings of mobile and immobile species. There was good agreement between observed and predicted estimates of species richness and abundance when the models were validated on a further five independent sites. Models to predict the abundance of 11 common butterfly species were also produced. These varied considerably in their predictive power and validity between species. The results clearly demonstrated the beneficial effects of targeted habitat creation for butterflies which is promoted under the Agri-environment Schemes, especially the recently introduced pollen and nectar seed mixtures (WM2) available under the Countryside Stewardship Scheme. The models confirmed the importance of shelter, floristically diverse field margins and the availability of nectar resources from legume species in explaining the abundance of immobile butterfly species in arable landscapes. These sources of nectar and the presence of larval host plants in the crucifer family were important factors in explaining the abundance of mobile species. The results are discussed in terms of the potential of this approach for: (i) assessing habitat quality for butterflies in intensively managed landscapes; (ii) enhancing the value of butterfly monitoring schemes in explaining changes in butterfly abundance at the site and national scale; and (iii) informing habitat management and restoration guidelines for butterfly conservation on arable farmland.

The potential of habitat-based models was explored to predict the occurrence of carabid beetles in arable conditions. It was hypothesised that: (i) the habitats surrounding a location were good predictors of the occurrence of the most common carabid species; (ii) the current knowledge on habitat associations for some individual species was sufficient to develop accurate predictive models. The performance of knowledge-based models was assessed for eight well-studied carabid species. Rule sets were produced using an extensive database describing the nature and condition of the habitats recorded within a 50 m radius of the sampling sites. The performance was compared to a more classical approach based on logistic regression (LR) models, using the same original information summarised into 19 variables by correspondence analysis (CA). The performance of the rule-based (RB) models was higher than expected by chance for species occurring in less than 70% of the sites (k>0.4) and was relatively consistent across the three areas of England where they were tested. Models developed for widespread species had a high prediction success (PS) but no discriminatory ability (low k value). LR and RB approaches gave comparable results for species of average prevalence (30–70%) while for species occurring in less than 30% of the sampled sites, the RB approach performed significantly better than the LR one. It is suggested that knowledge-based approaches could be used more widely to predict the distribution of invertebrate species. The effect of species prevalence and the potential application of knowledge-based habitat-models in the context of biodiversity assessment are discussed.

Around 11% of arable land in England was set-aside in the mid-1990s as part of the Common Agricultural Policy (CAP). The scheme allowed both annual and longer-term exclusion from cropping. The most widespread green cover was natural regeneration, followed by non-food crops and sown grass covers. Impacts of set-aside management on agronomy and ecology were investigated using a questionnaire for farmers and field studies of plants, invertebrates and breeding birds on up to 200 set-aside fields, half rotational and half non-rotational. More detailed studies were conducted on crop diseases, vegetation dynamics and breeding birds. Plant species diversity on set-aside was greater in the west of England than in the east, and, on non-rotational naturally-regenerated set-aside, plant communities became increasingly dominated by grassland species with age. Gradients of powdery mildew and septoria leaf blotch infection levels were observed within cereal fields adjacent to rotational set-aside. Invertebrate pest species were more frequent in crops than in neighbouring set-aside, regardless of type. All groups of birds studied were found least on winter cereals, and most were found preferentially on rotational set-aside. Set-aside (especially rotational) has provided suitable habitats for breeding birds over very large areas, and may have helped to compensate for other changes in the farmed landscape detrimental to birds, without causing major agronomic problems. It is important that any scheme replacing set-aside should be over large enough total areas so that the benefits to farmland birds across landscapes are not reduced.

The area and number of woodlands within landscapes managed for shooting pheasants and other lowland game birds are contrasted with those not managed for game. The study locations were sample 1-km squares from the Countryside Survey (CS), a survey of the land cover of Great Britain. Two-hundred-and-thirty-two appropriate CS squares were divided into game and non-game squares on the basis of evidence of management for game. No significant differences were found in changes in woodland area or parcel number during the periods 1984-90 and 1990-98. Twelve matched pairs of game and non-game squares were selected, and the disposition of woodland was taken from maps of the 1870s, 1940s, 1960s and 1980s, recording total area, number of woodland parcels and parcel sizes. The number of parcels of woodland in game squares increased more than that in non-game squares during the period 1960s-1980s, but mean parcel size changed little. Landscapes where management for game has taken place have retained a greater proportio...

This paper describes how Countryside Survey 2000 (CS2000) and earlier Countryside Surveys in 1990 and 1984, can be used to develop an integrated view of the changes in land cover, landscape and biodiversity that have taken place at the regional scale in Great Britain. A particular concern is to develop an understanding of how the national patterns of stock and change are distributed across Great Britain, and whether such changes are leading to more or less regional differentiation in our landscapes and biodiversity. A further concern is how the structure of landscape is changing. A description of the major Environmental Zones that make up Great Britain is given. Analysis of the regional patterns of change observed suggests that there has been considerable geographical variation in the gains and losses of the stock of the Biodiversity Action Plan Broad Habitats. Between 1984 and 1990, in the lowlands of the south and west of England and Wales, there were significant increase in the area of the Arable and Horticultural and Broadleaved Woodland Broad Habitats, and a marked loss of Improved Grassland. Over the same period, in the uplands of England and Wales, significant losses of Acid Grassland were observed, with associated gains in Improved Grassland. The Environmental Zones in Scotland were more stable in terms of the changes in stock of Broad Habitats. In addition to the analysis of net changes in stock of the Broad Habitats, the paper provides an analysis of the exchanges of land between major cover categories or each of the Environmental Zones. In contrast to the regionally concentrated changes in habitat stock, more ubiquitous and uniform changes in habitat quality were detected between 1990 and 1998, which continue trends observed for the 1980s. The quality of freshwater habitats increased. However, there were declines in the quality for some terrestrial biotopes, as indicated by the loss of species diversity from agricultural habitats, and the gains in diversity in semi-natural habitats, such as Acid Grasslands, more usually associated with vegetation types that are poor in species. An important driver of qualitative change appears to be widespread nutrient enrichment from nitrogen. However, such processes are probably superimposed upon more local factors, such as changes in the way land is managed for agriculture. The importance of understanding the various drives of change for future countryside policy is emphasized.

Initiatives to restore characteristic plant species diversity to degraded habitats require target plant species populations to be established and maintained. In landscapes managed intensively for agriculture, species that are foci for restoration efforts may be scarce, being confined to core reserves of less-modified habitat or persisting as fragmented populations on linear landscape features. Botanical data from small and large-scale surveys across Britain was used to investigate whether grassland plants favoured by less intensive management persisted on field boundaries despite increasing productivity in the adjacent field. At low field productivity, field species richness was, on average, higher than in field boundaries. As productivity increased, boundary plots reduced in richness at a slower rate than adjacent fields thus boundaries became relatively richer in grassland species than adjacent fields. Species compositional similarity between fields and their boundaries also declined with increasing field productivity. Grassland field boundaries can function as refugia. However, the lower relative species richness of boundaries next to the least productive fields indicated that some plant species will, on average, be increasingly uncommon or absent in boundaries as field productivity increases. High residual variation in these relationships was linked to local variation in conditions between fields and their boundaries. Field boundaries next to highly productive grasslands appear to function as partial refugia for grassland plants. While highly species rich boundaries can locally occur next to species poor fields, the species richness of most boundaries falls well short of values typical of the least productive fields.

1. Recent changes in population size of butterflies and farmland birds across north-west European landscapes have been linked to the effects of agricultural intensification. Reduction in food supply has been postulated as one of the proximal causes of these trends but the generality of this explanation has not been tested at a large scale and across animal species. 2. Changes in abundance of food plants for butterfly larvae and lowland farmland birds in the British countryside were analysed for the period 1978–90 using data from fixed plots recorded as part of the countryside surveys of Britain. 3. Associations were sought between these changes and trends in population size of selected butterflies and birds recorded from long-term monitoring schemes. 4. No associations were found between change in abundance of food plants and either increasing, stable or decreasing animal groups. At the level of individual animal species, significantly more decreases than increases in food plant frequency were found for herbivorous bird species irrespective of population trend. The size of the reduction in food plant frequency was also significantly greater for the declining bird group than for stable or increasing groups. 5. Few significant associations were detected between population trend and food plant trend for butterfly species. However, the results suggested a positive relationship between increasing butterflies and increased abundance of Elytrigia repens and Urtica dioica. 6. Food plants that increased in abundance comprised species favoured by lack of management and increased nutrient availability. Increases in abundance were also associated with linear landscape features such as hedges and streamsides. Decreasing plant species included arable weeds and stress-tolerant species typical of unimproved grasslands. 7. Based on evidence of local associations between animal and food plant change and the need for viable populations of food plants to exist within the range of each animal species, we support measures designed to enhance and maintain populations of declining food plants. Much evidence now exists to identify practical measures that husband food resources for many bird and butterfly species. The challenge for conservation policy is to manage their implementation at scales necessary to influence national trends.

The maintenance of low-intensity farming is important for the conservation of habitats and species and is a particular issue in Europe as areas under extensive farming regimes continue to diminish. Current proposals for agricultural reform in Europe are seeking to retain and encourage extensive farming partly by seeking to redirect farm workers into non-farm activities such as leisure activities, marketing and processing. In 1991/1992, the botanical characteristics of grass fields on farms where farm households were engaged in non-farm activities (pluriactivity) were compared to those where the farm was fully employed in agriculture. This was done through a botanical and land use/management survey carried out on 71 lowland farms in the Grampian region of Scotland on which a socio-economic survey had been undertaken. Pluriactivity was found to be related to the socio-economic characteristics of the household, so therefore, could not be associated directly with the type and intensity of farming, and hence the botanical composition of the grass swards. The mean age of non-pluriactive farm households was significantly greater than that of pluriactive households and the farms were generally larger. Land management, particularly the rate of reseeding, had the greatest impact on the grass swards. All pluriactive farms had more plant species within their fields than non-pluriactive farms, but the greatest difference was between the non-pluriactive farms and those with off-farm work. The main conclusion is that land management has the greatest over-riding influence on the species composition of grass fields but that the type and intensity of management is influenced by the farm and household characteristics, particularly any involvement in non-agricultural activities. Households not involved in non-agricultural activities were more likely to be farming intensively. The implication of the study is that agricultural and rural policies need to recognise the ecological importance of smaller farms and in particular their association with off-farm work.

An analysis is presented of the ecological characteristics of ancient forest plant species in deciduous forests of Europe. Twenty-two literature sources were used to generate a list of 132 ancient forest plant species, described from at least eight countries in Europe. The affinity for ancient forests of these species differs considerably from country to country, but they have a definite ecological profile. There is a significant difference in the response of the ancient forest plant species compared with other forest plant species for a variety of ecological characteristics, based on Ellenberg indicators, plant strategies and phytosociological associations. Ancient forest plant species tend to be more shade-tolerant than the other forest plant species; dry and wet sites are avoided. They are typical of forest sites with an intermediate pH and nitrogen availability. Geophytes and hemicryptophytes are more frequent amongst ancient forest plant species. The stress-tolerant plant strategy type is significantly more abundant under the ancient forest species than expected when compared with other forest plant species and vice versa for the competitive plant strategy. This distinct ecological profile suggests that ancient forest plant species may be considered as a guild. The poor ability of these species to colonize new forest sites may be attributed to a complex of interacting variables: limited dispersal abilities (many have a short-distance dispersal strategy), low diaspore production and recruitment problems (e.g. low competitive ability). The regional variation in ancient forest plant species suggests that regional lists are more appropriate for assessing the nature conservation value of forests than one global European list. Due to their distinct ecological profile and low colonizing abilities, ancient forest plant species may be considered as important biodiversity indicators for forests.

In the current debate about the future of food quality, the merits of organic agriculture are frequently championed, but few studies have sought to integrate the changes in soil conditions, biodiversity and socio-economic welfare linked to the conversion from non-organic to organic production. This article aims to undertake this approach with respect to one case study. Its conclusions may not be representative for all organic conversions, but the findings are of relevance at a time of debate over changing patterns of subsidies and other incentives in agricultural policy. The study showed that there were demonstrable differences in overall environmental conditions in the comparison of organic and non-organic farming, with field evidence of increased species diversity, and an eventual improvement in the profitability of the organic farming regime. The broad conclusion is that there are definite environmental and economic advantages arising from organic agriculture that are not fully reflected in the present pattern of agricultural incentives. The study also showed that variations in farm management practice strongly influence the notion of on-farm and off-farm environmental consequences. The implications of these findings for the future of sustainable agriculture and for interdisciplinary science are also discussed.

Ten experimental management regimes, designed to quantify benefits to weed control and wildlife conservation on uncropped field edges of expanded width, were examined for effects on the weed flora within adjacent arable crops. The treatments involved cutting, sowing and herbicide regimes, with differing effects on plant and invertebrate populations. The relative abundance of all plant species within the adjacent crop edge was monitored using permanent quadrats between 1987 and 1991. The field edge management regimes affected neither the total relative plant abundance, nor the relative abundance of most common species, within the adjacent crop edge. While frequencies of Avena spp were initially greatest adjacent to margins cut in spring and autumn, this effect was lost through time, and the greater abundance of Phleum pratense and Leucanthemum vulgare adjacent to the field edges in which they had been sown presented no threat to good husbandry. The management of uncropped arable field edges to enhance biodiversity is very unlikely to affect weed levels within the crop, especially where they contain, or are sown with, non-invasive perennial species.

Summary Experimental grassland communities (turves) were exposed to supplemental levels of UV-B radiation (280–315 nm) at an outdoor facility, under treatment arrays of cellulose diacetate-filtered fluorescent lamps which also produce UV-A radiation (315–400 nm). Control treatments consisted of arrays of polyester-filtered lamps, which allowed for exposure to UV-A radiation alone, and arrays of unenergized lamps allowing for exposure to ambient levels of solar radiation.

1. Experimental grassland communities (turves) were exposed to elevated (60 Pa) and ambient (35 Pa) CO2 partial pressures (pCO2) in a Free-Air Carbon Dioxide Enrichment (FACE) experiment between 30 March 1995 and 4 July 1996. The vegetation was cut once during the experiment prior to the final harvest (harvest 2). 2. No significant treatment effects on total plant biomass at the whole turf level were detected, although biomass was typically about 25% higher under fumigation in year 1 and about 15% higher in year 2. 3. Biomass for two of the six sown species was significantly higher at harvest 2 than at harvest 1. There were no significant differences between individual species’ biomass under the two CO2 treatments at either harvest 1 or 2 or in terms of overall cumulative biomass. However, in four of the five sown species in both years biomass tended to be higher in the fumigated than in the control rings (Cerastium holosteiodes, Phleum pratense, Plantago lanceolata and Poa trivialis). In contrast, Lolium perenne showed increased biomass under the control treatment relative to the fumigated treatment in both years. Owing to the high variance both within and between rings for each of the two treatments the statistical power of most, but not all, of the analyses carried out was poor. 4. The relative proportions of each species in the turves under fumigated and control treatments was broadly similar after the first summer, with differences in the second year being mainly owing to the negative response of L. perenne to CO2 fumigation.

1. Evolutionary responses to climate change will depend on the presence of heritable variation within species populations for traits that increase fitness under the changing conditions. Patterns of ecotypic differentiation in relation to latitude in some species suggest that such variation exists in relation to temperature responses. Response to elevated CO2, whether heritable or not, is not expected to be related to latitudinal or climatic differences within temperate regions. 2. To test these ideas, seeds were collected from 10 populations of the outbreeding perennial grass Agrostis curtisii across its range in Europe from south Wales to Portugal. Plants were grown under ambient and elevated temperature and CO2 conditions, in a factorial design, in solardomes; two half sibs from each population were planted in separate pots in each of the two replicate domes with each combination of treatments. One half sib was harvested at the end of the first summer, the second at the end of the second summer. 3. Survival was uniformly high and flowering uniformly low across treatments and populations. 4. Responses to temperature and CO2 treatments varied over time for almost all populations. Treatment effects were not significant on plants harvested in year 1, although there was a trend towards higher shoot biomass under the elevated temperature and CO2 treatment. In year 2 shoot biomass was significantly higher under the elevated temperature treatment across all populations and there was a strong trend towards decreased biomass under elevated CO2. 5. There were no significant correlations of plant response to either CO2 or temperature with climate at origin. 6. These results warn of the dangers of extrapolating evolutionary plant responses to CO2 from short-term experiments.

Set‐aside was introduced in the European Community in 1988 on a voluntary basis and, under the reform of the Common Agricultural Policy in 1992, it was a condition for the receipt of area payments for most arable farms in England. The areas of set‐aside land reached around 527 000 ha in England in 1994–95, falling to 253 000 ha in 1996–97. The implications of set‐aside for landscape and biodiversity are discussed, drawbig on farm questionnaire surveys, supplemented by field studies of biodiversity. The majority of farmers adopted rotational set‐aside, and while crop yield and economic factors were the most important factors in selecting land to set‐aside, there were few signs of substantial differences between set‐aside and other areas of arable land. Most rotational set‐aside was under natural regeneration, sprayed with non‐selective herbicides in the spring. For the much less frequent non‐rotational set‐aside, there were similar areas of natural regeneration and sown grass covers. Other forms o...

Including ecological information within the planning process is problematic. Individual species response to landscape change will be complex and is often difficult to express in terms of cost or benefit. Pressure on land, particularly in densely populated countries such as the UK, means that land-use needs to be planned in all areas, urban and rural. Designing landscapes to conserve biodiversity is challenging, and a holistic perspective must be retained at all times. A Geographic Information System (GIS) is described which integrates ecological models of species occurrence with spatial data on known landscapes. The use of the tool is illustrated with a series of models of woodland birds within the fragmented landscape of East Anglia, England. Scenarios of woodland loss or gain can be visualised quickly through the creation of altered landscapes; the bird models can then be re-run and the predicted impact on species distributions displayed. The tool is generic, in that any species can be modelled at any scale if ecological models are available to describe its distribution in terms of landscape variables. It is argued that it remains the job of the ecologist to make knowledge about species distributions accessible to the planning process. The key to this is that mathematical models must be expressed spatially in a format suitable for scenario-testing.

The Arable Area Payments Scheme of the European Union has been in operation since 1992, paying farmers to set aside a portion of their arable land from production for 1 to 5 yr. Management of the land is prescribed, both in terms of timing and type. The scheme is potentially beneficial to the environment, as set-aside land can be used to improve bird, mammal, and insect habitats. However, environmental and agronomic objectives frequently conflict, particularly in the area of weed management. To predict weed growth and succession, a tool was required to model vegetation at set-aside sites using the key environmental factors, location, and soil that could account for differences in the weed species likely to be invasive. To this end, a Geographical Information System has been developed that links modeled species distributions to a model of successional change. The system has a simple menu structure allowing speedy manipulation of the data and models to predict the effects of management on the weed communities at known geographical locations.

Interactions between the weeds Bromus sterilis L., Galium aparine L. and Papaver rhoeas L. were investigated over 3 years of continuous winter wheat (Triticum aestivum L.) across a factorial combination of organic and conventional fertilizer, and ploughing and hand-roguing contrasted with minimum tillage and herbicide. The species were sown separately and together at 50 seeds m -2 per species at the start of the experiment in October 1989. In addition, there were weed-free and background-weed controls. Weed densities were monitored at roughly monthly intervals and crop yield recorded for three seasons. B. sterilis populations increased 10-fold under minimum tillage, but declined under ploughing. Densities of P. rhoeas remained largely low. G. aparine increased on the organically fertilized minimum-tillage plots, except where B. sterilis was present; the high densities of B. sterilis reduced the population size of G. aparine. Crop yield was influenced most strongly by the fertilizer treatment in the first season, but later the density of B. sterilis was by far the most important factor; the evidence of interactive effects of the different weed species on crop yield was weak at best. Interactive effects of arable weed species can be observed, but only at very high densities, and so are unlikely to be of widespread economic importance.

The vascular flora of 62 Danish beech forests of eastern Jutland ranging in size from 1-445 ha, was investigated for species-area relations. Species richness reflecting total diversity, forest diversity, and of different habitat groups, were corrected for non-linearity by means of a log-log power function transformation and regressed to forest area. The transformed forest species diversity showed a negative relationship with forest area. It is highly questionable whether the often stated positive correlation between forest area and species number is valid when the total species numbers are corrected for the area-error. The often stated theorem that the larger the forest, the smaller the disturbance, is not valid in Danish broad-leaved forests. On the contrary, if the number of ruderals is taken as an indication of human disturbance, the correlation of area with the proportion of ruderals to all species and to forest species, both failed to detect correlation with area. This is probably due to the less intensive management regimes in small forests compared with larger forests. A substantially larger number of forest species is found in ancient forest than in middle-aged forest. This shows the great importance of forest continuity for the species diversity. Lists of indicator species for ancient and old broad-leaved forest are presented. The corrected species diversity value is recommended as a good nature quality indicator, to be used in comparative studies and for assessing biological quality for management and conservation actions.

Methiocarb is a carbamate molluscicide widely used in pelleted form. Wood mice Apodemus sylvaticus are commonly found in arable fields and will eat methiocarb pellets. Two previous field studies on the impacts on arable wood mice of broadcasting methiocarb pellets produced contrasting results, the number of mice being temporarily reduced in one but not the other. The season of application is also likely to influence the degree of impact on populations but the previous trials were both in autumn. The aim of the present study was to determine the effects on wood mice of broadcast applications of methiocarb in both autumn and spring and to determine whether depression of brain and serum cholinesterase (ChE) activity, a biomarker of exposure, could be detected in mice alive on treated fields after application. In trials carried out in October 1994 and April 1995, there were decreases in the number of wood mice on arable fields following pesticide application. The October decline (78%) was greater than that in April (33%), even though the activity of the mice appeared to be more heavily centred on the hedgerows, where pellets were not applied, in the autumn. Despite the reductions in numbers, no depression of ChE activity was detected in mice captured alive after application, suggesting that either exposed animals were not captured or that reactivation of ChE activity was rapid. This study confirmed that broadcast application of methiocarb can reduce wood mouse populations on arable fields. It also demonstrated that such effects can occur irrespective of season and that measurement of ChE activity in mice trapped after application may fail to indicate that exposure of the population has occurred.

Butterfly transects were conducted on eight pairs of organic and conventional farms in the UK in 1994, and ten pairs of farms in 1995. Each transect included areas of conventional and organic farmland. All species seen, and the abundance of each species, were recorded separately for the uncropped field boundary and the crop edge. In both years, significantly more non-pest butterflies were recorded on organic than on conventional farmland, and more non-pest butterflies were recorded over the uncropped boundary habitat than over the crop edge habitat in both systems. By contrast, there was no significant difference in either year in the abundance of two pest species, Pieris brassicae (the large white) and Pieris rapae (the small white) between the two systems. Implications of the results for the conservation of butterflies within agricultural systems are discussed.

Weed communities, comprising 12 introduced species at constant starting densities and three species already present in the seed bank, were followed through three years of continuous winter wheat. The wheat and weeds were subjected to two treatments in a split-plot factorial design, organic contrasting with conventional fertilizer, and ploughing plus hand-roguing contrasting with minimum tillage plus herbicide. The minimum tilled plots developed in a uniform manner, and became dominated by very high densities of Anisantha sterilis. Agrostemma githago and Galium aparine also persisted in these plots at lower densities. The ploughed plots had a lower total density but a greater range of species. Stellaria media, Veronica persica and Avena fatua were the most common; other species occurred at lower densities. The major effect of fertilizer treatment was a greater initial increase by G. aparine on the organic, minimum tilled plots compared with the conventionally fertilized, minimum tilled plots. Species associated with minimum tillage were annuals with either no or a short term seed bank and autumn germination and rather predictable dynamics, whereas species that did well under ploughing were either spring germinating or had a persistent seed bank, implying greater annual variation in population size associated with weather conditions. There seemed no clear way to distinguish between those species which were abundant on the ploughed plots and those which were scarce under all conditions using readily accessible data.