Ecological impacts of arable intensification in Europe

Production costs of biodiversity zones on field and forest margins: a case study in Finland

This paper estimates and compares the costs incurred to a private landowner from establishing and managing 25-m wide biodiversity zones on field and forest margins in southern Finland. Crop and timber prices being at their long-term averages, current agricultural support paid and the real discount rate 3%, the average annual net costs per hectare of field and forest biodiversity zones were €30 ha(-1) and €108 ha(-1), respectively, the field zones being the less costly alternative in 95% of cases. This result is mainly due to the poor productivity of field cultivation relative to timber production under boreal climate conditions. In addition to soil quality, the initial stand structure affects the costs of both biodiversity zone types. It is less costly for a landowner to establish biodiversity zones in forests where no final felling is imminent but which already contain some tree volume. In field biodiversity zones, costs are slightly lower on fields where forest shading is great. Uneven-aged management practiced in forest biodiversity zones was found to lead to a 3-32% reduction in the net present value of forest land compared to conventional forest management. An increase in the real discount rate increases the relative efficiency of forest biodiversity zones.

Mosaic-level inference of the impact of land cover changes in agricultural landscapes on biodiversity: a case-study with a threatened grassland bird

Changes in land use/land cover are a major driver of biodiversity change in the Mediterranean region. Understanding how animal populations respond to these landscape changes often requires using landscape mosaics as the unit of investigation, but few previous studies have measured both response and explanatory variables at the land mosaic level. Here, we used a “whole-landscape” approach to assess the influence of regional variation in the land cover composition of 81 farmland mosaics (mean area of 2900 ha) on the population density of a threatened bird, the little bustard (Tetrax tetrax), in southern Portugal. Results showed that ca. 50% of the regional variability in the density of little bustards could be explained by three variables summarising the land cover composition and diversity in the studied mosaics. Little bustard breeding males attained higher population density in land mosaics with a low land cover diversity, with less forests, and dominated by grasslands. Land mosaic composition gradients showed that agricultural intensification was not reflected in a loss of land cover diversity, as in many other regions of Europe. On the contrary, it led to the introduction of new land cover types in homogenous farmland, which increased land cover diversity but reduced overall landscape suitability for the species. Based on these results, the impact of recent land cover changes in Europe on the little bustard populations is evaluated.

Pesticide monitoring in The Netherlands: can it be improved?

In The Netherlands, pesticide monitoring of the surface water is separately managed by different water authorities. These water authorities can decide when, where, and what pesticide will be monitored and at what frequency. To help make the decisions more reasonable and make the monitoring system more efficient and systematic, three new types of monitoring maps were developed. The maps are based on actual pesticide measurement from current monitoring system and crop data. Combined temporal and spatial distribution maps give an overview of the pesticide problem in the whole Netherlands. It can be used to develop a strategy in which season and where the pesticide should be intensively monitored. Temporal distribution map, together with the pesticide usage prediction map, provide information of individual pesticide. They help to find out when and at what frequency and which pesticide be monitored, based on which monitoring facilities can be applied more efficiently.

Are agricultural soils under a continental temperate climate susceptible to episodic reducing conditions and increased leaching of phosphorus?

Soil science research has probably underestimated the significance that short-term, episodic cycles of reduction and oxidation has had on phosphorus (P) reactivity. Here, the effects of eleven pulsed reduction-oxidation (including wet-dry) cycles on soil P dynamics are compared for 12 soils having contrasting properties and all overfertilised with respect to P. The laboratory based incubation conditions attempted to simulate transient waterlogging of the soil profile and involved repeated sampling and analysis of both the solution and solid phase P forms. An initial increase in P concentration in solution that occurred up to and including the fourth full cycle was followed by a sharp decline in concentration for all but one soil. Accompanying changes in the main extractable forms of P, which appeared to be cumulative, could be summarised as a general decline in the organic P fraction and an overall increase in amorphous associated inorganic forms of P. The fact that up to 60% of the total soil P was demonstrated to change its sensitivity for a particular extractant suggests that these operationally defined P forms are susceptible to transformation as a consequence of changing environmental conditions. There was also a suggestion that certain of the changes in P forms were irreversible. While the laboratory conditions imposed do represent extreme conditions the soils only experienced cyclic changes in their moisture regime. If timing and frequency of intense precipitation events are likely to increase, as predicted in many climate change scenarios, then these results suggest that the effects of episodic redox pulses may have implications for P cycling in agricultural soils.

Plant diversity partitioning in Mediterranean croplands: effects of farming intensity, field edge, and landscape context

Farmland biodiversity is affected by factors acting at various spatial scales. However, most studies to date have focused on the field or farm scales that only account for local (alpha) diversity, and these may underestimate the contribution of other diversity components (beta diversity) to total (gamma) farmland diversity. In this work, we aimed to identify the most suitable management options and the scale at which they should be implemented to maximize benefits for diversity. We used a multi-scale additive partitioning approach, with data on plant diversity from 640 plots in 32 cereal crop fields from three agricultural regions of central Spain that differed in landscape configuration. We analyzed the relative contribution to overall plant diversity of different diversity components at various spatial scales and how these diversity components responded to a set of local (application of agri-environment schemes [AES] and position within the field) and landscape (field size and landscape connectivity and composition) factors. Differences in species composition among regions and then among fields within regions contributed most to overall plant diversity. Positive edge effects were found on all diversity components at both the field- and regional scales, whereas application of AES benefited all diversity components only at the field scale. Landscape factors had strong influences on plant diversity, especially length of seminatural boundaries, which increased species richness at both the field and the regional scales. In addition, positive effects of percentage of nonproductive land-uses in the landscape were found on all diversity components at the regional scale. Results showed that components that contributed most to overall plant diversity were not benefited by current AES. We conclude that agri-environmental policies should incorporate and prioritize measures aimed at the maintenance of seminatural boundaries and patches of nonproductive habitats within agricultural landscapes, through landscape planning, cross-compliance, or high nature-value farmland programs. These options will help to conserve overall plant diversity at regional scales, as well as the spillover of plant species from such seminatural elements into crops, especially in Mediterranean areas that still harbor extensive farming and relatively complex landscapes.

Influences of plant species composition, fertilisation and Lolium perenne ingression on soil microbial community structure in three Irish grasslands

Semi-natural grassland soils are frequently fertilised for agricultural improvement. This practice often comes at a loss of the indigenous flora while fast-growing nitrogen-responsive species, such as Lolium perenne, take over. Since soil microbial communities depend on plant root exudates for carbon and nitrogen sources, this shift in vegetation is thought to influence soil microbial community structure. In this study, we investigated the influence of different plant species, fertilisation and L. perenne ingression on microbial communities in soils from three semi-natural Irish grasslands. Bacterial and fungal community compositions were determined by automated ribosomal intergenic spacer analysis, and community changes were linked to environmental factors by multivariate statistical analysis. Soil type had a strong effect on bacterial and fungal communities, mainly correlated to soil pH, as well as soil carbon and nitrogen status. Within each soil type, plant species composition was the main influencing factor followed by nitrogen fertilisation and finally Lolium ingression in the acidic upland and mesotrophic grassland. In the alkaline grassland, however, Lolium ingression had a stronger effect than fertilisation. Our results suggest that a change in plant species diversity strongly influences the microbial community structure, which may subsequently lead to significant changes in ecosystem functioning.

A comparison of land-sharing and land-sparing strategies for plant richness conservation in agricultural landscapes

Strategies for conserving plant diversity in agroecosystems generally focus on either expanding land area in non-crop habitat or enhancing diversity within crop fields through changes in within-field management practices. In this study, we compare effects on landscape-scale species richness from such land-sharing or land-sparing strategies. We collected data in arable field, grassland, pasture, and forest habitat types (1.6 ha sampled per habitat type) across a 100-km2 region of farmland in Lancaster County, Pennsylvania, USA. We fitted species-area relationships (SARs) for each habitat type and then combined extrapolations from the curves with estimates of community overlap to estimate richness in a 314.5-ha landscape. We then modified these baseline estimates by adjusting parameters in the SAR models to compare potential effects of land-sharing and land-sparing conservation practices on landscape richness. We found that species richness of the habitat types showed a strong inverse relationship to the relative land area of each type in the region, with 89 species in arable fields (66.5% of total land area), 153 in pastures (6.7%), 196 in forests (5.2%), and 213 in grasslands (2.9%). Relative to the baseline scenario, major changes in the richness of arable fields produced gains in landscape-scale richness comparable to a conversion of 3.1% of arable field area into grassland habitat. Sensitivity analysis of our model indicated that relative gains from land sparing would be greatest in landscapes with a low amount of non-crop habitat in the baseline scenario, but that in more complex landscapes land sharing would provide greater gains. These results indicate that the majority of plant species in agroecosystems are found in small fragments of non-crop habitat and suggest that, especially in landscapes with little non-crop habitat, richness can be more readily conserved through land-sparing approaches.

Expert knowledge-based assessment of farming practices for different biotic indicators using fuzzy logic

The study presented here describes a modeling approach for the ex-ante assessment of farming practices with respect to their risk for several single-species biodiversity indicators. The approach is based on fuzzy-logic techniques and, thus, is tolerant to the inclusion of sources of uncertain knowledge, such as expert judgment into the assessment. The result of the assessment is a so-called Index of Suitability (IS) for the five selected biotic indicators calculated per farming practice. Results of IS values are presented for the comparison of crops and for the comparison of several production alternatives per crop (e.g., organic vs. integrated farming, mineral vs. organic fertilization, and reduced vs. plow tillage). Altogether, the modeled results show that the different farming practices can greatly differ in terms of their suitability for the different biotic indicators and that the farmer has a certain scope of flexibility in opting for a farming practice that is more in favor of biodiversity conservation. Thus, the approach is apt to identify farming practices that contribute to biodiversity conservation and, moreover, enables the identification of farming practices that are suitable with respect to more than one biotic indicator.

Development of secondary woodland in oak wood pastures reduces the richness of rare epiphytic lichens

Wooded pastures with ancient trees were formerly abundant throughout Europe, but during the last century, grazing has largely been abandoned often resulting in dense forests. Ancient trees constitute habitat for many declining and threatened species, but the effects of secondary woodland on the biodiversity associated with these trees are largely unknown. We tested for difference in species richness, occurrence, and abundance of a set of nationally and regionally red-listed epiphytic lichens between ancient oaks located in secondary woodland and ancient oaks located in open conditions. We refined the test of the effect of secondary woodland by also including other explanatory variables. Species occurrence and abundance were modelled jointly using overdispersed zero-inflated Poisson models. The richness of the red-listed lichens on ancient oaks in secondary woodland was half of that compared with oaks growing in open conditions. The species-level analyses revealed that this was mainly the result of lower occupancy of two of the study species. The tree-level abundance of one species was also lower in secondary woodland. Potential explanations for this pattern are that the study lichens are adapted to desiccating conditions enhancing their population persistence by low competition or that open, windy conditions enhance their colonisation rate. This means that the development of secondary woodland is a threat to red-listed epiphytic lichens. We therefore suggest that woody vegetation is cleared and grazing resumed in abandoned oak pastures. Importantly, this will also benefit the vitality of the oaks.

Agricultural intensification and biodiversity partitioning in European landscapes comparing plants, carabids, and birds

Effects of agricultural intensification (AI) on biodiversity are often assessed on the plot scale, although processes determining diversity also operate on larger spatial scales. Here, we analyzed the diversity of vascular plants, carabid beetles, and birds in agricultural landscapes in cereal crop fields at the field (n = 1350), farm (n = 270), and European-region (n = 9) scale. We partitioned diversity into its additive components alpha, beta, and gamma, and assessed the relative contribution of beta diversity to total species richness at each spatial scale. AI was determined using pesticide and fertilizer inputs, as well as tillage operations and categorized into low, medium, and high levels. As AI was not significantly related to landscape complexity, we could disentangle potential AI effects on local vs. landscape community homogenization. AI negatively affected the species richness of plants and birds, but not carabid beetles, at all spatial scales. Hence, local AI was closely correlated to beta diversity on larger scales up to the farm and region level, and thereby was an indicator of farm- and region-wide biodiversity losses. At the scale of farms (12.83-20.52%) and regions (68.34-80.18%), beta diversity accounted for the major part of the total species richness for all three taxa, indicating great dissimilarity in environmental conditions on larger spatial scales. For plants, relative importance of alpha diversity decreased with AI, while relative importance of beta diversity on the farm scale increased with AI for carabids and birds. Hence, and in contrast to our expectations, AI does not necessarily homogenize local communities, presumably due to the heterogeneity of farming practices. In conclusion, a more detailed understanding of AI effects on diversity patterns of various taxa and at multiple spatial scales would contribute to more efficient agri-environmental schemes in agroecosystems.

Pesticide exposure, safety issues, and risk assessment indicators

Pesticides are widely used in agricultural production to prevent or control pests, diseases, weeds, and other plant pathogens in an effort to reduce or eliminate yield losses and maintain high product quality. Although pesticides are developed through very strict regulation processes to function with reasonable certainty and minimal impact on human health and the environment, serious concerns have been raised about health risks resulting from occupational exposure and from residues in food and drinking water. Occupational exposure to pesticides often occurs in the case of agricultural workers in open fields and greenhouses, workers in the pesticide industry, and exterminators of house pests. Exposure of the general population to pesticides occurs primarily through eating food and drinking water contaminated with pesticide residues, whereas substantial exposure can also occur in or around the home. Regarding the adverse effects on the environment (water, soil and air contamination from leaching, runoff, and spray drift, as well as the detrimental effects on wildlife, fish, plants, and other non-target organisms), many of these effects depend on the toxicity of the pesticide, the measures taken during its application, the dosage applied, the adsorption on soil colloids, the weather conditions prevailing after application, and how long the pesticide persists in the environment. Therefore, the risk assessment of the impact of pesticides either on human health or on the environment is not an easy and particularly accurate process because of differences in the periods and levels of exposure, the types of pesticides used (regarding toxicity and persistence), and the environmental characteristics of the areas where pesticides are usually applied. Also, the number of the criteria used and the method of their implementation to assess the adverse effects of pesticides on human health could affect risk assessment and would possibly affect the characterization of the already approved pesticides and the approval of the new compounds in the near future. Thus, new tools or techniques with greater reliability than those already existing are needed to predict the potential hazards of pesticides and thus contribute to reduction of the adverse effects on human health and the environment. On the other hand, the implementation of alternative cropping systems that are less dependent on pesticides, the development of new pesticides with novel modes of action and improved safety profiles, and the improvement of the already used pesticide formulations towards safer formulations (e.g., microcapsule suspensions) could reduce the adverse effects of farming and particularly the toxic effects of pesticides. In addition, the use of appropriate and well-maintained spraying equipment along with taking all precautions that are required in all stages of pesticide handling could minimize human exposure to pesticides and their potential adverse effects on the environment.

Assessing the effect of the time since transition to organic farming on plants and butterflies

1. Environmental changes may not always result in rapid changes in species distributions, abundances or diversity. In order to estimate the effects of, for example, land‐use changes caused by agri‐environment schemes (AES) on biodiversity and ecosystem services, information on the time‐lag between the application of the scheme and the responses of organisms is essential.

2. We examined the effects of time since transition (TST) to organic farming on plant species richness and butterfly species richness and abundance. Surveys were conducted in cereal fields and adjacent field margins on 60 farms, 20 conventional and 40 organic, in two regions in Sweden. The organic farms were transferred from conventional management between 1 and 25 years before the survey took place. The farms were selected along a gradient of landscape complexity, indicated by the proportion of arable land, so that farms with similar TST were represented in all landscape types. Organism responses were assessed using model averaging.

3. Plant and butterfly species richness was c. 20% higher on organic farms and butterfly abundance was about 60% higher, compared with conventional farms. Time since transition affected butterfly abundance gradually over the 25‐year period, resulting in a 100% increase. In contrast, no TST effect on plant or butterfly species richness was found, indicating that the main effect took place immediately after the transition to organic farming.

4. Increasing landscape complexity had a positive effect on butterfly species richness, but not on butterfly abundance or plant species richness. There was no indication that the speed of response to organic farming was affected by landscape complexity.

5.  Synthesis and applications. The effect of organic farming on diversity was rapid for plant and butterfly species richness, whereas butterfly abundance increased gradually with time since transition. If time‐lags in responses to AESs turn out to be common, long‐term effects would need to be included in management recommendations and policy to capture the full potential of such schemes.

Structural effects of the bioavailable fraction of pesticides in soil: suitability of elutriate testing

This study focused the ecotoxicological evaluation of four different pesticides (chlorpyrifos, glyphosate, vinclozolin, endosulfan), sprayed into an agricultural soil, using a standard battery of aquatic bioassays for testing of soil elutriates: Vibrio fischeri -Microtox(®); Pseudokirchneriella subcapitata growth inhibition; Daphnia magna acute and chronic toxicity. Despite relevant pesticide residues were recovered from the soil matrix (concentrations higher than 1000 μg kg(-1)), much lower concentrations could be retrieved from elutriates (highest records for endosulfan of ca. 250 ng L(-1)and 1400 ng L(-1); dissolved and particulate concentration, respectively) and little effects were generally found in the bioassays. Lethal effects (D. magna 48 h-EC50 of 36.8%) could be noticed following exposure to the endosulfan elutriate. Elutriates induced no toxicity on V. fischeri; algal growth was generally inhibited at high elutriate dilutions and stimulated at the lower elutriate dilutions; and no overall impairment of D. magna life-history was noticed. Results revealed that cross-contamination during field application, input of organic matter and nutrients by elutriates in test solutions, and choice of test species and endpoints may constrain the ecotoxicological assessment. Suitability of established aquatic bioassay test batteries for these purposes, and questioning on whether direct assays with soil organisms could be more protective tools is discussed.

Integrating objectives and scales for planning and implementing wetland restoration and creation in agricultural landscapes

Traditionally, wetland management strategies have focused on single familiar objectives, such as improving water quality, strengthening biodiversity, and providing flood control. Despite the relevant amount of studies focused on wetland creation or restoration with these and other objectives, still little is known on how to integrate objectives of wetland creation or restoration at different landscape scales. We have reviewed the literature to this aim, and based on the existing current knowledge, we propose a four step approach to take decisions in wetland creation or restoration planning. First, based on local needs and limitations we should elucidate what the wetland is needed for. Second, the scale at which wetland should be created or restored must be defined. Third, conflicts and compatibilities between creation or restoration objectives must then be carefully studied. Fourth, a creation or restoration strategy must be defined. The strategy can be either creating different unipurpose wetlands or multipurpose wetlands, or combinations of them at different landscape scales. In any case, in unipurpose wetland projects we recommend to pursue additional secondary objectives. Following these guidelines, restored and created wetlands would have more ecological functions, similar to natural wetlands, especially if spatial distribution in the landscape is considered. Restored and created wetlands could then provide an array of integrated environmental services adapted to local ecological and social needs.

Nitrogen, land and water inputs in changing cattle farming systems. A historical comparison for France, 19th-21st centuries

This paper provides an original account of the long-term regional metabolism in relation to the cattle rearing in western France starting by the precise formulation of animal diets at three key dates of the 19th, 20th and 21st centuries. We established links between the demand in fodder of the meat and dairy sectors and the necessary inputs of nitrogen, water and land as well as the land cover changes occurring on the affected local and remote cattle acreage. The average agricultural productivity for fodder supply is estimated at about 50 kg N/ha in the mid-19th, 54 kg N/ha in the early 20th and 150 kg N/ha at the turning of the 21st century. Jointly for the dairy and meat productions, the potential efficiency in the conversion of the vegetal into animal protein more than doubled over the studied period, passing from less than 9% in the 19th to 20% in the 21st century. The current cattle sector is sustained for about 25% by land situated beyond the regional frontiers and uses water at intensities that approach or exceed the availability of renewable water. The nitrogen pollution is expressed in terms of the Net Anthropogenic Nitrogen Inputs (NANI) and, by comparison to the N recovered in products, is used to define the N-Environmental Efficiency of the farming. We discuss the historical succession of the factors that contributed to the growth of the meat and milk production and make a comparison of the impacts and policy between the local and distant resources.

A specialist-generalist classification of the arable flora and its response to changes in agricultural practices

Background

Theory in ecology points out the potential link between the degree of specialisation of organisms and their responses to disturbances and suggests that this could be a key element for understanding the assembly of communities. We evaluated this question for the arable weed flora as this group has scarcely been the focus of ecological studies so far and because weeds are restricted to habitats characterised by very high degrees of disturbance. As such, weeds offer a case study to ask how specialization relates to abundance and distribution of species in relation to the varying disturbance regimes occurring in arable crops.

Results

We used data derived from an extensive national monitoring network of approximately 700 arable fields scattered across France to quantify the degree of specialisation of 152 weed species using six different ecological methods. We then explored the impact of the level of disturbance occurring in arable fields by comparing the degree of specialisation of weed communities in contrasting field situations.

The classification of species as specialist or generalist was consistent between different ecological indices. When applied on a large-scale data set across France, this classification highlighted that monoculture harbour significantly more specialists than crop rotations, suggesting that crop rotation increases abundance of generalist species rather than sets of species that are each specialised to the individual crop types grown in the rotation. Applied to a diachronic dataset, the classification also shows that the proportion of specialist weed species has significantly decreased in cultivated fields over the last 30 years which suggests a biotic homogenization of agricultural landscapes.

Conclusions

This study shows that the concept of generalist/specialist species is particularly relevant to understand the effect of anthropogenic disturbances on the evolution of plant community composition and that ecological theories developed in stable environments are valid in highly disturbed environments such as agro-ecosystems. The approach developed here to classify arable weeds according to the breadth of their ecological niche is robust and applicable to a wide range of organisms. It is also sensitive to disturbance regime and we show here that recent changes in agricultural practices, i.e. increased levels of disturbance have favoured the most generalist species, hence leading to biotic homogenisation in arable landscapes.

Sub-chronic effects of nitrate in drinking water on red-legged partridge (Alectoris rufa): oxidative stress and T-cell mediated immune function

In order to evaluate the effects of nitrates on birds, we have exposed captive red-legged partridges to nitrates concentrations of 0 (control), 100 (dwell water in farming areas) or 500 mg/l (fertirrigation level). The cellular immune response, plasma biochemistry, methemoglobin concentration (metHb), and oxidative stress biomarkers in blood and tissues were studied after two weeks of exposure. Several blood parameters such as aspartate aminotransferase, creatinine phosphokinase and lactate dehydrogenase activities and magnesium level decreased with nitrate exposure, whereas alkaline phosphatase activity and creatinine level increased. The oxidant effect of nitrates was evidenced by the increase in blood metHb, accompanied by the lipid peroxidation of red blood cells, the increased levels of oxidized glutathione (GSH) in liver, and the generation of oxidative DNA damage in plasma lymphocytes. GSH in erythrocytes was negatively correlated with blood metHb. The cellular immune function was slightly lower at partridges exposed to nitrates. These results suggest that adverse effects of nitrates on birds occur at concentrations potentially present in the field.

Recent landscape change at the ecoregion scale in Southern Québec (Canada), 1993-2001

Landsat images covering the St. Lawrence Lowlands (30,000 km(2)) and Appalachians (33,000 km(2)) ecoregions of southern Québec, Canada, have been classified for the years 1993 and 2001 to (1) quantify land use/land cover (LULC) changes and changes to agricultural landscapes and (2) relate LULC changes to changes of farm-related descriptors of economic and farming activities. Over 25 LULC classes were identified on each classification which were merged into 5 LULC classes (anthropogenic, annual crop, perennial crop, forest, water/wetlands) used to delineate a gradient of five types of agricultural landscapes. Transition matrices reveal a shift in major agricultural classes in the St. Lawrence Lowlands where perennial crops have been converted into annual crops. Furthermore, suburban sprawl was observed adjacent to major cities whereas overall forest cover was reduced. Changes in agricultural land classes were few in the agroforested landscapes of the Appalachian ecoregion. Landscapes dominated by intensive agriculture expanded onto adjacent regions previously under extensive agriculture. Most farm-related variables extracted from agriculture censuses showed an increase, reflecting an intensification of agriculture in both ecoregions though no clear association with LULC changes were revealed. Increase in annual crops may be related to intensive corn production associated with pig farming. Differences in landscape changes between the two ecoregions may be related to proximal causal factors such as soil topography and suitability for high-quality crops. Our analysis will provide baseline information to implement a monitoring program of habitat dynamics in this vast region.

Consequences of organic farming and landscape heterogeneity for species richness and abundance of farmland birds

It has been suggested that organic farming may benefit farmland biodiversity more in landscapes that have lost a significant part of its former landscape heterogeneity. We tested this hypothesis by comparing bird species richness and abundance during the breeding season in organic and conventional farms, matched to eliminate all differences not directly linked to the farming practice, situated in either homogeneous plains with only a little semi-natural habitat or in heterogeneous farmland landscapes with abundant field borders and semi-natural grasslands. The effect of farm management on species richness interacted with landscape structure, such that there was a positive relationship between organic farming and diversity only in homogeneous landscapes. This pattern was mainly dependent on the species richness of passerine birds, in particular those that were invertebrate feeders. Species richness of non-passerines was positively related to organic farming independent of the landscape context. Bird abundance was positively related to landscape heterogeneity but not to farm management. This was mainly because the abundance of passerines, particularly invertebrate feeders, was positively related to landscape heterogeneity. We suggest that invertebrate feeders particularly benefit from organic farming because of improved foraging conditions through increased invertebrate abundances in otherwise depauperate homogeneous landscapes. Although many seed-eaters also benefit from increased insect abundance, they may also utilize crop seed resources in homogeneous landscapes and conventional farms. The occurrence of an interactive effect of organic farming and landscape heterogeneity on bird diversity will have consequences for the optimal allocation of resources to restore the diversity of farmland birds.

Ecological impacts of early 21st century agricultural change in Europe--a review

The impacts of agricultural land use are far-reaching and extend to areas outside production. This paper provides an overview of the ecological status of agricultural systems across the European Union in the light of recent policy changes. It builds on the previous review of 2001 devoted to the impacts of agricultural intensification in Western Europe. The focus countries are the UK, The Netherlands, Boreal and Baltic countries, Portugal, Hungary and Romania, representing a geographical spread across Europe, but additional reference is made to other countries. Despite many adjustments to agricultural policy, intensification of production in some regions and concurrent abandonment in others remain the major threat to the ecology of agro-ecosystems impairing the state of soil, water and air and reducing biological diversity in agricultural landscapes. The impacts also extend to surrounding terrestrial and aquatic systems through water and aerial contamination and development of agricultural infrastructures (e.g. dams and irrigation channels). Improvements are also documented regionally, such as successful support of farmland species, and improved condition of watercourses and landscapes. This was attributed to agricultural policy targeted at the environment, improved environmental legislation, and new market opportunities. Research into ecosystem services associated with agriculture may provide further pressure to develop policy that is targeted at their continuous provisioning, fostering motivation of land managers to continue to protect and enhance them.

The dimensions of land use change in rural landscapes: lessons learnt from the GB Countryside Surveys

Rural landscapes are highly dynamic and their change impacts on a number of ecological processes such as the dynamics of biodiversity. Although a substantial amount of research has focused on quantifying these changes and their impact on biodiversity, most studies have focused on single dimensions of land use change. This lack of integration in land use change studies can be explained by the fact that data on the spatial, temporal, and ecological dimensions of land use are seldom available for the same geographical location. In this paper, the benefits of taking into account these three dimensions are illustrated with results derived from the Great Britain Countryside Surveys (CS), a large-scale monitoring programme designed to assess change in the extent and ecological condition of British habitats. The overview of CS results presented in this paper shows that (1) changes in land use composition will translate into a variety of spatial patterns; (2) the temporal stability of land use is often lower than can be expected; and (3) there can be large-scale shifts in the ecological condition of the land use types that form our rural landscapes. The benefits of integrated rural landscape studies are discussed in the context of other national monitoring programmes.

Phosphate addition and plant species alters microbial community structure in acidic upland grassland soil

Agricultural improvement (addition of fertilizers, liming) of seminatural acidic grasslands across Ireland and the UK has resulted in significant shifts in floristic composition, soil chemistry, and microbial community structure. Although several factors have been proposed as responsible for driving shifts in microbial communities, the exact causes of such changes are not well defined. Phosphate was added to grassland microcosms to investigate the effect on fungal and bacterial communities. Plant species typical of unimproved grasslands (Agrostis capillaris, Festuca ovina) and agriculturally improved grasslands (Lolium perenne) were grown, and phosphate was added 25 days after seed germination, with harvesting after a further 50 days. Phosphate addition significantly increased root biomass (p < 0.001) and shoot biomass (p < 0.05), soil pH (by 0.1 U), and microbial activity (by 5.33 mg triphenylformazan [TPF] g(-1) soil; p < 0.001). A slight decrease (by 0.257 mg biomass-C g(-1) soil; p < 0.05) in microbial biomass after phosphate addition was found. The presence of plant species significantly decreased soil pH (p < 0.05; by up to 0.2 U) and increased microbial activity (by up to 6.02 mg TPF g(-1) soil) but had no significant effect on microbial biomass. Microbial communities were profiled using automated ribosomal intergenic spacer analysis. Multidimensional scaling plots and canonical correspondence analysis revealed that phosphate addition and its interactions with upland grassland plant species resulted in considerable changes in the fungal and bacterial communities of upland soil. The fungal community structure was significantly affected by both phosphate (R = 0.948) and plant species (R = 0.857), and the bacterial community structure was also significantly affected by phosphate (R = 0.758) and plant species (R = 0.753). Differences in microbial community structure following P addition were also revealed by similarity percentage analysis. These data suggest that phosphate application may be an important contributor to microbial community structural change during agricultural management of upland grasslands.

Traditional olive orchards on sloping land: sustainability or abandonment?

Traditional olive orchards account for a large share of the area under olives in the EU, particularly in marginal areas, like those analysed in the OLIVERO project. In general, traditional olive growing can be described as a low-intensity production system, associated with old (sometimes very old) trees, grown at a low density, giving small yields and receiving low inputs of labour and materials. Though such systems are environmentally sustainable, their economic viability has become an issue, since EU policies favour more intensive and competitive systems. Orchards that have not been intensified seem to be threatened by the recent reform of the EU olive and olive oil policy, as income support has been decoupled from production. The main purpose of this paper is to identify the present constraints to traditional olive growing, and to recommend some private and public interventions to prevent its abandonment. During the OLIVERO project, traditional olive production systems were identified and described in five target areas (Trás-os-Montes--Portugal, Cordoba and Granada/Jaen--Spain, Basilicata/Salerno--Italy, and West Crete--Greece). The causes and consequences of abandonment are discussed, based on the analysis of the costs and returns, which revealed that these systems are barely economically sustainable. Their viability is only assured if reduced opportunity costs for family labour are accepted, and the olive growing is part-time. Based on these results, recommendations are made to prevent the abandonment of traditional olive growing and to preserve its environmental benefits.

Spatial and temporal analysis of pesticides concentrations in surface water: pesticides atlas

Dutch water boards have a well-established program for monitoring pesticide contamination of surface waters. These monitoring data have been processed into a graphic format accessible online and designed to provide insight into pesticide presence in Dutch surface waters and trends over time: the Pesticides Atlas (http://www.pesticidesatlas.nl). With this tool one can easily get maps of where a pesticide is being measured and where it might possibly constitute an environmental problem over the years. Presently, results of the periods 1997/1998 until 2005/2006 are available at the level of individual active ingredients. At a national level, the percentage of pesticides concentrations that exceed the maximum tolerable risk has declined 30% to 38% over the years 2003/2004 compared with 1997/1998. This means that surface water quality in the Netherlands has improved with respect to pesticides, however there are still many locations at which the measured concentrations exceed the environmental quality standards. The results on linking land use to pesticides concentrations were shown to assist in optimization of monitoring programs. By developing the present Internet tool, many new opportunities for environmental risk assessment and risk management were identified, e.g. optimization of monitoring strategies and communication to policymakers.

Incorporating private lands in conservation planning: protected areas in Britain

Evaluations of the effectiveness of protected areas often report their inadequate representation of regional variation in environmental conditions, land cover, and biological diversity. One frequent contributory explanation is the heavy reliance placed upon the designation of public as opposed to private lands for statutory protection. Given that protected area designation in Britain has no such constraint, and indeed that more than half of such areas are on private lands, we tested the a priori assumption that within this region the representation of environmental conditions and land cover within statutory protected areas would be more equitable. Despite the reduction in land ownership constraints on where protected areas can be established, a marked bias in protected area coverage remains. Protected areas in Britain tend toward regions of higher elevation, soils of lower economic potential, and coastal/estuarine habitat and fail adequately to represent areas of lower elevation and woodland habitats. Improving the current situation requires not only a more systematic approach to site selection, but a more equitable and diverse portfolio of incentives for private landowners to facilitate the decision to manage sites for conservation.

A site-related suitability analysis for the production of biomass as a contribution to sustainable regional land-use

The use of renewable energy in Europe offers the possibility of reducing greenhouse gas emissions, and contributes to energy security and independence. With the reform of the Common Agricultural Policy (CAP) and a variety of recently introduced national directives supporting renewable energy sources in the European Union, the economic attractiveness of bioenergy production has distinctly increased. This article combines an economic evaluation of biomass production with site-related natural conditions of the Havelland region, situated in the north-east area of Germany. Two methods for evaluating site-specific potential biomass yields were compared. For three example biomass crops, evaluations of yield estimations at agricultural lots for site-optimized suitability (SOS) and conventional suitability (CS) were carried out. Both modelling approaches were compared. The results of the GIS modelling indicate that the financial support for increasing the use of renewable energy with the German feed-in system, called Erneuerbare-Energien-Gesetz (EEG), will possibly lead to an increased cultivation of crops with high biomass output. This monocultural orientation of farming practices and the negative effects on the ecosystem could act in opposition to other environmental initiatives of the EU. The outputs of the SOS analysis show that high biomass production could be integrated into environmental policy proposals. Therefore, new EU policy should take modified subsidies into consideration in order to avoid developing conflicts between small-scale changes in landscape ecosystems caused by large-scale transformations in energy policy.