Forschung für eine naturgerechte Landwirtschaft

Eine Wende hin zu einer naturgerechten Landwirtschaft setzt voraus, dass auch in der Agrarforschung neue Akzente gesetzt werden. Eine Denkschrift* bringt auf den Punkt, was sich in Forschung, Lehre und Ausbildung ändern muss. Die Langfassung dieser Denkschrift, die in diesem Beitrag zusammengefasst wird, kann beim Bundesamt für Naturschutz, Konstantinstr. 110, D-53179 Bonn, Tel. 0228 - 8491 0, Fax - 8491 200, E-Mail [email protected], bezogen oder im Internet unter www.bfn.de/10/ eingesehen und unterzeichnet werden

A framework for a European network for a systematic environmental impact assessment of genetically modified organisms (GMO)

The assessment of the impacts of growing genetically modified (GM) crops remains a major political and scientific challenge in Europe. Concerns have been raised by the evidence of adverse and unexpected environmental effects and differing opinions on the outcomes of environmental risk assessments (ERA). The current regulatory system is hampered by insufficiently developed methods for GM crop safety testing and introduction studies. Improvement to the regulatory system needs to address the lack of well designed GM crop monitoring frameworks, professional and financial conflicts of interest within the ERA research and testing community, weaknesses in consideration of stakeholder interests and specific regional conditions, and the lack of comprehensive assessments that address the environmental and socio economic risk assessment interface. To address these challenges, we propose a European Network for systematic GMO impact assessment (ENSyGMO) with the aim directly to enhance ERA and post-market environmental monitoring (PMEM) of GM crops, to harmonize and ultimately secure the long-term socio-political impact of the ERA process and the PMEM in the EU. These goals would be achieved with a multi-dimensional and multi-sector approach to GM crop impact assessment, targeting the variability and complexity of the EU agro-environment and the relationship with relevant socio-economic factors. Specifically, we propose to develop and apply methodologies for both indicator and field site selection for GM crop ERA and PMEM, embedded in an EU-wide typology of agro-environments. These methodologies should be applied in a pan-European field testing network using GM crops. The design of the field experiments and the sampling methodology at these field sites should follow specific hypotheses on GM crop effects and use state-of-the art sampling, statistics and modelling approaches. To address public concerns and create confidence in the ENSyGMO results, actors with relevant specialist knowledge from various sectors should be involved

Towards a national ecosystem assessment in Germany

We present options for a National Ecosystem Assessment in Germany (NEA-DE) that could inform decision-makers on the state and trends of ecosystems and ecosystem services. Characterizing a NEA-DE, we argue that its cross-sectoral, integrative approach would have the advantages of increased scientific understanding, addressing specific policy questions and creating science-policy dialogues. Challenges include objections against a utilitarian perspective, reservations concerning power relations, and responsibilities concerning the funding

Regionalizing land use impacts on farmland birds

The environmental impacts of land use vary regionally. Differences in geomorphology, climate, landscape structure, and biotope inventories are regarded as the main causes of this variation. We present a methodological approach for identifying regional responses in land use type to large-scale changes and the implications for the provision of habitat for farmland birds. The methodological innovations of this approach are (i) the coupling of impact assessments with economic models, (ii) the linking of cropping techniques at the plot scale with the regional distribution of land use, and (iii) the integration of statistical or monitoring data on recent states. This approach allows for the regional differentiation of farmers’ responses to changing external conditions and for matching the ecological impacts of land use changes with regional environmental sensitivities. An exemplary scenario analysis was applied for a case study of an area in Germany, assessing the impacts of increased irrigation and the promotion of energy cropping on farmland birds, evaluated as a core indicator for farmland biodiversity. The potential effects on farmland birds were analyzed based on the intrinsic habitat values of the crops and cropping techniques. The results revealed that the strongest decrease in habitat availability for farmland birds occurred in regions with medium-to-low agricultural yields. As a result of the limited cropping alternatives, the increase in maize production was highest in marginal regions for both examined scenarios. Maize production replaced many crops with good-to-medium habitat suitability for birds. The declines in habitat quality were strongest in regions that are not in focus for conservation efforts for farmland birds

An analytical framework to link governance, agricultural production practices, and the provision of ecosystem services in agricultural landscapes

The provision of ecosystem services (ES) in agricultural landscapes depends, inter alia, on agricultural production, and can therefore be influenced by governance. To capture the impacts of governance on ES via agriculture, we proposed and tested an analytical framework – based on agricultural location theory – to describe possible agricultural impact pathways. These pathways show how different governance approaches (e.g. hierarchical, market-based, collaborative, and their hybrids) influence site and farm conditions, which in turn influence agricultural production practices and thus ES provision. The framework was applied to three European case study regions in the Netherlands, Germany, and Austria. The sub-objectives were: i) to identify regional governance approaches and assess how well they reflect the regional specifics, as a basis for applying the framework; and, by applying the framework, to: ii) investigate how these governance approaches then differ in their agricultural impact pathways and thus effects on agriculture; and iii) evaluate their respective influence on ES provision. The governance approaches were compiled and analysed from several sources, e.g. legal documents and grey literature from regional sources, regional workshops, and consultation with stakeholders. The analyses showed that different governance types indeed differ in how well they accommodate regional specifics in their agricultural impact pathways, and thus in their influence on agriculture and ES provision. Overall, the analytical framework is suited to highlighting the agricultural perspective in the ES concept and to exploring the constraints and opportunities for farmers to adopt agricultural production practices that favour the provision of ES as environmental public goods

Consequences of isolation distances on the allocation of GM maize fields in agricultural landscapes of Germany

BACKGROUND: Coexistence measures such as isolation distances aim at minimizing conflicts between genetically modified (GM) and non-GM agricultural systems. Depending on landscape structure such as field sizes, field distribution and cropping patterns, these measures may spatially restrict GM cropping. Additional restrictions on GM cropping may be caused by environmental concerns, for instance protected sites or habitats of selected species may require isolation distances. To explore possible GM cropping restrictions in German agricultural landscapes, we conducted scenario simulations with 10% and 70% GM maize cropping shares, 1,000-m isolation distances to protected sites, and 150- and 300-m isolation distances to neighboring conventional and organic maize fields, respectively. While previous simulation studies applied smaller isolation distances (40 to 50 m), our research question was whether the conservative nature of isolation distances in Germany constitutes limitations to GM maize cropping. We investigated a variety of landscapes on two spatial scales: 4 federal states and 42 rural counties. RESULTS: On the state scale, we found that the maximum percentage of fields planted with GM maize compared to all potentially available fields was approximately 30%, indicating no limitation to GM cropping. On the scale of counties, the relevance and variability of landscape metrics was much greater. This resulted in potential limitations to GM cropping, especially for counties with more than 40% maize share. One thousand-meter isolation distances to protected sites had only marginal effects on the area available for GM cropping. CONCLUSIONS: Isolation distances usually disregard landscape specifics. Our results suggest that the average shares of arable areas and 1,000-m distances to protected areas do not limit the allocation of GM maize. Limitations may occur in counties with more than 40% maize

Supporting Agricultural Ecosystem Services through the Integration of Perennial Polycultures into Crop Rotations

This review analyzes the potential role and long-term effects of field perennial polycultures (mixtures) in agricultural systems, with the aim of reducing the trade-offs between provisioning and regulating ecosystem services. First, crop rotations are identified as a suitable tool for the assessment of the long-term effects of perennial polycultures on ecosystem services, which are not visible at the single-crop level. Second, the ability of perennial polycultures to support ecosystem services when used in crop rotations is quantified through eight agricultural ecosystem services. Legume–grass mixtures and wildflower mixtures are used as examples of perennial polycultures, and compared with silage maize as a typical crop for biomass production. Perennial polycultures enhance soil fertility, soil protection, climate regulation, pollination, pest and weed control, and landscape aesthetics compared with maize. They also score lower for biomass production compared with maize, which confirms the trade-off between provisioning and regulating ecosystem services. However, the additional positive factors provided by perennial polycultures, such as reduced costs for mineral fertilizer, pesticides, and soil tillage, and a significant preceding crop effect that increases the yields of subsequent crops, should be taken into account. However, a full assessment of agricultural ecosystem services requires a more holistic analysis that is beyond the capabilities of current frameworks

Assessing the habitat suitability of agricultural landscapes for characteristic breeding bird guilds using landscape metrics

Many of the processes behind the decline of farmland birds can be related to modifications in landscape structure (composition and configuration), which can partly be expressed quantitatively with measurable or computable indices, i.e. landscape metrics. This paper aims to identify statistical relationships between the occurrence of birds and the landscape structure. We present a method that combines two comprehensive procedures: the “landscape-centred approach” and “guild classification”. Our study is based on more than 20,000 individual bird observations based on a 4-year bird monitoring approach in a typical agricultural area in the north-eastern German lowlands. Five characteristic bird guilds, each with three characteristic species, are defined for the typical habitat types of that area: farmland, grassland, hedgerow, forest and settlement. The suitability of each sample plot for each guild is indicated by the level of persistence (LOP) of occurrence of three respective species. Thus, the sample plots can be classified as “preferred” or “less preferred” depending on the lower and upper quartiles of the LOP values. The landscape structure is characterized by 16 different landscape metrics expressing various aspects of landscape composition and configuration. For each guild, the three landscape metrics with the strongest rank correlation with the LOP values and that are not mutually dependent were identified. For four of the bird guilds, the classification success was better than 80%, compared with only 66% for the grassland bird guild. A subset of six landscape metrics proved to be the most meaningful and sufficiently classified the sample areas with respect to bird guild suitability. In addition, derived logistic functions allowed the production of guild-specific habitat suitability maps for the whole landscape. The analytical results show that the proposed approach is appropriate to assess the habitat suitability of agricultural landscapes for characteristic bird guilds