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Abstract Background Biodiversity loss is particularly pronounced in agroecosystems. Agricultural fields cover about one-third of the European Union and are crucial habitats for many species. At the same time, agricultural fields receive the highest pesticide input in European landscapes. Non-target species, including plants and arthropods, closely related to targeted pests, are directly affected by pesticides. Direct effects on these lower trophic levels cascade through the food web, resulting in indirect effects via the loss of food and habitat for subsequent trophic levels. The overarching goals of the European pesticide legislation require governments to sufficiently consider direct and indirect effects on plants and arthropods when authorising pesticides. This publication provides an overview of a workshop's findings in 2023 on whether the current pesticide risk assessment adequately addresses these requirements. Results Effects due to in-field exposure to pesticides are currently not assessed for plants and inadequately assessed for arthropods, resulting in an impairment of the food web support and biodiversity. Deficiencies lie within the risk assessment, as defined in the terrestrial guidance document from 2002. To overcome this problem, we introduce a two-step assessment method feasible for risk assessors, that is to determine (i) whether a pesticide product might have severe impacts on plants or arthropods and (ii) whether these effects extend to a broad taxonomic spectrum. When each step is fulfilled, it can be concluded that the in-field exposure of the pesticide use under assessment could lead to unacceptable direct effects on non-target species in-field and thus subsequent indirect effects on the food web. While our primary focus is to improve risk assessment methodologies, it is crucial to note that risk mitigation measures, such as conservation headlands, exist in cases where risks from in-field exposure have been identified. Conclusions We advocate that direct and indirect effects caused by in-field exposure to pesticides need to be adequately included in the risk assessment and risk management as soon as possible. To achieve this, we provide recommendations for the authorities including an evaluation method. Implementing this method would address a major deficiency in the current in-field pesticide risk assessment and ensure better protection of biodiversity.

Bees are the most important group of insect pollinators, but their populations are declining. To gain a better understanding of wild bee responses to different stressors (e.g. land-use change) and conservation measures, regional and national monitoring schemes are currently being established in Germany, which is used here as a model region, and in many other countries. We offer perspectives on how to best design future bee monitoring programs with a focus on evaluating the implementation of conservation measures. We discuss different traditional and novel sampling methods, their efficacy depending on research questions and the life-history traits of target species, and how greater standardization of wild bee sampling and monitoring methods can make data more comparable, contributing to the identification of general trends and mechanisms driving bee populations. Furthermore, the potential impact of bee sampling itself on bee populations is discussed.

Abstract Perennial energy crops (PECs) can reduce the negative impacts of intensive silage maize cultivation on agroecosystems in Central Europe. Furthermore, the remaining vegetation of PECs after harvest may provide suitable habitat and more beneficial overwintering conditions for arthropods than maize. It was hypothesized that after harvest and in winter, arthropod abundance and biomass are higher in PECs than in silage maize. In a field experiment arranged in a factorial split‐plot design of eight main plots (plot size: 240 m2), the two PECs cup plant (Silphium perfoliatum L.) and field grass were compared with silage maize (Zea mays L.) regarding their suitability as autumn (post‐harvest) and overwintering habitats for arthropods. Soil temperature, moisture as well as biomass and abundance of autumn‐active and overwintering arthropods were analyzed for these three crops. Suction sampling was used during autumn and emerging arthropods were sampled with emergence trap sets in spring. In PEC plots, soils were moister and less exposed to cold temperatures than in silage maize. Compared with silage maize, total arthropod abundance and biomass were higher in PEC plots for both sampling periods. Results were similar for most examined arthropod taxa. The results of this study demonstrate that, compared with silage maize, PECs provide suitable post‐harvest habitats and constitute more suitable overwintering habitats for arthropods. Differences are likely to be based on lack of disturbance and the provision of vegetation structures after harvest that function as overwintering habitats for arthropods. It can be concluded that the positive effects of PECs on ground arthropods are not limited to their growing time but continue to a certain extend after harvest and during winter.

Agriculture can be transformed to enhance farmland biodiversity and food systems’ sustainability through agroecological principles tailored to the current interplay between farmland biodiversity and agricultural production on all agricultural land.

Abstract Flower strips have become a prevalent measure in agricultural landscapes to counteract biodiversity loss and especially promote pollinators. Although their benefits for pollinating insects have been frequently evaluated and reported, generalized conclusions about optimal settings for effective flower strips are still difficult. From the perspective of pollinators, flower strips vary distinctly in habitat quality, and the same applies for the control sites selected for scientific studies. In this study, we used a meta‐analytic approach based on a systematic review of recent studies (2009–2020) to analyze the relationship between flower strip effectiveness for pollinators and the contrast in habitat quality between flower strips and control sites. We extracted 350 data entries from 29 of 172 studies based on available data for richness or abundance of the pollinator taxa groups Apiformes, Lepidoptera and Syrphidae as response variables, for both flower strips and control treatments. All flower strips and control treatments were assigned a habitat quality score including information on spatial dimension, floral resources and management. Moreover, we included information on landscape complexity as measured by percent cover of seminatural habitats in the studied landscape. In general, our results of meta‐analytical models showed an increasing effect size of flower strips on pollinators for higher contrasts in habitat quality between flower strips and control treatments. This relationship was consistent across pollinator taxa and different levels of landscape complexity. Altogether, in terms of pollinator habitat quality, high‐quality flower strips were more attractive than low‐quality flower strips, and the reported effectiveness of flower strips decreased from low‐quality to high‐quality control treatments. We recommend that results of future studies evaluating flower strips for pollinators are always linked with the contrast in habitat quality between selected flower strips and control treatments.

Abstract Environmental heterogeneity is an important driver of ecological communities. Here, we assessed the effects of local and landscape spatial environmental heterogeneity on ant community structure in temperate seminatural upland grasslands of Central Germany. We surveyed 33 grassland sites representing a gradient in elevation and landscape composition. Local environmental heterogeneity was measured in terms of variability of temperature and moisture within and between grasslands sites. Grassland management type (pasture vs. meadows) was additionally included as a local environmental heterogeneity measure. The complexity of habitat types in the surroundings of grassland sites was used as a measure of landscape environmental heterogeneity. As descriptors of ant community structure, we considered species composition in terms of nest density, community evenness, and functional response traits. We found that extensively grazed pastures and within‐site heterogeneity in soil moisture at local scale, and a high diversity of land cover types at the landscape scale affected ant species composition by promoting higher nest densities of some species. Ant community evenness was high in wetter grasslands with low within‐site variability in soil moisture and surrounded by a less diverse landscape. Fourth‐corner models revealed that ant community structure response to environmental heterogeneity was mediated mainly by worker size, colony size, and life history traits related with colony reproduction and foundation. We discuss how within‐site local variability in soil moisture and low‐intensity grazing promote ant species densities and highlight the role of habitat temperature and humidity affecting community evenness. We hypothesize that a higher diversity of land cover types in a forest‐dominated landscape buffers less favorable environmental conditions for ant species establishment and dispersal between grasslands. We conclude that spatial environmental heterogeneity at local and landscape scale plays an important role as deterministic force in filtering ant species and, along with neutral processes (e.g., stochastic colonization), in shaping ant community structure in temperate seminatural upland grasslands.

We investigated the effects of the areal proportion, spatial distribution and plant composition (quality) of flower strips in agricultural landscapes on the size of honeybee colonies using individual-based models (BEESCOUT, BEEHAVE). For this purpose, we developed 25 landscape scenarios for an intensively used landscape (3 × 3 km) in Havelland (Brandenburg, Germany). In the scenarios, we varied areal proportion (0.22–1.04%), distribution (clustered vs. even) and quality (high vs. low pollen and nectar supply) of flower strips. Then, we simulated the response of honeybee colony size to the landscape scenarios over twelve years with 100 repetitions per scenario. Colony size increased with increasing areal proportion and more even distribution of flower strips. However, this was only true for flower strips of high quality, whereas low-quality flower strips did not benefit the honeybee colonies. Our approach can help to pinpoint optimal quality, areal proportion and distribution of additional food sources for honeybees provided by flower strips in agricultural landscapes.

Background: Transforming food systems is necessary to address the global issues of severe biodiversity loss, hunger, and malnutrition as well as the consequences of the rapidly advancing climate change. Agroecology as a systemic approach has been recognised as a promising path of change exemplified in various case studies strengthening this transformation. The aim of this study is to get insight specifically for Austria and Germany in providing an overview of the advancement in agroecology in both countries and identify agroecology-related initiatives. Methods: 21 interviews with experts were conducted to determine the recognition, understanding, and development of agroecology in Austria and Germany in terms of movement, practice, policies, education, and research. In addition, information about agroecology-related initiatives was collected from interviews with 24 representatives of initiatives and literature analysis. Data was analysed according to five activity categories under which agroecology manifest: movement, practice, living lab, science and research infrastructure, and training and education. Results: Results show that the term agroecology is not commonly used in Austria and Germany, where the concept is mainly associated to a scientific discipline. Practices considered agroecological are implemented primarily through organic agriculture, which is very developed in Austria and to a lesser extent in Germany. Many networks, food policy councils, associations, and scientific projects related to agroecology exist, each with specific purposes and ambitions to change farming and food systems. While most selected initiatives do not explicitly refer to agroecology, all follow certain agroecological principles and aim at contributing to accelerate the agroecological transition. Conclusions: Clarifying the concept of agroecology, overcoming economic and political barriers as well as fostering participation of a multitude of stakeholders in the transition is essential for the future development of agroecology in Austria and Germany.

Extensively managed grasslands are globally recognized for their high biodiversity value. Over the past century, a continuous loss and degradation of grassland habitats has been observed across Europe that is mainly attributable to agricultural intensification and land abandonment. Particularly insects have suffered from the loss of grassland habitats due to land-use change and the decrease in habitat quality, either due to an increase in livestock density, higher mowing frequency, and an increase in nitrogen fertilization, or by abandonment. However, only a few studies have used nationwide datasets to analyse the effects of land cover and land-use intensity on insects. It further remains largely unexplored how these effects are modulated by species traits, i.e. habitat specialisation and mobility. Using nationwide butterfly data originating from the German Butterfly Monitoring Scheme, we investigated the effect of three indicators related to land cover and agricultural land-use intensity on species richness as well as trait composition of butterfly communities. Based on agricultural census data at the municipality scale, we calculated the share of permanent grasslands (measure of habitat availability), the total livestock density (proxy for organic fertilization) and the livestock density of domestic herbivores (proxy for management intensity in grasslands) within a 2 km buffer surrounding each butterfly transect. To analyse the relationships between butterflies and indicators of land cover and land-use intensity, we applied generalised linear mixed effect models. We found a negative relationship between butterfly species richness and the livestock density of domestic herbivores. Further, the ratio of butterfly generalist to specialist species shifted towards generalists and the size of butterflies increased with higher herbivore livestock density, indicating a shift in communities towards mobile habitat generalists. Our results are in accordance with previous studies carried out across smaller geographic extents, highlighting the importance of low herbivore livestock densities to halt the loss of pollinating insects and safeguard biodiversity and associated ecosystem services in agricultural landscapes. We here demonstrate that indicators based on livestock distribution data at the municipality scale can provide insights into processes and spatial diversity patterns of butterflies at the national level. Further, we highlight potentials and limitations of using agricultural census data to quantify and assess effects of land cover and land-use intensity on butterflies, and make recommendations for further research needs.