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The public promotion of renewable energies is expected to increase the number of biogas plants and stimulate energy crops cultivation (e.g. maize) in Germany. In order to assess the indirect effects of the resulting land-use changes on biodiversity, we developed six land-use scenarios and simulated the responses of six farmland wildlife species with the spatially explicit agent-based model system ALMaSS. The scenarios differed in composition and spatial configuration of arable crops. We implemented scenarios where maize for energy production replaced 15% and 30% of the area covered by other cash crops. Biogas maize farms were either randomly distributed or located within small or large aggregation clusters. The animal species investigated were skylark (Alauda arvensis), grey partridge (Perdix perdix), European brown hare (Lepus europaeus), field vole (Microtus agrestis), a linyphiid spider (Erigone atra) and a carabid beetle (Bembidion lampros). The changes in crop composition had a negative effect on the population sizes of skylark, partridge and hare and a positive effect on the population sizes of spider and beetle and no effect on the population size of vole. An aggregated cultivation of maize amplified these effects for skylark. Species responses to changes in the crop composition were consistent across three differently structured landscapes. Our work suggests that with the compliance to some recommendations, negative effects of biogas-related land-use change on the populations of the six representative farmland species can largely be avoided.

a b s t r a c tKettle holes are small, pond-like, depressional wetlands in young moraine landscapes. They mostly undergo a wet-dry cycle and have a high potential for biological species diversity. However, their biodiversity and habitat function is often greatly impacted by surrounding intensive agricultural land use practices.In this study, we used statistical analysis of a large data set from the federal state of Brandenburg (Northeast Germany) to characterise the macrophyte species richness of kettle holes in an interregional context and to determine the factors that influence macrophyte occurrence. We proposed that (1) specific environmental factors, (2) hydrogeomorphic kettle hole types and (3) the regional topography have a major impact on macrophyte species richness. The evaluation of the data was performed using the General Linear Model (GLM) and Canonical Correspondence Analysis (CCA). Each of the analysed factors addresses different parts of the macrophyte species richness, including the target variables overall species richness, plant life and growth forms as well as Red List species.None of the analysis showed effects of the tested environmental factors on overall macrophytes species richness, but on the richness of plant life and growth forms as well as on Red List species. We identified hydroperiod, depth, shore width, kettle hole area, pH, electric conductivity, carbonate hardness and oxygen as key factors for the prediction of species richness of plant life and growth forms. Furthermore, we demonstrate that hydrogeomorphic kettle hole types account for relevant parts of variation in species richness and are useful interregional and integrative indicators to identify kettle holes with protection priority for macrophytes.

Natural landscape elements (NLEs) in agricultural landscapes contribute to biodiversity and ecosystem services, but are also regarded as an obstacle for large‐scale agricultural production. However, the effects of NLEs on crop yield have rarely been measured. Here, we investigated how different bordering structures, such as agricultural roads, field‐to‐field borders, forests, hedgerows, and kettle holes, influence agricultural yields. We hypothesized that (a) yield values at field borders differ from mid‐field yields and that (b) the extent of this change in yields depends on the bordering structure. We measured winter wheat yields along transects with log‐scaled distances from the border into the agricultural field within two intensively managed agricultural landscapes in Germany (2014 near Göttingen, and 2015–2017 in the Uckermark). We observed a yield loss adjacent to every investigated bordering structure of 11%–38% in comparison with mid‐field yields. However, depending on the bordering structure, this yield loss disappeared at different distances. While the proximity of kettle holes did not affect yields more than neighboring agricultural fields, woody landscape elements had strong effects on winter wheat yields. Notably, 95% of mid‐field yields could already be reached at a distance of 11.3 m from a kettle hole and at a distance of 17.8 m from hedgerows as well as forest borders. Our findings suggest that yield losses are especially relevant directly adjacent to woody landscape elements, but not adjacent to in‐field water bodies. This highlights the potential to simultaneously counteract yield losses close to the field border and enhance biodiversity by combining different NLEs in agricultural landscapes such as creating strips of extensive grassland vegetation between woody landscape elements and agricultural fields. In conclusion, our results can be used to quantify ecocompensations to find optimal solutions for the delivery of productive and regulative ecosystem services in heterogeneous agricultural landscapes.

The aim of the study was to explore the impact of climate and land use type on species richness and abundance of arable weeds found as casual aliens in Finland. We used an empirical data set collected along a European climate gradient, from which 163 plants were selected for the analyses. Using generalised linear modelling (GLMM) and redundancy analysis (RDA), we compared species richness and abundance of all species and three functional groups (dicotyledons and grasses, C 3 and C 4 species, alien and native species to Europe), as well as occurrence of the 13 most common individual species between three land use types (fallow, low-input and conventionally cultivated) and six regions. In general, fallowing and low-input cultivation, as well as warmer climate, supported greater weed species richness and abundance. Temperature was found to be a more important factor for weed abundance than land use. The only exception was C 4 species richness, which did not respond to either factor. The impact of land use was independent of climate for all variables, except C 4 species abundance. Non-cultivated fallows had more weeds than cultivated fields, in most cases. No difference was found in the species richness and abundance of grasses or in the occurrence of individual species between low-input and conventionally cultivated fields. It was evident that climate and land use affect the distribution of arable weed species currently found as casual aliens in Finland. This suggests that climate warming will increase the risk of the population establishment of new weed species in northern regions.

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