Search

Abstract Background The intensification of the agricultural practices in Europe over the last decades has drastically transformed the agroecosystems. The simplification of the landscape, the loss of semi-natural habitats and the application of chemicals on crops led to biodiversity decline in agricultural landscapes, raising substantial concerns about the loss of essential ecosystem services, such as pollination or pest control. Depending on the location, the scale and the regional context, different indicator species groups (ISGs) are regularly surveyed to assess the state and trend of biodiversity changes in agroecosystems. Although the high diversity of these ISGs allows assessing different biodiversity aspects (e.g., trophic levels, bio-physical compartments, scale of indication), it complicates the interpretation of the results and thus their practical application. In addition, species diversity metrics are various, from simple species counts to more complex measurements of diversity indices, sometimes with antagonistic responses. Here, to meet the pressing need for synthesis in this complex topic, we follow a standardized systematic map protocol to collect and summarize the literature reporting field evidence of the effects of the main agricultural management practices (AMPs) in arable crops, grasslands and ecological infrastructures on a set of ISGs in European lowland farming areas. Methods Searches of literature were made using online publication databases, search engine and specialist websites in English. Gathered publications were screened for relevance following inclusion/exclusion criteria published in a prior protocol. We extracted and mapped information about experimental design, monitoring methods, ISGs and AMPs studied and the diversity measures presented in each included publication. These parameters are structured in available data coding sheets. Results The search gathered 20,162 references from which 1208 remained after full text eligibility screening. Main areas studied are in Western Europe, and the number of studies increased exponentially from 1984 to 2022. Most publications are experimental and on-farm studies which assess AMPs effects at the field scale. Main studied AMPs are fertilization, grazing, organic farming, tillage, mowing and herbicide application. Most ISGs used to study their impacts are flora, carabids, spiders, birds, bees and annelids, often combined with other ISGs. The combinations between AMPs and ISGs studied are detailed as well as monitoring methods. The most used diversity measures are abundance, species richness, Shannon index, evenness, and community composition. Conclusions We identified several knowledge clusters: (1) organic farming, fertilization, tillage, grazing and mowing impact on a wide range of ISGs, (2) flora response to agricultural practices, (3) annelids response to agronomic interventions that impact soil structure (e.g., tillage, fertilization, crop rotation, crop residue management), (4) butterflies and orthopterans response to mowing and grazing effects in grasslands, (5) the use of bird monitoring for the impact for assessing the efficiency of AES implementation at the landscape scale. We highlight that further research should be conducted on ISGs that are until now poorly studied regarding agricultural practices, such as amphibians, reptiles, gastropods, millipedes and centipedes. More field evidence of the effects of diversification practices such as intercropping, undersowing, intermediate cropping, and agroforestry are needed to draw conclusions on their benefits on biodiversity.

Ecosystem services and biodiversity are frequently measured by field-scale indicators. Yet, many important agricultural and economic drivers as well as agri-environmental policies operate at larger sales, to which field-scale indicators first need to be upscaled. Therefore, this perspective is focussed on upscaling approaches from field to farm or to landscape scale. To understand how ecosystem services and biodiversity are affected by farm-scale drivers and to inform future decision- and policy-making while exploiting existing data sources, these need to be upscaled and analysed at farm scale. However, how this is done best for different types of indicators for ecosystems services and biodiversity received little attention so far.In this work, we propose and discuss different options for upscaling ecosystem service and biodiversity indicators from field to farm scale. We base our novel conceptual work on a large body of literature and demonstrate that before deciding on an upscaling approach, different aspects of the indicators and the purpose of the assessment need to be considered. Our propositions start at the point where field-scale data is available for aggregation at farm scale. Such an aggregation needs to consider the relationship between ecosystem service supply and the benefit provided, i.e., the supply-benefit relationship, which describes how a change in supply affects the resulting benefit for farmers and/or society. We argue that this relationship can also be conceptualized for biodiversity, with benefit being the value of a field or farm for biodiversity conservation.Because benefit does often not continuously increase with supply, but can exhibit breaking points defined by thresholds in supply, the shape of the supply-benefit relationship varies among different ecosystem services and biodiversity components. For example, for upscaling biodiversity indicators, a conservation value needs to consider that conservation benefit might non-linearly change with supply, i.e., habitat quality and quantity, and becomes marginal below certain thresholds. Only when such potential thresholds are considered, a suitable upscaling approach can be chosen from the approaches that we present in this work. While some indicators can be upscaled using a simple area-weighted total or average, for others, thresholds in supply are of great relevance for determining the best upscaling approach. We conclude that upscaling indicators to the farm scale holds untapped potential to inform agri-environmental assessments and future policies. By presenting and discussing suitable approaches for different types of indicators, we hope to facilitate upscaling as a tool to support agri-environmental decision-making in the future.

Agri-environment schemes (AES) have become important tools for farmland biodiversity conservation, providing suitable habitats, resources, and connectivity within the agricultural landscapes. Bats are rarely studied in relation to AES effectiveness in contrast to birds, even though their presence and activity as biological control agents on insects, especially pest species, can be important for agricultural crops. While the role of hedgerows for bat occurrence and activity, as well as for their prey's diversity and abundance has been widely studied, the role of other AESs such as flower fields remains unclear. We monitored the activity of the main functional groups (edge, narrow and open space foragers) using ultrasound recorders, as well as potential prey abundances using light traps, across 35 study sites representing different AES in Central Germany from late July to September 2018. The sampled AES consisted of annual flower fields, mixed flower fields (with annual and biennial vegetation), perennial flower fields (sown every 5 years), hedgerows (surrounded by meadows and agricultural fields), and were compared to winter wheat (control) in a balanced design. Bat activity over hedgerows increased threefold for edge space foragers and sevenfold for narrow space foragers compared to wheat fields. Compared to wheat fields, narrow space forager activity increased fourfold over perennial flower fields, threefold over annual and twofold over mixed flower fields. This group's activity over hedgerows also increased almost threefold compared to mixed flower fields. However, the number of feeding buzzes and prey abundance did not differ significantly between AES. We detected foraging group-specific differences in bat activity between the studied AES. Thus, to promote bats in agricultural landscapes and to ensure their biological control services, it is important to establish more AES, such as hedgerows and flower fields, to increase their diversity and connectivity in intensively used agricultural landscapes.

Abstract Background The intensification of the agricultural practices in Europe over the last decades has drastically transformed the agroecosystems. The simplification of the landscape, the loss of semi-natural habitats and the application of chemicals on crops are known to have led to biodiversity decline in agricultural landscapes, raising substantial concerns about the loss of essential ecosystem services, such as pollination or pest control. Depending on the location, the scale and the regional context, different indicator species groups (ISGs) are often surveyed to assess the state and trend of biodiversity changes in agroecosystems. Although the high diversity of these ISGs allows a broad overview of the biodiversity, it complicates the interpretation of the results and thus their application. In addition, species diversity metrics are various, from simple species counts to more complex measurements of diversity indices, sometimes with antagonistic responses. Here, to meet the pressing need for synthesis in this complex topic, we will follow a standardized systematic map protocol to collect and summarize the literature reporting the effects of the main European lowland agricultural management practices (AMPs) on a set of ISGs. Methods Following the systematic evidence synthesis standards, we developed the question to address in the systematic map using the PICO framework. We established a preliminary search string by combining search terms for the categories Population (ISGs), Intervention (AMPs) and Outcome (species diversity), as well as with two additional groups (Environment—to focus on lowland crop and grassland—and Location—to restrict the study area to Europe). We will conduct a comprehensive literature search of relevant peer-reviewed and grey literature using Web of Science and CABI platforms, Google Scholar, specialized websites and through our professional collaborator network. The comprehensiveness of the search will be assessed by comparing the literature collected to a test-list of ninety relevant articles. The repeatability of the literature screening process will be ensured by a list of inclusion/exclusion criteria and inter-reviewer consistency statistical tests. Data extraction will be organized in three complementary tables (article references, study characteristics, species diversity), on which we will perform queries to produce the tables, figures and maps that will compose the systematic map.

Although most of the wild bee species are ground-nesting, little is known about their nesting requirements and the conservation measures to promote ground-nesting bees. Calcareous grasslands are one of the most species-rich habitats in Central Europe and therefore essential for protecting bee diversity. The management practices of calcareous grasslands are so far often focused on plant populations, but in order to support declining insect populations, additional measures have to be considered for nature conservation. As wild bees depend on the availability of nesting sites, we studied the effects of locally increased bare ground availability on ground-nesting bees on four large and four small calcareous grasslands in Central Germany. Vegetation cover of 24 experimental plots (1 m²) was removed. The number of bee nests as well as the presence of bees on these plots (here: nesting activity) were compared to 24 control plots during six sampling runs. Results showed that the number of bee nests on experimental plots was fourteen times higher compared to control plots, positively related to the surrounding flower cover and higher on steeper slopes, independent of grassland area. Moreover, the observed nesting activity on experimental plots was 2.5 times higher compared to the control and positively related to the currently prevailing soil surface temperature. Bee abundance quantified during transect walks increased on grasslands with a generally higher bare ground availability and a higher flower cover. In conclusion, our study emphasizes the need to consider the availability of nesting resources to promote the vast majority of wild bees, which are ground-nesting. They benefited from bare ground availability as well as adjacent floral resources, and experimental removal of the vegetation cover appeared to be a major, so far underestimated conservation practice.

Background Automated sound recorders are a popular sampling tool in ecology. However, the microphones themselves received little attention so far, and specifications that determine the recordings’ sound quality are seldom mentioned. Here, we demonstrate the importance of microphone signal-to-noise ratio for sampling sonant animals. Methods We tested 12 different microphone models in the field and measured their signal-to-noise ratios and detection ranges. We also measured the vocalisation activity of birds and bats that they recorded, the bird species richness, the bat call types richness, as well as the performance of automated detection of bird and bat calls. We tested the relationship of each one of these measures with signal-to-noise ratio in statistical models. Results Microphone signal-to-noise ratio positively affects the sound detection space areas, which increased by a factor of 1.7 for audible sound, and 10 for ultrasound, from the lowest to the highest signal-to-noise ratio microphone. Consequently, the sampled vocalisation activity increased by a factor of 1.6 for birds, and 9.7 for bats. Correspondingly, the species pool of birds and bats could not be completely detected by the microphones with lower signal-to-noise ratio. The performance of automated detection of bird and bat calls, as measured by its precision and recall, increased significantly with microphone signal-to-noise ratio. Discussion Microphone signal-to-noise ratio is a crucial characteristic of a sound recording system, positively affecting the acoustic sampling performance of birds and bats. It should be maximised by choosing appropriate microphones, and be quantified independently, especially in the ultrasound range.