Semi-natural Habitats Research Articles

Agricultural irrigation development in Castilla y León (Spain): driving forces and outcomes for landscape and sustainability in the 21st century

ContextAgriculture relies on irrigation in many parts of the world, and the need for irrigation is increasing due to rising demands for agricultural products and climate change-induced alterations in rainfall patterns. However, irrigated agriculture has been found to damage ecosystems and threaten landscape sustainability.ObjectivesAgainst this background, there has been a recent development towards large-scale irrigation in Spain. The aim of this study is to understand this development at the landscape level and its impact in the context of landscape sustainability.MethodsWe focused on two study sites in Castilla y León using a mixed-methods approach. We studied driving forces, landscape changes, and sustainability outcomes through document analysis, interviews, and aerial photograph analysis.ResultsThe development of a landscape-level underground pipe network took place at one study site and is planned for the second study site. Interviewees perceived institutional and social driving forces as particularly influential and technological driving forces as less influential. Political and economic driving forces were often interlinked. The irrigation development tied to land consolidation led to landscape changes, such as the removal of trees and increases in field size. Thus, in terms of environmental sustainability, trade-offs were found, while social sustainability outcomes were mainly positive. The impact on farmers’ economic security varied.ConclusionsFor further landscape-level irrigation developments, we recommend integrating preserving seminatural habitats and the structural diversity of the agricultural landscape in planning processes. We also recommend a shift towards more water efficient crops, evapotranspiration management, and a new funding scheme for farmers to offset rising electricity costs.

Short‐Term Grasslands in Agriculture Support Both Natural Enemy and Phytophagous Arthropod Populations

ABSTRACTSimplified agricultural land with high chemical input is increasingly replacing natural habitats in many parts of the world. This loss and fragmentation of natural areas may have profound impacts on an array of wildlife, including predatory arthropods that provide natural biocontrol of agricultural pests. There is increasing interest in utilising short‐term seminatural habitat restoration in agricultural systems to support populations of beneficial organisms. We assessed the impact of two types of short‐term set‐asides on the diversity and abundance/activity density of phytophagous and predatory arthropods. We found that flower‐enhanced set‐asides supported higher abundances of both phytophagous and predatory arthropods compared to control crop fields. In addition, we found that both set‐aside types (flower enhanced and traditional) supported a more active and diverse community of beneficial predatory carabid beetles, with particularly strong trends in set‐asides supplemented with flowering plants. These results suggest that small‐scale, temporary, seminatural habitats in agricultural systems provide support for a diverse and abundant community of both beneficial and phytophagous arthropods.

Multi-Annual Study of Eriogaster catax (Linnaeus, 1758) (Lepidoptera, Lasiocampidae) Oviposition Strategy in Transylvania's Largest Population: Key Insights for Species Conservation and Local Land Management.

This study provides new insights into the oviposition strategy of Eriogaster catax (Linnaeus, 1758) (Lepidoptera, Lasiocampidae), an endangered species of moth found in semi-natural habitats within agricultural landscapes. Protected under various European directives and listed as Data Deficient by the IUCN, E. catax inhabits warmer regions of the Western Palearctic. Despite noted geographic variations in its ecological preferences, few studies have statistically significant data on its ecology. Our six-year study, conducted within the largest known population of E. catax. in Romania, reveals critical data on its oviposition preferences, including the species' tendency to utilize Prunus spinosa L. and Crataegus monogyna Jacq. shrubs at an average height of 80.48 ± 34.3 cm, with most nests placed within the 41-80 cm range and containing an average of 186 ± 22 eggs. The study also addresses the species' vulnerability to human activities such as bush trimming, agricultural burning, and uncontrolled grazing, particularly due to its low oviposition height. These findings underscore the negative impact of overgrazing and burning practices, particularly when conducted on a large scale, on the conservation of E. catax. The detailed ecological requirements identified in this study are essential for developing effective conservation strategies and habitat management practices. Furthermore, the study highlights the importance of local community involvement and public education in raising awareness about biodiversity and the conservation of endangered species.

A New Record of Elymnias Caudata Butler, 1871 (Insecta: Lepidoptera: Nymphalidae) from Nagpur in Central India

Urban areas harbour diverse butterfly species in isolated and fragmented habitats such as parks, remnants of natural and semi-natural habitats and other such green areas. An Indian endemic nymphalid butterfly species, Elymnias caudata Butler, 1871 (tailed palmfly), has mostly been reported from south-western parts of the southern region of India. According to the previous record, this species is unknown from Nagpur, a city in Central India. Here, Elymnias caudata is recorded from Nagpur for the first time, and it shows that the distribution range of this species is wider than previously known. This is the northernmost record of Elymnias caudata in India.

Wild Bee Conservation in Viticulture: Effects of Semi-Natural Habitats, Organic Management, and Fungicide Reduction.

In agricultural landscapes, the removal of semi-natural habitats (SNH) and the intensive use of pesticides contribute to declines of biodiversity, including crop pollinators such as bees (Hymenoptera: Apoidea). However, effects of pesticide use and landscape characteristics on bees have rarely been studied together. In this study, we investigated how SNH in the surrounding landscape, organic and conventional management, and the reduction of fungicides affect wild bee diversity in 32 vineyards in southwest Germany. We used yellow pan traps to sample bees in a crossed design of management (organic vs. conventional) and fungicide use (reduced in fungus-resistant grape varieties vs. regular) along a gradient with increasing proportions of SNH in the surrounding landscape. Higher proportions of SNH influenced species composition of bees and increased the abundance and richness of above-ground-nesting species. Organic vineyards had a 49% higher abundance of bees compared to conventional vineyards. The reduction of fungicides did not affect bee diversity nor abundance. The absence of a response to fungicide intensity suggests that the benefit of organically managed vineyards to wild bees was through differences in their vegetation management, which is in line with the positive response of bees to SNH in the surrounding landscape. Synthesis and applications: Our study underlines that the local provision of diverse vegetation in vineyards and the landscape-scale provision of suitable SNH are key factors for wild bee conservation in viticulture.

Assessment of Common Ragweed (Ambrosia Artemisiifolia L.) Seed Predation in Crop Fields and Their Adjacent Semi-Natural Habitats in Hungary

Ambrosia artemisiifolia has turned into a noxious weed species in agricultural fields and landscapes in Europe. Durable control options are still needed to limit the abundance of this species. Weed seed consumption by naturally occurring seed predators is a key ecosystem service in agricultural areas. Seed predation levels of common ragweed were examined in wheat and maize fields and adjacent semi-natural habitats (SNHs). To evaluate the weed seeds’ exposure to invertebrate seed predators, 20 cards each were set on the soil surface inside the crop field and in SNHs with four replications. Twenty seeds of ragweed were attached to sandpaper. Seed removal was assessed every 24 h of exposure for 5 days in June and November 2019, October 2020, and June 2021. The seed consumption level was measured according to the number of removed seeds from the seed cards. High consumption rates of ragweed seeds were found in all sampling rounds in both seasons and habitats. The seed predation rates in 2019 were stronger within crop fields in summer than in autumn with a slight difference between SNHs and inside fields. Our results demonstrate the possibility of seed predation contributing to Integrated Plant Protection (IPM) of common ragweed in rural areas.

Effects of sown and spontaneous inter-row vegetation on weeds and beneficial arthropods in vineyards

The intensification of crop management has resulted in a decline of biodiversity in the last decades, in particular through habitat loss, fragmentation and degradation. Semi-natural habitats within agricultural landscapes such as hedges, grasslands or herbaceous field margins, provide resources and refuge to beneficial arthropods. In vineyards, extensively used inter-row vegetation may be functionally equivalent to such semi-natural habitats and sowing of plant species rich in floral resources may improve habitat functions. In this study, three types of vineyard inter-row vegetation treatments were compared in 15 vineyards of South-eastern France: (1) sowing a high-diversity seed mixture (HD) with a high number of nectariferous plant species, (2) spontaneous vegetation, and (3) tilled inter-rows. We monitored the inter-row vegetation including problematic weeds, the abundance of beneficial arthropods, and the predation of sentinel prey. The invasive weedy grass species Cynodon dactylon showed a lower cover in HD inter-rows than in spontaneous vegetation, whereas no differences were found for the invasive herb Erigeron sumatrensis. Both weed species were still best controlled in tilled inter-rows. Beneficial arthropods were less abundant in tilled than in spontaneously vegetated and sown inter-rows. Day predation was higher in HD inter-rows than in spontaneous vegetation although no significant differences were found for observed predators. Over all treatments, plant species richness, flower and grass cover had a positive influence on several beneficial arthropod groups. Our results highlight the positive effects of species-rich inter-row vegetation on weed control, beneficial arthropod abundance and predation but also showed that further research is needed to improve the efficiency beyond services already provided by spontaneous vegetation.

Semi-natural habitats are key to breeding bird diversity in intensified vineyard landscapes across Europe

In climatically suitable regions across Europe, vineyards can be the dominant perennial crop type. While many wine-growing landscapes are intensively managed, they may still be an attractive habitat for a wide range of bird species. In this study we investigated how breeding birds in three wine-growing regions in Europe (Germany: Palatinate, France: Bordeaux, Austria: Leithaberg) are influenced by the composition of the landscape, focussing on woody semi-natural vegetation.We recorded bird vocalizations with autonomous sound recorders in 93 landscapes across Europe. Bird species were identified according to their songs and calls. The landscape in a 200-m buffer around the recording points was mapped. In total, we recorded 72 bird species, including species typical for vineyard landscapes such as cirl bunting (Emberiza cirlus), hoopoe (Upupa epops) and turtle dove (Streptopelia turtur). For all three countries we found that an increase in overall woody vegetation in the landscape led to an increase in species richness and altered community composition. Most species were recorded in landscapes with abundant hedges, small woods and tree rows rather than in vineyard-dominated landscapes but e.g. woodlark (Lullula arborea) and linnet (Linaria cannabina) showed an opposite preference.We conclude that in intensively used wine-growing landscapes the ongoing decline in farmland birds and the ecosystem services they provide can be reversed by the reintroduction of semi-natural woody vegetation between vineyards. These in many cases linear structural elements can be included in the landscape with only small losses in production area.

The role of wild bees and cavity-nesting wasps as ecological indicators of the last traditionally managed meadows in Eastern Europe.

The number of wild bees and cavity-nesting wasps is abundant in agricultural areas and they contribute significantly to ecosystem services. Due to their specialization in nesting sites and food sources, these groups are sensitive to habitat condition changes and they are therefore important indicators for environmental impact assessments. As semi-natural habitats are steadily declining and often understudied, their significance for research is increasingly recognized. During this research, the role of wild bee species and cavity-nesting Hymenopteran taxa as indicators was examined, along the unique combination of high nature value and traditional land use habitats in Eastern Europe, Transylvania. Transects and trap nests were used to test the diversity and abundance of wild bees and cavity-nesting Hymenopterans to identify possible differences between highly protected and less protected areas. The differences in taxonomic groups between the sites and the potential effects of landscape structure on wild bees and cavity-nesting Hymenopterans were also assessed. We detected a high diversity of wild bee species and a significant species replacement from one study year to another. Among the nest-building Hymenopteran taxa, the majority of nests was built by Trypoxylon sp. during both study years, with a stronger dominance in the second year. The different taxonomic groups of wild bees and cavity-nesting Hymenopterans showed differences in their habitat affinities. The majority of the sampled bumblebee species as well as Trypoxylon sp. had an affinity towards the study sites located within the highly protected study area. Altogether, we found different habitat preferences for different Hymenopteran groups (both wild bees and wasps) and conclude that these groups definitely have the potential to serve as indicators for differences in the intensity of land use.

Remote sensing reveals the importance of seminatural habitat and irrigation on aphid biocontrol in arid agroecosystems

Abstract Remote sensing and spatial analyses are increasingly used to understand the role of seminatural habitats in biocontrol, but knowing how to best leverage these tools is a persistent challenge. In arid agroecosystems, irrigation often exaggerates the differences between crop fields and their interspaces. Weeds adjacent to irrigated fields are thus often some of the only persistent vegetation. Remote sensing may be essential to capture the effect of this fine‐scale variation on pest biocontrol. We examined the role of land‐cover in determining the degree of aphid pest pressure and biocontrol in irrigated alfalfa fields in the Great Basin Desert (Nevada, USA). We experimentally manipulated predator densities to determine true agents of aphid biocontrol in this system. We then assessed land‐cover and spatial scale using alternative methods to determine the approaches that best defined the combined direct and indirect effects of seminatural habitat on aphid pest suppression. A remote‐sensing approach revealed the importance of land‐cover to aphid biocontrol more clearly than conventional vegetation surveys. In particular, remote sensing revealed that weedy patches within alfalfa fields reduced aphid densities, whereas flood irrigation increased aphid densities. Our experiments confirmed that coccinellid beetles are important aphid biocontrol agents. Coccinellids were positively associated with weedy land‐cover that was spatially close to alfalfa fields, particularly in the spring. Other predator taxa were also associated with distinct landscape features, though these associations varied between spring and fall. Solution: Weedy seminatural habitat near alfalfa fields, occurring along field margins and the banks of irrigation ditches, was positively associated with the density of coccinellid beetles and associated aphid pest suppression. Remote sensing excelled at identifying these areas and their effects, highlighting its utility as a management tool. Preserving these weedy areas can enhance aphid biocontrol, but farmers must consider potential trade‐offs between the control of insect‐pests and weeds.

Gardens reduce seasonal hunger gaps for farmland pollinators.

Gardens can benefit pollinators living in surrounding farmland landscapes, but the reason for their value is not clear. Gardens are no different from many semi-natural farmland habitats in terms of the quantity of floral resources (pollen and nectar) they produce, but the timing of their resource supply is very different, which may explain their value. We show that gardens provide 15% of overall annual nectar in farmland landscapes in Southwest UK, but between 50% and 95% during early spring and late summer when farmland supplies are low. Gardens can therefore reduce seasonal nectar gaps experienced by farmland bumblebees. Consistent with this pattern, bumblebee activity increased in gardens relative to farmland during early spring and late summer. An agent-based model reinforces this point, showing that timing, not quantity, of garden nectar supply enhances bumblebee colony growth and survival in farmland. We show that over 90% of farmland in Great Britain is within 1 km of a garden and therefore positive actions by gardeners could have widespread spillover benefits for pollinators across the country. Given the widespread distribution of gardens around the world, we highlight their important interplay with surrounding landscapes for pollinator ecology and conservation.

Insect conservation in agricultural landscapes needs both high crop heterogeneity and semi-natural habitats

Identifying landscapes that are suitable for both biodiversity conservation and agricultural production is a major challenge. Traditionally, much research has focused on biodiversity conservation outside of agricultural production areas, e.g., in semi-natural habitats. In contrast, recent research has mainly focused on the potential of crop heterogeneity. This includes both compositional (crop diversity) and configurational heterogeneity (field border density). However, if and how crop heterogeneity, and semi-natural habitats interact to shape insect diversity in agricultural landscapes remains poorly understood. Here we investigated the combined effects of crop diversity, field border density, and semi-natural habitats (i.e., grassland proportion, hedge density) on insect diversity. We sampled insect communities from 14 – 17 June 2021 with pan traps in 27 study landscapes (500 m x 500 m) covering independent gradients of these landscape variables and identified a total of 587 insect species with DNA metabarcoding. We found that field border density mediated the effects of crop diversity, grassland proportion, and hedge density on insect richness. At low levels of field border density (i.e., landscapes with mostly large fields), effects were either neutral (crop diversity), negative (grassland proportion) or weakly positive (hedge density). By contrast, at high levels of field border density, crop diversity, grassland proportion, and hedge density all exerted positive effects on insect richness. Responses to crop heterogeneity and semi-natural habitat differed among trophic groups of insects (decomposers, herbivores, parasitoids, predators). While variation in richness of herbivorous insects followed the patterns of the overall richness, decomposer richness was not related to any of the investigated variables. Predator richness increased with hedge density in landscapes, whereas parasitoid richness increased when high levels of field border density and grassland proportion coincided. Our study shows that increasing crop heterogeneity is a viable strategy for promoting insect diversity in agricultural landscapes. However, the effects of the amount of remaining semi-natural habitats, such as grassland or hedges, are mediated by configurational heterogeneity, and vary between trophic groups. Efforts to conserve insects in agricultural landscapes must therefore focus on both increasing the heterogeneity of the crop matrix by promoting crop diversity and increasing the density of field borders, while also maintaining or restoring semi-natural habitats as important source habitats for insect species.

Serotonin drives aggression and social behaviors of laboratory male mice in a semi-natural environment.

Aggression is an adaptive social behavior crucial for the stability and prosperity of social groups. When uncontrolled, aggression leads to pathological violence that disrupts group structure and individual wellbeing. The comorbidity of uncontrolled aggression across different psychopathologies makes it a potential endophenotype of mental disorders with the same neurobiological substrates. Serotonin plays a critical role in regulating impulsive and aggressive behaviors. Mice lacking in brain serotonin, due to the ablation of tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme in serotonin synthesis, could serve as a potential model for studying pathological aggression. Home cage monitoring allows for the continuous observation and quantification of social and non-social behaviors in group-housed, freely-moving mice. Using an ethological approach, we investigated the impact of central serotonin ablation on the everyday expression of social and non-social behaviors and their correlations in undisturbed, group-living Tph2-deficient and wildtype mice. By training a machine learning algorithm on behavioral time series, "allogrooming", "struggling at feeder", and "eating" emerged as key behaviors dissociating one genotype from the other. Although Tph2-deficient mice exhibited characteristics of pathological aggression and reduced communication compared to wildtype animals, they still demonstrated affiliative huddle behaviors to normal levels. Altogether, such a distinct and dynamic phenotype of Tph2-deficient mice influenced the group's structure and the subsequent development of its hierarchical organization. These aspects were analyzed using social network analysis and the Glicko rating methods. This study demonstrates the importance of the ethological approach for understanding the global impact of pathological aggression on various aspects of life, both at the individual and group levels. Home cage monitoring allows the observation of the natural behaviors of mice in a semi-natural habitat, providing an accurate representation of real-world phenomena and pathological mechanisms. The results of this study provide insights into the neurobiological substrate of pathological aggression and its potential role in complex brain disorders.

Patch shape, connectivity and functional groups moderate the responses of bird diversity to agricultural diversification — A meta-analysis

Agricultural expansion and intensification pose significant threats to global biodiversity. However, the conservation of agricultural biodiversity is essential for harmonizing agricultural production with ecological sustainability. Agricultural diversification can mitigate the negative impacts of agriculture on ecosystem functioning and biodiversity. Characteristics of the broader landscape may also play an important moderating role in diversified agricultural landscapes, but are not fully solved. To bridge this gap, we conducted a meta-analysis of peer-reviewed studies to compare bird abundance and species richness in diversified agricultural landscapes compared to those in simplified farmlands and natural landscapes. We also explored the moderating role of species functional groups and 11 metrics of landscape composition, configuration and heterogeneity. We found a generally positive effect of perimeter-to-area ratio of farmland patches, connectivity within farmland patches, and connectivity within patches of natural and semi-natural habitats on bird abundance and species richness. Responses to other landscape metrics were less consistent. For pollinators, the abundance was higher in diversified agricultural landscapes compared to control groups, and particularly when compared to natural landscapes. For natural enemies, the species richness was significantly lower in diversified agricultural landscapes than in natural landscapes, while their abundance was not. The overall abundance and species richness of granivores and frugivores in diversified agricultural landscapes were comparable to those in control landscapes. These results indicated landscape type of control groups, species functional groups, and their interactions had consistent impacts on the responses of bird diversity. We found a vital role of farmland patch shape and connectivity within farmland and habitat patches for bird conservation in diversified agricultural landscapes, which has been rarely reported in previous studies. These insights underscore the need for policymakers and managers to develop farmland management and planning strategies at multiple scales to fulfill growing human demands while achieving biodiversity conservation objectives.

Impacts of forest extent, configuration and landscape context on presence of declining breeding Eurasian curlew Numenius arquata and implications for planning new woodland

In response to the combined impacts of the climate and biodiversity crises, as well as for timber security and increased recreational access to green spaces, there is a global drive to increase tree cover. In the UK, an estimated 1.5 million ha of afforestation are required to meet its carbon net-zero emissions targets (Committee on Climate Change, 2018). Despite the potential benefits, careful consideration must be given to the impacts of woodland creation on species adapted to open habitats. To investigate potential risks and mitigation for the IUCN Near Threatened Eurasian curlew Numenius arquata, a national spatially extensive field-scale dataset was used to investigate the relationships between curlew presence during the breeding season and a range of forest and landscape variables at two different spatial scales (0.5 km and 1 km). Variables included forest extent and configuration, and interaction between forests and extent of semi-natural open habitats, moorland management and topography. At both spatial scales, a negative relationship existed between extent of forest and the probability of curlew presence, and at 1 km, between probability of presence and the number of forest patches. However, these negative patterns depended on landscape context and were reduced where there was a greater quantity of semi-natural open habitat, such as moorland or rough grassland, and moorland management present. Overall, the findings emphasise the need to consider the impacts of woodland creation projects on species adapted to open habitats. However, the results suggest that these impacts can be influenced by landscape. These results could help inform decisions regarding the appropriateness of woodland creation in different landscapes and possible mitigation measures that could be applied against the risks created by afforestation.

Assessing pollinator abundance and services to enhance agricultural sustainability and crop yield optimization in the Qilian Mountains

ContextPollination services are critical to crop production and human livelihoods, linking natural ecosystems directly to agricultural production systems. However, pollination services and pollinators are under constant threat from land-use changes and various other environmental pressures. ObjectiveIn this study, employing a case study of the entire Qilian Mountains in northwest China, the distribution of nectar sources in different land use types in the study area was determined through field survey and literature. MethodsBased on 1990–2020 land use data, crop yield data, crop prices, pollinating bee species and nectar plants data. We used the Gross Ecological Product (GEP) accounting and InVEST model of pollination services and assessed the status and trends of pollination services, the risks posed by land use changes and environmental pressures, and suggested potential solutions for mitigating identified risks. Results and conclusionsThe results of the study showed that (1) nectar sources and nesting areas' potential distribution closely correlates with land use types; (2) the Pollinator abundance index (PAI) is above 0.30, a high level, and the Pollination potential index (PPI) is between 0.15 and 0.30, a medium level, with both indices generally increasing over the past 40 years; (3) Human economic activities and land management policies had the most significant impact on pollination services, with 15.57 % and 14.02 %, respectively. Climate change (temperature, precipitation, extreme events) and invasive alien species had relatively minor impacts, accounting for 0.14 % and 0.15 %, respectively. (4) The Qilian Mountains will face a new risk, whether monoculture or the expansion of pollinator-dependent crops could lead to habitat homogenization issues, potentially affecting pollinator abundance and diversity. SignificanceWe recommend that future plans emphasize the provision of pollinator nesting resources along with floral resources, restoration of semi-natural and natural habitats adjacent to crops, adjustment of cropping patterns, and implementation of agricultural diversification, which will help to ensure pollinator diversity and sustainability of agroecosystem pollination services.

The relative influence of agricultural abandonment and semi-natural habitats on parasitoid diversity and community composition.

Wild biodiversity is usually larger in semi-natural habitats than in croplands, but this pattern is not ubiquitous because it varies among taxa and geographic regions. Knowing how the diversity of natural enemies is structured at the landscape level is important to better understand when semi-natural habitats promote the conservation of natural enemies and ultimately enhance biocontrol. We explore the relative influence of agricultural abandonment and the proportion of semi-natural habitats at the landscape level on the diversity and abundance of parasitoid wasps in the Ichneumonidae family. We studied changes in parasitoid diversity both at local and regional scales (i.e. alpha vs beta diversity), and both at the taxonomic and functional level (i.e. species vs guild identities). We extracted landscape features in circular buffers of varying radii to perform a multi-scale analysis, and to assess at which scale landscape-level effects influenced parasitoid assemblages. We found that parasitoid alpha and beta diversity decreased with an increasing proportion of semi-natural habitats. The multi-scale analysis revealed that for this group of natural enemies, landscape-level effects occur at mid to low distances (i.e. less than 500m). Our results provide insights into the origin of pest natural enemies, their spillover to croplands, and may help to understand under which circumstances semi-natural habitats fail at promoting biocontrol services.

What evidence exists on the effect of the main European lowland crop and grassland management practices on biodiversity indicator species groups? a systematic map

BackgroundThe 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.MethodsSearches 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.ResultsThe 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.ConclusionsWe 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.

Semi-natural habitats mitigate the impact of food shortage on honey bees in farmlands

Landscape simplification and the loss of semi-natural habitats are identified as important drivers of insect pollinator decline in farmlands, by disrupting the availability of floral resources and facilitating the occurrence of food shortages. Food shortages can lead to accelerated behavioral maturation in honey bees, with potential consequences for colony survival. However, little is known about the magnitude of behavioral maturation mediated by to food shortage under real field conditions, and whether it could be mitigated by the presence of semi-natural habitats. Here, we monitored the lifespan (LSP), age at first exit (AFE), foraging tenure, and foraging intensity of 1035 honey bees along a landscape gradient of semi-natural habitats in farmlands. We found a clear acceleration of behavioral maturation of bees during the food shortage season, with precocity in AFE between 6 and 10 days earlier and reduced LSP by 5 to 9 days, with no effect on foraging tenure or foraging intensity. We also found that higher proportions of semi-natural habitats mitigated behavioral maturation of bees by up to 6 days. Beyond the direct effects on adult bees, we found no delayed effect of larval feeding status on adult life-history traits or foraging behavior. Nevertheless, our results strongly advocate the implementation of policies aimed at increasing the coverage of semi-natural environments (e.g., grasslands, forests, hedgerows) in intensive agricultural landscapes to support honey bee survival and pollinator conservation.

Landscape crop diversity contributes to higher pollination effectiveness and positively affects rapeseed quality in Mediterranean agricultural landscapes

Pollination is crucial for biodiversity and food security. Heterogeneous agricultural landscapes have a positive effect on pollinator abundance and enhance crop production and quality. In this study, we explored the effects of three landscape features (past crop diversity measured as the Equivalent Richness of crop functional Groups in the previous year [ERGp], semi-natural habitat percentage [SNH], and mean field size [MFS]) and pollinator densities (wild bees [WB] and honey bees [HB]) on pollination and seed quantity and quality in rapeseed crops. Surveying the pollinator density in 20 rapeseed fields revealed a positive relationship with ERGp in the landscape. A pollinator exclusion experiment compared bagged and open-pollinated self-compatible rapeseed plants and revealed insect pollination effectiveness (fruits per flower and number of seeds per pod) and seed quality (oil content). Seed parameters were evaluated in relation to pollinator density (WB-HB) and landscape characteristics. The ERGp emerged as a crucial landscape feature that positively impacted WB density. When insect pollinators were excluded, plants exhibited reduced pollination effectiveness and seed quality. Analysis of open-pollinated plants highlighted ERGp as the most influential variable, positively affecting both sets of parameters. The MFS and SNH showed different but important relationships. Total tocopherol and α-tocopherol were positively correlated with pollinator density in HB, whereas WB showed a positive correlation with γ-tocopherol levels. Increased ERGp positively affected pollinator density and pollination effectiveness, thereby improving oilseed rape production quantity and quality. This study provides new insights into agroecosystem management and pollinator-friendly practices.