Ecosystem Services In Agroecosystems Research Articles

Management practices influence biocontrol potential of generalist predators in maize cropping systems

AbstractIntensification of conventional agriculture is a leading cause of negative environmental impact, loss of biodiversity, and reduced delivery of ecosystem services in agroecosystems. Maize, due to its growth habits and cultivation management, provides a poor habitat for beneficial arthropods. Several strategies are available to make maize cropping systems more sustainable and to promote biodiversity at field level. The present study evaluates the effects of various maize cropping systems – precisely, maize continuous monoculture, maize multiple cropping, and three mixed cropping systems (maize‐runner bean, maize‐sorghum, and maize‐flower strips) – on generalist predators and their biological control potential. Overall, we found that the reference system with maize continuous monoculture and conventional crop management had the lowest activity of generalist predators compared in particular to the low‐input mixed cropping systems. Higher activity density and biocontrol potential were found in the systems that provided a dense and permanent vegetation cover of the ground (i.e., maize/sorghum, maize/flower strip). Although these effects were not consistent for all the parameters investigated and for every sampling date, we conclude that generalist predators can benefit from more conservative management practices in maize systems, thereby enhancing their biological pest control potential. Furthermore, spatial intercropping may represent a valid alternative to the conventional monocultural crop system to support the delivery of biodiversity‐mediated ecosystem services towards a more sustainable system.

Spontaneous flowering vegetation favours hoverflies and parasitoid wasps in apple orchards but has low cascading effects on biological pest control

Floral resources support several ecosystem services in agroecosystems, such as pollination or biological control. Many beneficial organisms feed on nectar or pollen for an important part of their life cycle. Providing adequate and sufficient floral resources through the conservation of spontaneous flowering vegetation may be a strategy to improve biological pest control. However, the role of spontaneous flowering plant species has mainly been evaluated in the recruitment of natural enemies. Cascading effects on pest regulation and damage reduction are rarely studied. Here we evaluated the effect of spontaneous flowering vegetation on pest regulation in 18 Mediterranean apple orchards. We focused on two main apple pests, Cydia pomonella and Dysaphis plantaginea, and on two groups of their natural enemies depending on floral resources: hoverflies and parasitoid wasps. We combined generalised linear mixed models and piecewise structural equation models to test for direct and indirect effects of spontaneous flowering plant species on beneficial insects (hoverflies, parasitoid wasps, wild bees and honeybees) and on pest regulation. We also tested for potential negative interactions between honeybees and hoverflies, parasitoid wasps or wild bees. There was a positive and significant effect of insect-pollinated flowers on hoverflies, parasitoid wasps and bees, but small cascading effects on D. plantaginea or C. pomonella density and associated damage. There was no significant relationship between honeybees and hoverflies, parasitoid wasps or wild bees. The reduction of D. plantaginea infestation was partially mediated by hoverfly abundance. Furthermore, we observed effects of spontaneous flowering vegetation on pest regulation and damage reduction independent of hoverfly and parasitoid wasp abundances. These results highlight the importance of conserving floral resources to support biological control of apple pests. Further studies are needed to better understand interactions between spontaneous flowering vegetation and crop management practices to promote sustainable pest regulation strategies.

FunBies, a model for integrated assessment of functional biodiversity of weed communities in agro-ecosystem

Agrobiodiversity, by producing beneficial ecosystem services (ESs), could improve the sustainability of cropping systems. There is a number of studies reporting the use of indicators for quantifying ESs. However, there are no indicators which might be applied at local scale and allowing an integrated assessment of a wide range of ESs in agro-ecosystems. The objectives of the present research were: (i) to describe a model for integrated assessment of functional biodiversity in agro-ecosystems, denominated FunBies, (ii) to show how it was validated, and (iii) to present results of its application. FunBies is featured by an empiric model component, a conceptual component that takes into account the whole range of ESs identified by the Millennium Ecosystems Assessment and by a multi-criteria linear additive model including the whole set of functional traits potentially supplied by herbaceous plant communities. The model was validated by a panel of experts. Results at cropping system level indicated that organic systems have the potential to supply considerably higher ESs than conventional systems. ES provision increases in time together with the evolution of the phytocoenosis. FunBies potential applications include: (i) design of biodiversity components within agro-ecosystems, and (ii) justification and sizing of organic payments.

Environmental and management factors drive biological communities and ecosystem services in agroecosystems along an urban-natural gradient

Biodiversity, ecosystem services and farming are inextricably linked. Peri-urban agricultural landscapes host wild species, provide essential services, and benefit citizens of nearby towns. We investigated the environmental and management factors that influence avian communities, pollinating insects and two key ecosystem services (pollination and nature-based recreation) along an urban-natural gradient dominated by agricultural areas (vineyards, apple orchards and grasslands) in northern Italy. Flower visiting-insects were mainly affected by management and environmental-climatic variables. The presence of flowers at the margins and within vineyard and apple orchard inter-rows best predicted the abundance of pollinators and flower-visiting insects in general. Different flower species exerted variable effects on different groups; a mix of flowering species should be recommended for supporting pollinators. Sward height and grassland cover promoted flower-visiting insect abundance, which was negatively affected by vineyards and apple orchards. Bird communities were mainly shaped by land-use/land-cover and management variables. Landscape heterogeneity and linear elements had a major positive effect on birds. Apple orchards negatively influenced species richness and the abundance of most avian species, while vineyards negatively impacted on overall bird abundance; hedgerows positively affected richness. Nature-based recreation was greater in areas with low or intermediate vineyard or urban cover. Apple orchards and intensively managed grasslands had negative, and waterways positive, effects on recreation. Peri-urban agricultural landscapes are important for biodiversity and ecosystem services, but apple orchards and large vineyards appear largely unsuitable. Maintaining heterogeneous landscapes and implementing biodiversity-friendly practices can further promote benefits for biodiversity and visitors and local populations. Synergic strategies that simultaneously promote the conservation of biodiversity and the supply of ecosystem services could be easily developed and implemented.

Predator-prey traits and foraging habitat shape the diet of a common insectivorous bat

Individual and species traits may determine the functional relationships between predators and their prey, with clear consequences for the ecosystem services potentially associated with predation. Bats are well-known potential deliverers of ecosystem services in agroecosystems through predation of pest arthropods that may affect crop production. Here we test the role of individual and prey traits in shaping the dietary habits of the Savi's pipistrelle (Hypsugo savii), a common bat species that frequently occurs in agroecosystems across the Mediterranean area, assessing diet composition and trait-based biases through molecular tools and multivariate testing techniques. DNA metabarcoding identified 173 distinct prey taxa in bats sampled in the Vesuvius National Park (Southern Italy). The diet was strongly dominated by pest insects associated with agricultural areas, which covered 57% of the overall prey diversity, some representing major pests of high economic relevance. The multivariate analyses detected strong relationships between diet composition, sampling date, and individual bat body conditions. Larger bats consumed larger prey items, and prey consumed later in the season (August) were smaller than those eaten in early summer (July) and were typical of less natural habitats. Hypsugo savii is potentially an important pest suppressor in the agroecosystems of the Mediterranean region and the functional relationships between the traits of individual bats and their prey set the basis for a quantitative assessment of the associated ecosystem service. We also remark on the value of bat diet studies in aiding the surveillance of arthropod species relevant to agriculture, human health, and biodiversity conservation.

Plant functional diversity is affected by weed management through processes of trait convergence and divergence.

Weed management involving tillage and/or herbicides has generally led to a decline of plant diversity in agroecosystems, with negative impacts on ecosystem services provision. The use of plant covers has become the predominant alternative in vineyard management, with numerous studies focusing on analyzing the advantages and disadvantages of plant covers compared to the aforementioned management. Although the impacts of weed management on taxonomic diversity have been widely studied, many gaps remain on their effects on plant functional diversity. As plant functional diversity is linked to the delivery of key ecosystem services in agroecosystems, understanding these effects could enable the development of more sustainable practices. From 2008 to 2018, a long-term trial was carried out in a Mediterranean vineyard to assess different agricultural practices. In this article, we examined how weed management, as well as irrigation use, could affect plant functional diversity. Based on 10 functional traits, such as plant height, specific leaf area or seed mass, we measured different indices of functional diversity and used null models to detect processes of trait convergence and divergence. Our results revealed that weed management and irrigation use had a significant effect on plant functional diversity. Mown plots showed the highest functional richness but were functionally convergent, since mowing was a strong functional filter on most of the traits. Tillage also behaved as a functional filter on some vegetative traits, but favored the divergence of certain reproductive traits. Herbicide-treated and irrigated plots showed the highest values of functional divergence by promoting more competitive species with more divergent trait values. The effect of weed management on these community assembly processes was shaped by the use of irrigation in vineyard rows, leading to functional divergence in those vegetative traits related to resource acquisition and seed mass. These results suggest that greater functional diversity may be associated with the bias caused by higher occurrence of competitive species (e.g. Convolvulus arvensis, Sonchus asper) with contrasting values for certain traits. Therefore, since these species are considered harmful to crops, higher plant functional diversity might not be a desirable indicator in agroecosystems.

How weed management influence plant community composition, taxonomic diversity and crop yield: A long-term study in a Mediterranean vineyard

Agricultural expansion and intensification is a major driver of biodiversity loss. Conventional weed management (e.g. tillage, herbicide) has encouraged the promotion of a few more competitive species over a wide range of arable plants that are now in decline. A reduction in plant diversity would negatively affect the provision of key ecosystem services in agroecosystems. In vineyards, the use of plant covers has emerged as the principal alternative to conventional weed management, providing multiple ecosystem services such as enhance biodiversity, but usually with a decrease in yields in Mediterranean vineyards. This long-term study assessed how weed management (herbicide, mowing, tillage) influenced plant community composition, taxonomic diversity and vineyard yield. Plant surveys and grape yield measurements were carried out from 2015 to 2018 in an experiment established in 2008. Effects on plant community composition were analysed, focusing on two groups: noxious grapevine weeds and terophytic grassland species. In addition, three fundamental components of taxonomic diversity were measured: β-diversity, evenness and species richness. Linear mixed models and generalised linear mixed model were used to examine the response of different variables to weed management. Position (row, inter-row) as well as the indirect effect of adjacent management on the subplots were also included as fixed factors. Furthermore, the percentage of bare soil, related to disturbance degree associated with management, was explored as a potential predictor of taxonomic diversity and vineyard yield. Results indicated that plant community composition was affected by weed management and to a lesser extent by position. Noxious grapevine weeds were more abundant in herbicide-sprayed rows, while terophytic grasslands species showed a higher presence in mown subplots. Weed management had a strong effect on bare soil, which proved to be a good predictor of the variables studied. Indeed, the highest species richness were associated with the lowest percentages of bare soil (mown subplots), while the lowest values were found at high percentages of bare soil (tilled subplots). Herbicide showed intermediate values, with a response dependent on adjacent management. On the other hand, vineyard yields were higher with increased bare soil, although with the consequent loss of species richness. Conversely, mowing in spontaneous plant covers caused a decrease in yield, but still production was within the maximum limit established by the Regulatory Council, while increasing the species richness and a significant presence of therophytic grasslands species. These findings could foster the development of more sustainable management in Mediterranean vineyards.

Habitat selection by a predator of rodent pests is resilient to wildfire in a vineyard agroecosystem.

Conservation of uncultivated habitats can increase the potential for ecosystem services in agroecosystems, but these lands are also susceptible to wildfires in the arid western United States. In Napa Valley, California, abundant rodent pests and an interest in integrated pest management have led wine producers to use nest boxes to attract Barn Owls (Tyto furcata) to winegrape vineyards. The viability of this practice as a method to control rodent pests depends heavily on the amount of hunting effort that Barn Owls expend in vineyards, which is known to be influenced by the amount of uncultivated land cover types surrounding the nest box. Wildfires burned nearly 60,000 ha of mainly urban and uncultivated lands surrounding Napa Valley in 2017, altering Barn Owl habitats. We compared GPS tracking data from 32 Barn Owls nesting in 24 individual nest boxes before and after the fires to analyze their hunting habitat selection. Owls with burned areas available to them after the fires had home ranges that shifted toward the fires, but selection was not strongly associated with burned areas. Though there was some spatial use of burned areas, selection of land cover types was similar for birds before and after the fires and in burned and unburned areas. The strongest selection was for areas closest to the nest box, and most recorded locations were in grassland, though selection indicated that owls used land cover types in proportion to their availability. Overall, habitat selection was resilient to changes caused by wildfires. These results are important for farmers who use nest boxes as a means of rodent control, which may be affected after dramatic disturbance events, especially as wildfires increase in the western United States.

Organic soil fertility amendments enhance surface-dwelling beetle diversity in a sub-humid tropical environment under conservation agriculture

ABSTRACT Surface-dwelling beetles offer ecosystem services in agro-ecosystems including biological pest control and organic matter decomposition. This study was conducted to investigate beetle community response to six years of tillage, crop residue application, crop rotation and soil fertility amendments (low fertiliser, high fertiliser, manure, manure + low fertiliser and manure + 60 kg N ha−1) treatments. Reduced tillage increased beetle abundance by 4.6% relative to soil inversion tillage. Crop residue application increased the abundances of Platynus assimilis, Zophosis boei and total beetles by two to three times. Meanwhile, Renatiella reticulata increased by 628.6% in high fertiliser compared to manure + 60 kg N ha−1, manure + low fertiliser and the control. In crop rotation + crop residue retention plots, application of sole manure at 10 t ha−1 increased the Shannon index by 360–365% relative to manure + 60 kg N ha−1 and manure + low fertiliser. Based on the findings in this study, it can be concluded that reduced tillage, retention of crop residues on the soil surface and application of manure increase surface-dwelling beetle abundance and diversity.

Towards an enhanced indication of provisioning ecosystem services in agro-ecosystems

Provisioning ecosystem services play a vital role in sustaining human well-being. Agro-ecosystems contribute a significant share of these services, besides food and fodder and also fuel and fibre as well as regulating and cultural ecosystem services. Until now, the indication of provisioning ecosystem services of agro-ecosystems has been based almost only on yield numbers of agricultural products. Such an indication is problematic due to several reasons which include a disregard of the role of significant anthropogenic contributions to ecosystem service co-generation, external environmental effects and strong dependence on site conditions. We argue for an enhanced indication of provisioning ecosystem services that considers multiple aspects of their delivery. The conceptual base for such an indication has been made by prior publications which have been reviewed. Relevant points were taken up in this article and condensed into a conceptual model in order to develop a more holistic and expanded set of indictors, which was then exemplarily applied and tested in three case studies in Germany. The case studies represent different natural conditions, and the indicator set application showed that ecosystem services (ES) flow—in terms of output alone—does not characterise agro-ecosystems sufficiently. The proposed aspects of provisioning ecosystem services can give a fuller picture, for example, by input-output relationships, as it is possible by just using single indicators. Uncertainties as well as pros and cons of such an approach are elaborated. Finally, recommendations for an enhanced indication of provisioning ecosystem services in agro-ecosystems that can help to integrate agricultural principles with ideas of sustainability and site-specific land use are derived.

Multi‐year nest box occupancy and short‐term resilience to wildfire disturbance by barn owls in a vineyard agroecosystem

AbstractLandscape composition can strongly affect the delivery of ecosystem services in agroecosystems. Conserving uncultivated habitats can support ecosystem services, but in Mediterranean biomes, these lands can also increase the area susceptible to wildfires. In the world‐renowned wine‐producing region of Napa Valley, California, wine grape growers install nest boxes to attract American barn owls (Tyto furcata), which may reduce rodent crop damage. Annual monitoring of 273 nest boxes began in 2015, and devastating wildfires burned approximately 60,000 ha in the region in 2017, including homes and businesses, as well as some vineyards and uncultivated land. The goal of this study was to determine whether changes in nest box occupancy were attributed to wildfires, nest box design, land cover type, or some combination of these variables. Occupancy surveys before and after these wildfires revealed changes in habitat selection at the nest scale. Occupancy increased during the study, reaching its highest point after the fires. Owls were found breeding in recently burned areas that were previously unoccupied and modeling results showed that nest box occupancy had a positive relationship with burned areas, particularly with edges of the fire perimeter. Barn owls also consistently showed a strong preference for taller nest boxes that were surrounded by more grassland than other land cover types and a moderate selection for wooden over plastic boxes. These results illustrate an incentive for the conservation of uncultivated habitat, particularly grassland, in vineyard ecosystems, and they provide an example of a mobile pest predator’s response to wildfire disturbance. In this case, results suggest an agroecosystem service made resilient to wildfire by the owls’ selection of burned and uncultivated habitats.

A two-part modelling approach reveals a positive effect of pollinator biodiversity in boosting the pollination of apple flowers

Pollinator biodiversity may benefit crop pollination. Yet benefits in agro-ecosystems may be context-dependent and offset by agronomic or other limiting orchard-specific or tree-specific factors that obscure biodiversity-ecosystem service relationships. To test if crop pollination benefitted from pollinator biodiversity, we sampled local wild bee communities in five organic and five Integrated Pest Management (IPM) apple orchards in Germany and experimentally measured the pollination success of apple flowers, quantified as the number of pollen tubes reaching the base of styles. Using standard statistical modelling approaches for over-dispersed count data, we found little or no effect of wild bee biodiversity on pollination success, irrespectively of farm management (organic versus IPM). There was, however, a positive relationship between the number of pollen tubes in insect-pollinated and pollen-supplemented flowers across trees and orchards, suggesting confounding effects of local tree- or orchard-specific factors limiting pollination success. Using a statistical two-part hurdle model which allowed us to separate (i) the probability of pollination and (ii) the quantity of pollination, we were able to demonstrate that the collective effects of local tree/orchard factors acted as a primary limiting threshold for pollination success. Once the threshold was crossed, the hurdle model demonstrated that increasing wild bee abundance enhanced pollination success of apple trees. We advocate the use of statistical two-part models as a more powerful approach to identifying limiting factors of, and the role of biodiversity in, crop pollination and potentially other ecosystem services in agro-ecosystems.

Effects of weed biodiversity on the ecosystem service of weed seed predation along a farming intensity gradient

Weed biodiversity plays a key role in supporting food webs and ecosystem services in agroecosystems. One important service, that reduces weed abundance, is the predation of weed seeds by invertebrates and vertebrates. In this context weed biodiversity may be supportive in maintaining seed predator prevalence. This however, can be highly influenced by farming systems. In the present study we examined the connections between weed diversity, carabid beetle diversity and weed seed predation (WSP) rate. Additionally, the influence of a farming intensity gradient on WSP rate and predator groups was evaluated. An on-farm experiment on the Eastern Swabian Alps was set up from 2015 to 2017, where we determined the weed diversity, carabid beetle diversity using pitfall traps and WSP rates and predator groups by utilizing seed cards and exclosure cages. There was a linear correlation between weed diversity and carabid beetle diversity as well as a pattern showing that intermediate diversity of carabid beetles (3–8 species) exhibited the highest WSP rates by invertebrates. However, a direct connection between weed diversity and WSP was not detected. Farming intensity had no consistent influence on WSP, rather year and specific agronomic measures like cover cropping most presumably affected WSP. Carabid beetle communities were similar in 2016 and 2017 with omnivorous species dominating in the conventional fields and granivorous species in extensively managed fields. The most efficient seed predators were vertebrates. The promotion of beneficial predators and ecosystem services like WSP is possible by designing appropriate management strategies. Key components of these strategies should be the conservation of plant diversity and the utilization of weed control strategies such as cover cropping that provide suitable habitats for beneficial predators.

Ecosystem service delivery by cover crop mixtures and monocultures is context dependent

AbstractWhile cover crops and mixtures are increasingly used to provide ecosystem services in agroecosystems, some fundamental questions remain about how cover crop performance and composition vary in different conditions, limiting optimal cover crop use. We conducted a field experiment at a research farm in New York, including a subset of treatments in three working farm fields. We selected two common cover crops, hairy vetch (Vicia villosa Roth), a legume, and common wheat (Triticum aestivum L.), a grass, with multiple cultivars of each. We looked at the effect of cover crop composition spanning intraspecific and grass–legume mixtures on five ecosystem services: cover crop productivity, weed suppression, total biomass nitrogen, soil N retention, and long‐term N supply via legume fixed N. We did not find intraspecific diversity to have an effect on any ecosystem services we measured, nor was that response context dependent. We did observe significant ecosystem service improvements in the grass–legume mixture, though this was context dependent and the performance of the mixture varied relative to the monocultures at different farm sites. Regardless of this interaction however, the grass–legume mixture was as good as or better than either monoculture for all services and sites, except soil N accrual at one site. Consequently, increasing complexity in cover crops through grass–legume mixtures is a low risk practice that may have the potential to deliver ecosystem service outcomes greater than those of monocultures across a range of growing conditions.

Pesticides and land cover heterogeneity affect functional group and taxonomic diversity of arthropods in rice agroecosystems

Biodiversity can be characterised across several dimensions, which are crucial for the evaluation of ecosystem services. Functional diversity, a key aspect of biodiversity, provides a more realistic characterisation of the functioning of ecological communities than only studying their taxonomic diversity. The relevance of functional ecology studies has steadily increased in agroecosystems. However, the combined effects of pesticides and land cover heterogeneity on the taxonomic and functional diversity of arthropod communities have been studied less frequently. We sampled arthropods during the dry season in 19 rice fields located in two different regions of Northern Vietnam. We assorted the arthropods into functional groups corresponding to different feeding habits and calculated the taxonomic and functional group diversities. Finally, we analysed the impacts of pesticide applications and land cover heterogeneity on both diversity measures. Taxonomic and functional group diversity measures were highly correlated. In turn, both diversity measures responded similarly to land cover heterogeneity and pesticides. Land cover heterogeneity had positive effects on taxonomic and functional group diversity, mainly at the early stage of rice crops. Conversely, the impact of pesticide application on both diversity measures was strongly negative. Our results suggest that rice agroecosystems can be more sustainable by increasing landscape heterogeneity and a reduced pesticide use. Such schemes may help to maintain higher levels of biodiversity that ensure ecosystem functioning, which will be therefore likely beneficial to provide ecosystem services in agroecosystems.

CHALLENGES AND TRENDS IN THE VALUATION OF ECOSYSTEM SERVICES IN AGRO-ECOSYSTEMS: A SYSTEMATIC REVISION

<p><strong>Background.</strong> Climate change, the loss of ecosystems, the increase of poverty, the rise of marginality within rural communities and the decrease of food security, are global concerns in need of urgent attention. In this regard, an important number of studies focus on studying the way agro-ecosystems may face such challenges, as they provide ecosystem services (ES), which generate higher levels of resilience, adaptability, productivity and self-sufficiency. Hence, the valuation of ecosystem services plays a relevant role in the decision-making process toward the design and management of agro-ecosystems. Nevertheless, the assignment of value to these ES is usually done exclusively under the economic-monetary dimension, thus leaving other dimensions of value aside. <strong>Objective.</strong> To propose a hierarchical structure of Ecosystem Services assessment that integrates the value dimensions principles and criteria. <strong>Methodology</strong>. The method employed to define the hierarchical structure was a comprehensive literature review the fields of Agroecology and Ecological Economics, based on information search strategy and classification. 182 scientific publications were full paper screened within the period between 2000 and 2017. <strong>Implications.</strong> Outcomes of this work provide a foundation for further discussion of ES assessments and its potential application in agro-ecosystem and specific contexts. <strong>Conclusion.</strong> There is an important number of studies identifying the significance of ES in agroecosystems from different dimensions. Nevertheless, such works do not associate their importance with the value of such services. Therefore, it remains a challenge for research projects to achieve relating their contributions to their multidimensional valuation.</p>

Distribution of ecosystem services within oilseed rape fields: Effects of field defects on pest and weed seed predation rates

Frequent extreme weather events, which jeopardize agriculture by affecting crop health, characterize the ongoing climate change. Temporary patches where sown plants are poorly developed (hereafter “field defects”) are likely to increase with climate change and can be colonized by other plant species. Although perennial non-crop habitats can act as refuges for beneficial insects in agricultural landscapes and increase ecosystem services (ESs) in neighbouring arable fields, the relevance of field defects is unknown. Here, we quantified two ESs (pest and weed seed predation) in field defects within oilseed rape crops and related the ES levels with the activity-density of ground beetles and temperature. In 10 fields, we used artificial caterpillars made of plasticine and seed cards of two weed species (Taraxacum sp. and Stellaria sp.) to quantify the ESs in two sampling periods (spring and summer) and three habitat types: field defects, crops grown in standard conditions (field interiors) and crop-defect boundaries. Ground beetles were sampled using pitfall traps and classified into feeding guilds and body-size classes. Insects and mammals were the main pest predators, and predation increased in summer but did not differ among habitats. Seed predation rates for both species were significantly higher in summer. Predation upon Taraxacum seeds was higher in the field interiors, whereas the predation rate upon Stellaria seeds was significantly higher in the field interiors and defects compared to that in the crop-defect boundaries. The predation rate by insects increased with the activity-density of the medium- and large-sized carnivorous carabids, whereas the seed predation rate for both weed species was positively related to the activity-density of medium-sized herbivorous carabids. Finally, the mean and maximum temperatures were negatively linked to the predation rates on artificial caterpillars and seeds of Taraxacum, respectively. Our results suggest that these ephemeral habitats are not related to a strong decrease in ecosystem services; thus, field defects may not cause substantial changes in ES provisioning. We confirmed that ground beetles are important providers of both investigated ESs and showed that microclimatic conditions might play an important role in the regulation of ESs in agroecosystems.

Trade-offs in the provisioning and stability of ecosystem services in agroecosystems.

Changes in land use generate trade-offs in the delivery of ecosystem services in agricultural landscapes. However, we know little about how the stability of ecosystem services responds to landscape composition, and what ecological mechanisms underlie these trade-offs. Here, we develop a model to investigate the dynamics of three ecosystem services in intensively managed agroecosystems, i.e., pollination-independent crop yield, crop pollination, and biodiversity. Our model reveals trade-offs and synergies imposed by landscape composition that affect not only the magnitude but also the stability of ecosystem service delivery. Trade-offs involving crop pollination are strongly affected by the degree to which crops depend on pollination and by their relative requirement for pollinator densities. We show conditions for crop production to increase with biodiversity and decreasing crop area, reconciling farmers' profitability and biodiversity conservation. Our results further suggest that, for pollination-dependent crops, management strategies that focus on maximizing yield will often overlook its stability. Given that agriculture has become more pollination-dependent over time, it is essential to understand the mechanisms driving these trade-offs to ensure food security.

Facing the gap: exploring research on local knowledge of insect-provided services in agroecosystems

ABSTRACTSustainable agroecosystems must be managed to support biodiversity conservation and food production, which occur at the interface of regional/national policy frameworks, and local knowledge and perspectives. This paper examines the current breadth of research examining farmer knowledge of beneficial insect activities that provide ecosystem services (or benefits) in agroecosystems. We identify patterns and gaps in the literature and opportunities for future research. We found 34 studies that explicitly focused on and documented local knowledge of how insect taxa provided ecosystem services in agroecosystems, the majority of which were immediately observable in farmers’ daily practice: pest control (n = 26), pollination (n = 4). We suggest that there is a need for greater investigation of local knowledge of the breadth of ecosystem services provided by insects and identify key research areas that are opportunities for investigation.

Legume Cover Crops and Tillage Impact Nitrogen Dynamics in Organic Corn Production

Core Ideas Reduced tillage of legume cover crops releases significant amount of N coupled with corn N uptake.Roller crimper termination of legumes releases nitrogen at similar total amounts to disking.Increased experimentation needed to improve corn population and yields in roller crimped stands. Cover cropping and reduced tillage are two management practices that increase ecosystem services in agroecosystems. However, their interactive effects on N dynamics and cash crop yield are underexplored. In this study, four different termination approaches, employing no‐till and tillage, and organic and conventional techniques were used with four winter annual leguminous cover crop species to investigate the combined effect on plant‐available nitrogen (PAN) and subsequent organic corn (Zea mays L.) yield. Termination treatments included roller‐crimping, flail‐mowing, disking, and herbicide application with cover crops of Austrian winter pea (Pisum sativum L. subs. arvense, AWP), hairy vetch (Vicia villosa var. AU Early Cover, HV), balansa clover [Trifolium michelianum Savi ssp. balansae (Boiss.) Ponert, BC] and crimson clover (Trifolium incarnatum var. Dixie, CC). Plant‐available N (NO3− and NH4+) was determined using biweekly soil inorganic N extractions and resin probes. Cover crop biomass, cover crop C/N ratio, and cover crop total N were measured prior to termination. Nitrogen was most available from AWP and HV across termination methods at 6 to 10 wk after termination. Disked HV contributed highest levels of N across all 16 cropping by termination combinations. Highest biomass N was found in HV (226 kg ha−1), followed by AWP (189 kg ha−1) and CC (181 kg ha−1). Corn yield ranged widely, from 0.23 Mg ha−1 in 0 N control to >9 Mg ha−1 in HV and AWP treatments. Cover crop species plays an important role in N dynamics, frequently influencing soil processes to a more significant degree than termination approach.