scholarly journals An energetics-based honeybee nectar-foraging model used to assess the potential for landscape-level pesticide exposure dilution

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2293 ◽  
Author(s):  
Johannes M. Baveco ◽  
Andreas Focks ◽  
Dick Belgers ◽  
Jozef J.M. van der Steen ◽  
Jos J.T.I. Boesten ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Spatial Data ◽  
Pesticide Exposure ◽  
Energetic Efficiency ◽  
Natural Habitats ◽  
Patch Choice ◽  
Nectar Foraging ◽  
Crop Fields ◽  
Resource Patches ◽  
The Impact

Estimating the exposure of honeybees to pesticides on a landscape scale requires models of their spatial foraging behaviour. For this purpose, we developed a mechanistic, energetics-based model for a single day of nectar foraging in complex landscape mosaics. Net energetic efficiency determined resource patch choice. In one version of the model a single optimal patch was selected each hour. In another version, recruitment of foragers was simulated and several patches could be exploited simultaneously. Resource availability changed during the day due to depletion and/or intrinsic properties of the resource (anthesis). The model accounted for the impact of patch distance and size, resource depletion and replenishment, competition with other nectar foragers, and seasonal and diurnal patterns in availability of nectar-providing crops and wild flowers. From the model we derived simple rules for resource patch selection, e.g., for landscapes with mass-flowering crops only, net energetic efficiency would be proportional to the ratio of the energetic content of the nectar divided by distance to the hive. We also determined maximum distances at which resources like oilseed rape and clover were still energetically attractive. We used the model to assess the potential for pesticide exposure dilution in landscapes of different composition and complexity. Dilution means a lower concentration in nectar arriving at the hive compared to the concentration in nectar at a treated field and can result from foraging effort being diverted away from treated fields. Applying the model for all possible hive locations over a large area, distributions of dilution factors were obtained that were characterised by their 90-percentile value. For an area for which detailed spatial data on crops and off-field semi-natural habitats were available, we tested three landscape management scenarios that were expected to lead to exposure dilution: providing alternative resources than the target crop (oilseed rape) in the form of (i) other untreated crop fields, (ii) flower strips of different widths at field edges (off-crop in-field resources), and (iii) resources on off-field (semi-natural) habitats. For both model versions, significant dilution occurred only when alternative resource patches were equal or more attractive than oilseed rape, nearby and numerous and only in case of flower strips and off-field habitats. On an area-base, flower strips were more than one order of magnitude more effective than off-field habitats, the main reason being that flower strips had an optimal location. The two model versions differed in the predicted number of resource patches exploited over the day, but mainly in landscapes with numerous small resource patches. In landscapes consisting of few large resource patches (crop fields) both versions predicted the use of a small number of patches.

scholarly journals An energetics-based honeybee nectar-foraging model used to assess the potential for landscape-level pesticide exposure dilution

2015 ◽  
Author(s):  
Johannes M Baveco ◽  
Andreas Focks ◽  
Dick Belgers ◽  
Jozef JM van der Steen ◽  
Jos JTI Boesten ◽  
...  
Keyword(s):  
Spatial Data ◽  
Pesticide Exposure ◽  
Resource Depletion ◽  
Landscape Scale ◽  
Average Concentration ◽  
Energetic Efficiency ◽  
Patch Selection ◽  
Natural Habitats ◽  
Nectar Foraging ◽  
The Impact

Estimating the exposure of honeybees to pesticides on a landscape scale requires models of their spatial foraging behaviour. For this purpose, we developed a mechanistic, energetics-based model for a single day of nectar foraging in complex landscape mosaics. The hive population was assumed to select the resource patch with highest net energetic efficiency in perfect knowledge of its environment. During the day the optimal patch could change, due to resource depletion or related to the characteristics of the resource (i.e., the period flowers were open and provided nectar). By quantifying foraging costs and yield in terms of energy, we accounted for the impact of field distance and size, the occurrence of resource depletion and the characteristics of the resource type (crops and wild flowers), like seasonal and diurnal patterns in availability.From the model we derived simple rules for resource patch selection, e.g., for landscapes with mass-flowering crops, the net energetic efficiency would be proportional to the ratio of the energetic content of the nectar of the crop divided by distance of crop field to the hive. Also, we determined maximum distances at which resources like oilseed rape and clover could still be energetically attractive.We used the model to assess the potential for pesticide exposure dilution in landscapes of different composition and complexity. Dilution implied a lower average concentration in nectar arriving at the hive, resulting from foraging effort being diverted away from treated fields. Applying the model for all possible hive locations in a landscape, landscape-specific distributions of dilution values were obtained.For a case study area for which detailed spatial data were available, we tested three scenarios that were expected to lead to exposure dilution: the presence of i) equally attractive crop fields in the neighbourhood of a treated field, ii) highly attractive flowers strips of different widths at the edges of treated fields (off-crop in-field resources), and iii) highly attractive resources on off-field (semi-natural) habitats. The results indicated significant dilution at landscape scale only from flowers strips of more than 5 m wide and off-field habitats. On an area-base, flowers strips were approximately 10 times as effective as off-field habitats, the main reason being that the flowers strips had an optimal location, always at the edges of treated fields.

scholarly journals An energetics-based honeybee nectar-foraging model used to assess the potential for landscape-level pesticide exposure dilution

2015 ◽  
Author(s):  
Johannes M Baveco ◽  
Andreas Focks ◽  
Dick Belgers ◽  
Jozef JM van der Steen ◽  
Jos JTI Boesten ◽  
...  
Keyword(s):  
Spatial Data ◽  
Pesticide Exposure ◽  
Resource Depletion ◽  
Landscape Scale ◽  
Average Concentration ◽  
Energetic Efficiency ◽  
Patch Selection ◽  
Natural Habitats ◽  
Nectar Foraging ◽  
The Impact

Estimating the exposure of honeybees to pesticides on a landscape scale requires models of their spatial foraging behaviour. For this purpose, we developed a mechanistic, energetics-based model for a single day of nectar foraging in complex landscape mosaics. The hive population was assumed to select the resource patch with highest net energetic efficiency in perfect knowledge of its environment. During the day the optimal patch could change, due to resource depletion or related to the characteristics of the resource (i.e., the period flowers were open and provided nectar). By quantifying foraging costs and yield in terms of energy, we accounted for the impact of field distance and size, the occurrence of resource depletion and the characteristics of the resource type (crops and wild flowers), like seasonal and diurnal patterns in availability.From the model we derived simple rules for resource patch selection, e.g., for landscapes with mass-flowering crops, the net energetic efficiency would be proportional to the ratio of the energetic content of the nectar of the crop divided by distance of crop field to the hive. Also, we determined maximum distances at which resources like oilseed rape and clover could still be energetically attractive.We used the model to assess the potential for pesticide exposure dilution in landscapes of different composition and complexity. Dilution implied a lower average concentration in nectar arriving at the hive, resulting from foraging effort being diverted away from treated fields. Applying the model for all possible hive locations in a landscape, landscape-specific distributions of dilution values were obtained.For a case study area for which detailed spatial data were available, we tested three scenarios that were expected to lead to exposure dilution: the presence of i) equally attractive crop fields in the neighbourhood of a treated field, ii) highly attractive flowers strips of different widths at the edges of treated fields (off-crop in-field resources), and iii) highly attractive resources on off-field (semi-natural) habitats. The results indicated significant dilution at landscape scale only from flowers strips of more than 5 m wide and off-field habitats. On an area-base, flowers strips were approximately 10 times as effective as off-field habitats, the main reason being that the flowers strips had an optimal location, always at the edges of treated fields.

scholarly journals Aphid–Plant–Phytovirus Pathosystems: Influencing Factors from Vector Behaviour to Virus Spread

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 502
Author(s):  
Junior Corneille Fingu-Mabola ◽  
Frédéric Francis
Keyword(s):  
Influencing Factors ◽  
Virus Transmission ◽  
Physical Factors ◽  
Factors Affecting ◽  
Vector Borne Diseases ◽  
Vector Behaviour ◽  
Crop Fields ◽  
Host Seeking ◽  
The Impact ◽  
Vector Efficiency

Aphids are responsible for the spread of more than half of the known phytovirus species. Virus transmission within the plant–aphid–phytovirus pathosystem depends on vector mobility which allows the aphid to reach its host plant and on vector efficiency in terms of ability to transmit phytoviruses. However, several other factors can influence the phytoviruses transmission process and have significant epidemiological consequences. In this review, we aimed to analyse the aphid behaviours and influencing factors affecting phytovirus spread. We discussed the impact of vector host-seeking and dispersal behaviours mostly involved in aphid-born phytovirus spread but also the effect of feeding behaviours and life history traits involved in plant–aphid–phytovirus relationships on vector performances. We also noted that these behaviours are influenced by factors inherent to the interactions between pathosystem components (mode of transmission of phytoviruses, vector efficiency, plant resistance, …) and several biological, biochemical, chemical or physical factors related to the environment of these pathosystem components, most of them being manipulated as means to control vector-borne diseases in the crop fields.

scholarly journals Assessing Habitat Vulnerability and Loss of Naturalness: Applying the GLOBIO3 Model in the Czech Republic

2021 ◽  
Vol 13 (10) ◽  
pp. 5355
Author(s):  
Vilém Pechanec ◽  
Ondřej Cudlín ◽  
Miloš Zapletal ◽  
Jan Purkyt ◽  
Lenka Štěrbová ◽  
...  
Keyword(s):  
Land Use ◽  
Czech Republic ◽  
Habitat Quality ◽  
Species Abundance ◽  
Biodiversity Loss ◽  
Infrastructure Development ◽  
Natural Habitats ◽  
The Czech Republic ◽  
New Equation ◽  
The Impact

Global and regional biodiversity loss is caused by several drivers including urban development, land use intensification, overexploitation of natural resources, environmental pollution, and climate change. The main aim of our study was to adapt the GLOBIO3 model to the conditions of the Czech Republic (CR) to assess loss of naturalness and biodiversity vulnerability at the habitat level on a detailed scale across the entire CR. An additional aim was to assess the main drivers affecting the biodiversity of habitat types. The GLOBIO3 model was adapted to CZ-GLOBIO by adapting global to local scales and using habitat quality and naturalness data instead of species occurrence data. The total mean species abundance (MSA) index of habitat quality, calculated from the spatial overlay of the four MSA indicators by our new equation, reached the value 0.62. The total value of MSA for natural and near-natural habitats was found to be affected mainly by infrastructure development and fragmentation. Simultaneously, intensity of land use change and atmospheric nitrogen deposition contributed primarily to the low total value of MSA for distant natural habitats. The CZ-GLOBIO model can be an important tool in political decision making to reduce the impact of the main drivers on habitat biodiversity in the CR.

scholarly journals Sublethal concentrations of clothianidin affect honey bee colony growth and hive CO2 concentration

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
William G. Meikle ◽  
John J. Adamczyk ◽  
Milagra Weiss ◽  
Janie Ross ◽  
Chris Werle ◽  
...  
Keyword(s):  
Honey Bee ◽  
Pesticide Exposure ◽  
Co2 Concentration ◽  
Colony Growth ◽  
Control Group ◽  
Brood Production ◽  
Weight Losses ◽  
Bee Colony ◽  
The Impact ◽  
Bee Colonies

AbstractThe effects of agricultural pesticide exposure upon honey bee colonies is of increasing interest to beekeepers and researchers, and the impact of neonicotinoid pesticides in particular has come under intense scrutiny. To explore potential colony-level effects of a neonicotinoid pesticide at field-relevant concentrations, honey bee colonies were fed 5- and 20-ppb concentrations of clothianidin in sugar syrup while control colonies were fed unadulterated syrup. Two experiments were conducted in successive years at the same site in southern Arizona, and one in the high rainfall environment of Mississippi. Across all three experiments, adult bee masses were about 21% lower among colonies fed 20-ppb clothianidin than the untreated control group, but no effects of treatment on brood production were observed. Average daily hive weight losses per day in the 5-ppb clothianidin colonies were about 39% lower post-treatment than in the 20-ppb clothianidin colonies, indicating lower consumption and/or better foraging, but the dry weights of newly-emerged adult bees were on average 6–7% lower in the 5-ppb group compared to the other groups, suggesting a nutritional problem in the 5-ppb group. Internal hive CO2 concentration was higher on average in colonies fed 20-ppb clothianidin, which could have resulted from greater CO2 production and/or reduced ventilating activity. Hive temperature average and daily variability were not affected by clothianidin exposure but did differ significantly among trials. Clothianidin was found to be, like imidacloprid, highly stable in honey in the hive environment over several months.

scholarly journals Leveraging Road Characteristics and Contributor Behaviour for Assessing Road Type Quality in OSM

2021 ◽  
Vol 10 (7) ◽  
pp. 436
Author(s):  
Amerah Alghanim ◽  
Musfira Jilani ◽  
Michela Bertolotto ◽  
Gavin McArdle
Keyword(s):  
Machine Learning ◽  
Spatial Data ◽  
Classification Accuracy ◽  
Supervised Machine Learning ◽  
Machine Learning Techniques ◽  
Data Set ◽  
Semantic Inference ◽  
Road Type ◽  
The Impact

Volunteered Geographic Information (VGI) is often collected by non-expert users. This raises concerns about the quality and veracity of such data. There has been much effort to understand and quantify the quality of VGI. Extrinsic measures which compare VGI to authoritative data sources such as National Mapping Agencies are common but the cost and slow update frequency of such data hinder the task. On the other hand, intrinsic measures which compare the data to heuristics or models built from the VGI data are becoming increasingly popular. Supervised machine learning techniques are particularly suitable for intrinsic measures of quality where they can infer and predict the properties of spatial data. In this article we are interested in assessing the quality of semantic information, such as the road type, associated with data in OpenStreetMap (OSM). We have developed a machine learning approach which utilises new intrinsic input features collected from the VGI dataset. Specifically, using our proposed novel approach we obtained an average classification accuracy of 84.12%. This result outperforms existing techniques on the same semantic inference task. The trustworthiness of the data used for developing and training machine learning models is important. To address this issue we have also developed a new measure for this using direct and indirect characteristics of OSM data such as its edit history along with an assessment of the users who contributed the data. An evaluation of the impact of data determined to be trustworthy within the machine learning model shows that the trusted data collected with the new approach improves the prediction accuracy of our machine learning technique. Specifically, our results demonstrate that the classification accuracy of our developed model is 87.75% when applied to a trusted dataset and 57.98% when applied to an untrusted dataset. Consequently, such results can be used to assess the quality of OSM and suggest improvements to the data set.

scholarly journals Econometric Analysis of the Impact of Propensities on Economic Occurrences: A Macroeconomic Perspective

2012 ◽  
Vol 10 (2) ◽  
pp. 138-154 ◽  
Author(s):  
Mariusz Doszyń
Keyword(s):  
Spatial Data ◽  
Fixed Effects ◽  
Classical Model ◽  
Econometric Analysis ◽  
Dummy Variables ◽  
Macroeconomic Variables ◽  
Current State ◽  
Famous Book ◽  
Direct Models ◽  
The Impact

Econometric Analysis of the Impact of Propensities on Economic Occurrences: A Macroeconomic PerspectiveThe main aim of this article was the specification of problems connected with analysis of impact of human propensities on economic occurrences and also a proposition of econometric tools enabling the identification of this impact. According to the meaning of propensities in economics the current state of knowledge is mostly an effect of considerations presented by J.M. Keynes in his famous book "The General Theory of Employment, Interest and Money" where J.M. Keynes proposed such economic categories as the average and marginal propensities. One of the goals of the presented deliberations was to specify problems related with economic theory of propensities. Such propensities as a propensity to consume, to save, to invest and thesaurisation were particularly carefully analysed. The impact of these propensities on basic macroeconomic variables was considered with respect to the classical model, the neoclassical Solow-Swan model and theIS-LMscheme. In case of spatial data the effects of the impact of propensities could be analysed by means of models with dummy variables showing presence of given propensities. A procedure enabling the construction of such variables was proposed. In case of time series, conceptions delivered by the integration and cointegration theory could be applied. Especially such models as VAR and VECM could be useful. Models for panel data enable direct (models with fixed effects) or indirect (models with random effects) consideration of the impact of propensities on the analysed processes.

scholarly journals Relationship between Prenatal or Postnatal Exposure to Pesticides and Obesity: A Systematic Review

2021 ◽  
Vol 18 (13) ◽  
pp. 7170
Author(s):  
Helena Pinos ◽  
Beatriz Carrillo ◽  
Ana Merchán ◽  
Judit Biosca-Brull ◽  
Cristian Pérez-Fernández ◽  
...  
Keyword(s):  
Systematic Review ◽  
Body Weight ◽  
Weight Control ◽  
Animal Studies ◽  
Pesticide Exposure ◽  
Endocrine Disrupting Chemicals ◽  
Overweight And Obesity ◽  
Postnatal Exposure ◽  
Body Weight Control ◽  
The Impact

In recent years, the worldwide prevalence of overweight and obesity among adults and children has dramatically increased. The conventional model regarding the onset of obesity is based on an imbalance between energy intake and expenditure. However, other possible environmental factors involved, such as the exposure to chemicals like pesticides, cannot be discarded. These compounds could act as endocrine-disrupting chemicals (EDC) that may interfere with hormone activity related to several mechanisms involved in body weight control. The main objective of this study was to systematically review the data provided in the scientific literature for a possible association between prenatal and postnatal exposure to pesticides and obesity in offspring. A total of 25 human and 9 animal studies were analyzed. The prenatal, perinatal, and postnatal exposure to organophosphate, organochlorine, pyrethroid, neonicotinoid, and carbamate, as well as a combined pesticide exposure was reviewed. This systematic review reveals that the effects of pesticide exposure on body weight are mostly inconclusive, finding conflicting results in both humans and experimental animals. The outcomes reviewed are dependent on many factors, including dosage and route of administration, species, sex, and treatment duration. More research is needed to effectively evaluate the impact of the combined effects of different pesticides on human health.

scholarly journals Invasive Scots Pine, Pinus sylvestris, Replacing Corema, Corema conradii, Heathland in the Annapolis Valley, Nova Scotia

2005 ◽  
Vol 119 (2) ◽  
pp. 237 ◽  
Author(s):  
Paul M. Catling ◽  
Susan Carbyn
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Vascular Plants ◽  
Dominant Species ◽  
Vascular Plant ◽  
Agricultural Crops ◽  
Deschampsia Flexuosa ◽  
Natural Habitats ◽  
Annapolis Valley ◽  
The Impact

Examination of air photos from 1930, 1970 and 2002 revealed stands of the European Scots Pine (Pinus sylvestris) invading remnants of natural Corema (Corema conradii) heathland in the Annapolis valley. To document the impact of the introduced pines, four natural habitats were compared with two adjacent habitats already invaded by the pines. All surveyed habitats had been dominated by Corema heath based on air photos taken in 1930. Twenty 1 m2 quadrats were used to record presence and cover of vascular plants at each site. The invasive alien pines reduce the native cover to 12%. Vascular plant biodiversity is reduced to less than 42% and the cover of the heathland dominant, Corema conradii, is reduced from over 100 % to less than 2%. with Deschampsia flexuosa becoming the dominant species. The modified ecosystem and loss of biodiversity has economic impacts through loss of pollinators of agricultural crops and loss of germplasm of native crop relatives.

scholarly journals USING PROPENSITY SCORE MATCHING METHOD TO ESTIMATE THE IMPACT OF VIETGAP PROGRAM ON THE HEALTH OF FARMERS IN THUA THIEN HUE PROVINCE, VIETNAM

2017 ◽  
Vol 126 (5B) ◽  
pp. 17
Author(s):  
Trần Huỳnh Bảo Châu
Keyword(s):  
Health Status ◽  
Propensity Score ◽  
Propensity Score Matching ◽  
Pesticide Exposure ◽  
Agricultural Practices ◽  
Health Problems ◽  
Vegetable Production ◽  
Matching Method ◽  
Environment Friendly ◽  
The Impact

<p><strong>Abstract:</strong></p><p>This study estimates the impact value of the VietGAP program when applied to vegetable production on the health of farmers in Thua Thien Hue province. By employing the propensity score matching (PSM) method, our findings show that the VietGAP program has a significant impact on farmers’ health. In particular, the program reduces farmers’ health problems due to pesticide exposure by 15.6 %, 22.9 %, 25.5 %, and 23.6 %, respectively, from four types of matching. This study provides evidence of the positive impacts of the VietGAP program on the health status of farmers in Thua Thien Hue province. It is therefore hoped that the production, consumption, and management solutions provided by the VietGAP program can encourage farmers to use environment-friendly agricultural practices.</p><p><strong>Keywords: </strong>propensity score matching (PSM) method, VietGAP program, farmers’ health</p>

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