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No negative effects of boat sound playbacks on olfactory-mediated food finding behaviour of shore crabs in a T-maze
2021
Hubert, J. | van Bemmelen, J.J. | Slabbekoorn, H.
Anthropogenic noise underwater is increasingly recognized as a pollutant for marine ecology, as marine life often relies on sound for orientation and communication. However, noise may not only interfere with processes mediated through sound, but also have effects across sensory modalities. To understand the mechanisms of the impact of anthropogenic sound to its full extent, we also need to study cross-sensory interference. To study this, we examined the effect of boat sound playbacks on olfactory-mediated food finding behaviour of shore crabs. We utilized opaque T-mazes with a consistent water flow from both ends towards the starting zone, while one end contained a dead food item. In this way, there were no visual or auditory cues and crabs could only find the food based on olfaction. We did not find an overall effect of boat sound on food finding success, foraging duration or walking distance. However, after excluding deviant data from one out of the six different boat stimuli, we found that crabs were faster to reach the food during boat sound playbacks. These results, with and without the deviant data, seem to contradict an earlier field study in which fewer crabs aggregated around a food source during elevated noise levels. We hypothesise that this difference could be explained by a difference in hunger level, with the current T-maze crabs being hungrier than the free-ranging crabs. Hunger level may affect the motivation to find food and the decision to avoid or take risks, but further research is needed to test this. In conclusion, we did not find unequivocal evidence for a negative impact of boat sound on the processing or use of olfactory cues. Nevertheless, the distinct pattern warrants follow up and calls for even larger replicate samples of acoustic stimuli for noise exposure experiments.
Afficher plus [+] Moins [-]When ambient noise impairs parent-offspring communication
2016
Lucass, Carsten | Eens, Marcel | Müller, Wendt
Ambient noise has increased in extent, duration and intensity with significant implications for species’ lives. Birds especially, because they heavily rely on vocal communication, are highly sensitive towards noise pollution. Noise can impair the quality of a territory or hamper the transmission of vocal signals such as song. The latter has significant fitness consequences as it may erode partner preferences in the context of mate choice. Additional fitness costs may arise if noise masks communication between soliciting offspring and providing parents during the period of parental care. Here, we experimentally manipulated the acoustic environment of blue tit (Cyanistes caeruleus) families within their nest boxes with playbacks of previously recorded highway noise and investigated the consequences on parent-offspring communication. We hypothesized that noise interferes with the acoustic cues of parental arrival and vocal components of offspring begging. As such we expected an increase in the frequency of missed detections, when nestlings fail to respond to the returning parent, and a decrease in parental provisioning rates. Parents significantly reduced their rate of provisioning in noisy conditions compared to a control treatment. This reduction is likely to be the consequence of a parental misinterpretation of the offspring hunger level, as we found that nestlings fail to respond to the returning parent more frequently in the presence of noise. Noise also potentially masks vocal begging components, again contributing to parental underestimation of offspring requirements. Either way, it appears that noise impaired parent-offspring communication is likely to reduce reproductive success.
Afficher plus [+] Moins [-]A common fungicide, Pristine®, impairs olfactory associative learning performance in honey bees (Apis mellifera)
2021
DesJardins, Nicole S. | Fisher, Adrian | Ozturk, Cahit | Fewell, Jennifer H. | DeGrandi-Hoffman, Gloria | Harrison, Jon F. | Smith, Brian H.
Although fungicides were previously considered to be safe for important agricultural pollinators such as honey bees, recent evidence has shown that they can cause a number of behavioral and physiological sublethal effects. Here, we focus on the fungicide Pristine® (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin), which is sprayed during the blooming period on a variety of crops and is known to affect honey bee mitochondria at field-relevant levels. To date, no study has tested the effects of a field-relevant concentration of a fungicide on associative learning ability in honey bees. We tested whether chronic, colony-level exposure at field-relevant and higher concentrations of Pristine® impairs performance on the proboscis extension reflex (PER) paradigm, an associative learning task. Learning performance was reduced at higher field-relevant concentrations of Pristine®. The reductions in learning performance could not be explained by effects on hunger or motivation, as sucrose responsiveness was not affected by Pristine® exposure. To determine whether Pristine®‘s negative effects on learning performance were mediated at a specific life stage, we conducted a cross-fostering experiment that exposed bees to the fungicide either only as larvae, only as adults, or during both stages. We found that exposure across the entire life was necessary to significantly reduce learning performance, although non-significant reductions occurred when bees were exposed during just one stage. Our study provides strong evidence that Pristine® has significant sublethal effects on learning performance. As associative learning is a necessary ability for foraging, our results raise concerns that Pristine® could impair foraging abilities and substantially weaken colony health.
Afficher plus [+] Moins [-]Investigating food insecurity, health and environment-related factors, and agricultural commercialization in Southwestern Nigeria: evidence from smallholder farming households
2022
Otekunrin, Olutosin Ademola
Hunger and food insecurity remained some of the serious challenges facing our world in present time with great concerns from Sub-Saharan Africa especially countries like Nigeria. This study investigates food insecurity (FI), health and environment-related factors, and agricultural commercialization among smallholder farm households. This study was conducted in Southwestern Nigeria utilizing cross-sectional survey data from 352 farm households and employed multi-stage sampling procedure. The household FI levels was determined using food insecurity access scale (HFIAS), crop commercialization index (CCI) was used to compute each household’s CCI (four levels), while ordered logit model was used to analyse factors influencing FI. Health and environment-related factors’ access were assessed across each FI category. The results indicated that about 13% of cassava farm households are non-participant in the marketing of their produce. The findings revealed that less than 20%, 30%. and 40% of households in all four FI categories had access to piped water, improved toilet facilities, and electricity respectively. The ordered logit regression analysis indicated that age, gender, education level, farm experience, nonfarm income, and ownership of motorcycle significantly influencing FI in the study areas. Therefore, this study stressed the implementation of policy actions capable of promoting rural infrastructure development that will lead to increased agricultural production, marketing, and improved quality of life of rural dwellers.
Afficher plus [+] Moins [-]Does agricultural ecosystem cause environmental pollution in Pakistan? Promise and menace
2018
Ullah, Arif | Khan, Dilawar | Khan, Imran | Zheng, Shaofeng
The increasing trend of atmospheric carbon dioxide (CO₂) is the main cause of harmful anthropogenic greenhouse gas emissions, which may result in environmental pollution, global warming, and climate change. These issues are expected to adversely affect the agricultural ecosystem and well-being of the society. In order to minimize food insecurity and prevent hunger, a timely adaptation is desirable to reduce potential losses and to seek alternatives for promoting a global knowledge system for agricultural sustainability. This paper examines the causal relationship between agricultural ecosystem and CO₂ emissions as an environmental pollution indicator in Pakistan from the period 1972 to 2014 by employing Johansen cointegration, autoregressive distributed lag (ARDL) model, and Granger causality approach. The Johansen cointegration results show that there is a significant long-run relationship between the agricultural ecosystem and the CO₂ emissions. The long-run relationship shows that a 1% increase in biomass burned crop residues, emissions of CO₂ equivalent of nitrous oxide (N₂O) from synthetic fertilizers, stock of livestock, agricultural machinery, cereal production, and other crop productions will increase CO₂ emissions by 1.29, 0.05, 0.45, 0.05, 0.03, and 0.65%, respectively. Further, our finding detects that there is a bidirectional causality of CO₂ emissions with rice area paddy harvested, cereal production, and other crop productions. The impulse response function analysis displays that biomass-burned crop residues, stock of livestock, agriculture machinery, cereal production, and other crop productions are significantly contributing to CO₂ emissions in Pakistan.
Afficher plus [+] Moins [-]The causal nexus between carbon dioxide emissions and agricultural ecosystem—an econometric approach
2017
Asumadu-Sarkodie, Samuel | Owusu, Phebe Asantewaa
Achieving a long-term food security and preventing hunger include a better nutrition through sustainable systems of production, distribution, and consumption. Nonetheless, the quest for an alternative to increasing global food supply to meet the growing demand has led to the use of poor agricultural practices that promote climate change. Given the contribution of the agricultural ecosystem towards greenhouse gas (GHG) emissions, this study investigated the causal nexus between carbon dioxide emissions and agricultural ecosystem by employing a data spanning from 1961 to 2012. Evidence from long-run elasticity shows that a 1 % increase in the area of rice paddy harvested will increase carbon dioxide emissions by 1.49 %, a 1 % increase in biomass-burned crop residues will increase carbon dioxide emissions by 1.00 %, a 1 % increase in cereal production will increase carbon dioxide emissions by 1.38 %, and a 1 % increase in agricultural machinery will decrease carbon dioxide emissions by 0.09 % in the long run. There was a bidirectional causality between carbon dioxide emissions, cereal production, and biomass-burned crop residues. The Granger causality shows that the agricultural ecosystem in Ghana is sensitive to climate change vulnerability.
Afficher plus [+] Moins [-]Yield gap analysis of major food crops in Pakistan: prospects for food security
2021
Khan, Imran | Lei, Hongdou | Khan, Ahmad | Muhammad, Ihsan | Javeed, Tehseen | Khan, Asif | Huo, Xuexi
The concept of yield gap analysis can be used to meet the growing demands for agricultural products. Sustainable development goals (e.g. SDG1 and SDG2) to end poverty and hunger require sustainable increases in agricultural production in developing countries, particularly in South Asia and Africa. The aim of this paper is to assess the spatial heterogeneity of the potential and actual yields of major food crops and to determine the yield gaps at the provincial and national levels in Pakistan. The regional test yields of the registered cultivars were used to determine the potential grain yields and total potential grain production levels in each province of Pakistan. The yield gaps were then calculated by comparing the potential and actual yields of the selected major food crops. With a substantial exploitation rate of 0.38 in total grain production, a significant potential gap was found at the national level. The results revealed that the national potential of total grain production is 100,933 Mg, and the actual national grain production from 2015 to 2016 was 38,227 Mg, with a production gap of 62,706 Mg. The results further revealed that the maize crop had the highest potential gap on a national basis, followed by wheat and rice. Meanwhile, on provincial basis, the total production gaps of Punjab, Sindh, Khyber Pakhtunkhwa and Balochistan are 43,776 Mg, 9649.3 Mg, 6772.1 Mg and 2510.7 Mg, respectively. Moreover, based on climate, temperature, rainfall and topography, the yield gaps varied from crop to crop and from province to province. To increase grain yields and close the yield gaps of the major crops, the farmland infrastructure should be strengthened and resource allocations should be optimized. The findings of this study can provide conclusive data for national grain production, protection and food security.
Afficher plus [+] Moins [-]Causal relationship between agricultural production and carbon dioxide emissions in selected emerging economies
2018
Appiah, Kingsley | Du, Jianguo | Poku, John
Continuous threat posed by climate change caused by carbon dioxide emission has reignited global advocacy to confront its negative ramification with the greatest possible firmness. Global food security and agriculture face major challenges under climate change as a result of the potential negative effect of production and implementation of sectoral action to limit global warming. Overall, agricultural greenhouse emissions continue to rise and the analysis of superior data on emissions from farming, livestock, and fisheries can help countries identify opportunities to contemporaneously reduce emissions and address their food security. This study seeks to contribute to the recent literature by examining the causal relationship between agriculture production and carbon dioxide emissions in selected emerging economies for the period 1971 to 2013. The study, therefore, disaggregated agriculture production into crop production index and livestock production index to explicate the distinct and to find individual variable contribution to carbon dioxide emissions. By using FMOLS and DOLS, empirical results indicate that 1% increase in economic growth, crop production index, and livestock production index will cause a proportional increase in carbon dioxide emission by 17%, 28%, and 28% correspondingly, while 1% increase in energy consumption and population improves the environment of emerging economies. The direction of causality among the variables was, accordingly, examined using PMG estimator. Potentially, for emerging countries to achieve Sustainable Development Goal of ensuring zero hunger for their citizenry requires the need to alter their farming production techniques and also adopt agricultural technology method, which is more environmentally friendly.
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