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Aquatic subsidies transport anthropogenic nitrogen to riparian spiders
2011
Akamatsu, Fumikazu | Toda, Hideshige
Stable nitrogen isotopic composition (δ¹⁵N) of aquatic biota increases with anthropogenic N inputs such as sewage and livestock waste downstream. Increase in δ¹⁵N of riparian spiders downstream may reflect the anthropogenic pollution exposure through predation on aquatic insects. A two-source mixing model based on stable carbon isotopic composition showed the greatest dependence on aquatic insects (84%) by horizontal web-building spiders, followed by intermediate (48%) and low (31%) dependence by cursorial and vertical web-building spiders, respectively. The spider body size was negatively correlated with the dietary proportion of aquatic insects and spider δ¹⁵N. The aquatic subsidies transported anthropogenic N to smaller riparian spiders downstream. This transport of anthropogenic N was regulated by spider’s guild designation and body size.
Mostrar más [+] Menos [-]Driving factors of total-factor substitution efficiency of chemical fertilizer input and related environmental regulation policy: A case study of Zhejiang Province
2020
Yang, Jianhui | Lin, Yaoben
Based on the panel data of 63 counties of Zhejiang Province from 2003 to 2017, this paper studied the total-factor substitution efficiency of chemical fertilizer input and its spatial-temporal evolution by using the Super-efficiency DEA(Data Envelopment Analysis) model, locational Gini coefficient and Theil index. And the driving factors of the total-factor substitution efficiency of chemical fertilizer input were analyzed by constructing the Panel Tobit model. The results showed that: the comprehensive efficiency of total-factor substitution for chemical fertilizer input in Zhejiang Province is low, and technical efficiency is the main drive for promoting comprehensive efficiency; Gini coefficient is below the warning line of 0.4, and the difference of substitution efficiency, relatively small, mainly comes from the contribution within the region, and the difference ratio of contribution by the Southwestern Zhejiang is rapidly increasing. In detail, financial investment in agriculture serve as the greatest the driving force, and government chemical fertilizer input subsidies have a significantly negative effect. Therefore, we should improve the subsidy policy system, increase government investment in agricultural infrastructure, adjust the structure of agroindustry and improve the income of rural residents under the premise of reducing the fertilizer input intensity.
Mostrar más [+] Menos [-]Indoor PM2.5 in an urban zone with heavy wood smoke pollution: The case of Temuco, Chile
2018
Jorquera, Héctor | Barraza, Francisco | Heyer, Johanna | Valdivia, Gonzalo | Schiappacasse, Luis N. | Montoya, Lupita D.
Temuco is a mid-size city representative of severe wood smoke pollution in southern Chile; however, little is known about the indoor air quality in this region. A field measurement campaign at 63 households in the Temuco urban area was conducted in winter 2014 and is reported here. In this study, indoor and outdoor (24-hr) PM2.5 and its elemental composition were measured and compared. Infiltration parameters and outdoor/indoor contributions to indoor PM2.5 were also determined. A statistical evaluation of how various air quality interventions and household features influence indoor PM2.5 was also performed.This study determined median indoor and outdoor PM2.5 concentrations of 44.4 and 41.8 μg/m3, respectively. An average infiltration factor (0.62 ± 0.06) was estimated using sulfur as a tracer species. Using a simple mass balance approach, median indoor and outdoor contributions to indoor PM2.5 concentrations were then estimated as 12.5 and 26.5 μg/m3, respectively; therefore, 68% of indoor PM2.5 comes from outdoor infiltration. This high percentage is due to high outdoor pollution and relatively high household air exchange rates (median: 1.06 h−1).This study found that S, Br and Rb were dominated by outdoor contributions, while Si, Ca, Ti, Fe and As originated from indoor sources. Using continuous indoor and outdoor PM2.5 measurements, a median indoor source strength of 75 μg PM2.5/min was estimated for the diurnal period, similar to literature results. For the evening period, the median estimate rose to 135 μg PM2.5/min, reflecting a more intense wood burning associated to cooking and space heating at night.Statistical test results (at the 90% confidence level) support the ongoing woodstove replacement program (reducing emissions) and household weatherization subsidies (reducing heating demand) for improving indoor air quality in southern Chile, and suggest that a cookstove improvement program might be helpful as well.
Mostrar más [+] Menos [-]Thiacloprid affects trophic interaction between gammarids and mayflies
2012
Englert, D. | Bundschuh, M. | Schulz, R.
Neonicotinoid insecticides like thiacloprid enter agricultural surface waters, where they may affect predator–prey-interactions, which are of central importance for ecosystems as well as the functions these systems provide. The effects of field relevant thiacloprid concentrations on the leaf consumption of Gammarus fossarum (Amphipoda) were assessed over 96 h (n = 13–17) in conjunction with its predation on Baetis rhodani (Ephemeroptera) nymphs. The predation by Gammarus increased significantly at 0.50–1.00 μg/L. Simultaneously, its leaf consumption decreased with increasing thiacloprid concentration. As a consequence of the increased predation at 1.00 μg/L, gammarids' dry weight rose significantly by 15% compared to the control. At 4.00 μg/L, the reduced leaf consumption was not compensated by an increase in predation causing a significantly reduced dry weight of Gammarus (∼20%). These results may finally suggest that thiacloprid adversely affects trophic interactions, potentially translating into alterations in ecosystem functions, like leaf litter breakdown and aquatic-terrestrial subsidies.
Mostrar más [+] Menos [-]Gull-derived trace elements trigger small-scale contamination in a remote Mediterranean nature reserve
2013
Signa, Geraldina | Mazzola, Antonio | Tramati, Cecilia Doriana | Vizzini, Salvatrice
The role of a yellow-legged gull (Larus michahellis) small colony in conveying trace elements (As, Cd, Cr, Cu, Ni, Pb, THg, V, Zn) was assessed in a Mediterranean nature reserve (Marinello ponds) at various spatial and temporal scales. Trace element concentrations in guano were high and seasonally variable. In contrast, contamination in the ponds was not influenced by season but showed strong spatial variability among ponds, according to the different guano input. Biogenic enrichment factor B confirmed the role of gulls in the release of trace elements through guano subsidies. In addition, comparing trace element pond concentrations to the US NOAA’s SQGs, As, Cu and Ni showed contamination levels associated with possible negative biological effects. Thus, this study reflects the need to take seabirds into account as key factors influencing ecological processes and contamination levels even in remote areas, especially around the Mediterranean, where these birds are abundant but overlooked.
Mostrar más [+] Menos [-]Dispersal and assimilation of an aquaculture waste subsidy in a low productivity coastal environment
2017
White, C.A. | Nichols, P.D. | Ross, D.J. | Dempster, T.
To understand dispersal and assimilation of aquaculture waste subsidies in a naturally low-productivity environment, we applied a novel, rapid transmethylation technique to analyse sediment and biota fatty acid composition. This technique was initially validated at Atlantic salmon farms in Macquarie Harbour, Australia, where sediments were collected at farm and control locations. Subsequently, sediment, benthic polychaete and zooplankton were sampled at sites 0, 50, 250, 500 and 1000m distant from multiple cages. Results demonstrated an acute deposition zone up to 50m from cages and a diffuse zone extending 500m from cages. Changes in sediment concentration of linoleic acid, oleic acid and total fatty acids were effective tracers of farm deposition. Bacterial biomarkers indicated that aquaculture waste stimulates bacterial productivity in sediments, with elevated biomarker concentrations also detected in benthic polychaetes. Overall, fatty acid analysis was a sensitive technique to characterize the benthic footprint of aquaculture influence.
Mostrar más [+] Menos [-]Policies and instruments for reducing nitrogen oxide emissions from stationary sources in the Netherlands
1998
Jonge, L. de (Ministry of Housing, Spatial Planning and the Environment, The Hague (Netherlands))
Uncovering the driving forces of carbon dioxide emissions in Chinese manufacturing industry: An intersectoral analysis
2019
Shi, Yingying | Han, Botang | Zafar, Muhammad Wasif | Wei, Zixiang
As the pillar of national economy, manufacturing industry is the largest primary energy consumer and emitter of carbon dioxide (CO₂) in China. Therefore, capturing the determinants of CO₂ emissions in manufacturing industry is extremely important for national efforts to mitigate carbon emissions. This paper explores the major driving forces behind CO₂ emission changes in China’s manufacturing industry during 2000–2015 from perspectives of the whole sector and 28 subsectors, by applying the temporal logarithmic mean Divisia index (LMDI) method. Moreover, an intersectoral LMDI model is built to uncover the intersectoral discrepancies of CO₂ emissions among 28 subsectors. The temporal analysis indicates that industrial activity and energy intensity are crucial factors respectively contributing to the increase and mitigation of CO₂ emissions. The intersectoral analysis reveals that energy intensity is the dominant factor responsible for the intersectoral discrepancies of CO₂ emissions among 28 subsectors. The great mitigation towards CO₂ emissions can be achieved if energy efficiency is largely improved in carbon-intensive subsectors. Priority should be given by governments to the industrial technology advancement, such as subsidies for energy-saving technological transformation and promotion of international advanced techniques and equipment, which can greatly improve production efficiency and mitigate emissions in manufacturing industry.
Mostrar más [+] Menos [-]Agricultural technologies and carbon emissions: evidence from Jordanian economy
2018
Ismael, Mohanad | Surūjī, Fatḥī | Boutabba, MohamedAmine
Theoretically, agriculture can be the victim and the cause of climate change. Using annual data for the period of 1970–2014, this study examines the interaction between agriculture technology factors and the environment in terms of carbon emissions in Jordan. The results provide evidence for unidirectional causality running from machinery, subsidies, and other transfers, rural access to an improved water source and fertilizers to carbon emissions. The results also reveal the existence of bidirectional causality between the real income and carbon emissions. The variance error decompositions highlight the importance of subsidies and machinery in explaining carbon emissions. They also show that fertilizers, the crop and livestock production, the land under cereal production, the water access, the agricultural value added, and the real income have an increasing effect on carbon emissions over the forecast period. These results are important so that policy-makers can build up strategies and take in considerations the indicators in order to reduce carbon emissions in Jordan.
Mostrar más [+] Menos [-]Interaction between enterprises and consumers in a market of carbon-labeled products: a game theoretical analysis
2018
Zhao, Rui | Han, Jiaojie | Zhong, Shaozhuo | Huang, Ya
This paper applies an evolutionary game theoretical analysis combined with system dynamics to model strategic interaction between enterprises and consumers with bounded rationality in a carbon-labeled product market. Through the game theoretical analysis, possible equilibriums are predicted between these two players, in order to provide market recommendations for promotion of carbon-labeled products. The simulation results indicated that it is impossible to promote the carbon-labeled products relying on the market’s inherent functions. After incorporating dynamic subsidies, both of the players have evolutionary stable strategies, revealing it has an incentive impact on the market. Limitations of the game theoretical analysis are discussed to lay out a foundation for further study.
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