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11.
This is the first report showing that using honeybee (Apis mellifera) and wild pollinators complementary pollination can enhance soybean productivity (Glycine max). Current industrial production of soybean involves autopollination and high loads of pesticides. Therefore, growers have neglected possible biotic pollination despite suggestions that soybean benefit from insect pollinators. Reports advocating possible biotic pollination are based on experiments where bees are caged with flowering plants and the absence of pesticides, thus not in field conditions. Therefore, here we compared in field conditions soybean yield produced (1) independently of biotic pollinators, (2) with wild pollinators and (3) with honeybee colonies. Results showed an increase of +6.34 % of soybean yield in areas where wild pollinators had free access to flowers. The introduction of honeybee colonies further raised the yield of +18.09 %. Our findings therefore show that, though soybean is autogamous, allowing pollination by wild pollinators leads to higher yields. Moreover, adding honeybee mitigates pollination deficits and improves yield compared to current practices.  相似文献   
12.
PM10 continental rural background aerosols were collected during a summer field campaign (August–September 2006) at Lamas de Ôlo in the upper zone of the Alvão Natural Park, a mountain region of northern Portugal. In addition to the determination of the carbonaceous content by a thermal–optical method, the organic speciation of aerosols was performed by gas chromatography–mass spectrometry in an effort to evaluate photo-oxidation products of biogenic volatile organic compounds and other markers for source characterization. The detailed analysis revealed relatively high concentrations of polyols and short-chain dicarboxylic, tricarboxylic, hydroxycarboxylic, and oxocarboxylic acids, many of which are thought to be indicators of secondary aerosol formation, accounting for about 70% of global chromatographically resolved mass. Major photo-oxidation products of α- and β-pinene have been detected. The tracers for the photo-oxidation of isoprene comprise two diastereoisomeric 2-methyltetrols, C5-alkene triols, and 2-methylglyceric acid, which have only recently been elucidated. In addition, the occurrence of levoglucosan and other biomass combustion tracers indicates that the site was affected by wildfires. This source contributed to more than 80% of the organic carbon mass during a period of strong forest fire influence.  相似文献   
13.
The objective of this work was to develop a fast and practical method of weed seedbank evaluation to generate spatially distributed maps for use in site-specific weed management. Soil cores were collected at 0.20 m depth, air-dried, and then submitted to seedling growth in greenhouse. The sampling grid of 20 by 20 m was georeferenced by Global Positioning System, obtaining 73 soil cores with three replicates. During the greenhouse trial, there were two peaks of weed seedling growth: one in 119 days after water irrigation and another after KNO3 application. Weeds seedbank maps were obtained at different stages of seedling growth. The Pearson correlation was 0.99 for Brachiaria plantaginea seedbank map, 0.95 for Commelina benghalensis, and 0.85 for Cyperus rotudus generated at 119 days compared with 392 days after seedling growth in the greenhouse. The Brachiaria plantaginea seedbank map evaluated at 35 days presented correlation of 0.97 with 392 days. It was concluded that, for site-specific weed seedbank management, the evaluation of seedling growth in greenhouse until the first emergence peak is enough to generate weed seedbank maps.  相似文献   
14.
This paper investigates multi-stakeholder arrangements initiated by businesses and NGOs from the North that aim to enhance a more sustainable agricultural production at specific localities in Southern countries. We aim to better understand the search for concerted action in multi-actor arrangements. Therefore, this paper presents a diagnostic framework with three strategic challenges the partnership projects are facing: linking global economic objectives to local needs, values and interests; bridging public and private interests and responsibilities; and seeking trade-offs between social, environmental and economic values. Starting from the partnerships’ Theory of Change, this diagnostic framework is applied to comparative case studies of partnership projects in the cocoa sector in Indonesia, which are part of a Northern-based public–private partnership to improve farmers’ prospective. It is concluded that the economic reality faced by the farmers differs from that of the Northern actors; collaboration with governments is difficult because of different organizational cultures; and the partnership projects underestimate the strength of vested social relations the smallholders are part of. Overall, the initiators of the partnerships seem to work with a too restricted economic interpretation of the local reality.  相似文献   
15.
Ecological science contributes to solving a broad range of environmental problems. However, lack of ecological literacy in practice often limits application of this knowledge. In this paper, we highlight a critical but often overlooked demand on ecological literacy: to enable professionals of various careers to apply scientific knowledge when faced with environmental problems. Current university courses on ecology often fail to persuade students that ecological science provides important tools for environmental problem solving. We propose problem-based learning to improve the understanding of ecological science and its usefulness for real-world environmental issues that professionals in careers as diverse as engineering, public health, architecture, social sciences, or management will address. Courses should set clear learning objectives for cognitive skills they expect students to acquire. Thus, professionals in different fields will be enabled to improve environmental decision-making processes and to participate effectively in multidisciplinary work groups charged with tackling environmental issues.  相似文献   
16.
17.
Contamination by heavy metals is the result of different industrial activities. The presence of heavy metals in soil and water causes serious problems, as these materials are not biodegradable and do contaminate both biological systems and the subsoil. Biological surface-active compounds otherwise known as biosurfactants in general and rhamnolipids biosurfactants in particular have been successfully employed in the remediation of environments contaminated with heavy metal ions. The aim of the present review is to highlight potential applications of these tensioactive compounds for use in environmental heavy metals removal and bioremediation and processes involved.  相似文献   
18.
Certified management systems have increasingly been applied by firms in recent decades and now cover the management of health and safety, principally through the OHSAS 18001 standard. In order to become certified, firms must not only observe the relevant legislation, but also improve performance and raise goals within health and safety on a continuous basis. The article examines how certified occupational and health management systems influence this process to evaluate how far they hinder or support learning. It presents a model with which it is possible to identify and analyse improvement processes. The model is applied to five cases from a qualitative study of Danish manufacturers with certified health and safety management systems. The cases illustrate the wide variation in health and safety management among certified firms.Certification is found to support lower levels of continuous improvement performance in handling health and safety issues. However, more advanced improvement practices are shown to be connected to the integration of health and safety in other managerial areas, as well as to the employment of similar advanced improvement processes within firms. The article argues that certified health and safety management does not obstruct learning, and can support advanced learning. Improvement practices with regard to health and safety are mainly dependent upon the firm’s overall organisational processes and do not automatically arise from the standard alone.  相似文献   
19.
Environmental Science and Pollution Research - The growing demand for products with lower environmental impact and the extensive applicability of cellulose nanofibrils (CNFs) have received...  相似文献   
20.
The main objective of this paper is to implement a coupled three-dimensional physical and ecological model for the Aveiro coast, and to apply it to study the temperature and the phytoplankton biomass spatial distributions along the coastal ecosystem. The Aveiro coast is located at Portugal within the upwelling system of the Atlantic Iberian coast, characterized by nutrients availability and phytoplankton biomass accumulation, from April to October. In order to implement the ecological model, its validation was assessed by comparing simulations to data relative to the horizontal and vertical distributions of the temperature, nutrients and phytoplankton biomass, obtained during the CICLOS I survey off the Portuguese coast [Moita, M.T., 2001. Estrutura, Variabilidade e Dinâmica do Fitoplâncton na Costa de Portugal Continental. PhD Thesis. Faculdade de Ciências da Universidade de Lisboa, 272 pp.]. A sensitivity analysis of the model has been performed in order to assess the influence of the main ecological model variables. The simulation results show that the model is capable of predicting realistic the temperature, the nutrients and the chlorophyll-a distributions for the study area. The scenarios evidence the setup of a thermal stratification pattern resulting from the upwelling of deep and rich in nutrients water to the surface layer and a chlorophyll-a maxima extending offshore, along the picnocline and the nutricline. The results confirm the crucial role played by the physical processes in the phytoplankton bloom along the Aveiro coast. They also evidence the close link between the surface phytoplankton distribution and the surface temperature distribution.  相似文献   
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