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861.
J. W. Chapman Trevor Williams Ana M. Martínez Juan Cisneros Primitivo Caballero Ronald D. Cave Dave Goulson 《Behavioral ecology and sociobiology》2000,48(4):321-327
The incidence of cannibalism of larval Spodoptera frugiperda (Lepidoptera: Noctuidae) on maize under field conditions was investigated using field cages. Cannibalism was found to account
for approximately 40% mortality when maize plants were infested with two or four fourth-instar larvae over a 3-day period.
Field trials examined the effect of larval density on the prevalence of natural enemies of S. frugiperda. The abundance of predators (earwigs, staphylinids, other predatory beetles, and Chrysoperla spp.) was significantly greater on maize plants with higher levels of larval feeding damage, while the relationship between
predator abundance and number of S. frugiperda larvae per plant was less clear. As larval damage is probably a more reliable indicator of previous larval density than numbers
collected at an evaluation, this indicates that predation risk will be greater for larvae living in large groups. Parasitism
accounted for 7.1% mortality of larvae in sorghum, and involved six species of Hymenoptera and Tachinidae. There was no effect
of larval density or within-plant distribution on the probability of larval attack by parasitoids. The selective benefits
of cannibalism, in relation to the risk of predation and parasitism, are discussed.
Received: 23 March 2000 / Accepted: 24 June 2000 相似文献
862.
Charbel Jose Chiappetta Jabbour Ana Beatriz Lopes de Sousa Jabbour 《International Journal of Green Energy》2016,13(9):907-910
This work presents empirical evidence of the main challenges in managing/leading academic research groups on clean and green technologies in Brazilian universities. We also present evidence about the main barriers to the effective creation of innovation and technology transfer of these clean and green technologies. Empirical evidence come from PhD researchers/academics who lead/manage official research groups on clean (environmental, green) technologies. Results show the following: (a) The main challenges of managing research groups are the lack of an innovative culture, the lack of partnership with an industrial sector, and the necessity of keeping laboratories updated; (b) the main barriers to innovation and technology transfer are difficulties in not having enough researchers and staff members, assessments of academic performance that do not consider innovation, and an uncertain national legislation on clean technology. Based on these and others’ findings, we suggest that policymakers working on clean and green technologies pay attention to act and develop initiatives focusing on the following: providing direct financial support for laboratory improvement, linking academics and practitioners from the industrial sector, and providing training and development programs on clean and green technologies’ legislation and financial issues, such as the payoff of clean and green technologies and opportunities from green investors. 相似文献
863.
Célia Alves Ana I. Calvo Liliana Marques Amaya Castro Teresa Nunes Esther Coz Roberto Fraile 《Environmental science and pollution research international》2014,21(21):12390-12402
An indoor/outdoor monitoring programme of PM10 was carried out in two sports venues (a fronton and a gymnasium). Levels always below 50 μg m?3 were obtained in the fronton and outdoor air. Due to the climbing chalk and the constant process of resuspension, concentrations above 150 μg m?3 were registered in the gymnasium. The chalk dust contributed to CO3 2? concentrations of 32?±?9.4 μg m?3 in this sports facility, which represented, on average, 18 % of the PM10 mass. Here, the carbonate levels were 128 times higher than those registered outdoors. Much lower concentrations, around 1 μg m?3, were measured in the fronton. The chalk dust is also responsible for the high Mg2+ concentrations in the gym (4.7?±?0.89 μg m?3), unfolding a PM10 mass fraction of 2.7 %. Total carbon accounted for almost 30 % of PM10 in both indoor spaces. Aerosol size distributions were bimodal and revealed a clear dependence on physical activities and characteristics of the sports facilities. The use of climbing chalk in the gymnasium contributed significantly to the coarse mode. The average geometric mean diameter, geometric standard deviation and total number of coarse particles were 0.77 μm, 2.79 cm?3 and 28 cm?3, respectively. 相似文献
864.
Soil quality, as a measure of the soil's capacity to function, can be assessed by indicators based on physical, chemical, and biological properties. Here we report on the assessment of soil quality in 21 rice (Oryza sativa) fields under three rice production systems (semi-direct, pre-germinated, and conventional) on four soil textural classes in the Camaqu? region of Rio Grande do Sul, Brazil. The objectives of our study were: (i) to identify soil quality indicators that discriminate both management systems and soil textural classes, (ii) to establish a minimum data set of soil quality indicators and (iii) to test whether this minimum data set is correlated with yield. Twenty-nine soil biological, chemical, and physical properties were evaluated to characterize regional soil quality. Soil quality assessment was based on factor and discriminant analysis. Bulk density, available water, and micronutrients (Cu, Zn, and Mn) were the most powerful soil properties in distinguishing among different soil textural classes. Organic matter, earthworms, micronutrients (Cu and Mn), and mean weight diameter were the most powerful soil properties in assessing differences in soil quality among the rice management systems. Manganese was the property most strongly correlated with yield (adjusted r2 = 0.365, P = 0.001). The merits of sub-dividing samples according to texture and the linkage between soil quality indicators, soil functioning, plant performance, and soil management options are discussed in particular. 相似文献
865.
To address the dearth of literature on the relations between local residents in urban areas and nearby higher-order exurban
protected areas, this study examined the perceptions of Columbia (South Carolina) residents toward Congaree National Park.
Mail-out survey results from a random sample of 455 adult residents showed positive overall attitudes toward the park, although
this did not extend to a desire to personally volunteer in park activities. Cluster analysis on the basis of seven perceptual
statements produced three groups: “very enthusiastic park supporters” (VEPS), accounting for one fourth of the sample; “less
enthusiastic park supporters” (LEPS), accounting for approximately one half of the sample; and “ambivalents” (AMBS), accounting
for the rest. The AMBS tend to be younger than members of the other clusters and have higher income, but enthusiasm was more
clearly related to high levels of interaction and awareness relative to the park. Managerial implications of the study are
considered, including the need to encourage higher levels of park awareness and visitation, as well as more ecologically responsible
behavior, among residents of the greater Columbia urban area. 相似文献
866.
867.
868.
Water scarcity has become a key issue in water management. There are two contrasting positions regarding scarcity as a source of conflict or cooperation. Accordingly, it is worth exploring what exactly are the conditions that make water scarcity a source of conflict or cooperation. The history of water conflicts has shown that people are more likely to kill around a water hole than when conflicts grow into national or international issues. This suggests that there may be an inverse relationship between the level of violence and the scale at which the water conflict takes place. A common problem in environmental management has been the lack of effective mechanisms to handle conflict. In the majority of these cases, the main shortcoming was an inability of the parties to identify their differences. Therefore, this research explores the idea that understanding the causes of conflict from the outset, followed by an evaluation, at the local scale, of the conditions, is a necessary precondition to finding appropriate and sustainable solutions. With this background in mind, the objective of this paper is to employ a conflict assessment process in order to explore to the extent to which a collaborative dialogue among stakeholders can be an appropriate approach to conflict resolution. A case study in Mexico is employed as a testing ground. 相似文献
869.
Ana Cruz del Álamo María Isabel Pariente Ioanna Vasiliadou Beatriz Padrino Daniel Puyol Raúl Molina Fernando Martínez 《Environmental science and pollution research international》2018,25(35):34884-34892
Conventional wastewater treatment plants (WWTPs) are not able to remove completely some emerging contaminants, such as residual pharmaceutical compounds (PCs) with potential ecotoxicity to water bodies. An advanced bio-oxidation process (ABOP) using white-rot fungi (WRF) has been proposed as alternative biological treatment for degradation of non-biodegradable compounds. A synthetic and real wastewater spiked with 12 PCs at 50 μg L?1 was treated by means of ABOP based on WRF in a rotating biological contactor (RBC) at 1 day of hydraulic retention time (HRT). The ABOP achieved a remarkable biological performance in terms of TOC removal and reduction of N-NH4 + and P-PO4 3? nutrients. Likewise, 5 of the 12 PCs were eliminated with removal efficiencies ranging from 80 to 95%, whereas 6 of 12 PCs were eliminated with removal values ranging from 50 to 70%. The anaerobic digestion of the fungal sludge generated upon the treatment was also evaluated, obtaining a methane yield of 250 mL CH4 gVS ?1. These results evidenced that the proposed ABOP is a promising alternative for the sustainable wastewater treatment of urban effluents, combining advanced oxidation with biological operation for the removal of emerging PCs and energy recovery. 相似文献
870.
Richard J. Ladle João V. L. Firmino Ana C. M. Malhado Armando Rodríguez‐Durán 《Conservation biology》2012,26(6):978-982
The term hot cave is used to describe some subterranean chambers in the Neotropics that are characterized by constantly high ambient temperatures generated by the body heat of high densities of certain bat species. Many of these species have limited geographic ranges, and some occur only in the hot‐cave environment. In addition to the bats, the stable microclimate and abundant bat guano provides refuge and food for a high diversity of invertebrates. Hot caves have so far been described in the Caribbean and in a few isolated locations from Mexico to Brazil, although there is some evidence that similar caves may be present throughout the tropics. The existing literature suggests these poorly known ecosystems, with their unique combination of geomorphology and bat‐generated microclimate, are particularly sensitive to disturbance and face multiple threats from urbanization, agricultural development, mining, and tourism. Diversidad No Explorada y Potencial de Conservación de Cuevas Neotropicales Calientes 相似文献