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471.
Respiration induced by substrate and bacteria diversity after application of diuron,hexazinone, and sulfometuron-methyl alone and in mixture 总被引:1,自引:0,他引:1
Fabrícia Cristina Dos Reis Valdemar Luiz Tornisielo Bianca A. B. Martins Adijailton José de Souza Pedro Avelino Maia De Andrade Fernando Dini Andreote 《Journal of environmental science and health. Part. B》2013,48(7):560-568
AbstractAfter application, herbicides often reach the soil and affect non-target soil microorganisms, decreasing their population, diversity or affecting metabolic activity. Therefore, laboratory studies were performed to evaluate the effects of diuron, hexazinone and sulfometuron-methyl alone and mixed upon carbon transformation by soil microorganisms in clayey and sandy soils and the effect on bacterial diversity and structure. Control treatment without herbicide application was also performed. Sub-samples from the control and herbicide treatments (10?g – in triplicate) were collected before herbicide application and 7, 14, 28 and 42?days after treatment (DAT), then 1?mL of 14C-glucose solution was applied. The released 14CO2 was trapped in 2?M NaOH solution and the radioactivity was analyzed by liquid scintillation counting (LSC), 12?h after glucose application. The effect of herbicides on bacterial diversity was evaluated by T-RFLP. The experiment was conducted in a complete randomized design. Hexazinone did not affect 14CO2 evolution. Diuron showed a greater 14CO2 evolution in sandy and clayey soil, while sulfometuron-methyl led to an increase in sandy soil, at 42 DAT. A greater evolution of carbon was observed in the treatment with herbicide mixture in sandy soil, compared with the same treatment in clayey soil or control. However, the herbicide mixture application did not affect the soil biological activity measured by the respiration rate induced by substrate. On the other hand, the herbicide mixtures affected the bacterial diversity in both soils, being the strongest effect to diuron and sulfometuron-methyl in clayey soil and hexazinone in sandy soil. 相似文献
472.
Breeding Birds as a Farm Product 总被引:3,自引:0,他引:3
Abstract: Since the 1950s, meadowbird populations have been under increasing threat from radical changes in farming practices. We studied the possibilities for conserving meadowbirds on modern, intensive dairy farms in the Netherlands. Here, the conventional strategy for the conservation of meadowbirds is to restrict farming intensity and compensate farmers for their production losses. To increase the breeding success of meadowbirds, however, dairy farmers can fine-tune farming practices to yearly and local circumstances. Because this fine-tuning is difficult to enforce by legislation, we propose that farmers be paid for clutches bred on their land. Thus, farmers are paid for what they produce, but not restricted in their farming practices. The results of the first small-scale experiments, in which breeding success was compared between farms where farmers were paid for meadowbird clutches and farms where farmers were not paid, are encouraging. Breeding success of meadowbirds was significantly higher where farmers were paid than where they were not ( breeding success of Lapwing [ Vanellus vanellus ]: 64.7% on paid farms, 48.2% on unpaid farms; Black-tailed Godwit [ Limosa limosa ]: 63.1% paid, 39.3% unpaid). The effects on meadowbird populations could not yet be detected. The per-clutch payment system is less expensive than compensation for income losses: paying for clutches costs 40 Euro per clutch, whereas compensating for income losses costs 100–400 Euro per clutch (1 Euro is approximately equal to 1 U.S. dollar). Farmers are enthusiastic, and the system encourages cooperation between farmers and nature conservationists. 相似文献
473.
Exploration and exploitation of food sources by social insect colonies: a revision of the scout-recruit concept 总被引:3,自引:3,他引:0
Social insect colonies need to explore and exploit multiple food sources simultaneously and efficiently. At the individual
level, this colony-level behaviour has been thought to be taken care of by two types of individual: scouts that independently
search for food, and recruits that are directed by nest mates to a food source. However, recent analyses show that this strict
division of labour between scouts and recruits is untenable. Therefore, a modified concept is presented here that comprises
the possible behavioural states of an individual forager (novice forager, scout, recruit, employed forager, unemployed experienced
forager, inspector and reactivated forager) and the transitions between them. The available empirical data are reviewed in
the light of both the old and the new concept, and probabilities for the different transitions are derived for the case of
the honey-bee. The modified concept distinguishes three types of foragers that may be involved in the exploration behaviour
of the colony: novice bees that become scouts, unemployed experienced bees that scout, and lost recruits, i.e. bees that discover
a food source other than the one to which they were directed to by their nest mates. An advantage of the modified concept
is that it allows for a better comparison of studies investigating the different roles performed by social insect foragers
during their individual foraging histories.
Received: 29 December 1999 / Revised: 25 February 2000 / Accepted: 16 October 2000 相似文献
474.
We focused on male harassment on different female color morphs of the damselfly Ischnura elegans and on variation in morph-specific mating avoidance tactics by females. In I. elegans, one of the female morphs is colored like the conspecific male (andromorphs) while the other morphs are not (gynomorphs). Our first goal was to quantify morph-specific male mating attempts, hence male harassment, in populations with manipulated population parameters (densities, sex ratios, and proportion of andromorphs). Second, we examined the female's perspective by looking for potential differences in morph-specific mating avoidance tactics and success of those tactics in a natural population. Differences in population conditions did influence the number of male mating attempts per morph. The less frequent female morph was always subject to fewer mating attempts, which contradicts earlier hypotheses on mimicry, but supports those that assume that males learn to recognize female morphs. Gynomorphs occupy less open habitat and often fly away when a male approaches, while andromorphs use more open habitat, do not fly large distances and directly face approaching males. Female morphs did not differ in the proportion of successful mating-avoidance attempts. Our results suggest that the maintenance of the color polymorphism is most probably the result of interactive selective forces depending on variation in all population conditions, instead of solely density- or frequency-dependent selection within populations. 相似文献
475.
476.
智能化建筑=绿色建筑 总被引:1,自引:0,他引:1
在过去的十年中 ,“智能化建筑”这个术语已经被广泛地用于描述新的高技术建筑物 .这一术语在亚洲已经相当流行 ,那里有许多最大的新建筑建设项目 .智能化建筑的概念自然与对环境无害的“绿色建筑物”有关 .本文对 Brengel技术中心作了介绍 ,它是由美国绿色建筑理事会 (USGBC)能源和环境设计指导 (LEED)绿色建筑评定体系首批认证的 12个建筑物之一 . 相似文献
477.
Hilber T Maier J Scheffknecht G Agraniotis M Grammelis P Kakaras E Glorius T Becker U Derichs W Schiffer HP De Jong M Torri L 《Journal of the Air & Waste Management Association (1995)》2007,57(10):1178-1189
The 1999/31 Elemental Carbon Directive sets strict rules on the disposal of untreated municipal solid waste in the European Union countries and forces a reduction of the biodegradable quantities disposed off to landfills up to 35% of the amount produced in 1995 in the coming decade. More environmentally friendly waste management options shall be promoted under the framework of the Community Waste Strategy ([96] 399 Final). In this context, the production and thermal use of solid recovered fuels (SRFs), derived from nonhazardous bioresidues and mixed- and mono-waste streams, could be a key element in a future waste management system. Within the scope of the European Demonstration Project, RECOFUEL, SRF cocombustion was demonstrated in two large-scale lignite-fired coal boilers at RWE power station in Weisweiler, Germany. As a consequence of the high biogenic share of the cocombusted material, this approach can be considered beneficial following European Directive 2001/77/EC on electricity from renewable energy sources (directive). During the experimental campaign, the share of SRF in the overall thermal input was adjusted to approximately 2%, resulting into a feeding rate of approximately 25 t/hr. The measurement campaign included boiler measurements in different locations, fuel and ash sampling, and its characterization. The corrosion rates were monitored by dedicated corrosion probes. The overall results showed no significant influence of SRF cocombustion on boiler operation, emissions behavior, and residues quality for the thermal shares applied. Also, no effect of the increased chlorine concentration of the recovered fuel was observed in the flue gas path after the desulfurization unit. 相似文献
478.
While moving towards a flux-based approach, exposure-based ozone metrics are still a practical measure for summarising ambient
air quality. Ozone hourly concentrations for the period 2000–2004 from sites in the Mediterranean Italy (≤600 m a.s.l.) were
examined to define the O3 summary statistic in the area, and to determine how O3 exposure indices correlate to each other. Thirty-four of the most common O3 exposure metrics were calculated. The results show that background O3 pollution in Italy exceeds the European and North American standards. The exceedances of the target value, information and
alert thresholds set by the 2002/3/CE Directive should encourage Italy to take the appropriate measures to reduce the risk.
All the O3 exposure indices, except the maximum permissible ozone concentration (MPOC) for forests, point to the potential for negative
effects on vegetation and human health across Italy. As indices evaluated significantly correlated with each other, we suggest
use of the most biologically meaningful metric when summarizing air quality information. 相似文献
479.
Effects of the tsunami on fisheries and coastal livelihood: a case study of tsunami-ravaged southern Sri Lanka 总被引:2,自引:0,他引:2
Beyond the death toll, the tsunami of 26 December 2004 crippled many of the livelihood assets (human, social, physical, financial and natural) available to assist those directly affected. Drawing on surveys of three villages in three districts in the south of Sri Lanka, this paper describes the livelihood asset building capacity of the fishing communities. Assessments are also made of the impact of the tsunami on coastal communities and the impact of government policy on rebuilding. A livelihood asset score was calculated for each village by comparing their strengths in capacity building. In all aspects of capital building, including human, social, financial, physical and natural capital, the fishing community in Tangalle was significantly ahead of the fishing communities in Hikkaduwa and Weligama. Experienced fishermen with better educational backgrounds had a significant influence on the capacity building of livelihood assets. Relocation and resettlement plans brought persistent uncertainty to fishermen in Hikkaduwa and Weligama and threatened to disrupt their community bonds and social networks. 相似文献
480.
Eduardo Girotto Carlos A. Ceretta Gustavo Brunetto Alcione Miotto Tadeu L. Tiecher Lessandro De Conti Cledimar R. Lourenzi Felipe Lorensini Paulo I. Gubiani Leandro S. da Silva Fernando T. Nicoloso 《Environmental monitoring and assessment》2014,186(12):9051-9063
Grapevines grown on acid soils with low fertility in southern Brazil are treated with intense foliar applications of copper (Cu) fungicides, resulting in an increased level of Cu in the soil and increased toxicity. The present study evaluated the accumulation and bioavailability of Cu, and soils with varying levels of Cu from the main producing regions of southern Brazil were collected. The forms of Cu present in the soil were assessed using chemical extractants; additionally, oat cultivation was performed, reflecting the use of the plant as an indicator of Cu bioavailability. Cu accumulated in the topsoil, mainly in bioavailable forms, and there was also an increase of Cu up to a depth of 0.4 m. Cu was primarily found in the mineral fraction, with apparent saturation of the soil organic matter functional groups. Inceptisol and Alfisol soils with a long history of cupric fungicide application were found to have levels of Cu toxic to oat plants. Furthermore, accumulated copper in Alfisol soil from the Campanha Gaúcha region of the state of Rio Grande do Sul had higher bioavailability compared to Cu accumulated in Inceptisol soil from the Serra Gaúcha region. In addition, the copper concentration in roots was found to serve as an indicator of Cu bioavailability in soil, but not of copper phytotoxicity in plants. 相似文献