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971.
In recent years, significant advances have been made in business organization and management. The growing demands of clients as well as the globalization of world markets are among the many factors that have led to the establishment of systems of quality control and environmental management as a competitive strategy for businesses. When compared to other professional sectors, the construction sector has been slower to respond to environmental problems and to adopt Environmental Management Systems (EMS). In the world today the ISO 14001 standard is currently the main frame of reference used by construction companies to implement this type of management system. This article presents the results of a general study regarding the evaluation of the application of the ISO 14001 standard at civil engineering construction worksites in the Community of Madrid (Spain), specifically pertaining to requirement 4.4.1, Resources, roles, responsibilities, and authority. According to requirement 4.4.1, company executives should appoint people responsible for implementing the EMS and also specify their responsibilities and functions. The personnel designated for supervising environmental work should also have sufficient authority to establish and maintain the EMS. The results obtained were the following: - EMS supervisors did not generally possess adequate training and solid experience in construction work and in the environment. Furthermore, supervisors were usually forced to combine their environmental work with other tasks, which made their job even more difficult. - Generally speaking, supervisors were not given sufficient authority and autonomy because productivity at the construction site had priority over environmental management. This was due to the fact that the company management did not have a respectful attitude toward the environment, nor was the management actively involved in the establishment of the EMS. - Insufficient resources were allocated to the Environmental Management Unit. As a result, the application of EMSs in construction projects often appeared to be more of a formality, which was merely a way of maintaining the certification of the Environmental Management System. It was more a means of meeting the requirements for submitting a tender to contracting organisms rather than an indicator of any real commitment to improving the environmental performance of construction companies. 相似文献
972.
Large quantities of floating macroalgae are traveling in coastal waters of the SE Pacific and in other temperate climate zones.
While afloat, these algae are potentially exposed to full solar radiation, including UVA and UVB, which can have profound
effects on their physiological and growth performance. Latitudinal variations in UV-radiation (UVR) are hypothesized to affect
floating algae differently with higher impacts at low latitudes than at high latitudes. In addition, UVR together with grazing
might accelerate the demise of floating kelps. This hypothesis was tested with outdoor laboratory experiments in which sporophytes
of the giant kelp Macrocystis pyrifera (L.) C. Agardh were exposed to a combination of different UVR regimes (PAR only, PAR + UV) and grazing at three sites along
the Chilean coast (20°S, 30°S, and 40°S). A latitudinal trend in irradiance was detected with increasing values from 40°S
to 20°S. Surprisingly, floating M. pyrifera responded with a high acclimation potential within this latitudinal UVR gradient. At 20°S, floating kelps were slightly sensitive
to UVR, which was reflected in reduced blade growth. At 30°S, physiological responses were hardly affected by the prevailing
irradiance but sporophyte growth and thus persistence mainly depended on the presence or absence of amphipod grazers. At high
latitudes, grazing had only minor impacts on algal biomass and blade growth, and kelps thrived well under all tested environmental
conditions. Overall, our results reveal that floating M. pyrifera was only slightly affected by UVR and that sporophytes can efficiently acclimate over a latitudinal UVR gradient that spans
from 20°S to 40°S. Given this high acclimation potential, we suggest that these (and possibly other) positively buoyant algae
are important dispersal agents over a wide range of temperate latitude conditions. 相似文献
973.
Monferrán MV Galanti LN Bonansea RI Amé MV Wunderlin DA 《Journal of environmental monitoring : JEM》2011,13(2):398-409
We report a combined two-year seasonal monitoring of Suquía River basin using both chemical parameters and biomarkers measured in Jenynsia multidentata, aiming to correlate external levels of contaminants with the response of oxidative stress biomarkers in this fish. Identified pollution sources correspond to city sewage as well as agricultural and small industry activities downstream from Córdoba city. Physicochemical parameters integrated into a water quality index (WQI) were measured in Suquía River during dry and wet seasons. Ag, Mn, Cu, Cr, Ni, Fe, Pb and Zn were also monitored in water and sediment samples. Biomarkers include detoxication and antioxidant enzymes: catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and glutathione reductase (GR). Enzymes showed a pollution dependent response, with increased activities in fish collected close to the sewage exit and progressive drop further downstream, matching changes in the Water Quality index. The combined use of biomarkers with water quality parameters allowed both the identification of pollution sources and the evaluation of effects of contaminants on the aquatic biota. 相似文献
974.
Santacatalina M Carratalá A Mantilla E 《Journal of environmental monitoring : JEM》2011,13(6):1634-1645
This work presents the results of a 4-year study on sulfur dioxide (SO(2)) ground-level concentrations in an area of southeastern Spain, the L'Alacantí region, where the cement industry is important and coke use extends to other industries as well. The main source of SO(2) emissions in the area was found to be a the Lepold cement plant (one of the two cement plants in the area). The high levels of SO(2) probably extend back to 1920 when this plant began operations. Both local and Mediterranean-scale meteorological processes influence the SO(2) ground-level concentration and together explain the dispersion dynamics of this pollutant. The location and topography of the study zone result in NW Atlantic advections and E-SE sea breezes being the dominant atmospheric circulation patterns in the area. Under stable meteorological conditions, minor local circulations are also relevant to the SO(2) concentration levels. The high frequency of local circulations determines a concentration pattern that changes during the day, with impacts occurring preferentially in a W-NW direction from the source at midday (sea breeze and strong thermal mixture), and in a SE direction at night. This causes the SO(2) concentrations to present well-defined diurnal cycles with well-differentiated shapes depending on the location of the sampling station relative to the source. The dependence of SO(2) 10 min levels on the wind origin and speed throughout the day has been evaluated by studying statistical parameters including P95, P50 and arithmetic mean. Exceedances occur under specific dispersion conditions at distances less than 1 km from the source. However, the source is traceable at larger distances and the levels are higher than typical urban ones. P95 was used as an estimator of the occurrence of larger levels or impacts. Leeward of NW winds and the source, at night and in early morning, P95 levels are comprised between 30 and 55 μg m(-3). In contrast, with SE winds and at midday, P95 levels stay at 17 μg m(-3). The same P95 was obtained for winds lower than 5 m s(-1), which represent 89% of the winds in the area. However, stronger winds can have P95 levels above 125 μg m(-3). 相似文献
975.
García-Palacios P Bowker MA Maestre FT Soliveres S Valladares F Papadopoulos J Escudero A 《Ecological applications》2011,21(7):2806-2821
Roadside grasslands undergoing secondary succession are abundant, and represent ecologically meaningful examples of novel, human-created ecosystems. Interactions between plant and soil communities (hereafter plant-soil interactions) are of major importance in understanding the role of biotic control in ecosystem functioning, but little is known about these links in the context of ecosystem restoration and succession. The assessment of the key biotic communities and interactions driving ecosystem development will help practitioners to better allocate the limited resources devoted to roadside grassland restoration. We surveyed roadside grasslands from three successional stages (0-2, 7-9, and >20 years) in two Mediterranean regions of Spain. Structural equation modeling was used to evaluate how interactions between plants, biological soil crusts (BSCs), and soil microbial functional diversity (soil microorganisms) affect indicators of ecosystem development and restoration: plant similarity to the reference ecosystem, erosion control, and soil C storage and N accumulation. Changes in plant community composition along the successional gradient exerted the strongest influence on these indicators. High BSC cover was associated with high soil stability, and high soil microbial functional diversity from late-successional stages was associated with high soil fertility. Contrary to our expectations, the indirect effects of plants, mediated by either BSCs or soil microorganisms, were very weak in both regions, suggesting a minor role for plant-soil interactions upon ecosystem development indicators over long periods. Our results suggest that natural vegetation dynamics effectively improved ecosystem development within a time frame of 20 years in the grasslands evaluated. They also indicate that this time could be shortened if management actions focus on: (1) maintaining well-conserved natural areas close to roadsides to enhance plant compositional changes towards late-successional stages, (2) increasing BSC cover in areas under strong erosion risk, to avoid soil loss, and (3) enhancing soil microbial functional diversity in resource-limited areas, to enhance soil C and N accumulation. 相似文献
976.
Angel Pérez-Ruzafa Concepción Marcos Isabel María Pérez-Ruzafa María Pérez-Marcos 《Journal of Coastal Conservation》2011,15(3):369-392
The European Water Framework Directive (WFD) establishes a well differentiated typology of water bodies on the basis of scientific
and biological criteria. For coastal waters, such criteria have long been established, while for transitional waters they
are still under discussion. One of the difficulties when applying the WFD to coastal lagoons is to include them in only one
of these categories, and while there is no doubt about the nature of estuaries as transitional waters, there is some controversy
concerning lagoons. To what extent, reference conditions may be similar for estuaries and lagoons, or whether features common
to all coastal lagoons are more important for differentiating them from other water bodies than the fact that there is (or
is not) any fresh water influence, is something that remains unclear and is discussed in this work. Coastal lagoons and estuaries
form part of a continuum between continental and marine aquatic ecosystems. Shelter, strong boundaries or gradients with adjacent
ecosystems, anomalies in salinity regarding freshwater or marine ecosystems, shallowness, etc. all contribute to the high
biological productivity of estuaries and lagoons and determine common ecological guilds in the species inhabiting them. On
the other hand, fresh water influence, the spatial organization of gradients and environmental variability (longitudinal one-dimensional
gradients in estuaries versus complex patterns and three-dimensional heterogeneity in lagoons) constitute the main differences,
since these factors affect both the species composition and the dominance of certain ecological guilds and, probably, the
system’s complexity and homeostatic capability. In the context of the WFD, coastal lagoons and estuaries are closer to each
other than they are to continental or marine waters, and, on the basis of the shared features, they could be intercalibrated
and managed together. However, coastal lagoons cannot be considered transitional waters according to the present definition.
To assume that fresh water influence is an inherent characteristic to these ecosystems could lead to important changes in
the ecological organization and functioning of coastal lagoons where natural fresh water input is low or null. In our opinion,
the present day definition of transitional waters should be changed substituting the criterion of fresh water influence by
another based on common features, such as relative isolation and anomalies in salinity in water bodies with marine influence.
Otherwise, coastal lagoons should be considered a particularly characteristic type of water mass for establishing reference
conditions of ecological status. 相似文献
977.
Luděk Bartoš Jitka Bartošová Jan Pluháček Jana Šindelářová 《Behavioral ecology and sociobiology》2011,65(8):1567-1572
Based on questionnaires from horse breeders, we found that bringing a pregnant mare which had been mated away from home into
a vicinity of a familiar male who was not the father of her foetus increased probability of pregnancy disruption. These mares
aborted in 31% of cases, while none of those mated within the home stable aborted. Repeated sexual activity either by a stallion
or dominant gelding from the normal home group was observed shortly after the mare came from away-mating. Pregnant mares isolated
from home males by a fence were even seen soliciting them over the fence. We speculate that, once returned to the home “herd”,
and introduced to familiar males, mares were more likely to terminate their pregnancy to save energy and avoid likely future
infanticidal loss of their progeny by dominant male(s) of the home social group. This is a newly discovered phenomenon where
a mare manipulates the male’s paternity assessment by promiscuous mating. It may explain a common increased incidence of foetal
loss in domestic horses occurring in nearly 40% of pregnancies. We conclude that the common practice of transporting the mare
for mating and then bringing her back to an environment with males, stallions or geldings, which did not sire the foetus,
is the main cause of high percentages of pregnancy disruption in domestic horses. 相似文献
978.
Sandra L. Marín Laura Nahuelhual Cristian EcheverríaWilliam E. Grant 《Ecological modelling》2011,222(15):2841-2855
We describe a simulation model representing the most important human and natural factors driving land use and cover changes (LUCC) in southern Chile. We evaluate the model by examining its ability to simulate LUCC observed over the past three decades, conduct a sensitivity analysis of simulated trends to changes in important model parameters, and use the model to project likely landscape transformations over the next decade under “as usual,” “pessimistic,” and four “optimistic” scenarios. The model consists of five submodels representing LUCC on two distinct soil formations (volcanic ash and gleysols) and four major land use categories: native forest, agricultural land, shrubland, and urban land. Land use and cover sub-categories include old growth forests, secondary forests, and low and flooded shrubland. The model simulated well general historic trends in forest cover, agricultural land, shrubland, and urban land: from a forest-dominated landscape in 1976 to a landscape dominated by shrubland and agricultural land by 2007. Forest loss, forest degradation by logging and clearing for agriculture were the most important direct drivers of LUCC: forest logging and clearing were most important from 1976 to 1985, whereas after 1985 logging for firewood, driven by population growth, was most important. Sensitivity analysis indicated that model projections of general trends in the main land use and cover categories were not overly sensitive to changes in important model parameters, although further study is necessary to improve our estimates of the proportion of pasture requirements supplied by clearing low shrubland. Projections of LUCC suggested that a reduced amount of secondary forest would be left by 2017 if no actions are taken to reduce forest loss (“as usual”). Increasing population (“pessimistic scenario”) resulted in similar trajectories than those predicted by the as usual scenario, whereas reducing logging for firewood and increasing forest recruitment from shrubland could reduce loss of native forest by nearly one-third (“optimistic scenarios”). Surprisingly, shrubland exhibited the most complex and influential dynamics in all scenarios, being the immediate outcome of forest loss and the main long-term source of land for agriculture, urban expansion, and forest recovery. Few studies in Chile, or elsewhere, have considered the importance of this intermediate successional stage. Of the scenarios simulated, financial incentives targeted toward channeling shrubland into regenerated forest seemed most promising, although obstacles to such a management strategy exist. 相似文献
979.
Edna González-Bernal Gregory P. Brown Elisa Cabrera-Guzmán Richard Shine 《Behavioral ecology and sociobiology》2011,65(7):1367-1375
The foraging sites selected by an ambush forager can strongly affect its feeding opportunities. Foraging cane toads (Rhinella marina) typically select open areas, often under artificial lights that attract insects. We conducted experimental trials in the
field, using rubber mats placed under lights, to explore the influence of substrate color and rugosity on prey availability
(numbers, sizes, and types of insects) and toad foraging success. A mat's color (black vs. white) and rugosity (smooth vs.
rough) did not influence the numbers, sizes, or kinds of insects that were attracted to it, but toads actively preferred to
feed on rugose white mats (50% of prey-capture events, vs. a null of 25%). White backgrounds provided better visual contrast
of the (mostly dark) insects, and manipulations of prey color in the laboratory showed that contrast was critical in toad
foraging success. Insects landing on rugose backgrounds were slower to leave, again increasing capture opportunities for toads.
Thus, cane toads actively select backgrounds that maximize prey-capture opportunities, a bias driven by the ways that substrate
attributes influence ease of prey detection and capture rather than by absolute prey densities. 相似文献
980.
Guillaume Péron Yves Ferrand François Gossmann Claudine Bastat Michel Guénézan Olivier Gimenez 《Behavioral ecology and sociobiology》2011,65(10):1949-1955
During unpredictable adverse conditions, endotherms can engage in emergency behaviors (movement, torpor, hyperphagia) to maintain
energy balance and reduce mortality hazards. Bird “escape migration” is one of the most visible of these behaviors. In this
study, we focus on a Eurasian Woodcock Scolopax rusticola population. Seasonal migrations bring this population from its breeding grounds in Eastern and Northern Europe to its wintering
grounds in France. A varying number of these birds are also regularly reported from Spain, supposedly during additional escape
movements that occur in winter. Using models that account for the imperfect detection rate of individuals and a large (>44,000
individuals) dataset combining information from the wintering and breeding ranges, we show that severe winters significantly
reduced survival probability, but that migration to Spain increased only during the most intense cold spell that occurred
over the 20-year study period. This suggests that the decision to resume migration during the winter is submitted to a threshold
mechanism, which we discuss in the light of current models of migratory behavior. 相似文献