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901.
José L. Mateos Paloma Fernández Del Pino Francisco J. Gutiérrez Mañero María Ruiz Palomino Juan J. Colon José A. Lucas García 《Chemistry and Ecology》2013,29(2):125-152
Microbial communities (phospholipid fatty acid pattern, bacterial growing strategies, eco-physiological index (EPI) and total bacteria counts, as a number of heterotrophic cuhurable bacteria), substrate-induced respiration (SIR), and nitrogen mineralization were studied in three Mediterranean soils at three different depth levels (A, B and C). Soils were experimentally treated with a final concentration of 1000 ppm of trace metals (Cu2+, Zn2+, Al3+, Fe2+, Pb2+, Ni2+, Mn2+, Cr3+ and Cd2+). Soils were stored in 571 plastic containers for one year, and watered with 1001 during this period. Leachate was recovered through a bottom tap. Samples of the three depths were studied. Soil microbial communities showed different effects to other studies presented in the literature, but carried out on non-Mediterranean soils. Dramatic differences were found between treated soils and untreated ones, but not between soils or horizons. the treated soil displayed a decrease in CFUs, SIR N-mineralization and EPI together with a dominance of r-growing strategists. the relative moles percent of several PLFAs, especially 15:0, 16: 1ω7, cy17: 0, br18:0 and 18: 1ω7 decreased because of the pollution of soils, whereas 10Me16, 18:2ω6, cy19:0, i16:0 and br17:0 showed higher values than in untreated soils. 相似文献
902.
Copper, iron, lead, manganese, and zinc contents were determined in various phyla of macroalgae typical of the rocky mesolittoral zone of Cuba and widely distributed in the Caribbean Region. the samples were collected in different zones along the shores of Havana City which are more or less influenced by anthropogenic activities. Differences in metal contents were observed due to seasonal variations and differences between sampling sites. of the analyzed species, only one brown alga, Padina vickersiae is considered as a suitable candidate for the monitoring of metal contamination. 相似文献
903.
A study has been made of the leaching of Cd, Zn, Pb, Cu, Tl and As in three representative soils of the zone affected by the spill from a pyrite mine in Aznalcollar (Sevilla, Spain) employing packed soil columns. According to the breakthrough and cumulative leaching curves, the relative mobilities of the different toxic elements in the columns are as follows: Tl > Cd > Zn > As > Cu > Pb. The results also show that the soils themselves have a good capacity for immobilizing the soluble fraction of the elements from the spilled mud, this capacity varying as follows: clayey soil with a high carbonate content > clayey soil with a moderate carbonate content > sandy‐clay loam soil with a low carbonate content. The results obtained in the work are a valuable contribution to the necessary assessment of the impact of the toxic spill on underground waters. 相似文献
904.
Ángel F. Herrera-Ulloa Anthony T. Charles Salvador E. Lluch-Cota Hermán Ramirez-Aguirre Sergio Hernández-Váquez Alfredo Ortega-Rubio 《国际发展与全球生态学杂志》2013,20(4):353-360
Sustainable development, as a multi-dimensional concept, is difficult to measure. Some efforts using indicators and indices have appeared in recent years, but most were developed on a national scale. Use of sustainability indicators has proven valuable for attaining better management of the environment by minimizing information gaps and maximizing community capabilities in terms of economic, social, environmental, and institutional sustainability dimensions. However, at least in the case of developing countries, the potential exists that national sustainability measures, based on national level indicators, may mask problems in sub-national zones with highly unsustainable conditions. This paper proposes a methodology to evaluate sustainable development at a local level, the use of which could be helpful in comparing different regions within a country or even among different countries. National sustainability indicators should result from a combination (whether additive or proportional) of regional sustainability indicators, as developed in this paper. 相似文献
905.
Veronika Holcová Jan Šíma Keith Edwards Eva Semančíková Jiří Dušek Hana Šantrůčková 《国际发展与全球生态学杂志》2013,20(5):362-367
Retention times of treated water in a constructed wetland (CW) with horizontal subsurface flow were determined both in the vegetative and non-vegetative periods of 2005. Tracer experiments were performed using fluorescein, an organic compound detectable at extremely low concentrations. Nominal and tracer retention times were determined and compared. Winter tracer retention time (TRT 194 h) and nominal retention time (nHRT 190 h) were nearly exactly equal, while summer TRT (335 h) was approximately twofold higher than nHRT (158 h). Residence time distribution function (RTD) was used to compare retention times obtained for the vegetative and non-vegetative periods. The obtained results document a significant influence of dense common reed vegetation on retention characteristics of the studied system. Common reed can convert a significant volume of water from liquid to gas via evapotranspiration (ET) and thus prolong water retention times in the system. This is very important both technically and ecologically. Longer retention times mean a longer time for microbiological decay of wastewater. Water converted from liquid to gas causes cooling of the microclimate, which is very important, especially in intensively cultivated areas with a lack of water. 相似文献
906.
Arsenic bioaccessibility in a gold mining area: a health risk assessment for children 总被引:1,自引:0,他引:1
Ono FB Guilherme LR Penido ES Carvalho GS Hale B Toujaguez R Bundschuh J 《Environmental geochemistry and health》2012,34(4):457-465
High concentrations of total arsenic (As) have been measured in soils of gold mining areas of Brazil. However, bioaccessibility tests have not yet been conducted on those materials, which is essential for better health risk estimates. This study aimed at?evaluating As bioaccessibility in samples from a gold mining area located in Brazil and assessing children's exposure to As-contaminated materials. Samples were collected from different materials (a control and four As-contaminated soils/sediments) found in a gold mine area located in Paracatu (MG), Brazil. Total and bioaccessible As concentrations were determined for all samples. The control soil presented the lowest As concentrations, while all other materials contained high total As concentrations (up to 2,666?mg?kg(-1)) and low bioaccessible As percentage (<4.2%), indicating a low risk from exposure of resident children next to this area. The calculated dose of exposure indicated that, except for the pond tailings, in all other areas, the exposure route considering soil ingestion contributed at most to 9.7% of the maximum As allowed ingestion per day (0.3?μg?kg(-1) BW day(-1)). 相似文献
907.
The Salí River Basin in north-west Argentina (7,000 km2) is composed of a sequence of Tertiary and Quaternary loess deposits, which have been substantially reworked by fluvial and
aeolian processes. As with other areas of the Chaco-Pampean Plain, groundwater in the basin suffers a range of chemical quality
problems, including arsenic (concentrations in the range of 12.2–1,660 μg L−1), fluoride (50–8,740 μg L−1), boron (34.0–9,550 μg L−1), vanadium (30.7–300 μg L−1) and uranium (0.03–125 μg L−1). Shallow groundwater (depths up to 15 m) has particularly high concentrations of these elements. Exceedances above WHO (2011) guideline values are 100% for As, 35% for B, 21% for U and 17% for F. Concentrations in deep (>200 m) and artesian groundwater
in the basin are also often high, though less extreme than at shallow depths. The waters are oxidizing, with often high bicarbonate
concentrations (50.0–1,260 mg L−1) and pH (6.28–9.24). The ultimate sources of these trace elements are the volcanic components of the loess deposits, although
sorption reactions involving secondary Al and Fe oxides also regulate the distribution and mobility of trace elements in the
aquifers. In addition, concentrations of chromium lie in range of 79.4–232 μg L−1 in shallow groundwater, 129–250 μg L−1 in deep groundwater and 110–218 μg L−1 in artesian groundwater. All exceed the WHO guideline value of 50 μg L−1. Their origin is likely to be predominantly geogenic, present as chromate in the ambient oxic and alkaline aquifer conditions. 相似文献
908.
Gábor?HerczegEmail author László?Zsolt?Garamszegi 《Behavioral ecology and sociobiology》2012,66(1):161-169
The study of correlations between different behaviours in a population—referred to as behavioural syndromes—has begun to flourish
during recent years. However, the evolutionary mechanisms that cause behavioural traits to vary non-independently from each
other are still poorly understood. Here, we bring behavioural syndromes into a new perspective, in which the phenomenon is
regarded at the individual level and on a continuous scale instead of as a population-level presence/absence trait. As the
correlation between behaviours is never perfect (i.e. r < 1), individuals are likely to vary in how consistently they behave. Therefore, we can predict that if behavioural syndromes
at the population level are results of natural selection, the consistency in a suite of behaviours—and not the behavioural
configuration per se—should be heritable and involve fitness advantages at the individual level. We define a variable that
describes the individual deviation from the hypothetical perfect correlation predicted by the syndrome. The use of such a
variable depicting the consistency of behaviours of individuals allows us to make solid evolutionary inferences about correlated
behaviours from patterns of individual instead of population variation. We suggest that, by adopting the concept of syndrome deviation, understanding the evolution of behavioural syndromes and, in particular, testing competing evolutionary hypotheses about
the origin of behavioural syndromes becomes possible in a more rigorous manner than before. 相似文献
909.
Francisco?Santiago-QuesadaEmail author José?A.?Masero Sora?M.?Estrella Juan?M.?Sánchez-Guzmán 《Behavioral ecology and sociobiology》2012,66(3):397-405
There is a large literature dealing with daily foraging routines of wild birds during the non-breeding season. While different
laboratory studies have showed that some bird activity patterns are a persistent property of the circadian system, most of
field studies preclude the potential role of an endogenous circadian rhythm in controlling bird’s foraging routines. In this
study we compared the patterns of diurnal foraging activity and intake rates of migrating black-tailed godwits, Limosa limosa (radio-tagged and non-tagged individuals) at two stopover sites (habitats) with different environmental characteristics,
aiming at identifying proximate factors of bird activity routines. To gain insights into the role of food availability in
control of such foraging routines, we also estimated foraging activity patterns in captive godwits subjected to constant food
availability. Captive and wild black-tailed godwits showed a persistent bimodal activity pattern through daylight period.
Food availability had a significant effect on the intake rates, but had a subtler effect on foraging and intake rate rhythms.
Temperature and wind speed (combined in a weather index) showed non-significant effects on both rhythms. Although we could
not discard a role for natural diurnal changes in light intensity, an important timing cue, our findings support the idea
that an endogenous circadian rhythm could be an important proximate factor regulating foraging activity and food items taken
per unit time of wild black-tailed godwits during migration. 相似文献
910.
Ebensperger LA Sobrero R Quirici V Castro RA Tolhuysen LO Vargas F Burger JR Quispe R Villavicencio CP Vásquez RA Hayes LD 《Behavioral ecology and sociobiology》2012,66(2):261-274
Intraspecific variation in sociality is thought to reflect a trade-off between current fitness benefits and costs that emerge from individuals' decision to join or leave groups. Since those benefits and costs may be influenced by ecological conditions, ecological variation remains a major, ultimate cause of intraspecific variation in sociality. Intraspecific comparisons of mammalian sociality across populations facing different environmental conditions have not provided a consistent relationship between ecological variation and group-living. Thus, we studied two populations of the communally rearing rodent Octodon degus to determine how co-variation between sociality and ecology supports alternative ecological causes of group living. In particular, we examined how variables linked to predation risk, thermal conditions, burrowing costs, and food availability predicted temporal and population variation in sociality. Our study revealed population and temporal variation in total group size and group composition that covaried with population and yearly differences in ecology. In particular, predation risk and burrowing costs are supported as drivers of this social variation in degus. Thermal differences, food quantity and quality were not significant predictors of social group size. In contrast to between populations, social variation within populations was largely uncoupled from ecological differences. 相似文献