排序方式: 共有56条查询结果,搜索用时 15 毫秒
51.
Montserrat Bacardit Lluís Camarero 《Environmental science and pollution research international》2010,17(9):1606-1621
Background, aim, and scope
High mountain soils constitute a long-term cumulative record of atmospherically deposited trace elements from both natural and anthropogenic sources. The main aims of this study were to determine the level of major and trace metals (Al, Ti, Mn, Fe, and Zr) of lithologic origin and airborne contaminating trace elements (Ni, Cu, Zn, As, Cd, and Pb) in soils in the Central Pyrenees as an indication of background contamination over SW Europe, to establish whether there is a spatial pattern of accumulation of trace elements in soils as a function of altitude, and to examine whether altitude-related physicochemical properties of soils affect the accumulation of major metals and trace elements. 相似文献52.
F. Rossi R. M. Forster F. Montserrat M. Ponti A. Terlizzi T. Ysebaert J. J. Middelburg 《Marine Biology》2007,151(6):2077-2090
The effect of physical disturbance in the form of trampling on the benthic environment of an intertidal mudflat was investigated.
Intense trampling was created as unintended side-effect by benthic ecologists during field experiments in spring and summer
2005, when a mid-shore area of 25 × 25 m was visited twice per month by on average five researchers for a period of 8 months.
At the putatively-impacted location (I) (25 × 25 m) and two nearby control locations (Cs) (25 × 25 m each), three sites (4 × 4 m) were randomly selected and at each site, three plots (50 × 50 cm) were sampled after
18 and 40 days from the end of the disturbance. Multivariate and univariate asymmetrical analyses tested for changes in the
macrofaunal assemblage, biomass of microphytobenthos and various sediment properties (grain-size, water content, NH4 and NO3 concentrations in the pore water) between the two control locations (Cs) and the putatively-impacted location (I). There were no detectable changes in the sediment properties and microphytobenthos biomass, but variability at small scale
was observed. Microphytobenthos and NH4 were correlated at I to the number of footprints, as estimated by the percentage cover of physical depressions. This indicated that trampling
could have an impact at small scales, but more investigation is needed. Trampling, instead, clearly modified the abundance
and population dynamics of the clam Macoma balthica (L.) and the cockle Cerastoderma edule (L.). There was a negative impact on adults of both species, probably because footsteps directly killed or buried the animals,
provoking asphyxia. Conversely, trampling indirectly enhanced recruitment rate of M. balthica, while small-sized C. edule did not react to the trampling. It was likely that small animals could recover more quickly because trampling occurred during
the growing season and there was a continuous supply of larvae and juveniles. In addition, trampling might have weakened negative
adult-juvenile interactions between adult cockles and juvenile M. balthica, thus facilitating the recruitment. Our findings indicated that human trampling is a relevant source of disturbance for the
conservation and management of mudflats. During the growing season recovery can be fast, but in the long-term it might lead
towards the dominance of M. balthica to the cost of C. edule, thereby affecting ecosystem functioning. 相似文献
53.
Habitat structure affects intraguild predation 总被引:4,自引:0,他引:4
Intraguild predation is thought to be ubiquitous in natural food webs. Yet, theory on intraguild predation predicts the intraguild prey to persist only under limited conditions. This gap between theory and empirical observations needs scrutiny. One reason might be that theory has focused on equilibrium dynamics and a limited set of species (usually three) that interact in well-mixed populations in unstructured habitats, and these assumptions will often not hold in natural systems. In this review, we focus on the effects of habitat structure on intraguild predation. Habitat structure could reduce encounter rates between predators and prey and could create refuges for prey. In both cases, habitat structure could reduce the strength of intraguild interactions, thereby facilitating species coexistence. A meta-analysis of studies on manipulation of habitat structure shows that intraguild prey indeed suffer less from intraguild predation in structured habitats. This was further confirmed by a meta-analysis in which studies on intraguild predation were classified according to habitat structure. Intraguild predation reduced densities of the intraguild prey significantly more in habitats with little structure than in habitats rich in structure. The effect of intraguild predation on the shared prey was negative, and not significantly affected by habitat structure. We conclude that habitat structure may increase persistence of the intraguild prey by decreasing the strength of the interaction between intraguild predator and intraguild prey. 相似文献
54.
Francisco?García-González Montserrat?GomendioEmail author 《Behavioral ecology and sociobiology》2003,53(6):385-392
Phyllomorpha laciniata Vill. (Heteroptera, Coreidae) females lay eggs on the host plant and on the backs of conspecifics. Since egg survival is greater when eggs develop on the backs of conspecifics than when laid on plants, we predict that females should prefer to lay eggs on conspecifics. In addition, because conspecifics are a high-quality site that represents a limiting resource, females should experience oviposition stimulation upon an encounter with a conspecific. Our results reveal that, when both the host plant and conspecifics are available simultaneously, females lay eggs preferentially on conspecifics. The results also support the second prediction, since females housed with conspecifics lay more than twice the number of eggs than isolated females. Isolated females do not seem to retain eggs, suggesting that oviposition stimulation is the result of an acceleration of egg-maturation rates. Other studies have found oviposition stimulation by mating and have suggested that it is the result of male strategies to increase short-term male reproductive success at some cost to females. The evolutionary scenario of our model organism seems to be quite different since females benefit greatly from increasing egg laying when there are conspecifics, because the advantages in terms of offspring survival are likely to translate into substantial increases in female reproductive success. 相似文献
55.
Gálvez-Iriqui Alma Carolina García-Romo Joel Said Cortez-Rocha Mario Onofre Burgos-Hernández Armando Burboa-Zazueta María Guadalupe Luque-Alcaraz Ana Guadalupe Calderón-Santoyo Montserrat Argüelles-Monal Waldo Manuel Plascencia-Jatomea Maribel 《Environmental science and pollution research international》2021,28(3):3051-3065
Environmental Science and Pollution Research - Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo... 相似文献
56.
Aitana Sevilla Miguel Luis Rodríguez Ángela García-Maraver Montserrat Zamorano 《Waste management (New York, N.Y.)》2013,33(5):1037-1046
Urban surfaces receive waste deposits from natural and human sources, which create a negative visual impact and are identified as potentially significant contributors to water and air pollution. Local councils are usually responsible for the sweep of roads and footpaths to keep the environment clean and free of litter. Quality controls are useful in order to check whether the services are being executed according to the quantity, quality and performance standards that are provided. In this sense, several factors might affect the efficiency of the management of cleaning and waste collection services; however, only a few contributions are available in the literature on the various aspects associated with the level of street cleanliness. In this paper, the suitability of a Cleanliness Index has been checked, for the case of Granada (South of Spain), in order to contribute to the proper management of public expenditure, improving the quality and cost of an essential service for any municipality. Results have concluded that the city exhibits a good level of cleanliness, although the standard of cleaning varied from one area of the city to another. The Cleaning Index fits well to the general situation of the different districts of Granada and thus, it could be considered a useful tool for measuring the level of cleanliness of the streets of the city and for evaluating the organization of the cleaning service, such that an outsourced company would not be responsible for controlling all the cleaning services. 相似文献