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231.
In Europe, bromadiolone, an anticoagulant rodenticide authorized for plant protection, may be applied intensively in fields to control rodents. The high level of poisoning of wildlife that follows such treatments over large areas has been frequently reported. In France, bromadiolone has been used to control water voles (Arvicola terrestris) since the 1980s. Both regulation and practices of rodent control have evolved during the last 15 years to restrict the quantity of poisoned bait used by farmers. This has led to a drastic reduction of the number of cases of poisoned wildlife reported by the French surveillance network SAGIR. During the autumn and winter 2011, favorable weather conditions and high vole densities led to the staging of several hundreds of Red Kites (Milvus milvus) in the Puy‐de‐Dôme department (central France). At the same time, intensive treatments with bromadiolone were performed in this area. Although no misuse has been mentioned by the authorities following controls, 28 Red Kites and 16 Common Buzzards (Buteo buteo) were found dead during surveys in November and December 2011. For all these birds, poisoning by bromadiolone as the main cause of death was either confirmed or highly suspected. Other observations suggest a possible impact of bromadiolone on the breeding population of Red Kites in this area during the spring 2011. French regulation of vole control for plant protection is currently under revision, and we believe this event calls for more sustainable management of rodent outbreaks. Based on large‐scale experiments undertaken in eastern France, we propose that direct control of voles at low density (with trapping or limited chemical treatments) and mechanical destruction of vole tunnels, mole control, landscape management, and predator fostering be included in future regulation because such practices could help resolve conservation and agricultural issues. Envenenamiento No Intencional de Fauna Silvestre y Propuestas para un Manejo Sustentable de Roedores.  相似文献   
232.
Biodiversity surrogates and indicators are commonly used in conservation management. The focal species approach (FSA) is one method for identifying biodiversity surrogates, and it is underpinned by the hypothesis that management aimed at a particular focal species will confer protection on co‐occurring species. This concept has been the subject of much debate, in part because the validity of the FSA has not been subject to detailed empirical assessment of the extent to which a given focal species actually co‐occurs with other species in an assemblage. To address this knowledge gap, we used large‐scale, long‐term data sets of temperate woodland birds to select focal species associated with threatening processes such as habitat isolation and loss of key vegetation attributes. We quantified co‐occurrence patterns among focal species, species in the wider bird assemblage, and species of conservation concern. Some, but not all, focal species were associated with high levels of species richness. One of our selected focal species was negatively associated with the occurrence of other species (i.e., it was an antisurrogate)—a previously undescribed property of nominated focal species. Furthermore, combinations of focal species were not associated with substantially elevated levels of bird species richness, relative to levels associated with individual species. Our results suggest that although there is some merit to the underpinning concept of the FSA, there is also a need to ensure that actions are sufficiently flexible because management tightly focused on a given focal species may not benefit some other species, including species of conservation concern, such of which might not occur in species‐rich assemblages. Una Evaluación Empírica de la Hipótesis de Especie Focal  相似文献   
233.
Ramp‐up or soft‐start procedures (i.e., gradual increase in the source level) are used to mitigate the effect of sonar sound on marine mammals, although no one to date has tested whether ramp‐up procedures are effective at reducing the effect of sound on marine mammals. We investigated the effectiveness of ramp‐up procedures in reducing the area within which changes in hearing thresholds can occur. We modeled the level of sound killer whales (Orcinus orca) were exposed to from a generic sonar operation preceded by different ramp‐up schemes. In our model, ramp‐up procedures reduced the risk of killer whales receiving sounds of sufficient intensity to affect their hearing. The effectiveness of the ramp‐up procedure depended strongly on the assumed response threshold and differed with ramp‐up duration, although extending the duration of the ramp up beyond 5 min did not add much to its predicted mitigating effect. The main factors that limited effectiveness of ramp up in a typical antisubmarine warfare scenario were high source level, rapid moving sonar source, and long silences between consecutive sonar transmissions. Our exposure modeling approach can be used to evaluate and optimize mitigation procedures. Modelado de la Efectividad de los Incrementos Graduales en el Nivel de la Fuente para Mitigar Efectos de Sonar sobre Mamíferos Marinos  相似文献   
234.
Conservation scientists and resource managers often have to design monitoring programs for species that are rare or patchily distributed across large landscapes. Such programs are frequently expensive and seldom can be conducted by one entity. It is essential that a prospective power analysis be undertaken to ensure stated monitoring goals are feasible. We developed a spatially based simulation program that accounts for natural history, habitat use, and sampling scheme to investigate the power of monitoring protocols to detect trends in population abundance over time with occupancy‐based methods. We analyzed monitoring schemes with different sampling efforts for wolverine (Gulo gulo) populations in 2 areas of the U.S. Rocky Mountains. The relation between occupancy and abundance was nonlinear and depended on landscape, population size, and movement parameters. With current estimates for population size and detection probability in the northern U.S. Rockies, most sampling schemes were only able to detect large declines in abundance in the simulations (i.e., 50% decline over 10 years). For small populations reestablishing in the Southern Rockies, occupancy‐based methods had enough power to detect population trends only when populations were increasing dramatically (e.g., doubling or tripling in 10 years), regardless of sampling effort. In general, increasing the number of cells sampled or the per‐visit detection probability had a much greater effect on power than the number of visits conducted during a survey. Although our results are specific to wolverines, this approach could easily be adapted to other territorial species. Poder de Análisis Espacialmente Explícito para el Monitoreo Basado en Ocupación del Glotón (Gulo gulo) en las Montañas Rocallosas de Estados Unidos  相似文献   
235.
236.
We describe conservation built on local expertise such that it constitutes a hybrid form of traditional and bureaucratic knowledge. Researchers regularly ask how local knowledge might be applied to programs linked to protected areas. By examining the production of conservation knowledge in southern Mexico, we assert local expertise is already central to conservation. However, bureaucratic norms and social identity differences between lay experts and conservation practitioners prevent the public valuing of traditional knowledge. We make this point by contrasting 2 examples. The first is a master's thesis survey of local experts regarding the biology of the King Vulture (Sarcoramphus papa) in which data collection took place in communities adjacent to the Calakmul Biosphere Reserve. The second is a workshop sponsored by the same reserve that instructed farmers on how to monitor endangered species, including the King Vulture. In both examples, conservation knowledge would not have existed without traditional knowledge. In both examples, this traditional knowledge is absent from scientific reporting. On the basis of these findings, we suggest conservation outcomes may be improved by recognizing the knowledge contributions local experts already make to conservation programming. Mejorando los Resultados de la Conservación con la Percepción de Expertos y Burócratas Locales Haenn et al.  相似文献   
237.
Previous research has indicated that offenses are better predictors of subsequent crashes than crashes themselves. We examined this hypothesis for 13,800 young beginning drivers in Michigan for up to nine years during the initial years of driving. Our analyses indicated that previous-year offenses are better predictors of both subsequent-year offenses and crashes than either previous-year crashes or at-fault crashes. This finding also held for the apparently higher-risk subset of subsequent-year serious offenses and at-fault crashes. Although there were no gender differences in the predictive power of crashes, it was found that the predictive power of previous offenses to subsequent serious offenses was significantly stronger for women than for men. The predictive power of incidents appeared to increase somewhat with increasing driving experience, suggesting that early incidents may be more attributable to inexperience, a characteristic of all beginning drivers, while later incidents may be more attributable to individual differences.  相似文献   
238.

This investigation was undertaken to survey the fungal and mycotoxin contamination of South African wheat ranging from that growing in the field to processed wheat products. Samples of wheat were taken from various growing areas in South Africa and screened for fungi and mycotoxins, using a range of methodologies, including chromatography, immunoaffinity/fluorimetry, and cytotoxicity testing. Similar samples were taken from supermarkets and retail outlets in South Africa and analyzed in a similar manner. The result showed that a range of fungi and mycotoxins could be detected in wheat in all these sample types. The major fungal contaminants were Fusarium spp. and their attendant mycotoxins, in particular deoxynivalenol, which is in keeping with the observations made in the rest of the world. An interesting observation was that samples of wheat taken from the field with heavy Fusarium contamination were contaminated with fumonisin B1, which is not normally associated with this crop. Of more concern were the low but persistent levels of mycotoxins and fungi in wheat-based products sold directly to the public.  相似文献   
239.

Agricultural pharmaceuticals are a major environmental concern because of their hazardous effects on human and wildlife. This study analyzed phospholipid ester-linked fatty acids (PLFAs) and quinones to investigate the effects of a steroid (17β-estradiol) and agricultural antibiotics (chlortetracycline and tylosin) on soil microbes in the laboratory. Two different types of soil were used: Sequatchie loam (0.8% organic matter) and LaDelle silt loam (9.2% organic matter). The soils were spiked with 17β-estradiol and antibiotics, alone or in combination. In Sequatchie loam, 17β-estradiol significantly increased the microbial biomass, especially the biomarkers for beta proteobacteria (16:1ω7c, 18:1ω7c, Cy17:0, and UQ-8). The coexistence of antibiotics decreased the stimulatory effect of 17β-estradiol on the microbial community. In LaDelle silt loam, there were no significant differences in total microbial biomass and their microbial community structure among the treatments. Overall, 17β-estradiol changed the microbial community of soil and the presence of antibiotics nullified the effect of 17β-estradiol. However, the effects of 17β-estradiol and antibiotics on soil microbes were sensitive to the soil properties, as seen in the LaDelle silt loam.  相似文献   
240.
The Response of Avian Feeding Guilds to Tropical Forest Disturbance   总被引:1,自引:0,他引:1  
Abstract:  Anthropogenic habitat disturbance is a major threat to tropical forests and understanding the ecological consequences of this disturbance is crucial for the conservation of biodiversity. There have been many attempts to determine the ecological traits associated with bird species' vulnerability to disturbance, but no attempt has been made to synthesize these studies to show consensus. We analyzed data from 57 published studies (covering 1214 bird species) that investigated the response of tropical bird assemblages to moderate forest disturbance (e.g., selective logging). Our results show that the mean abundance of species from six commonly reported feeding guilds responded differently to disturbance and that species' ecological traits (body size, local population size, and geographic range size) and evolutionary relationships may influence responses in some guilds. Granivore abundance increased significantly and insectivore and frugivore abundance decreased significantly following disturbance. These general conclusions were robust to the effects of ecological traits and phylogeny. Responses of carnivores, nectarivores, and omnivores were less clear, but analyses that accounted for phylogeny indicated that these guilds declined following disturbance. In contrast to the other guilds, the reported responses of carnivores and nectarivores differed among regions (Asia vs. Neotropics) and were influenced by the sampling protocols used in different studies (e.g., time since disturbance), which may explain the difficulty in detecting general responses to disturbance in these guilds. Overall, general patterns governed the responses of species to habitat disturbance, and the differential responses of guilds suggested that disturbance affects trophic organization and thus ecosystem functioning.  相似文献   
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