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181.
Simone L. Stevenson Skipton N. C. Woolley Jon Barnett Piers Dunstan 《Conservation biology》2020,34(3):622-631
Marine protected areas (MPAs) are the preferred tool for preventing marine biodiversity loss, as reflected in international protected area targets. Although the area covered by MPAs is expanding, there is a concern that opposition from resource users is driving them into already low-use locations, whereas high-pressure areas remain unprotected, which has serious implications for biodiversity conservation. We tested the spatial relationships between different human-induced pressures on marine biodiversity and global MPAs. We used global, modeled pressure data and the World Database on Protected Areas to calculate the levels of 15 different human-induced pressures inside and outside the world's MPAs. We fitted binomial generalized linear models to the data to determine whether each pressure had a positive or negative effect on the likelihood of an area being protected and whether this effect changed with different categories of protection. Pelagic and artisanal fishing, shipping, and introductions of invasive species by ships had a negative relationship with protection, and this relationship persisted under even the least restrictive categories of protection (e.g., protected areas classified as category VI under the International Union for Conservation of Nature, a category that permits sustainable use). In contrast, pressures from dispersed, diffusive sources (e.g., pollution and ocean acidification) had positive relationships with protection. Our results showed that MPAs are systematically established in areas where there is low political opposition, limiting the capacity of existing MPAs to manage key drivers of biodiversity loss. We suggest that conservation efforts focus on biodiversity outcomes and effective reduction of pressures rather than prescribing area-based targets, and that alternative approaches to conservation are needed in areas where protection is not feasible. 相似文献
182.
Following years of progress in designing and executing cleanups of contaminants at waste sites, the U.S. Air Force, state regulatory groups, and others are crafting methods to evaluate broader considerations of risk in remedial decisions. Integrating worker and climate risks into remediation efforts may confer significant benefits, but challenges exist to identifying, assessing, and accounting for them in the remedial process. For sites where future risk posed by contamination far exceeds the risk posed to workers who may be exposed to the contaminants during the remedial process, limiting the range of decision inputs to those presented by the site conditions made sense and provided a net benefit to human health and the environment. There are other sites, however, where future risk posed by the in situ contamination are at levels comparable to the real risks posed to workers, ecology, and even emerging concerns about climate change. For these sites, a net risk reduction cannot be assumed to be a result of remedial action, challenging the remedial community to develop new approaches to ensure positive results. © 2009 Wiley Periodicals, Inc. 相似文献
183.
The Yellow River in transition 总被引:3,自引:0,他引:3
Like many parts of the world, the Yellow River basin has problems associated with water scarcity, pollution, and flood risk. Analyses that focus only on the physical characteristics of these problems miss some of their most important social drivers. In this paper we identify some interlocking changes that have occurred as a consequence of economic reforms begun in China in 1978, and the implications of these changes for the Yellow River. The reforms have caused changes in the organisation of household production, increasing urbanisation and urban affluence, rapid industrialisation, and large scale spatial shifts in agricultural production. Rather than specific decisions it is these gradual changes that have affected the current status of the Yellow River and its basin. Our analysis suggests that at least some solutions to water problems in the Yellow River lie outside the basin, and beyond the realm of science or technology. 相似文献
184.
Kaye Nigel B. Robinson Dylan M. Akhter Romana Ahsanullah Md Safwan Jordan TaJon A. Martinez Oscar E. 《Environmental Fluid Mechanics》2022,22(4):763-787
Environmental Fluid Mechanics - Buoyant turbulent plumes are often categorized by their geometry and described as either round plumes, issuing from a point source, or line/planar plumes, issuing... 相似文献
185.
Choosing an appropriate home range model is important for describing space use by animals and understanding the ecological processes affecting animal movement. Traditional approaches for choosing among home range models have not resulted in general, consistent, and unambiguous criteria that can be applied to individual data sets. We present a new application of information-theoretic model selection that overcomes many of the limitations of traditional approaches, as follows. (1) It alleviates the need to know the true home range to assess home range models, thus allowing performance to be evaluated with data on individual animals. (2) The best model can be chosen from a set of candidate models with the proper balance between fit and complexity. (3) If candidate home range models are based on underlying ecological processes, researchers can use the selected model not only to describe the home range, but also to infer the importance of various ecological processes affecting animal movements within the home range. 相似文献
186.
Dennis F. Kahlbaum Jon M. Heuss George T. Wolff 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1070-1078
ABSTRACT Because the U. S. Environmental Protection Agency (EPA) has changed the National Ambient Air Quality Standards (NAAQS) for ambient particulate matter (PM), there is a great deal of interest in determining recent PM trends. This paper examines trends in PM10 (i.e., particulate matter less than 10 micrometers in diameter) for areas of the United States based on their attainment status—for PM10 and ozone nonattainment and attainment areas. The analysis also focuses on urban, suburban, and rural areas, and eastern and western areas. The time period of evaluation is from 1988 through 1995. To shed further light on the ambient PM10 trends, trends in ambient SO2, NO2, and volatile organic compounds (VOCs) are also analyzed. Finally, trends in emission inventories of SO2, NOx, VOCs, and PM10 are evaluated. Results of the analysis show that widespread and similar reductions in PM10 levels have occurred over the last seven years. Annual reductions range from 3.0% to 3.8%, with the greatest reductions coming in PM10 nonattainment areas, but with very significant reductions also in PM10 attainment areas, ozone attainment areas, and rural areas. The widespread reductions appear to be due to a set of controls or common factors that are having a fairly uniform effect in all of the areas. The consistency of the reductions in different areas suggests that the reductions may also be primarily in the fine particles (i.e., those less than 2.5 micrometers in diameter, or PM2.5), which are more readily transported than coarse particles. 相似文献
187.
188.
Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis Beetle & Young) communities frequently are mowed in an attempt to increase perennial herbaceous vegetation. However, there
is limited information as to whether expected benefits of mowing are realized when applied to Wyoming big sagebrush communities
with intact understory vegetation. We compared vegetation and soil nutrient concentrations in mowed and undisturbed reference
plots in Wyoming big sagebrush plant communities at eight sites for three years post-treatment. Mowing generally did not increase
perennial herbaceous vegetation cover, density, or biomass production (P > 0.05). Annual forbs and exotic annual grasses were generally greater in the mowed compared to the reference treatment (P < 0.05). By the third year post-treatment annual forb and annual grass biomass production was more than nine and sevenfold
higher in the mowed than reference treatment, respectively. Our results imply that the application of mowing treatments in
Wyoming big sagebrush plant communities does not increase perennial herbaceous vegetation, but may increase the risk that
exotic annual grasses will dominate the herbaceous vegetation. We suggest that mowing Wyoming big sagebrush communities with
intact understories does not produce the expected benefits. However, the applicability of our results to Wyoming big sagebrush
communities with greater sagebrush cover and/or degraded understories needs to be evaluated. 相似文献
189.
Pollinators may mediate selection on traits affecting pollinator attraction and effectiveness, and while nonadditive effects of traits influencing the two components of pollination success are expected when seed production is pollen limited, they have been little studied. In a factorial design, we manipulated one putative attraction trait (number of flowers) and one putative efficiency trait (spur length) previously shown to be subject to pollinator-mediated selection in the deceptive orchid Dactylorhiza lapponica. Removal of half of the flowers reduced pollen removal, proportion of flowers receiving pollen, fruit set, and fruit mass compared to unmanipulated plants, while spur-tip removal increased fruit set and fruit mass but did not affect pollen removal or proportion of flowers receiving pollen. The effect of spur-tip removal on fruit mass was stronger among plants with intact number of flowers compared to plants with experimentally reduced number of flowers. The results demonstrate that number of flowers and spur length are direct targets of selection and may affect female fitness nonadditively. More generally, they show that the adaptive value of a given trait can depend on floral context and illustrate how experimental approaches can advance our understanding of the evolution of trait combinations. 相似文献
190.
Rudge CV Calderon IM Rudge MV Volpato G Silva JL Duarte G Neto CM Sass N Mattar R Röllin HB Thomassen Y Odland JØ 《Journal of environmental monitoring : JEM》2011,13(3):563-571
This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of S?o Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 μg L?1, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 μg L?1 (0.01-0.58 μg L?1) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 μg L?1 (0.06 μg L?1-4.35 μg L?1); median Pb level was 16.2 μg L?1 (3.5-57.7 μg L?1) and no differences between sites were observed for both metals. Median Mn level was 16.7 μg L?1 (7.0-39.7 μg L?1), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 μg L?1 and 1.1 μg L?1 (median 0.25 μg L?1) and As level was 0.60 μg L?1 (0.10-3.8 μg L?1) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 μg L?1 (36-233 μg L?1), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in S?o Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners. 相似文献