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691.
Three studies used digital color photographs to compare responses to natural scenes, skylines after dark, and skylines during the day (seven of each). Study 1 had 59 respondents rate the pleasantness of each scene. They gave similar ratings to Night Skylines and Natural Scenes, and rated each as more pleasant than the Day Skylines. Study 2 had 56 other participants choose from each of seven sets of each kind of scene the one they would most like to have as a framed print in their home or office, and to report the reasons. Participants chose Night Skylines most often, followed by Natural Scenes and then Day Skylines. While participants most often picked attractive as a reason for their choice, those who chose Night Skylines also picked exciting as the reason, and those who picked Natural Scenes also picked relaxing or peaceful as a reason. Study 3 obtained ratings of selected formal features of each scene. The 23 judges rated the Natural scenes as more natural, orderly, open, and curvilinear, less complex, and as having smoother transitions than either Day or Night Skylines; and they judged the Night Skylines as higher in complexity but lower in order than Day Skylines. The results suggest that preferences in relation to the scene categories may well depend on a mix of their formal characteristics and their content. 相似文献
692.
Decision makers responsible for natural resource management often complain that science delivers fragmented information that
is not useful at the scale of implementation. We offer a way of negotiating complex problems by putting forward a requisite
simplicity. A requisite simplicity attempts to discard some detail, while retaining conceptual clarity and scientific rigor,
and helps us move to a new position where we can benefit from new knowledge. We illustrate the above using three case studies:
elephant densities and vegetation change in a national park, the use of rules of thumb to support decision making in agriculture,
and the management of salt in irrigation. We identify potential requisite simplicities that can allow us to generate new understanding,
lead to action and provide opportunities for structured learning. 相似文献
693.
Rebecca Lave 《Journal of the American Water Resources Association》2009,45(6):1519-1532
Lave, Rebecca, 2009. The Controversy Over Natural Channel Design: Substantive Explanations and Potential Avenues for Resolution. Journal of the American Water Resources Association (JAWRA) 45(6):1519‐1532. Abstract: The controversy over Natural Channel Design (NCD) has perplexed, and sometimes paralyzed, the stream restoration community in the United States for more than a decade. Despite the high level of energy expended by participants on both sides, the content of the discussion has not advanced significantly. The two sides seem to be talking past each other, rather than engaging in constructive conversation. This paper attempts to start that conversation. Based on five years of primarily social science research, this paper explains the key components of the NCD approach, evaluates a number of the most common objections raised by its critics, offers a brief explanation for the widespread use of NCD, and concludes with suggestions about how to bring the controversy to a close. 相似文献
694.
Mining activities in Rakha copper mine (Jharkhand, India) were ceased in the year 2001, leaving a huge amount of untreated
tailings in the nearby tailings pond. The copper tailings contained high concentrations of heavy metals (total Cu, Ni concentrations
1779, 564 mgkg−1, respectively), and low contents of major nutrient elements and organic matter. Tailings are often very unstable, and a potential
vegetation cover may reduce the erosion or immobilize the toxicants to surrounding environment by phytostabilization. However,
high shoot concentrations of elements might disperse them and could be harmful to grazing animals. The objective of this study
was to find out which of the three properties; low-accumulation, root accumulation or shoot accumulation of elements (Cu,
Ni, Mn, Zn, Pb, Cd and Co), occur in the semi aquatic species Ammania baccifera growing on copper tailings. Roots of this species accumulated high levels of Cu, even more than 1000 mg kg−1, DW. Metals accumulated by A. baccifera were mostly distributed in root tissues, suggesting that an exclusion strategy for metal tolerance widely exists in them.
Thus, establishment of such plant on copper tailings can be a safe method to stabilize the metals. 相似文献
695.
Podlaski R 《Environmental monitoring and assessment》2007,135(1-3):339-351
Tree damage, gauged by the amount of defoliation, is one of the basic criteria used to determine treatments for protected
and economic forests. Monitoring should include an assessment of the degree of tree damage in different spatial scales. Therefore,
in addition to the commonly applied large-area methods, small-area methods should be used. The aim of the paper is to present
the results of the accuracy assessment of a small-area method, proposed by Podlaski (2005) [Podlaski, R. (2005). Inventory of the degree of tree defoliation in small areas. Forest Ecology and Management, 215, 361–377], for monitoring the degree of tree damage. The degree of tree damage was shown in sub-blocks P3 of the system of information on natural environment (SINUS). To estimate the spatial distribution of the degree of tree defoliation,
survey sampling, based on simple random sampling with replacement (SRSWR), was used. The degree of damage to fir (Abies alba Mill.) and beech (Fagus sylvatica L.) was analysed in the Święty Krzyż forest section in the Świętokrzyski National Park. The maximum total estimation errors
for the proportion of trees with a degree zero of damage, and with second and third degrees of damage together (for α = 0.05) were at most 30.8% for fir and 24.3% for beech trees. For standard, small-area evaluations, these are satisfactory
values. In the Święty Krzyż forest section, the number of P3 sub-blocks with 0.00–5.00% of undamaged trees and with 80.01–100.00% of moderately- or severely-damaged trees was significantly
greater for fir than for beech. These results indicate that the fir population was unhealthier than the beech group in the
study area. P3 sub-blocks of the SINUS system, in which the proportion of the healthiest trees was highest, were situated at the forest
margin, bordering on meadows and arable fields (in the case of fir) and forming dense patches consisting of several sub-blocks,
or occurring singly in the whole study area (in the case of beech). The results show the significant differentiation of forest
tree health in small areas. 相似文献
696.
Perrino C Canepari S Cardarelli E Catrambone M Sargolini T 《Environmental monitoring and assessment》2007,128(1-3):133-151
A field study was carried out at six locations in the Lazio region (Central Italy) aimed at characterising atmospheric particulate
matter (PM10 and PM2.5) from the point of view of the chemical composition and grain size distribution of the particles, the mixing properties of
the atmosphere, the frequency and relevance of natural events. The combination of four different analytical techniques (ion
chromatography, X-ray fluorescence and ICP for inorganic components, thermo-optical analysis for carbon compounds) yielded
sound results in terms of characterisation of the air masses. During the first three months of the study (October-December
2004), many pollution events of natural (sea-salt or desert dust episodes) or anthropogenic nature were identified and characterised.
More than 90% of the collected mass was identified by chemical analysis. The central role played by the mixing properties
of the lower atmosphere when pollution events occurred was highlighted. The results show a major impact of primary anthropogenic
pollutants on traffic stations and a homogeneous distribution of secondary pollutants over the regional area. An evaluation
of the sources of PM and an identification of possible reliable tracers were obtained using a chemical fractionation procedure. 相似文献
697.
This paper empirically estimates the economic impacts of a large-scale public investment in natural infrastructure aimed at adapting to climate change and increasing coastal resilience. I utilize temporal and spatial variation in investment in dunes to provide a hedonic property value estimate of the economic benefits. I identify the net effect of treatment utilizing the doubly robust Oaxaca-Blinder estimator and show that coastal housing price increases attributable to constructed dunes are approximately 3.6%. A decomposition of the average impact suggests that the policy intervention generates ancillary costs related to impaired ocean views and privacy concerns that partially offset large protection benefits. 相似文献
698.
In late 1990s, USEPA/FDA made an important connection regarding the presence of elevated levels of dioxins (e.g., 1500 ng kg−1 TEQ) in ball clays mined in Mississippi (USA) from a geological deposit dated to ∼40 million years (Mississippi Embayment) that stretches over several states (northern part of Mississippi to Kentucky) and levels of dioxins in selected animal food sources. Following a recent beach nourishment program along the mid-Atlantic coast of the US, a number of dark gray, blue tinted nuggets of varying sizes were found on beach strands and near the shoreline. Using the presence of these balls of clay (shape, color, and knowledge regarding their use in pottery) on the beach, together with our direct experience analyzing ball clays for dioxins, we made a possible association between these clays and elevated dioxins. Concerns regarding the potential of nourishment programs to cause severe damage to our beaches drove us to test the dioxin content of nourishment exposed clays. A number of the nuggets, along with freshly dredged and deposited sand (collected the morning after nourishment) with the same coloration, and others (sun-bleached), collected approximately 2 weeks after the completion of the nourishment efforts, were analyzed for the presence of PCDD/Fs, PCBs, and selected semi-volatile chlorinated organics. The clay PCDD/F WHO2005-TEQs (dry weight; ND = DL; EMPC = EMPC) ranged from 0.41 to 5.78 ng kg−1 with an average of 2.64 ng kg−1, whereas the sand sample’s TEQs ranged from 0.18 to 0.31 ng kg−1 PCDD/F WHO-2005, with an average of 0.22 ng kg−1. The average total tetra- through octachlorinated dibenzo-p-dioxin concentration was 2700 ng kg−1 (with a maximum of 5800 ng kg−1) for the clays and 8.5 ng kg−1 (with a maximum of 16.8 ng kg−1) for the sand samples. The congener 2,3,7,8-TCDD (TEF = 1) was detected in half of the clay samples (0.11-0.77 ng kg−1). All of the clay and sand samples displayed an unambiguous and dominating 1,4,6,9-chlorination pattern across homolog groups. No other chlorinated aromatics were detected above background levels. The observations, along with the absence or an extremely low level of polychlorinated dibenzofurans, together with the mineralogical analysis, supports the conclusion that off-shore dredging activities are reaching reservoir sources containing dioxin-tainted, smectic/kaolinite clay minerals. Subsequent beach erosion provides additional environmental releases over time, as buried balls of clay from previous nourishment efforts become exposed. 相似文献
699.
Per Angelstam Marine Elbakidze Robert Axelsson Niels Elers Koch Tatiana I. Tyupenko Alexandr N. Mariev Lennart Myhrman 《Ambio》2013,42(2):111-115
This special issue of AMBIO presents a new approach to sustainability science that goes beyond interdisciplinary research. Using coupled natural and human systems, or landscapes, as multiple case studies in Europe’s East and West knowledge production and learning toward transdisciplinary research was applied in Sweden, countries in Central and Eastern Europe, and Russia. First, the research group Forest-Landscape-Society summarizes the research program (2005–2012) behind this special issue of AMBIO and its development to participate in transdisciplinary research. Second, stakeholders at multiple levels provide their views on the new approach presented and reported. 相似文献
700.
Rajiv Kumar Mir Irfan Ul Haq Ankush Raina Ankush Anand 《International Journal of Sustainable Engineering》2019,12(3):212-220
The growing industrial demand for sustainable materials has led to a paradigm shift in the focus from synthetic polymers towards natural fibres. This paper deals with the challenges and opportunities associated with the use of natural fibre-reinforced polymer composites in various industrial applications. Natural fibres being biodegradable, light in weight, cost-effective and environment friendly are good candidate materials for modern industrial applications. Use of natural fibres in various industries with a focus on automotive and furniture industry has been discussed. The commonly used natural fibres in polymer composites including jute, hemp, sisal, kenaf, bamboo, cotton, flax, abaca, coir etc. have been dealt with in this paper. The literature revealed that tensile strength and other mechanical properties of these fibres are comparable to synthetic fibres like glass or carbon fibres. However, the temperature stability of polymers limits their extensive use and remains an issue to be addressed. 相似文献