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371.
The current status of the oak and oak-pine forests in the Sierra de La Laguna range of the Baja California peninsula is examined from four perspectives: (1) the structural analysis of the woodlands; (2) the natural regeneration of hurricane windfall clearings and its effect on the oak-pine community; (3) the density, mortality, size, and commercial potential of the only pine species Pinus lagunae; and (4) the possible destruction of this endemic species by attack from moths. These factors were evaluated to make recommendations regarding the management and/or commercialization of the forest resources of this proposed Biosphere Reserve. Results show that the oak woodlands occurring at low elevations contain many tropical plants from the tropical dry forest that surrounds these woodlands, and that the tropical elements decrease at higher altitudes. In forest gaps, oaks were more abundant than pines. Gaps contained a lower diversity of perennial plants than mature oak-pine forest. P. lagunae has a high adult mortality, which can be attributed to the joint effect of fire and insect attack. Results indicate that the forest in this region does not have timber-yielding potential because of the small area it covers and because of the low tree diameters and volume, which are insufficient to carry out a continuous and income-producing extraction of the pine resource of Baja California Sur. Finally, options for management are discussed and future studies are proposed to determine the life cycle and extent of the moth populations. 相似文献
372.
Stavroula Tasiopoulou Alessandro M. Chiodini Francesca Vellere Sara Visentin 《Journal of environmental science and health. Part. B》2013,48(7):835-841
Organic agriculture, with its restrictions on the use of synthetic chemical inputs, seems to offer a low-residue alternative to conventional methods. In Europe, the Council Regulation n. 2092/91/EEC regulates the production and trade of organic products and foodstuffs; national and regional legislation in Italy gives specific guidance on the surveillance of organic agriculture. However, monitoring of specific chemical residues in organic foodstuffs is part of the regular controls on food, aiming to safeguard consumer's health. Monitoring programs are coordinated at the national level by the Ministry of Health and at local level by Regional authorities. In Lombardy, in accordance with the provisions of the General Directorate of Health of the Region and under the supervision of the 15 Local Health Units, a monitoring program of pesticide residues in food of plant origin is undertaken every year. The International Centre for Pesticides and Health Risk Prevention (ICPS), on behalf of the General Directorate of Health of the Region of Lombardy, has been collecting and elaborating the data resulting from the analysis of food samples, carried out by the local laboratories. During the period 2002–2005, a total of 3508 samples food of plant origin were analyzed for pesticide residues, among which were 266 samples of organic farming products. Commodities were classified into groups (citrus fruits, legumes, vegetables, potatoes, processed products, cereals, and fruit other than citrus) and the outcomes of the analyses were reported by year, origin of the sample and presence/absence of pesticide residues. Results showed that the vast majority of organic farming products were in conformity with the relevant legislation and did not contain detectable pesticide residues. A limited amount of samples had residues at concentration below the Maximum Residue Limit (MRL). Only in one sample the residue level was above the MRL, however it did not pose a concern for public health, as demonstrated by the outcomes of dietary risk assessment. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives. There is a widespread belief that organic agriculture products are safer and healthier than conventional foods. It is difficult to come to conclusions, but what should be made clear to the consumer is that “organic” does not automatically equal “safe”. In the absence of adequate comparative data, additional studies in this area of research are required. 相似文献
373.
374.
Sara Dolnicar Anna Hurlimann Long Duc Nghiem 《Journal of environmental management》2010,91(6):1288-1293
This study aims to provide conclusive evidence that information about water from alternative sources increases public acceptance. We conducted an experiment with 1000 Australian respondents asking them about their acceptance of recycled and desalinated water for a range of purposes under two conditions: 1) no information provided and 2) information about the production process provided. Results indicate that – both for desalinated and recycled water – the stated likelihood of use increases significantly if people are provided with information about the production process. This has major implications for public policy makers indicating that providing factual information (as opposed to persuasive campaigns) will increase public support of water augmentation projects. 相似文献
375.
376.
Sara kaffashi Mad Nasir Shamsudin Alias Radam Khalid Abdul Rahim Mohd Rusli Yacob Azizi Muda Muhammad Yazid 《Regional Environmental Change》2011,11(4):925-934
Wetlands are among the most productive ecosystems on the earth. They produce various market and non-market goods and services,
which have a significant role in human welfare. Despite the great opportunities from sustainable development, wetlands all
over the world are under serious threat from a diverse range of non-sustainable activities. One of the major reasons for excessive
depletion and the conversion of wetland resources is due to underestimating the non-market values of wetlands during development
decisions. Shadegan International Wetland (SIW) in southern Iran is one of these wetland areas that is threatened by undervaluation
and overexploitation from commercial activities. This study utilizes the contingent valuation method to estimate the economic
benefits of SIW from the view point of peoples’ willingness to pay (WTP). The logit model was defined based on dichotomous
choice to measure individuals’ WTP. The estimated mean WTP was US$ 1.74 per household as a onetime donation. This study concludes
that the benefits of SIW to society could encourage managers to set priorities to ensure that the health of the ecosystem,
its integrity, and its uniqueness would be conserved in a proper manner. 相似文献
377.
378.
Sara Kaffashi Mad Nasir Shamsudin Alias Radam Khalid Abdul Rahim Mohd Rusli Yacob 《The Environmentalist》2013,33(2):251-260
The inclusion of both non-use values and values placed by non-users provide more reliable results about the real values of wetlands. A choice experiment method was conducted to estimate the willingness to pay for environmental conservation in non-users’ communities adjacent to the Shadegan International Wetland (SIW) in Iran. A random parameter logit (RPL) model was developed to derive the marginal value and compensating surplus of the respondents for five attributes of the non-market values of SIW. The trade-off between five different wetland attributes showed that water quality improvement and biodiversity conservation were the most highly valued attributes. The results demonstrated that about 66 % of non-users were willing to donate money for the contribution in SIW conservation, suggesting that non-users have the potential to contribute to SIW conservation programs. 相似文献
379.
Damla Kaner Ayfer Saraç Bahire Filiz Şenkal 《Environmental geochemistry and health》2010,32(4):321-325
A new polymeric resin with amino sulfonic acid pendant functions has been prepared for the extraction of acidic and basic
dyes from water. Beaded polymer supports were prepared by suspension polymerization of vinyl benzyl chloride (0.9 mol) and
ethylene glycol dimethacrylate (0.1 mol). The resulting copolymer beads were modified with amino methane sulfonic acid. The
dye adsorption capacity of the resin was found as 0.16 g dye/g resin for ramazol black and 0.15 g dye/g resin for crystal
violet. The pH depending measurements and dye sorption kinetics of the resin were also investigated. 相似文献
380.