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111.
With the potential expansion of forest conservation programs spurred by climate-change agreements, there is a need to measure the extent to which such programs achieve their intended results. Conventional methods for evaluating conservation impact tend to be biased because they do not compare like areas or account for spatial relations. We assessed the effect of a conservation initiative that combined designation of protected areas with payments for environmental services to conserve over wintering habitat for the monarch butterfly (Danaus plexippus) in Mexico. To do so, we used a spatial-matching estimator that matches covariates among polygons and their neighbors. We measured avoided forest loss (avoided disturbance and deforestation) by comparing forest cover on protected and unprotected lands that were similar in terms of accessibility, governance, and forest type. Whereas conventional estimates of avoided forest loss suggest that conservation initiatives did not protect forest cover, we found evidence that the conservation measures are preserving forest cover. We found that the conservation measures protected between 200 ha and 710 ha (3-16%) of forest that is high-quality habitat for monarch butterflies, but had a smaller effect on total forest cover, preserving between 0 ha and 200 ha (0-2.5%) of forest with canopy cover >70%. We suggest that future estimates of avoided forest loss be analyzed spatially to account for how forest loss occurs across the landscape. Given the forthcoming demand from donors and carbon financiers for estimates of avoided forest loss, we anticipate our methods and results will contribute to future studies that estimate the outcome of conservation efforts.  相似文献   
112.
The Little Egret, Egretta garzetta, has breeding colonies in the island of Chikly (in the lake of Tunis) and in Thyna saltpans (in the gulf of Gabès), two important Tunisian wetlands that are strongly affected by anthropogenic activity. Here, we used E. garzetta chick feathers for environmental monitoring of breeding grounds of this species. Since trophic ecology is fundamental when interpreting contamination levels, our approach combined both trace-element (Hg, Pb, Cd, and Se) and stable-isotope analysis of ??13C, ??15N, and ??34S. Hg, Se, and ??15N levels were higher in specimens collected on Chikly than in Thyna. These observations highlight the degree of eutrophication of the lake of Tunis. Yellow-legged gulls (Larus michahellis) breeding in the same areas also feeds in the lake and attains similar concentrations of Hg and Se. In Thyna, egrets and gulls exploit distinct foraging habitats, as demonstrated by stable isotope analysis. The highest Hg and Se concentrations were found in Thyna. This result is consistent with greater exploitation of marine resources from the gulf of Gabès.  相似文献   
113.
The concentration activity of radon-222 has been monitored, with some interruptions, from 1997 to 2005 in the end section of a slightly rising, dead-end, 38-m long tunnel located in the Phulchoki hill, near Kathmandu, Nepal. While a high concentration varying from 6 x 10(3) Bq m(-3) to 10 x 10(3) Bq m(-3) is observed from May to September (rainy summer season), the concentration remains at a low level of about 200 Bq m(-3) from October to March (dry winter season). This reduction of radon concentration is associated with natural ventilation of the tunnel, which, contrary to expectations for a rising tunnel, takes place mainly from October to March when the outside air temperature drops below the average tunnel temperature. This interpretation is supported by temperature measurements in the atmosphere of the tunnel, a few meters away from the entrance. The temporal variations of the diurnal amplitude of this temperature indeed follow the ventilation rate deduced from the radon measurements. In the absence of significant ventilation (summer season), the radon exhalation flux at the rock surface into the tunnel atmosphere can be inferred; it exhibits a yearly variation with additional transient reductions associated with heavy rainfall, likely to be due to water infiltration. No effect of atmospheric pressure variations on the radon concentration is observed in this tunnel. This experiment illustrates how small differences in the location and geometry of a tunnel can lead to vastly different behaviours of the radon concentration versus time. This observation has consequences for the estimation of the dose rate and the practicability of radon monitoring for tectonic purposes in underground environments.  相似文献   
114.
This paper analyzes the co-benefits of introducing a time variant carbon (C) tax scheme in Nepal, a hydropower resourceful country, by using a bottom up integrated energy system model based on the MARKet ALlocation (MARKAL) framework with time horizon of 2005–2050. It discusses the effects of C tax on energy mix, environmental emissions, energy supply security, energy efficiency, energy system cost, and employment benefit. The study shows that the C tax (that gradually increases from US13/tCO < sub > 2 < /sub > e in 2015 to US 13/tCO2e in 2015 to US 200/tCO2e by 2050) results in a reduction of the cumulative emission of greenhouse gases by 83.9 million tons CO2e (12%) as compared to that in the base case. With the introduction of the C tax, there would be a need for additional hydropower capacity of 945 MW by 2050 as compared to the capacity in the base case. The emission of local pollutants consisting of sulphur dioxide (SO2), nitrogen oxides (NOx) and non-methane volatile organic compound (NMVOC) in 2050 would be reduced by 12%, 7% and 1% respectively under the C tax scenario. Total amount of imported energy would decrease by 13%, which corresponds to a reduction in discounted net fuel import cost by 5% during the study period. Furthermore, the C tax would result in new employment generation of 151 thousand man-years associated with the additional hydropower capacity requirement.  相似文献   
115.
Environmental Science and Pollution Research - Clean water production using green energy supply plays a significant role in the globe’s health and economic development. In recent years, so...  相似文献   
116.
Environment Systems and Decisions - Early warning systems for weather events are becoming widespread as technological capacities develop. For warnings to be effective, they must allow enough lead...  相似文献   
117.
Amyotrophic lateral sclerosis (ALS), a progressive disorder that usually runs a fatal course within 2–5 years of onset, is characterized by loss of motor neurons in the cortex, brain stem, and spinal cord. In this study mercury (Hg) concentrations were determined in blood samples of 40 ALS patients, of whom 24 ALS patients were from the Ganga plain region and their metal levels were found to be significantly higher. In contrast, Hg levels in the 16 ALS patients from non-Ganga plain regions whose levels were similar to those of the control subjects. Mercury in stream water samples and freshly deposited stream sediment were determined in the locations of patients’ native residences along the Ganga plain region and metal levels were found to be higher than the threshold guideline values for Hg in stream waters recommended by WHO. The geo-accumulation index in selected sites of freshly deposited stream sediment ranged from moderate to highly polluted. The high levels of Hg observed in ALS patients may potentially alter the redox status of neuronal cell components and induce cell-death pathways.  相似文献   
118.
Data from National Health and Nutrition Examination Survey for children aged 6–11 years for 1999–2014 were used to study time trends and factors affecting the urinary levels of barium, cobalt, cesium, molybdenum, lead, antimony, thallium, and tungsten. Adjusted levels in urine declined every two years by 5.9% for barium, by 1.2% for cesium, by 18.2% for lead, and by 14% for antimony. For every additional smoker smoking inside a home, the levels of barium increased by 10.6% and for lead by 10%, but for tungsten levels decreased by 7.7%.  相似文献   
119.
Over 350 European Integrated Coastal Zone Management (ICZM) ‘best practice’ case studies are documented in the OURCOAST online public database, to ensure that lessons learned from experiences and practices are shared and improve coastal management practices. However, concrete criteria for ‘best practice’ are missing and a critical evaluation of the success of these case studies did not take place. We present an indicator-based tool and methodology that allows assessing the progress towards sustainability of ICZM measures. An indicator-based tool was applied to 18 thematically different coastal case studies using two different methods: a fast screening and an analysis in-depth assessment. Both methods used help to identify strengths and weaknesses of ICZM and their contribution to sustainable development. However, indicator scores were highly affected by evaluators’ background and perception. The tool is user-friendly and easy to apply, it indicates what progress has made towards sustainability and to which extent targets have been met.  相似文献   
120.
Many breeding seabird species are central-place foragers and constrained to find productive prey patches within their foraging ranges. We assessed how different populations of a pelagic seabird species, the Cory’s shearwater Calonectris diomedea, breeding in oceanic and neritic conditions, cope with these constraints in the North Atlantic, during both incubation and chick-rearing periods. We analysed 237 foraging trips to study the movements and oceanographic characteristics of foraging habitats of seven different populations of Cory’s shearwaters. Generally, oceanic populations exhibited higher foraging effort, by travelling more time and to more distant areas, and larger home ranges and feeding areas, than the neritic population (i.e. breeding on an island within the Portuguese continental platform). On their short trips (i.e. ≤4 days), birds from the different populations fed mostly in shallower waters around the colony. During long trips (i.e. ≥5 days), feeding areas of both oceanic and neritic populations were characterized by high concentration values of chlorophyll-a, low sea-surface temperature and shallower habitats, with oceanic populations of the Azores exploiting areas north of the islands over known seamounts and frontal regions. Birds from other oceanic population (Selvagens) also exploited the African continental shelf system on their long trips. The home ranges of the different populations overlapped widely, but there was a general spatial segregation in terms of the core feeding areas at the population level. Core feeding areas and areas of foraging overlap between different populations should be important to inform conservation management measures, such as the definition of Marine Important Bird Areas for seabirds over the North Atlantic.  相似文献   
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