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51.
Gert Jan Reinds Maximilian Posch 《Environmental pollution (Barking, Essex : 1987)》2009,157(4):1258-1269
The dynamic soil chemistry model SMART was applied to 121 intensive forest monitoring plots (mainly located in western and northern Europe) for which both element input (deposition) and element concentrations in the soil solution were available. After calibration of poorly known parameters, the model accurately simulated soil solution concentrations for most plots as indicated by goodness-of-fit measures, although some of the intra-annual variation especially in nitrate and aluminium concentrations could not be reproduced. Model evaluations of two emission-deposition scenarios (current legislation and maximum feasible reductions) for the period 1970-2030 show a strong reduction in sulphate concentrations between 1980 and 2000 in the soil due to the high reductions in sulphur emissions. However, current legislation hardly reduces future nitrogen concentrations, whereas maximum feasible reductions reduces them by more than half. Maximum feasible reductions are also more effective in increasing pH and reducing aluminium concentrations, mostly below ‘critical’ values. 相似文献
52.
Ludovic Castro Aurlien Dommergue Christophe Ferrari Laurent Maron 《Atmospheric environment (Oxford, England : 1994)》2009,43(35):5708-5711
In the mid 1980s the study of ozone reactivity gained a significant interest with the discoveries of the stratospheric ozone hole (Farman et al., 1985) and of the ozone depletion events in the polar boundary layer (Oltmans et al., 1989). In the stratosphere, the mechanism involves heterogeneous reactions on polar stratospheric clouds that lead to chlorine activation (Solomon et al., 1986). In contrast, tropospheric ozone depletion occurring during polar springtime rather involves reactive bromine species. They are released during a series of photochemical and heterogeneous reactions often called the bromine explosion (see the review of Simpson et al., 2007). In this reaction sequence, an essential step is the generation of photolyzable Br2, the precursor of two Br atoms, via the multiphasic reaction (1):(1) The production of reactive HOBr could occur with the oxidation of BrO by HO2. 相似文献
HOBr + Br− + H+ → H2O + Br2
53.
The role of remote sensing in hydrological modelling of the Okavango Delta, Botswana 总被引:1,自引:0,他引:1
Milzow C Kgotlhang L Kinzelbach W Meier P Bauer-Gottwein P 《Journal of environmental management》2009,90(7):2252-2260
A coupled surface water-groundwater model of the Okavango Delta has been built based on the United States Geological Survey software MODFLOW 2000 including the SFR2 package for stream-flow routing. It will provide a new tool for evaluating water management and climate change scenarios. The delta's size and limited accessibility make direct, on the ground data acquisition difficult. Remote sensing methods are the most promising source of acquiring spatially distributed data for both model input parameters and calibration. Topography, aquifer thickness, channel positions, evapotranspiration and precipitation data are all based on remote sensing. Simulated flooding patterns are compared to patterns derived from visible to thermal NOAA-AVHRR data and microwave radar ENVISAT-ASAR data. 相似文献
54.
Dölarslan ES 《Journal of environmental management》2009,90(1):25-35
This paper reviews the effects of six post-modern management concepts as applied to Turkish forestry. Up to now, Turkish forestry has been constrained, both in terms of its operations and internal organization, by a highly bureaucratic system. The application of new thinking in forestry management, however, has recently resulted in new organizational and production concepts that promise to address problems specific to this Turkish industry and bring about positive changes. This paper will elucidate these specific issues and demonstrate how post-modern management thinking is influencing the administration and operational capacity of Turkish forestry within its current structure. 相似文献
55.
Ecological disturbances of forests by insects have a complex array of associated human dimensions presenting complications
for natural resource decision making and relationships between stakeholders and managers. This article discusses the human
context of forest disturbances by insects by reviewing four cases of bark beetle forest disturbance from British Columbia
in Canada, Bavarian Forest National Park in Germany, the Kenai Peninsula in Alaska, and the north central region of Colorado.
Findings and lessons learned from these studies are outlined along with their implications for managing forest disturbances
by insects in general. Conclusions focus on the need to assess the broad array of impacts and risks perceived by local residents
and the capacity for local action and involvement in managing forest disturbances. Communication and interaction between resource
managers and local stakeholders can facilitate the identification of management priorities and potentially reduce some of
the risks associated with forest disturbances by insects. 相似文献
56.
Frank Merry Britaldo Soares-Filho Daniel Nepstad Gregory Amacher Hermann Rodrigues 《Environmental management》2009,44(3):395-407
Logging has been a much maligned feature of frontier development in the Amazon. Most discussions ignore the fact that logging
can be part of a renewable, environmentally benign, and broadly equitable economic activity in these remote places. We estimate
there to be some 4.5 ± 1.35 billion m3 of commercial timber volume in the Brazilian Amazon today, of which 1.2 billion m3 is currently profitable to harvest, with a total potential stumpage value of $15.4 billion. A successful forest sector in
the Brazilian Amazon will integrate timber harvesting on private lands and on unprotected and unsettled government lands with
timber concessions on public lands. If a legal, productive, timber industry can be established outside of protected areas,
it will deliver environmental benefits in synergy with those provided by the region’s network of protected areas, the latter
of which we estimate to have an opportunity cost from lost timber revenues of $2.3 billion over 30 years. Indeed, on all land
accessible to harvesting, the timber industry could produce an average of more than 16 million m3 per year over a 30-year harvest cycle—entirely outside of current protected areas—providing $4.8 billion in returns to landowners
and generating $1.8 billion in sawnwood sales tax revenue. This level of harvest could be profitably complemented with an
additional 10% from logging concessions on National Forests. This advance, however, should be realized only through widespread
adoption of reduced impact logging techniques. 相似文献
57.
Arun Kansal Mukesh Khare Chandra Shekhar Sharma 《Journal of Environmental Planning and Management》2009,52(7):881-899
This study estimates minimum marginal health benefits (morbidity reduction only) of air pollution control and total health benefits arising from regulatory intervention regarding the adoption of the World Bank emission guidelines (WBEG) for thermal power plants (TPPs) in Delhi. The Industrial Source Complex-Short-Term Version–3 (ISCST3) model has been used to estimate the contribution to air pollution from TPPs. The household health production function (avertive behaviour) has been used to value health benefits of air pollution control. The study revealed that the ambient air pollution due to TPPs is reduced by between 62.17% to 83.45% by adopting the WBEG. Annual marginal benefit due to reduction in exposure to air pollution by 1 μg m?3 is estimated to be US$0.353 per person. Total annual health benefits for adopting the WBEG for TPPs are estimated at US$235.19 million. This study provides a novel methodology to evaluate health benefits of regulatory intervention. 相似文献
58.
Fertilization with 2.5 t/ha limestone: (83% CaCO3, 8% MgO, 6% K2O, 3% P2O5) reduces the 137Cs transfer from spruce forest soil into plants like fern (Dryopteris carthusiana) and blackberry (Rubus fruticosus) by a factor of 2–5 during at least 11 years as measured by the aggregated transfer factor Tag. In 1997 and 2006 these results were confirmed by additional measurements of the 137Cs transfer factor TF, related to the root zone (Oh horizon), which were explained by the selective sorption of 137Cs in the root zone by measurements of the Radiocaesium Interception Potential (RIP) in fertilized (RIP > 179 meq/kg) and non-fertilized soils (RIP < 74 meq/kg). 相似文献
59.
Since WWII, forest management in Fennoscandia has primarily been based on even-aged stand management, clear cut harvesting and thinning from below. As an alternative, uneven-aged management, based on selection cutting of individual trees or small groups of trees, has been proposed. In this review we discuss the theoretical aspects of ecology and economics of the two management approaches. We also review peer-reviewed studies from boreal Fennoscandia, which have aimed at comparing the outcomes of uneven-aged and the conventional even-aged forest management. According to a common view the main obstacle of practicing uneven-aged forestry is its low economic performance. However, the reviewed studies did not offer any straightforward support for this view and several studies have found uneven-aged management to be fully competitive with existing even-aged management. Studies on the ecological aspects indicated that selection cuttings maintain mature or late-successional forest characteristics and species assemblages better than even-aged management, at least at the stand scale and in the short term. We conclude that although the number of relevant studies has increased in recent years, the ecological and economic performance of alternative management methods still remains poorly examined, especially for those stands with multiple tree species and also at wider spatial and temporal scales. For future research we advocate a strategy that fully takes into consideration the interdisciplinary nature of forest management and is better connected to social goals and latest theoretical and methodological developments in ecology and economics. 相似文献
60.
Forest degradation in West Africa is generally thought to have negative consequences on rural livelihoods but there is little overview of its effects in the region because the importance of forests to rural livelihoods has never been adequately quantified. Based on data from 1014 rural households across Burkina Faso and Ghana this paper attempts to fill this knowledge gap. We demonstrate that agricultural lands and the non-forest environment including parklands are considerably more valuable to poor as well as more well-off rural households than forests. Furthermore, product types supplied by the non-forest environment are almost identical with those from forests. Accordingly, forest clearance/degradation is profitable for and, hence, probably performed by rural people at large. We attribute rural people's high reliance on non-forest versus forest resources to the two countries' restrictive and inequitable forest policies which must be reformed to promote effective forest conservation, e.g., to mitigate climate change. 相似文献