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排序方式: 共有291条查询结果,搜索用时 203 毫秒
191.
Pieter Johannes Verkerk Giuliana Zanchi Marcus Lindner 《Environmental management》2014,53(6):1085-1094
Forest protection is one of the main measures to prevent loss of biological and landscape diversity. This study aimed to assess to what extent forests are currently protected and how felling restrictions affect the potential annual wood supply within 27 European Union member states, Norway, and Switzerland and to discuss trade-offs between intensified use of forest biomass and forest protection efforts. Protected forests covered 33 million ha (20 % of total forest area) in 2005, of which 16 million ha was protected for biodiversity and the remaining area for landscape diversity. Within the protected areas, on average 48 % of the volume cannot be harvested in forests protected for biodiversity and 40 % in forests protected for landscapes. Consequently, 73 million m3 (10 % of the annual theoretical potential supply from the total forest area) of wood cannot be felled from the protected forests in Europe. Protected forests do not necessarily affect wood supply given the current demand for wood in Europe. However, if demand for wood from European forests for material and energy use significantly increases, the impact of existing protected forest networks may become significant after all. On the other hand, wood harvesting is allowed to a fair extent in many protected areas. Hence, the question could be raised whether biodiversity and landscape diversity within designated areas are sufficiently protected. Careful planning is required to accommodate both the protection of biological and landscape diversity and demand for wood, while not forgetting all other services that forests provide. 相似文献
192.
Total TEQ emissions (PCDD/F and PCB) from industrial sources 总被引:3,自引:0,他引:3
Flue gas samples from eight different sources (industrial plants and crematories) have been analyzed for PCDD/Fs and PCBs and total Toxicity EQuivalents (TEQ) values have been calculated using the latest WHO toxicity equivalent factors from 1998. A contribution of PCBs to the Total TEQ up to 16% was found, within the 12 WHO-PCBs PCB-126 contributes mostly to the TEQ. Thermodynamic stability of PCBs was calculated semiempirically using the MOPAC program package and differences in the heat of formation (HoF) were compared to the distribution of PCBs in real samples. Partial correspondence between fact and theory could be found. 相似文献
193.
Isenberg G Edinger R Ebner J 《Environmental science and pollution research international》2002,9(2):99-104
Transportation contributes to energy consumption and greenhouse gas emissions, while sustainable mobility requires reductions in both areas. Alternative fuels from natural gas and from renewable resources can contribute in the mid and long-term to the fuel market for mobile as well as stationary applications. The lack of reliable data on emissions, energy chain efficiencies, and costs demonstrates the need for field tests and demonstration projects. Fuel cells offer the technology to use ‘new fuels’ in a highly efficient way. 相似文献
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