Extracts are important components of fuels. Fatty-extracts with high heating value （HV） are hypothe- sized by researchers as positively related to the HV of fuels. The Soxhlet extractor is typically used to extract ...Extracts are important components of fuels. Fatty-extracts with high heating value （HV） are hypothe- sized by researchers as positively related to the HV of fuels. The Soxhlet extractor is typically used to extract fatty-extracts but it has shortcomings, including long processing time （8-10 h） and the requirement for large amounts of organic solvent. Supercritical extraction is an alternate and useful technique for extraction of natural products. However, published studies rarely discuss the relationship between extracts and HV. In this study, we assessed the supercritical extracts （SUE） of forest fuels in the Great Xing＇an Mountains. Our results indicated that the optimum conditions for extraction of SuEs were 40-60 mesh, 40-50 MPa, 45℃, 80 min and a CO2 flow rate of 1.5-2.0 dm3/min. The Soxhlet extracts contents and the SuE contents were all related to HV. However, R2 of the coniferous samples （0.8499） and needle samples （0.9722） demonstrated that the correlation between HV and the SuE content was closer. We conclude that supercritical fatty-extracts provide a useful index of the HV of fuels, especially coniferous fuels. SuE data can be used in fire management, for example to estimate the rate of fire spread or fire intensity.展开更多
The present study was conducted on the Van Gujjar tribe inhabiting a sub-Himalayan tract in the North Western Himalayas of Uttarakhand State, India. The Van Gujjars have been practicing transmigration over hundreds of...The present study was conducted on the Van Gujjar tribe inhabiting a sub-Himalayan tract in the North Western Himalayas of Uttarakhand State, India. The Van Gujjars have been practicing transmigration over hundreds of years. They migrate each year with their households and livestock between summer and winter pastures. A few years ago with the announcement of the establish- ment of the Rajaji National Park, the tribe has been forced out of the forest area and rehabilitated outside the park, which has affected their lifestyle. The newly established rehabilitation colony in the Gandikhata area of Haridwar District of Uttarakhand State was taken as a case study. The aims of the present study were to understand and evaluate the socio-economic status of the Van Gujjars in their newly established rehabilitation colony, the utilization pattern of forest resources by the tribe and their relative preference for selec- tive trees for various uses. A total of 176 households were interviewed （giving equal weight to all economic classes and family every size） by using pre-structured questionnaires. The education level was very low （12.9%） and the average income per household was recorded as Rs. 36000 （approximately $ 803） per year. The major source of income was dairy production （80.6%） followed by labor employment （13.9%）, NTFPs （4.2%） and agricultural production （1.4%）. More than 90% of fuel wood and fodder is extracted from the forest. The average fuel wood and fodder consumptions per household per day were recorded as 25.86 and 21.58 kg, respectively. A total of 35 species of cultivated plants and 89 species of wild plants were found to be utilized as food sources. Selectively 25 wild tree species are well known as being used by the Van Gujjars as fodder, fuel wood, agricultural implements, household articles, dye, medicine, fiber and other products. According to their utility value, the most preferred and useful tree species is Ougeinia oojeinensis, followed by Terminalia alata, Bombax ceiba, Shorea robusta and Dalbergia sissoo,展开更多
The AFO （activating private forest owners to increase forest fuel supply） project was set up to discover the best tools for activating an important fraction of the 12 million PFOs （private forest owners） in Europe...The AFO （activating private forest owners to increase forest fuel supply） project was set up to discover the best tools for activating an important fraction of the 12 million PFOs （private forest owners） in Europe to supply wood fuel, especially to small and medium-sized heating plants. It aimed to increase the utilization of Europe＇s vast forest fuel reserves. This was expected to benefit both the economy of the forest owners and rural areas and increase the use of renewable energy sources. The project was carried out between 2009 and 2012. The project operated in selected target regions that have a high proportion of private forest ownership （France, Slovenia, Latvia and the UK）. It started by analyzing the potential wood fuel supply and use in relation to current regional markets. After assessing through inquiries the potential wood fuel supply and demand and the parties involved, the next step was to initiate and support the formation of wood fuel supply clusters and organize supply chains. This was followed by the dissemination of best practice examples from Austria and Finland--countries with the most expertise and long traditions of forest fuel production. In the last phase of the project, results and approved activation methods were disseminated to all 27 EU （European Union） countries.展开更多
There is enough evidence to show that the forest biomass has decreased significantly in the Indian Himalayan state of Himachal Pradesh. The government has responded through restrictive measures to check this decline. ...There is enough evidence to show that the forest biomass has decreased significantly in the Indian Himalayan state of Himachal Pradesh. The government has responded through restrictive measures to check this decline. Using tree biomass as proxy for degradation, we assessed the current state of biomass within dominant land use types and examined its implications for sustainability. The highest above-ground mean tree biomass density of 1158 t·ha-1 was recorded for the reserved forest followed by 728, 13, 11, 8, 5 and 3 t·ha-1in the protected forest, fallow land, cultivated-unirrigated land, grassland, orchard land and cultivated-irrigated land respectively. Of the total ac- cessible biomass, only 0.31% was extracted annually by the local people for fuel, fodder and other uses. Though, the current level of ex- traction may be sustainable in the short run, insufficient regeneration is observed for long term sustainability. Forest biomass production was simulated for the next 30 years with a logistic growth model and the relative significance of input variables in influencing system be- haviour was analysed through sensitivity analysis. The model results highlighted the declining forest resources in the long run. Positive response through appropriate government policies can, however, change the scenario for the better.展开更多
Forest wastes are renewable resources that can serve as sources of energy for heat and electricity generation. How these materials are managed in order to reduce their contribution to the release of greenhouse gases, ...Forest wastes are renewable resources that can serve as sources of energy for heat and electricity generation. How these materials are managed in order to reduce their contribution to the release of greenhouse gases, reduce subsequent climate change challenges and their potential use in bio-energy production has remained a myth in Nigeria. In this paper, extensive review of the literature was carried out to arrive at the findings. More than 93% of all wood processing industries in Nigeria are sawmills. In addition to sawmills there are the plywood mills, furniture processing industries, and particleboard mills. Sawdust is the major waste generated from wood processing in the various processing units. Currently, the most popular waste management practice in Nigeria is burning. Dumping in open spaces, riverbanks, and water bodies is also obtainable. There is no record of wood waste recycling for bio-fuel production at the moment. Wood wastes are reused for agricultural production (mulching, manure) and as firewood. These actions contribute to the release of greenhouse gases and subsequently contribute to global warming. There are policies and agencies put in place to address this menace but implementation is a problem. An increase in proper waste management education and awareness, and aid from developed countries in terms of providing the technology needed for recycling and incineration, will go a long way in ensuring the safety (from climate change and consequences) of the local people, the environment, and the world at large.展开更多
基金sponsored by the National Natural Science Foundation of China(Grant number:31170618)the National Key Technologies R&D Program of China(Grant number2011BAD32B05)
文摘Extracts are important components of fuels. Fatty-extracts with high heating value （HV） are hypothe- sized by researchers as positively related to the HV of fuels. The Soxhlet extractor is typically used to extract fatty-extracts but it has shortcomings, including long processing time （8-10 h） and the requirement for large amounts of organic solvent. Supercritical extraction is an alternate and useful technique for extraction of natural products. However, published studies rarely discuss the relationship between extracts and HV. In this study, we assessed the supercritical extracts （SUE） of forest fuels in the Great Xing＇an Mountains. Our results indicated that the optimum conditions for extraction of SuEs were 40-60 mesh, 40-50 MPa, 45℃, 80 min and a CO2 flow rate of 1.5-2.0 dm3/min. The Soxhlet extracts contents and the SuE contents were all related to HV. However, R2 of the coniferous samples （0.8499） and needle samples （0.9722） demonstrated that the correlation between HV and the SuE content was closer. We conclude that supercritical fatty-extracts provide a useful index of the HV of fuels, especially coniferous fuels. SuE data can be used in fire management, for example to estimate the rate of fire spread or fire intensity.
文摘The present study was conducted on the Van Gujjar tribe inhabiting a sub-Himalayan tract in the North Western Himalayas of Uttarakhand State, India. The Van Gujjars have been practicing transmigration over hundreds of years. They migrate each year with their households and livestock between summer and winter pastures. A few years ago with the announcement of the establish- ment of the Rajaji National Park, the tribe has been forced out of the forest area and rehabilitated outside the park, which has affected their lifestyle. The newly established rehabilitation colony in the Gandikhata area of Haridwar District of Uttarakhand State was taken as a case study. The aims of the present study were to understand and evaluate the socio-economic status of the Van Gujjars in their newly established rehabilitation colony, the utilization pattern of forest resources by the tribe and their relative preference for selec- tive trees for various uses. A total of 176 households were interviewed （giving equal weight to all economic classes and family every size） by using pre-structured questionnaires. The education level was very low （12.9%） and the average income per household was recorded as Rs. 36000 （approximately $ 803） per year. The major source of income was dairy production （80.6%） followed by labor employment （13.9%）, NTFPs （4.2%） and agricultural production （1.4%）. More than 90% of fuel wood and fodder is extracted from the forest. The average fuel wood and fodder consumptions per household per day were recorded as 25.86 and 21.58 kg, respectively. A total of 35 species of cultivated plants and 89 species of wild plants were found to be utilized as food sources. Selectively 25 wild tree species are well known as being used by the Van Gujjars as fodder, fuel wood, agricultural implements, household articles, dye, medicine, fiber and other products. According to their utility value, the most preferred and useful tree species is Ougeinia oojeinensis, followed by Terminalia alata, Bombax ceiba, Shorea robusta and Dalbergia sissoo,
文摘The AFO （activating private forest owners to increase forest fuel supply） project was set up to discover the best tools for activating an important fraction of the 12 million PFOs （private forest owners） in Europe to supply wood fuel, especially to small and medium-sized heating plants. It aimed to increase the utilization of Europe＇s vast forest fuel reserves. This was expected to benefit both the economy of the forest owners and rural areas and increase the use of renewable energy sources. The project was carried out between 2009 and 2012. The project operated in selected target regions that have a high proportion of private forest ownership （France, Slovenia, Latvia and the UK）. It started by analyzing the potential wood fuel supply and use in relation to current regional markets. After assessing through inquiries the potential wood fuel supply and demand and the parties involved, the next step was to initiate and support the formation of wood fuel supply clusters and organize supply chains. This was followed by the dissemination of best practice examples from Austria and Finland--countries with the most expertise and long traditions of forest fuel production. In the last phase of the project, results and approved activation methods were disseminated to all 27 EU （European Union） countries.
基金Norwegian University of life sciences,Aas,Norway (Sub Project Number 1526010,Main Project No 11526010)the Integrated Institute of Himalayan Studies (UGC Centre of Excellence),Shimla,India (Project Number 9-3/2005)
文摘There is enough evidence to show that the forest biomass has decreased significantly in the Indian Himalayan state of Himachal Pradesh. The government has responded through restrictive measures to check this decline. Using tree biomass as proxy for degradation, we assessed the current state of biomass within dominant land use types and examined its implications for sustainability. The highest above-ground mean tree biomass density of 1158 t·ha-1 was recorded for the reserved forest followed by 728, 13, 11, 8, 5 and 3 t·ha-1in the protected forest, fallow land, cultivated-unirrigated land, grassland, orchard land and cultivated-irrigated land respectively. Of the total ac- cessible biomass, only 0.31% was extracted annually by the local people for fuel, fodder and other uses. Though, the current level of ex- traction may be sustainable in the short run, insufficient regeneration is observed for long term sustainability. Forest biomass production was simulated for the next 30 years with a logistic growth model and the relative significance of input variables in influencing system be- haviour was analysed through sensitivity analysis. The model results highlighted the declining forest resources in the long run. Positive response through appropriate government policies can, however, change the scenario for the better.
文摘Forest wastes are renewable resources that can serve as sources of energy for heat and electricity generation. How these materials are managed in order to reduce their contribution to the release of greenhouse gases, reduce subsequent climate change challenges and their potential use in bio-energy production has remained a myth in Nigeria. In this paper, extensive review of the literature was carried out to arrive at the findings. More than 93% of all wood processing industries in Nigeria are sawmills. In addition to sawmills there are the plywood mills, furniture processing industries, and particleboard mills. Sawdust is the major waste generated from wood processing in the various processing units. Currently, the most popular waste management practice in Nigeria is burning. Dumping in open spaces, riverbanks, and water bodies is also obtainable. There is no record of wood waste recycling for bio-fuel production at the moment. Wood wastes are reused for agricultural production (mulching, manure) and as firewood. These actions contribute to the release of greenhouse gases and subsequently contribute to global warming. There are policies and agencies put in place to address this menace but implementation is a problem. An increase in proper waste management education and awareness, and aid from developed countries in terms of providing the technology needed for recycling and incineration, will go a long way in ensuring the safety (from climate change and consequences) of the local people, the environment, and the world at large.
