As people become increasingly aware of the irreplaceability of ecosystem services, defined as ＂the nataral environmental conditions and effects upon which peopic rely for existence that are formed and maintained by e...As people become increasingly aware of the irreplaceability of ecosystem services, defined as ＂the nataral environmental conditions and effects upon which peopic rely for existence that are formed and maintained by ecosystems and ecological processes＂, more emphasis is being placed on these services＇. In rectent years numerous studies have focused primarily on the sen,ices of natural ecosystems. This paper expands the scope of this field from natural ecosystems to semi-natuval ecosystems, i.e. cropland ecosystems, which are closely associated with human productivity and life. Taking Huantat County in Shandong Province as an example, the vegetation.based services of winter wheat/summer maize rotation systems and carton cropland ecosystems were systematically analyzed, including the material production, carbon dioxide fixation, oxygen release, water conservation, and nutrient recycling. These services were then evaluated in terms of economics through the applications of a market value technique, a substinaion engineering method and a shadow price method. The results indicated that the total economic value of cropland ecosystem vegetation.based services in Huantai County is 124.827.3 ×10^4 yuan. which is equivalent to 15.63% of the GDP of Hnantat County （798, 491 × 10^4 yuan）, Among these services, the gas regulation value is 82.698.3 × 10^4 yuan （66.25%）, the material production value is 38.049.4 × 10^4 yuan （30.48%）, the nutrient cycling value is 3257.3 × 10^4 ynan （2.61%）, and the water conservation value is 822.3 × 10^4 yuan （0.66%）. In addition, through the comparison between winter wheat/summer maize rotation systems and cotton cropland ecosystems, we conclude that the economic value of vegetation-based services provided by the former is much higher than that of the latter, which could provide a scientific guideline for adjusting the agricultural structure, Our study may facilitate the conservation of cropland ecosystems and promote effective use of vegetation-based services to achieve sustainable development of agriculture and guarantee nationwide food security.展开更多
Environmental, biological, socio-cultural and economic status variation existing in the Central Himalaya have led to the evolution of diverse and unique traditional agroecosystems, crop species and livestock, which fa...Environmental, biological, socio-cultural and economic status variation existing in the Central Himalaya have led to the evolution of diverse and unique traditional agroecosystems, crop species and livestock, which facilitate the traditional mountain farming societies to sustain themselves. Indigenous agroecosystems are highly site specific and differ from place to place, as they have evolved along divergent lines. For maintenance of traditional agrodiversity management the farmers of the Central Himalaya have evolved various types of crop rotations in consonance with the varied environmental conditions and agronomic requirements. In irrigated fiat lands two crops are harvested in a year with negligible fallow period but in rainfed conditions if a cropping sequence is presumed to be starting after winter fallow phase then four major cropping seasons can be identified namely first kharif season （first crop season）, first rabi season （second crop season）, second kharif season （third crop season） and second rabi season （fourth crop season）. Highest crop diversity is present in kharif season in comparison to rabi season. Traditionally the fields are left fallow after harvest of the second kharif season crop. Important characteristics of agrodiversity management are the use of bullocks for draughtpower, human energy as labour, crop residues as animal feed and animal waste mixed with forest litter as organic input to restore soil fertility levels. Women provide most of the human labour except for ploughing and threshing grain. The present study deals with assessment of traditional agrodiversity management such as （i） crop diversity, （ii） realized yield under the traditional practices and （iii） assess the differences of realized yields under sole and mixed cropping systems. It indicated that crop rotation is an important feature of the Central Himalayan village ecosystem which helps to continue the diversity of species grown, as are the distribution of crops in the growing period and the management of soil fertility. The cropping diversity existing and the sequences practiced by the traditional farmers seems to have achieved high degree of specialization and thus even when the yield/biomass variations are about 6o%, the farmers continue to practice these sequences as they need to maintain diversity and synergistic relationships of crops in addition to manage the food and labour requirements for crop husbandry. Crop yields are generally higher in irrigated systems than rainfed systems and in sole cropping as compared with mixed cropping. However, gross biological and economic yields are higher in mixed cropping than sole cropping systems.展开更多
Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for ...Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem.展开更多
Rain water harvesting practices and their effects on the productivity of farming systems in the semi-arid areas of Nigeria have been investigated using participatory rural appraisal （PRA） technique. There was no dir...Rain water harvesting practices and their effects on the productivity of farming systems in the semi-arid areas of Nigeria have been investigated using participatory rural appraisal （PRA） technique. There was no direct water harvesting interventions by government agencies in the area. Farmers take advantage of naturally existing depressions and abandoned burrow pits close to their farmlands to harvest rain water for surface irrigation using petrol engine pumps. The reservoirs surveyed were found to be grossly inadequate in the drought period. Water budget analysis revealed that evaporation and seepage losses from reservoirs were high in both agro-ecological zone considered. The application of rain water harvesting practices was found to have increased farmers income by 61% and 125% in the Sahel and Sudan Savannah agro-ecological zones, respectively. Governments at all levels in these areas need to support these farmers in order to boost their production to achieve food security in these drought prone areas. Farmers lack timely access to farm credit and agricultural inputs; the indigenous water harvesting practices identified need to be enhanced with the aid of agricultural engineering extension services.展开更多
Circular agriculture is an inevitable course to realize positive cycle of ecology and harmonious development of rural areas. Beijing＇s mountainous areas depend on the background and orientation of ecological economy ...Circular agriculture is an inevitable course to realize positive cycle of ecology and harmonious development of rural areas. Beijing＇s mountainous areas depend on the background and orientation of ecological economy for sustainable development. It is of great significance to explore the development of the circular agriculture in the mountainous areas to facilitate sustainable use of agriculture resources. Beijing＇s mountainous areas have accumulated considerable experiences in boosting the circular agriculture. By summarizing the modes of circular agriculture in mountainous areas and analyzing their actual practices, the paper proposes we need to give high priority to strengthening publicity efforts, giving full play to resources advantages of mountainous areas, and establishing a management mechanism and operation mechanism to promote the development of circular agriculture in Beijing.展开更多
文摘As people become increasingly aware of the irreplaceability of ecosystem services, defined as ＂the nataral environmental conditions and effects upon which peopic rely for existence that are formed and maintained by ecosystems and ecological processes＂, more emphasis is being placed on these services＇. In rectent years numerous studies have focused primarily on the sen,ices of natural ecosystems. This paper expands the scope of this field from natural ecosystems to semi-natuval ecosystems, i.e. cropland ecosystems, which are closely associated with human productivity and life. Taking Huantat County in Shandong Province as an example, the vegetation.based services of winter wheat/summer maize rotation systems and carton cropland ecosystems were systematically analyzed, including the material production, carbon dioxide fixation, oxygen release, water conservation, and nutrient recycling. These services were then evaluated in terms of economics through the applications of a market value technique, a substinaion engineering method and a shadow price method. The results indicated that the total economic value of cropland ecosystem vegetation.based services in Huantai County is 124.827.3 ×10^4 yuan. which is equivalent to 15.63% of the GDP of Hnantat County （798, 491 × 10^4 yuan）, Among these services, the gas regulation value is 82.698.3 × 10^4 yuan （66.25%）, the material production value is 38.049.4 × 10^4 yuan （30.48%）, the nutrient cycling value is 3257.3 × 10^4 ynan （2.61%）, and the water conservation value is 822.3 × 10^4 yuan （0.66%）. In addition, through the comparison between winter wheat/summer maize rotation systems and cotton cropland ecosystems, we conclude that the economic value of vegetation-based services provided by the former is much higher than that of the latter, which could provide a scientific guideline for adjusting the agricultural structure, Our study may facilitate the conservation of cropland ecosystems and promote effective use of vegetation-based services to achieve sustainable development of agriculture and guarantee nationwide food security.
文摘Environmental, biological, socio-cultural and economic status variation existing in the Central Himalaya have led to the evolution of diverse and unique traditional agroecosystems, crop species and livestock, which facilitate the traditional mountain farming societies to sustain themselves. Indigenous agroecosystems are highly site specific and differ from place to place, as they have evolved along divergent lines. For maintenance of traditional agrodiversity management the farmers of the Central Himalaya have evolved various types of crop rotations in consonance with the varied environmental conditions and agronomic requirements. In irrigated fiat lands two crops are harvested in a year with negligible fallow period but in rainfed conditions if a cropping sequence is presumed to be starting after winter fallow phase then four major cropping seasons can be identified namely first kharif season （first crop season）, first rabi season （second crop season）, second kharif season （third crop season） and second rabi season （fourth crop season）. Highest crop diversity is present in kharif season in comparison to rabi season. Traditionally the fields are left fallow after harvest of the second kharif season crop. Important characteristics of agrodiversity management are the use of bullocks for draughtpower, human energy as labour, crop residues as animal feed and animal waste mixed with forest litter as organic input to restore soil fertility levels. Women provide most of the human labour except for ploughing and threshing grain. The present study deals with assessment of traditional agrodiversity management such as （i） crop diversity, （ii） realized yield under the traditional practices and （iii） assess the differences of realized yields under sole and mixed cropping systems. It indicated that crop rotation is an important feature of the Central Himalayan village ecosystem which helps to continue the diversity of species grown, as are the distribution of crops in the growing period and the management of soil fertility. The cropping diversity existing and the sequences practiced by the traditional farmers seems to have achieved high degree of specialization and thus even when the yield/biomass variations are about 6o%, the farmers continue to practice these sequences as they need to maintain diversity and synergistic relationships of crops in addition to manage the food and labour requirements for crop husbandry. Crop yields are generally higher in irrigated systems than rainfed systems and in sole cropping as compared with mixed cropping. However, gross biological and economic yields are higher in mixed cropping than sole cropping systems.
基金part of a project funded by "China Chengzhen New countryside Reconstruction Studies Program of Sichuan University" (Grant No.2007-03)
文摘Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem.
文摘Rain water harvesting practices and their effects on the productivity of farming systems in the semi-arid areas of Nigeria have been investigated using participatory rural appraisal （PRA） technique. There was no direct water harvesting interventions by government agencies in the area. Farmers take advantage of naturally existing depressions and abandoned burrow pits close to their farmlands to harvest rain water for surface irrigation using petrol engine pumps. The reservoirs surveyed were found to be grossly inadequate in the drought period. Water budget analysis revealed that evaporation and seepage losses from reservoirs were high in both agro-ecological zone considered. The application of rain water harvesting practices was found to have increased farmers income by 61% and 125% in the Sahel and Sudan Savannah agro-ecological zones, respectively. Governments at all levels in these areas need to support these farmers in order to boost their production to achieve food security in these drought prone areas. Farmers lack timely access to farm credit and agricultural inputs; the indigenous water harvesting practices identified need to be enhanced with the aid of agricultural engineering extension services.
基金Acknowledgments： The project was supported by the National Natural Science Foundation of China （No. 40671072）.
文摘Circular agriculture is an inevitable course to realize positive cycle of ecology and harmonious development of rural areas. Beijing＇s mountainous areas depend on the background and orientation of ecological economy for sustainable development. It is of great significance to explore the development of the circular agriculture in the mountainous areas to facilitate sustainable use of agriculture resources. Beijing＇s mountainous areas have accumulated considerable experiences in boosting the circular agriculture. By summarizing the modes of circular agriculture in mountainous areas and analyzing their actual practices, the paper proposes we need to give high priority to strengthening publicity efforts, giving full play to resources advantages of mountainous areas, and establishing a management mechanism and operation mechanism to promote the development of circular agriculture in Beijing.
