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1.
Crop production systems are the basis of human survival and development because they can produce grain and industrial raw materials. As one of the largest agricultural countries in the world, the sustainability of China's crop production system is being concerned widely with its economic development and increasing population. This study adopted emergy analysis to explore the comprehensive performance of this system. A set of emergy based indicator system was used to investigate its economic benefit, environmental pressure and sustainability from 2000 to 2010. The study results show that the purchased nonrenewable input makes the largest contribution to the total input (average value 60.73% of the total input), which mainly derived from agricultural mechanic equipments and chemical fertilizer; on the average, beans has the largest share (20.20%) to the total emergy output, next from rape seed (18.36%), then from peanuts (15.85%), fruits (15.74%), wheat (8.26%), rice (8.07%), corn (7.66%) and cotton (4.60%) accordingly, and the other four categories crops just have a contribution of 1.28%; the production efficiency of China's crop production system has been raised by 11.54% with decrease of the indicator unit emergy value of product (UEVP) from 1.82E09 sej/g to 1.61E09 sej/g, the dependence of this system on economic market has increased by 24.92% with growth of the indicator EIR from 6.22 to 7.77, its economic benefit has been reduced by 0.59% with decline of the indicator EYR from 1.69 to 1.68, and its environmental loading has raised by 57.89% with growth of the indicator ELR from 1.33 to 2.10; the sustainability of China's crop production system is reduced by 37.01% with decrease of the index ESI from 1.27 to 0.80, during this study period. Based on these study results, the following measures should be emphasized in future, including raising the efficiency of purchased non-renewable resources (especially agricultural mechanical equipments and chemical fertilizer), using other methods of cultivation inherently more sustainable (e.g. replacing chemical fertilizer with organic fertilizer, recycling organic wastes, biological control of agricultural pests, use of local renewable energy, and more), strengthening supervision of the related industrial processes and further promoting agricultural environmental protection.  相似文献   

2.
胡兵辉  廖允成 《生态学报》2009,29(9):4902-4910
农、牧户单元生态经济系统作为最基层的生产单位,关系着国家大政方针政策的落实和实施.运用能值理论及其分析方法,选择毛乌素沙地偏牧区的内蒙古自治区乌审旗苏力德苏木典型牧户生态经济系统和偏农区的陕西省榆阳区牛家梁镇典型农户生态经济系统作为研究对象,对两种不同产业偏重区产业模式的能值投入、产出结构状况进行对比分析,结合净能值产出率、能值投资率、环境负荷力、能值功率密度、单位面积生产力、人均能值用量、人均能值占有量、系统生产优势度、系统稳定性指数和系统可持续性指数共10项能值分析综合指标体系,全面系统地对农、牧户单元生态经济系统进行比较研究,定量描述典型农、牧户单元生态经济系统格局及其发展的总体特征.旨在为毛乌素沙地偏牧区和偏农区农、牧户经营层面的产业模式优化及发展提供策略选择.  相似文献   

3.
在问卷调查获取福建欠发达山区6种典型沼气运营模式基础上,分别应用能值分析法、温室气体减排量计算及成本效益分析法,比较6种模式沼气运营系统的能值投入与产出结构、系统功能和生态效应差异。结果显示:(1)在系统结构上,集中供气型主要利用不可再生购买能值的大量投入,取得高效的生产效率和经济效益,而自建自用型则以可再生购买能值的大量投入,对自然资源利用率高,环境负荷小;在系统性能上,因净能值产出率和能值交换率高,集中供气型比自建自用型的系统可持续发展性能更佳,其中销售型尤其突出。(2)在生态效益上,以养殖为主的集中供气型和纯养殖型的温室气体减排效应非常突出,而传统种养型、特色种植型和半工半农型的减排作用不明显。(3)在政府补贴下的财务特征上,集中供气型及纯养殖型虽有高效的生态效益但不符合农户财务投资标准;相反,特色种植型与半工半农型则因系统的低生态效益而不能满足政府补贴的社会经济预期,经济预期,仅传统种养型农户完全满足社会经济角度与农户角度的投资标准。针对养殖规模化发展趋势和欠发达山区能源利用现状,对沼气工程正确运营模式的选择提出相应的建议。  相似文献   

4.
王梦媛  高小叶  侯扶江 《生态学报》2019,39(5):1758-1771
通渭-渭源-夏河样带位于黄土高原向青藏高原过渡的生态区,是我国典型农牧交错带。长期以来,不合理的农业生产结构带来生态、经济等一系列问题,制约了该地区草地农业的持续发展。为此,从能值角度分析区域农业生产结构,可为农(牧)户决策提供理论依据,为优化区域农业生产结构提供科学依据。收集研究区农户作物和家畜生产的投入-产出数据,用能值方法分析农户生产系统结构特征、农户生产决策行为及生产系统耦合作用,用结构方程模型(SEM)分析农户生产系统能量的组分间流动。研究发现,随海拔增高,农户作物生产活动减少,作物总产出能值递减;尽管作物生产主要投入和产出要素相同,但同一作物不同地点的同一要素投入、产出能值和能值收益率均存在显著差异(P0.05);同一地点不同作物的同一要素投入、产出能值和能值收益率均差异显著(P0.05);作物生产投入要素中,有机肥能值在通渭和渭源均有较高贡献;作物投入和产出能值的农户生产决策阈值自东向西递减,在能值投入初始增加时,夏河农户作物生产规模扩增最为迅速。家畜养殖规模、能值投入和产出自东向西递增;通渭和渭源,小麦秸秆和苜蓿作为中间投入,能值贡献率达到80%;夏河家畜生产投入要素中,补饲粮食能值贡献率高达90%;家畜投入和产出能值的农户生产决策阈值点自东向西递增;能值收益率随耦合度的增加呈指数上升,通渭和渭源能值收益率的增加速度,随耦合度的增加趋于缓慢,而夏河能值收益率增速随耦合度的增加而上升。调整作物生产内部粮、经、饲产品比例结构,加强作物生产与家畜生产耦合作用,优化天然草地利用方式,实现生态效益最大化;阈值点调控农户生产决策行为,实现该区域农业生产结构优化。  相似文献   

5.
Emergy evaluation of organic rice-duck mutualism system   总被引:7,自引:1,他引:6  
Yun-Guan Xi  Pei Qin   《Ecological Engineering》2009,35(11):1677-1683
Rice-duck mutualism is one form of ecological engineering which makes use of the symbiotic relationship between rice and ducks to more effectively utilize materials, reduce chemical fertilizer and pesticide inputs, increase product safety and overall productivity and decrease the pollutants discharged from rice-fields. This is becoming a popular mode for organic rice production in China and it can be used as one measure taken in the drainage area to assist in the ecological rehabilitation of lakes. This study applied the emergy evaluation method to analyze the resource use and environmental impact of organic rice-duck mutualism (mode 1) compared with the conventional wheat/rice rotation system (mode 2) in the same farm to evaluate its sustainability and ecological and economic benefits and provide suggestions for optimizing this system. The results showed that mode 1 produced greater emergy benefits, and had higher self-organization, lower environmental pressure and higher product safety. The net emergy yield ratio (EYR), feedback ratio of yield emergy (FYE) and emergy sustainable index (ESI) of mode 1 were 1.57 times, 14.10 times and 8.71 times those of mode 2, respectively, and the emergy index of product safety (PSI) was 0 in mode 1 and −0.66 in mode 2. The emergy investment ratio (EIR) and environmental loading ratio (ELR) were 40.1 and 18.3% of those of mode 2. The economic benefit of mode 1 was lower than mode 2. The economic output, gross income and net income of mode 1 were 15.7, 10.8 and 35.4% less than those of mode 2, respectively, but using Em$, the output, gross income and net income of mode 1 were 47.4, 161.2, 87.3% higher than mode 2. With the development of markets for organic foods, mode 1 has the potential to achieve better economic benefits.  相似文献   

6.
江西省主要作物(稻、棉、油)生态经济系统综合分析评价   总被引:4,自引:0,他引:4  
孙卫民  欧一智  黄国勤 《生态学报》2013,33(18):5467-5476
基于成本收益分析和能值分析理论,构建经济效益指标和生态经济效益指标,对江西省水稻(早稻和晚稻)、棉花、油菜种植系统的经济效益、生态经济综合效益进行分析和评价。经济效益方面,分析比较了单位面积作物成本构成,构建了净利润(Rev)和净利润率(Prof)两个经济效益指标;生态经济方面,分析比较了单位面积能值投入产出构成,构建了能值投入率、能值产出率、环境负载率、宏观经济能值等四个能值评价指标。计算结果表明江西省水稻、棉花和油菜等作物的生产成本占主导地位,价格因素是影响种植成本最重要的因素。水稻主要是以生产物资费用为主,而棉花和油菜以人工费用为主。从产值和收益来看,Rev大小为棉花>晚稻>早稻>油菜,Prof大小为晚稻>棉花>早稻>油菜。水稻、棉花和油菜种植系统对自然更新资源的依靠程度较低,系统的维系主要依赖于外部购买能值的投入,其构成与生产成本构成是一致的。水稻、棉花和油菜等作物的种植系统能值投入率比较高,大小为棉花>早稻>晚稻>油菜,能值产出率:油菜>棉花>晚稻>早稻,造成生态环境压力为晚稻>早稻>油菜>棉花,宏观经济能值大小为油菜>棉花>晚稻>早稻。结果表明,江西省水稻、棉花、油菜种植系统是高度开放的系统,主要依赖购买能值,但是系统产出率不高,其环境压力也不大。研究结果可为深入认识江西水稻、棉花和油菜等主要作物种植系统提供一个新的视角,并为种植业可持续发展提供一定的参考价值。  相似文献   

7.
基于能值分析的中国海洋生态经济可持续发展评价   总被引:4,自引:0,他引:4  
韩增林  胡伟  钟敬秋  胡渊  刘天宝 《生态学报》2017,37(8):2563-2574
海洋生态经济可持续发展的研究既是生态经济研究的重要领域,也是海洋经济研究的重点领域。运用能值分析构建中国海洋生态经济系统能值分析模型和指标体系,以中国沿海地区及其附近海域为研究区域,利用2013年的数据对中国海洋生态经济系统的可持续发展水平进行能值测度。研究表明:(1)2013年,中国沿海各省的海洋生态经济总能值为1.70×10~(24)sej,可更新资源能值占主体地位。(2)受沿海各省海洋经济发展水平不同和区域海洋资源储量影响,中国沿海地区海洋生态经济能值密度分布差异较大,能值货币比率以上海为界,南高北低,高中低3种能值产出率结构并存且以中能值产出率结构为主。(3)中国海洋生态经济系统的生态承载力以高承载力和较高承载力为主,但局部地区海洋生态承载力偏低影响区域海洋生态系统平衡。中国海洋生态经济系统环境负载率较大,环境负载率高的地区与我国海洋经济发达地区高度耦合。(4)从可持续发展指数来看,中国海洋生态经济发展的整体可持续性较好,局部地区环境负载率过大和生态承载力偏低严重制约着区域海洋生态经济的可持续发展。  相似文献   

8.
An overall sustainability assessment should include changes in the economic return, the social benefits and the human intervention on the biophysical resources in order to highlight potential trade-off or synergies among them. In this work, we studied the performance of 36 cropping systems (CS) of the Pampa region, Argentina, which include three different crops, three increasing levels of technology adoption in four contrasting site conditions. For each CS, we simultaneously assessed 1) the ecosystem energy flow using the emergy synthesis; 2) the pesticide ecotoxicity using a simple dose-response model; and 3) the economic profit, in order to evaluate the influence of crop identity, technological level, and site location on the indicators values as well as to detect potential trade-offs between indicators. Results revealed that maize crop entailed the most sustainable indicator profile by exhibiting relative high emergy return, low non-renewable emergy use, low pesticide ecotoxicity, and high gross income. In addition, results showed a significant trade-off between economic profit and ecotoxicological risk in the CS studied. Further studies should be conducted for including more contrasting indicators in order to explore the potential trade-off among other ecosystem components as a promising way to identify sustainable crop management regimes for different production zones.  相似文献   

9.
The theory and indices of Odum's concept of emergy are explained. The environmental and economic inputs and sustainability of cassava chips production system are evaluated by emergy methodology. The emergy indices of cassava chips production system were calculated as follows: Tr (transformity) was 6.85E + 11 sej/kg, EYR (emergy yield ratio) was 1.11, ELR (environmental loading ratio) was 1.75, EIR (emergy investment ratio) was 9.33, and ESI (emergy sustainability indice) was 0.63. The emergy indices of four kinds of feedstock for fuel ethanol—corn, wheat, sugarcane, and cassava chips—were compared. Least solar energy was consumed when taking cassava chips as feedstock for fuel ethanol. According to the emergy indices, using cassava chips as the feedstock of fuel ethanol is helpful for sustainable development in China.  相似文献   

10.
内蒙古磴口县林业生态建设工程综合效益评价   总被引:1,自引:1,他引:0  
刘旭升  李献文  孙涛 《生态学报》2017,37(18):6196-6204
林业生态建设工程具有重要的经济、生态和社会效益。内蒙古磴口县是林业生态建设工程实施的重点地区,对该区域林业生态建设工程的综合效益进行评价,具有代表性意义。依据评价指标体系构建原则、相关文献资料和当地实际情况,构建磴口县林业生态建设工程综合评价体系;在此基础上,通过时间序列分析,完成1991—2015年磴口县的林业生态建设工程综合效益量化评价。结果表明:在林业生态建设工程评价体系中,经济、生态和社会3个方面所占比重不同,其中,国内生产总值、造林面积、吸收二氧化硫年增加价值、削减粉尘年增加价值及农民人均纯收入五项指标在综合效益评价中权重比例较大;近年来磴口县林业生态建设工程综合效益较1990—1999年期间有所提高,但波动幅度较大,而近年来研究区综合效益趋于稳定并略有上升。磴口县林业生态建设工程在改善区域生态环境、遏制沙化土地扩展等方面的成效相对显著,有效促进了地区经济发展。  相似文献   

11.
马文静  刘娟 《应用生态学报》2020,31(6):2029-2038
本文基于能值理论全面评估了2006—2016年中国的可持续发展水平,并根据一次能源投入比例的不同将各省份分为4组进行比较分析,讨论一次能源投入水平对省域间可持续发展水平的影响。结果表明: 2006—2016年,随着经济快速增长,一次能源投入比例不断上涨,使得我国整体生态经济系统的环境负荷由2.78升至3.13。同时,受进口增加的影响,能值产出率相对下降,可持续性指标下降至5.40。能值密度变化趋势与一次能源投入比例的变化基本一致,目前大多数省份依旧通过能源消费带动区域经济发展。其中,北京、上海等虽现代化经济高度发达,但环境压力同样高于其他省份,可持续发展水平不容乐观。以江苏为代表的南方省份能源投入较低而能值产出较高,表现出较高的可持续发展活力。因此,提升内陆地区能源利用效率、调整经济发展模式,并适当减缓发展强度,以缓解经济发展与环境保护之间的矛盾,可以令我国稳步实现生态经济的可持续发展。  相似文献   

12.
稻鸭共作有机农业模式的能值评估   总被引:33,自引:3,他引:30  
应用能值分析方法对稻鸭共作有机农业模式(模式Ⅰ)和对应的稻麦常规生产模式(模式Ⅱ)进行比较研究,并比较了两种模式的生态经济效益.结果表明,模式Ⅰ的能值效益高,自组织能力、可持续发展能力强,产品安全性高,净能值产出率(EYR)、系统产出能值反馈率(FYE)、能值可持续指标(ESI)分别是模式Ⅱ的1.57、14.1和8.71倍;基于能值的产品安全性指标(EIPS)模式Ⅰ为0,模式Ⅱ为-0.66;模式Ⅰ对环境的压力小于模式Ⅱ,能值投资率(EIR),环境负载率(ELR)分别是模式Ⅱ的40.1%和18.3%;但模式Ⅰ的经济效益低于模式Ⅱ,其产出、毛收入和净效益分别低于模式Ⅱ15.7%、9.6%和29.6%;以能值 货币价值计算,模式Ⅰ的产投比、毛收入和净收入分别高于模式Ⅱ50%、102.6%和136.4%.随着生产系统的优化和市场对有机食品认知程度的提高,模式Ⅰ的经济效益具有提高的潜力.  相似文献   

13.
将土地整治活动作为外界对农田生态系统(项目区)集中性的外部激励,以陕西关中凤翔县典型土地整治项目为例,分析了项目实施前后生态流(物质流、能量流、信息流)变化状况,建立了土地整治生态影响概念性模型,明确了相应生态流的流向与路径关系,使用可用能法和能值法测算项目区外部输入及生态产品输出,应用生态流分析法,对土地整治项目生态流和系统效率进行了定量计算。根据设定的土地整治工程使用年限,评估了项目实施后区域净生态价值、自然资源依赖度、可更新资源依赖度、生态产出率、生态承载力和生态可持续度等指标的时间变化过程。得到以下研究结果:(1)可用能法和能值法测算出的系统生态效益均呈现由项目建设初期陡降为负值,而后指数增加,再趋于平稳的过程;(2)可用能法测算出项目实施后的第29年,生态效益由亏转盈,体现出系统从被扰乱后恢复自然平衡状态的过程;(3)能值法测算出项目实施后的第4年,生态系统趋于平衡状态;(4)研究区土地整治项目的经济效益为负,于项目实施3a后趋于平稳,总投资中农业生产年投入占资金总额的78.35%。通过可用能和能值方法的结合,可以定量计算系统稳定性,为土地整治项目的物质、劳动力和资金投资选择等提供借鉴。  相似文献   

14.
The main water bodies in the Bogotá Savannah have been seriously polluted due to the mismanagement of domestic, agricultural, and industrial wastewater. While there are a number of wastewater treatment facilities in the region, most do not function properly. There is a great need for inexpensive and sustainable wastewater treatment systems that are not technologically sophisticated and that do not require intensive management. The main goal of this study was to quantify the performance and sustainability of treatment wetlands and existing wastewater treatment systems in this region. Using data from the literature, a treatment wetland model was developed, which focused on pollutant removal. The modeled performance was compared to a system of waste stabilization ponds and a sequencing batch reactor. The three systems were subject to cost analysis and an emergy evaluation, leading to the assessment of indicators of cost-benefit for comparison. The economic analysis suggested that the net annual cost of the treatment wetland was US$ 14,672, compared to US$ 14,201 for the stabilization ponds and US$ 54,887 for the batch reactor. The emergy evaluations show that the ponds have the lowest annual emergy flow (6.65 + 16 sej/yr), followed by the constructed wetland (2.88E+17 sej/yr) and the batch reactor (8.86E+17 sej/yr). These results were combined to estimate treatment ratios (contaminants removed per lifetime cost, and contaminants removed per total emergy), cost ratios (cost per volume of water, annual cost per capita, and construction cost per capita), and emergy ratios (treatment yield, renewable emergy, lifetime emprice, construction emprice, non-renewable emergy, empower density, environmental loading, total emergy per volume of water, and emergy per capita).  相似文献   

15.
旅游地生态效率测度的SBM-DEA模型及实证分析   总被引:8,自引:0,他引:8  
旅游地是典型的人地关系相互作用的特殊区域,旅游地的生态效率研究是其制定与实施包容性、持续性发展政策与措施的基础。采用基于时间序列、包含非期望产出的SBM-DEA模型方法,构建旅游地生态效率测度模型及评价指标体系,以黄山风景区为例,利用1981—2014年的投入产出数据,测度旅游地复合系统的生态效率,分析其演化特征和阶段,并利用Tobit回归模型对其影响因素进行实证检验。结果表明:(1)34年来,黄山风景区旅游生态效率(综合效率)不断提升,且具较大发展潜力,在分解效率中,技术效率较高,规模效率次之,规模效率是决定综合效率的关键因素;(2)旅游生态效率的演化经历了初期低效、快速成长、成熟高效、下行风险四个阶段,不同阶段效率的特征不同,影响因素也存在差异;(3)旅游生态效率完成了由规模报酬递增向递减的过渡,资源要素的投入冗余已成为现阶段阻碍生态效率的进一步提高的关键因素;(4)旅游发展水平、产业结构和技术水平对生态效率产生显著的正向影响,投资水平产生显著的负向影响,以废弃物末端治理为表征的环保规制对生态效率的提升作用并不显著。文章最后提出,在山岳型风景区发展初期,应尽可能扩大资源要素投入规模,进入成熟阶段后,则转向逐渐控制投入规模,改善技术能力和资源配置能力,摒弃过度依靠资源消耗和环境污染的粗放式发展模式,走精细化、可持续的发展道路。  相似文献   

16.
Emergy and economic analysis, accompanied by sensitivity analysis, were used to evaluate the ecological economic characteristics of three fish aquaculture systems on wetlands surrounding the Pearl River Estuary in China. The sustainability of these systems was compared to two aquaculture systems and two wetland systems, to provide reference conditions for the best use of limited wetland areas. We found that the three systems studied had similar emergy characteristics, despite their very different economic characteristics. Counter intuitively, the high economic input and output mode did not have higher environmental impact or lower sustainability compared with low economic input and output mode. Apparently, the sustainability of an intensive aquaculture system is determined mainly by how many natural renewable resources are exploited. The large differences in economic benefit and environmental impacts between the mangrove reserve and the aquaculture systems demonstrated the important role of nature reserves on preserving the sustainability of an estuary. Transformity (TR) and Emergy Yield Ratio (EYR) are both indicators of system efficiency, but from different points of view, and they produced opposite results in assessing the efficiency of the same system in this study. The ratio of EYR to TR might be used in addition to the EYR and transformity as a discreet perspective on overall system production efficiency.  相似文献   

17.
The theoretical framework and methodology of a water ecological–economic system (WEES) assessment based on emergy synthesis are proposed in this paper. Through calculating ecological and economic inputs and outputs within and outside the complex system, this paper discusses the system's economic situation, water resources development and system sustainability based on a series of emergy indicators. Besides traditional indices, following the principle of system assessment, four new indices, water emergy ratio (WER), water emergy utilization ratio (WEUR), water emergy self-support ratio (WESR), and water emergy density (WED) are formulated to assess the state of water resources development quantitatively. Taking the Zhengzhou water ecological–economic system as a study area, through the comparison of the systematic indicators of Zhengzhou with those of the selected Chinese cities, the general status of the Zhengzhou water ecological–economic system in China is identified. The results also show that most indicators of Beijing are located at middle levels among the selected Chinese cities. In particular, the sustainability, expressed by the indicators emergy-based sustainability index (ESI) and water resources population carrying capacity (WPC) were 1.34 and 1.94 million, respectively, in Zhengzhou in 2005, which indicates that the Zhengzhou WEES is in heavy pressure of water resources and is located at low levels of sustainability.  相似文献   

18.
中国人均灰水生态足迹变化驱动效应测度及时空分异   总被引:1,自引:0,他引:1  
张智雄  孙才志 《生态学报》2018,38(13):4596-4608
将传统灰水足迹和水生态足迹方法相结合,运用扩展的Kaya恒等式和LMDI指数分解方法对中国各省市的人均灰水生态足迹变化的驱动因素进行测度分析,充分考虑了资本和劳动力因素,选取经济活度效应,资本深化效应,资本效率效应,足迹强度效应,环境效率效应5个效应对人均灰水生态足迹变化的影响,结合ISODATA聚类模型对各效应进行空间聚类,从而分析各效应的空间特征。结果显示:中国人均灰水生态足迹产出变化是这5种因素共同作用的结果,资本深化效应和经济活度效应具有增量效应特点,而环境效率效应、足迹强度效应、资本效率效应呈减量效应特点;在各驱动效应的的强弱对比中,资本深化效应和足迹强度效应的特征较为明显。经济发展带动了科技进步也使得用水效率不断提高是足迹强度效应呈减量效应的主要原因;而工业化阶段经济向资本密集型转变是资本效率下降的主要原因。研究对中国灰水生态变化与资本要素之间的关系进行了探讨,对环保政策的调整及水资源可持续利用研究具有一定的参考价值。  相似文献   

19.
农业生产专业化、集约化背景下,种养分离越发严重,畜禽粪便排放与环境之间矛盾日益突出,农业可持续发展面临重大挑战.本研究以山东省为例,基于1999-2015年种养系统投入产出资料,利用能值的方法,定量分析了山东省域及市域种养系统可持续发展指数的空间格局及其演变趋势.结果表明:1999-2015年,山东省种养系统的可持续性减弱.可持续发展指数呈极显著下降趋势,2015年较1999年下降了22.0%;净能值产出率和环境负载率均呈极显著增加趋势,单位经济投入获得的利益显著增加,同时种养生产对环境的压力明显加大,这主要与电力、复合肥、农业机械等工业资源投入量的增加密切相关.山东省各地市种养系统可持续发展水平具有差异.大部分地市种养系统的可持续发展指数较高,而沿海地区(威海、烟台)和工业城市(淄博)则较低.同时,各地市种养系统的可持续发展态势也具有差异.鲁中和鲁南地区可持续性逐年减弱,鲁北地区可持续性逐年增强.以2015年为本底数据进行情景分析,发现种养高度结合(100%粪便有机肥替代化肥)情景的可持续发展指数可达8.4,是种养结合现状(30%粪便有机肥替代化肥)的2.6倍.  相似文献   

20.
农业生态系统是人类生存的最基本系统,对其结构和功能进行分析是破解农业生态环境问题的关键.本文应用能值分析理论并借助数据包络分析法、协整检验、误差修正模型等经济计量方法,对1997-2009年四川省及其21个地级市农业生态系统的运行动态、环境承载情况、运行效率、投入产出关系进行定量分析.结果表明: 研究期间,四川省处在由传统农业向现代农业过渡阶段,农业机械化水平不断提高,资源利用效率不断加强,结构优势度总体情况较好,而过度依赖经济能值的投入使系统可持续性能力逐年减弱;区域间农业生态系统发展状况的差异较大,成都平原区和川西高原区要么资源开发过度,要么资源利用不足,而四川丘陵地区农业生态系统富有活力和发展潜力,属于四川农业未来发展的重点区域;四川省农业生态系统总体运行效率较低,各地状况不一,既包括技术效率较低因素,也有规模不当的原因;四川省农业生态系统经济能值指标与产出能值之间存在长期均衡动态关系,但短期内的能值投入远未达到理想的产出状态.  相似文献   

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