鲆鲽类养殖不同产业链模式的经济效益比较研究

产业结构直接影响产业经济效益,而产业结构是产业链长期发展和优化的产物。产业链越长,分工经济越明显,但随之而来的交易环节增多会导致费用增加,分工带来的经济效益的提升有可能被交易费用的增加所抵消。同一产业内不同养殖户对产业链各环节的不同组合会形成不同的产业链模式。对不同产业链模式经济效益的比较研究,不仅有利于养殖户效益最大化,且有利于产业结构的优化,进而促进整个产业的发展。以我国鲆鲽类养殖为例,基于2013年不同鲆鲽类养殖模式经济效益的跟踪调查,用秩和检验的方法对"育苗+成鱼养殖"模式、"仅育苗"模式及"仅成鱼养殖"模式的成本、收益和资本回报率进行了对比分析。结果显示:(1)专业化分工程度越低的产业链模式,其可变成本越低,固定成本中的要素成本越高;(2)专业化分工程度越高的产业链模式,单位净收益越高,资本回报率越高。基于此,建议管理部门通过合理整顿市场来提高专业化分工程度,为养殖生产者经济效益提供更好的市场环境,建议养殖生产者加强技术创新和科学管理能力从而提高经济效益。     

INDUSTRIAL EVOLUTION: A CASE STUDY OF CHILEAN SALMON AQUACULTURE

Over the past two decades aquaculture has emerged as the preeminent source of salmon. The development and evolution of salmon aquaculture in Chile illustrates changes that have taken place to a greater or lesser extent in other salmon producing regions. Although initially comprised of small independent firms with heavy reliance on foreign technology and production inputs, the Chilean salmon aquaculture industry has evolved into a horizontally and vertically integrated complex of interdependent suppliers, producers, processors, distributors, and supporting entities. The structure and organization of industries evolve over time in response to changes in the price and availability of inputs, changes in the demand for outputs and output attributes, and changes in technology. The growing demand for traceability and assurance is a change in the demand for credence attributes. Firms that are able to organize to provide traceability and assurance at low cost will, ceteris paribus, have an advantage.     

INDUSTRIAL AGGLOMERATIONS: THE CASE OF THE SALMON INDUSTRY IN CHILE

Aquaculture experienced a significant global expansion at the end of the 20th century, becoming one of the fastest growing sectors of animal husbandry and production during that period. Chile's contribution to world expansion of salmon and trout production was notorious, given that in a short twenty five-year period it became one of the leading world producers. One prominent feature of salmon production in Chile is that the industry concentrated geographically in a limited area around Puerto Montt, in Region 10 of the country. Industry concentration cannot be exclusively explained in terms of natural advantages, and evidence is presented in favour of Venables's model (1996). A qualitative analysis of the evolution of the industry is presented to provide evidence of input-output linkages, economies of scale, competition and the progressive multiplication of inputs, applying two types of data sources: a review of the existing technical literature on the subject and in-depth interviews with 20 industry experts.     

资源型城市产业结构演进与城市化互动关系研究——以六盘水市钟山区为例

以六盘水钟山区为例,借助SPSS统计软件,运用相关分析、多元回归分析等方法,建立六盘水市钟山区城市化对应产业结构演进支撑模型和产业结构演进对应城市化反馈模型,通过对模型结果分析,揭示了六盘水钟山区城市化与产业结构演进的互动作用机理,以期为钟山区城市经济与产业发展及同类资源型城市的可持续发展提供借鉴。     

基于三螺旋模型的潍坊市蓝色高端产业集群创新研究

分析了潍坊市蓝色高端产业群发展现状,潍坊市蓝色高端产业集群目前发展迅速,但其产品科技成果的转化率较低、产业创新能力不强、集群整体竞争力不高。基于三螺旋模型,构建了潍坊市蓝色高端产业集群创新体系,以期通过加强政府-集群-高校的协同发展,加快其创新发展。     

浙江省农业产业结构的灰色关联度分析

近年来,随着农业经济的迅速发展,浙江省农业产业结构中存在的不合理因素日益凸显。通过运用灰色系统理论中的关联度分析方法,对浙江省近5年的农业内部各产业与农业总产值之间的关联性进行分析,结果表明,在浙江省农业内部各产业中,对农业总产值影响由大到小的因素依次为:农业、牧业、渔业、林业和服务业产值。     

我国大菱鲆产业价值链实证研究

随着规模的扩大,大菱鲆养殖产业逐渐从高利时代步入常利时代,各种深层次问题开始显现,产业升级已势在必行.着眼于产业内部,进行产业链优化整合可以提高产业运行效率、总利润和各环节的福利,是实现产业升级的切入点.基于实证调研,分析了我国大菱鲆产业链构成及产业价值链,初步研究结果表明,各环节价值增值量依次为:餐饮＞养殖＞育苗＞综...     

随州食用菌产业发展的问题与对策

本文在深入调查研究的基础上,针对湖北省随州市近年来食用菌产业发展中面对的主要问题,提出该产业发展的方向、应坚持的原则和采取的对策,指出今后产业发展必须强化两转(原料转换、品种转型)意识,采取5个方面的措施,从而保证该市生态环境和食用菌产业同时得到可持续发展。     

Stellera chamaejasme L. increases soil N availability, turnover rates and microbial biomass in an alpine meadow ecosystem on the eastern Tibetan Plateau of China

Plant species have been shown to have significant effects on soil nutrient pools and dynamics. Stellera chamaejasme L., a toxic perennial weed, has established and is now abundant in the alpine meadow on the eastern Tibetan Plateau of China since the 1960s. We quantified the effects of Stellera on carbon and nitrogen cycling in two topographic habitats, a flat valley and a south-facing slope, where Stellera was favored to spread within the study area. Aboveground litter biomass and tissue chemistry of aboveground litter and root were measured to explain the likely effects of Stellera on soil carbon and nutrient cycling. The sizes of various soil pools, e.g. nitrate, ammonium, inorganic phosphorus, microbial biomass, soil respiration and turnover rates including net mineralization, gross nitrification and denitrification were determined. The results showed that Stellera produced more aboveground litter than each of the co-occurring species. Aboveground litter of Stellera had higher tissue N and lower lignin:N than the other species. Stellera significantly increased surface soil (0-15 cm) organic matter, whereas no significant differences were found for organic C and total P in subsoil (15-30 cm) within and between patches of Stellera. Soil extractable nitrate concentrations in Stellera surface soil were 113% and 90% higher on the flat valley and on the south-facing slope, respectively. Both microbial biomass C and N were significantly higher in Stellera surface soil. Gross nitrification and microbial respiration were significantly higher in Stellera surface soil both on the flat valley and on the south-facing slope, whereas significant differences of denitrification were found only on the flat valley. The differences in the quantity and quality of aboveground litter are a likely mechanism responsible for the changes of soil properties.     

广东海洋产业发展分析及结构优化对策

广东海洋经济凭借优越的资源和区位条件得到了快速发展,对国民经济的贡献愈来愈高,已成为新的经济增长点.本文深入考察了广东海洋产业发展现状尤其是存在的问题;应用灰色系统理论对主要海洋产业进行了关联度分析,认为广东海洋产业结构优化,必须充分发挥市场和产业、政府和政策的正面功能.提出了坚持产业自发转型、政府积极推动和政策强效支撑的组合型对策.