我国发展大型海藻养殖碳汇产业的条件与政策建议

本文简要分析了我国大型海藻养殖业的发展现状,探讨了我国2000年以来海藻养殖种类、产量和面积的变动情况;分析了我国海带、紫菜、江蓠、麒麟菜等主要养殖海藻种类的碳含量,估算出我国大型海藻养殖业碳汇规模达到34.79万吨/年。大型海藻养殖具有碳含量高、可计量、养殖过程可控制等优点,可以作为一种新型的碳汇产业。     

食用海藻的市场调查

通过对食用海藻品种、价格、产地和消费意愿的市场调查,讨论了食用海藻的市场前景、亟待改进的加工问题及发展海藻养殖的现实意义,提出开展龙须菜养殖的建议.     

海藻活性物质在功能性食品中的应用研究

海藻中的活性物质种类繁多,如多糖类、萜类、多酚类等,可以被当今的诸多领域如食品、医药、动物饲料、食物添加剂等加以应用。本文简要介绍了海藻中活性物质的成分及其特殊的生理功能,分析了当前海藻活性物质在功能性食品中应用的研究价值,阐述了海藻活性物质在功能性食品中的运用,以及在开发海藻活性物质中存在的问题。     

中国古代利用海藻的考证

本文通过涉及海藻的我国主要历史文献和沿海各省主要地方志进行研究,考证了我国古代海藻利用的主要种类,及其利用价值和食用方法的主要史实,从而为了中国古代渔业历史提供一些参考。     

我国海藻的开发利用价值及产业化生产

本文分析了海藻的基本营养成分、营养特点、食用价值、药用价值、海藻肥的生产利用以及作为动物饲料添加剂等方面的利用,并且阐述了在生态保护、海洋药物、功能食品、动物饲料、生物活性物质开发应用、食品添加剂、有机肥料、微生物培养基、化工业以及生物能源等诸多领域发挥的重要作用.在此基础上,本文综述了海藻及其深加工产品在食品工业生产方面的开发利用现状,并提出了海藻在开发利用与产业化生产中的问题及相关建议.     

山东省沿海的可食用藻类

报道了山东省可食用海藻47种．隶属于23科29属。     

海藻需求旺盛

据报道，印尼科技研究与应用机构天然资源处助理加纳表示，目前世界的海藻需求每年达30万吨，在未来的需求将继续增加，因此可推动渔民种植海藻。     

泉州崇武沿海底栖经济海藻

泉州崇武沿海共有野生经济底栖海藻46种,其中蓝藻门有2种,绿藻门11种,红藻门24种,褐藻门9种。对这些海藻的资源、经济价值以及开发利用方面,作了阐述。     

开发利用海藻肥 促进农业可持续发展

海藻植物营养剂（海藻肥）是一项新兴的海藻深加工产品,经过十余年的发展,以海藻植物营养剂为核心原料的海藻肥,已成为我国的一个新兴产业。     

海藻肥乱象

近年来，有一种肥料被业内公认为名副其实的“贵族肥料”，这就是海藻肥。 海藻肥从2000年左右起步至今，短短10年间迅速发展：生产厂家38家，农业部登记产品78个。不过记者调查发现，其实市场上标称“海藻肥”的产品远不止这一数字，其中大部分是山寨货。     

现代中国外商企业林业政策与法律环境优化对策研究

自改革开放以来 ,外商企业直接投资中国林业的规模和质量迅速上升 ,投资区域集中在中国亚热带和热带地区 ,以合作、租赁以及收购等方式稳步发展。 2 0世纪 90年代开始 ,我国鼓励外商投资林业的法律环境基本形成 ;进入 2 1世纪 ,林业财政税收、森林采伐更新管理、森林资产抵押、森林资产的市场化等问题成为制约外资林业可持续发展的制度约束。本文就上述林业政策法律环境和问题进行了比较系统的整理 ,并提出了政策法律优化建议     

An evaluation framework for earthquake-responsive land administration

In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.     

Low-cost housing developments in South Africa miss the opportunities for household level urban greening

Most developing countries of the world are experiencing large-scale migration from rural to urban areas. Many new migrants end up in low-cost or informal areas and slums with attendant environmental concerns. One dimension of improved urban sustainability is the provision of green spaces and trees. Whilst many countries have urban greening programmes for public spaces and streets, few have considered the status and potential contribution of trees from resident's own gardens. This paper reports firstly on the policy environment for urban forestry and greening in South Africa and secondly on the maintenance, use and appreciation of trees on private homesteads of residents of new and older low-income suburbs as well as informal housing areas from three small towns in South Africa. In particular we examine if the most recent centrally planned and built low-income housing schemes (called RDP suburbs in South Africa) have considered and incorporated plans or spaces for urban greenery in peoples’ homesteads. We found that broad environmental and sustainability concerns and statements are common in urban development and housing policies, but specific guidelines for implementation are generally absent. More specifically, urban forestry and tree planting are rarely mentioned in the broader land use and environmental policies other than the national forest act and subsequent regulations, but even there it is relatively superficial. In the study towns the prevalence, density and number of species of trees was lowest in the new RDP suburbs relative to the township and informal areas. Consequently, the contribution of tree products to local livelihoods was also lower in the RDP areas. Yet there were no differences in the level of appreciation of the value and intangible benefits of trees between residents from the three different suburbs. This shows that the failure to plan for and accommodate trees in new low-cost housing developments is missing an opportunity to improve overall urban sustainability and liveability and constraining the potential flows of tangible and intangible benefits to urban residents. Making opportunities for such in older suburbs is challenging because of space limitations and cost implications of retrospective provisions, but incorporation into plans for new low-cost housing development should be possible.     

Endogenous institutional innovation and agroindustrialization on the Peruvian coast

This paper presents an analysis of endogenous institutional innovations that have recently emerged in the agroindustrial zone of Chincha, on the coast of Peru. These innovations include: (1) contracts between agroindustrial firms and large farmers, introduced by the firms themselves to assure timely delivery and compliance with strict requirements implied by the emerging demanding quality and safety standards for agro‐export of processed asparagus; (2) management services exchanged for labor supervision and land collateral in share tenancy contracts between a management company and “farmer companies” of small cotton farmers. These contracts introduced by the management company illustrate those described theoretically by Eswaran and Kotwal [Am. Econ. Rev. 75 (3), 352–367]. The nature and importance of these institutional changes are twofold: (1) They were induced institutional innovations driven by the requirements of agroindustrialization itself. (2) Together they had ambiguous employment and income impacts (tending to the negative). On the one hand, the emergence of asparagus and firm‐farm contracts reduced employment through exclusion of small farms and shifts to capital‐intensive crops. On the other hand, the reinforcement of smallholder cotton and the emergence of farmer companies increased employment and income of smallholders. The institutional innovation allowed them to reduce risk and increase profits and thus access some of the benefits of agroindustrialization and globalization. While processing firm‐farm contracts are common in Peru, as is the presence of NGOs bringing subsidized credit, the private management firm innovation is rare and new in Peru and apparently also in the region, and of great interest. In fact, policymakers and NGOs have recently discovered that this innovation is taking place and are asking hard questions about whether this innovation can and will be diffused. The interest in the private for‐profit institutional change is sharpened by growing doubts about how economically sustainable and widespread a response NGO help can be to small farmers in maintaining their participation in income‐enhancing agroindustrialization. Moreover, with changes in land laws and markets the fluidity of the situation is apparent, with agroindustrial firms even starting to ask themselves whether contracts with large farms are necessary and best.     

Land-use change and socio-ecological drivers of wetland conversion in Ha Tien Plain,Mekong Delta,Vietnam

The loss and degradation of wetlands in the Mekong Delta has been caused by a combination of human activities (social systems) and natural events (ecological systems). However, the complexity and interaction of these socio-ecological factors are poorly understood. This study provides a better understanding of the complex social-ecological factors affecting land-cover change in the Phu My Lepironia grassland conservation area, part of Kien Giang Biosphere Reserve, Vietnam. A systems thinking approach was used to determine the interaction between the social system and land-use and land-cover changes. Results indicate that ensuring food supply and improving income are the key endogenous drivers of wetland degradation in the study area. Over-exploitation of wetland resources and inappropriate agricultural practices are accelerating wetland conversion and degradation. The conflict and unclear land tenure, coupled with a desire for higher income, has driven the community to convert and reclaim large parts of the wetland. This process is also driven exogenously by wetland access and the fluctuation of commodity prices, which in-turn results in transition from traditional to extensive cropping systems and expansion of cultivated land into the protected wetland. The relationship between people and wetlands must be central to the development of wetland policies and wetland management approaches. This will improve how land use policy supports sustainable sources of food and income for the local community and concurrently reduce pressures on wetland degradation. Any efforts made to protect the remnant wetland grassland and its diverse ecosystem by regulation should be supplemented by developing and sustaining the relationship between social systems and ecological systems.     

Crop management,labour organization,and marketing: three key issues for improving sustainability in organic vegetable farming

Most market-garden farms that have converted to organic farming (OF) in the last few decades in France are small and diversified. Larger farms usually specialize in a few vegetable species and frequently face technical and economic problems when they convert to organics. Diversifying production may be a means of increasing sustainability due to larger crop rotations and varied marketing outlets, but it has various implications on farm management, especially labour organization and marketing. In the present study, we examined how an acceptable degree of species diversification can act as a lever to develop organic vegetable production by combining sociologist and agronomist points of view. Multidisciplinary surveys of 30 market-garden farms varying in usable surface area and degrees of crop diversification were carried out. Consequences on crop management, labour organization and skills, and marketing implications were described, and farm sustainability was assessed. Specialized farms of the sample had a rather industrial organization of labour and marketing and benefited from economy of scale to produce vegetables. But in the long term, they may suffer from low agronomical sustainability because of narrow crop rotations and intensive crop management. Diversified farms were more sustainable according the criteria studied, but they suffered from the extremely complex management of cropping systems. These results are discussed on both the farm and territorial levels. Collective marketing initiatives and social networks might help reach an acceptable degree of species diversification at the farm level. Potential innovative organizations are identified, which could facilitate the transition to OF.     

The effects of the Yuan‐dollar exchange rate on agricultural commodity trade between the United States,China, and their competitors

The United States claims that the undervaluation of Chinese currency, the Yuan, causes U.S. exports to China to decrease and imports from China to increase. Furthermore, because the Yuan is undervalued only against the dollar, U.S. competitors have an advantage in exporting to China and China has an advantage over its competitors in exporting to the United States. This study develops a theoretical model to analyze the effect of the Yuan undervaluation on prices, supply, demand, and trade in the United States, China, and their competitors. This study applies a cointegration/error‐correction model to empirically quantify the short‐run and long‐run effects of the devaluation of the Yuan on important agricultural commodities traded between the United States, China, and their competitors. These commodities include Chinese imports of milk, soybeans, and cotton from the United States and U.S. imports of beans, fruit juice, and fruit from China. The results show that Yuan devaluation causes Chinese imports of U.S. milk, soybeans, and cotton to decline and U.S. imports of beans, fruit juice, and fruit from China to increase in the short run and in the long run.     

Farm size and the determinants of productive efficiency in the Brazilian Center-West

This paper explores the determinants of technical efficiency, and the relationship between farm size and efficiency, in the Center-West of Brazil. This is the region where agricultural production and total factor productivity have grown the fastest since 1970. It is also a region characterised by unusually large farms. Technical efficiency is studied with Data Envelopment Analysis and county level data disaggregated by farm size and type of land tenure. The efficiency measure is regressed on a set of explanatory variables which includes farm size, type of land tenure, composition of output, access to institutions and indicators of technology and input usage. The relationship between farm size and efficiency is found to be non-linear, with efficiency first falling and then rising with size. Type of land tenure, access to institutions and markets, and modern inputs are found to be important determinants of the differences in efficiency across farms.     

新疆地区植被对水热条件的时滞响应

文章基于1981~2006年气温、降水及GIMMS-NDVI数据集,采用时滞相关分析法,以新疆地区为例,从植被对水热条件的响应时效与响应程度分析干旱生态系统植被对主要气候因子的月尺度记忆效应。结果表明:新疆地区植被对降水的响应一般以时滞2个月为主,对气温的响应一般以时滞1个月为主,植被对前期降水与对同期气温的响应程度较为明显。但不同气候区域、不同类型的植被对水热因子在记忆效应表现出明显的时空异质性:(1)从时滞响应时效来看,北疆地区植被对气温的响应滞后1个月,对降水的响应滞后2个月,南疆地区植被对气温与降水的响应均滞后2个月,天山山区植被对气温与降水的响应均滞后1个月;草甸草原、典型草原、荒漠草原及人工植被对气温的响应均滞后1个月,而沼泽植被对气温的响应时滞最长可达3个月,草甸与草原植被对降水的响应均滞后1个月,而荒漠、沼泽及人工植被对降水的响应则滞后2个月;(2)从时滞响应程度来看,北疆地区前1个月的降水对植被的影响程度大于同期与前2个月的影响程度,而气温对植被同期的影响程度大于前期(前1个月与前2个月),南疆地区前1个月的降水与气温对植被的影响程度均大于同期与前2个月,天山山区则是同期的降水与气温对植被的影响程度均大于前期(前1个月);草甸与草原植被同期对水热的响应相关程度均大于前期,荒漠与人工植被对前1个月的降水响应程度大于同期,而对温度的响应程度与降水正好相反,同期大于前期,沼泽植被对水热条件的响应程度与草甸与草原植被相反,均呈现为前期大于同期。此结果将有助于更加深入地认识西北干旱生态系统植被对气候变化影响的信息反馈。     

Assessment of social–ecological transitions in a peri-urban Ethiopian farming community

In a peri-urban poverty-stricken community in the outskirts of Addis Ababa, Ethiopia, 15 years of development efforts were undertaken by establishing an enterprise, which initially consisted of a horticultural farm and finally was composed of a multifunctional farm and a restaurant with a shop. The enterprise collaborated with BioEconomy Africa, which was charged with administrative, monitoring and facilitation tasks, and provided a training, demonstration and research facility. In the innovation process, the enterprise selected technologies and implemented them within the context of local economic and market conditions. The project benefitted from a flexible allocation of modest funds. This paper assesses the sustainability of the enterprise and the community on the basis of social–ecological system transformability and resilience. The scheme of the Food and Agriculture Organization is used to evaluate the transformability, while resilience is evaluated through self-organization capacity, disturbance absorption capacity, and learning and adaptability. The project period was divided into five Macro-phases. The transformability assessment of the enterprise revealed nonlinear and asynchronous dynamics of environmental sustainability, economic resilience, social well-being and governance that after reaching a minimum attained a maximum at the end of the period under observation. The resilience assessments showed that the self-organization capacity, the disturbance absorption capacity, and learning and adaptability slowly changed to reach a satisfactory level at the end of the observation period. The changes in transformability and resilience profoundly affected the livelihood of the community. The paper demonstrates the important role of agricultural in the development of poverty-stricken peri-urban communities and indicates that innovation processes and the efficiency of facilitation extension model implementation can be enhanced by applying adaptive project execution procedures. It can be concluded that the continuous monitoring and assessments of transformability and resilience are a prerequisite for efficiently moving the socio-ecological system on a smooth road towards a socially acceptable standard of living.