平衡膳食模式视角下粮食需求预测

[目的]随着时代的进步和社会经济的发展,对粮食安全内涵的理解也在逐步深化,粮食安全内涵不仅包括数量方面,还包括营养健康安全,保障居民营养健康成为粮食安全的新时代内涵。基于营养目标的粮食需求研究,建立营养—消费—生产的粮食生产模式,对引导居民合理健康消费和保障粮食安全具有十分重要的意义。[方法]文章首先分析了我国城乡居民营养消费状况,然后基于平衡膳食模式视角,引入标准人消费系数这一概念对我国未来粮食需求进行了更准确的预测。[结果]城镇居民粮食消费已达到高营养目标,但目前农村居民仅达到低营养目标水平,相当于21世纪初的城镇消费水平;考虑人口结构因素,2020年和2030年粮食需求总量分别为4.8亿t和5.6亿t,比没有考虑人口结构变化时分别减少8700万t和2 600万t。[结论]根据分析结果,提出以下几点政策建议:(1)宣传普及营养健康消费知识,引导居民合理膳食;(2)关注人口结构变动,及时调整粮食安全调控机制;(3)优化食品工业的产业机构升级,提高饲料粮转化率。     

Mapping mountain diversity: Ethnic minorities and land use land cover change in Vietnam's borderlands

In the complex agro-ecological conditions of Vietnam's northern borderlands, attempts by ethnic minority farmers to create sustainable livelihoods, along with the impacts of state development policies, have direct consequences for land use and land cover (LULC) change. In this paper we analyse the degree to which LULC has changed and diversified from 1999 to 2009 in Lào Cai Province and the underlying relationships with ethnic minority livelihood diversification strategies. We examine the correlation between LULC diversity and various socioeconomic and biophysical proxies using a spatial autoregressive model. Our findings indicate two major changes in LULC: an increase in closed canopy forest and substantial urban growth. LULC diversity increased between 1999 and 2009, suggesting a transition between land uses and/or a diversification of livelihood strategies. Socioeconomic proxies are significant predictors of LULC diversity in both years, while biophysical proxies are only effective predictors in 2009. In-depth interviews regarding state-led policies and ethnic minority livelihoods reveal some of the underlying mechanisms of such LULC transitions and associations.     

Chinese land policies and farmers’ adoption of organic fertilizer for saline soils

Soil salinization has become a global concern and poses a great threat to food production and sustainable land use. Land use policies are the main driver of saline soil farmland use in ecosystems. This paper proposes a theoretical framework for analyzing how saline soil farmland use is affected by land use practices of individual farm households. An empirical study, using an ordered probit model, was conducted based on questionnaire responses from farm households in 8 towns and 14 villages in eco-fragile areas in Shandong, Jilin and Xinjiang provinces. The results suggest that land tenure, state systems agricultural support, characteristics of a field parcel and characteristics of the farm households have different influences on farmer's land use in three regions. The adoption of organic fertilizer by individual households is constrained by the lack of stability and integrity in land tenure. Furthermore, the parcel of a field is generally small, sparsely distributed and often fragmented, which increases costs. Even subsidizing organic fertilizer does not necessarily help in its adoption. Given these challenges, this study makes recommendations for different regions that may promote the adoption of improved saline soil farmland cultivation methods by farmers.     

Land owners’ perception of land consolidation and their satisfaction with the results – Slovenian experiences

Land consolidation has been an important instrument of rural development for over a century throughout Europe. Nowadays, land consolidation can be an integral part of both rural and urban development projects, but the focus of our study is on land consolidation in rural areas. In addition to the efforts aimed at making agriculture and forestry more competitive through a comprehensive reallocation process, improvement of road and drainage networks, landscaping, environmental management, conservation projects, and other functions may be implemented in land consolidation. There are differences in the objectives and procedures of land consolidation among the countries. Beside the formal institutional framework of land consolidation, informal institutions can have a substantial influence on the implementation of land consolidation. In the article, the past experiences in the field of land consolidation in Slovenia are presented, which are still reflected in the limited acceptability of this instrument among land owners. Furthermore, the current institutional (legal) framework is analyzed in detail. The main objective of the research was to investigate the opinion of land consolidation participants about land consolidation. Based on the field survey conducted on a sample of private land owners involved in selected land consolidation projects we tried to define the advantages and disadvantages of the current practice. The main finding is that the active participation of land owners contributes to their comprehension of the aims and to their satisfaction with the results of the land consolidation. It has been shown that the active participation of land owners in the land consolidation is the basis for developing good practices; moreover, it affects the land owners’ perception of land consolidation. The transfer of knowledge and representation of good practices among actors are still needed, in particular because of bad experiences in the past (i.e. enforced and environmentally unfriendly projects) and the traditional emotional attachment to land among land owners. In parallel, there is a great need to provide an optimization of the land consolidation process in Slovenia.     

The role of public participation in encouraging changes in rural land use to reduce flood risk

Changes in rural land use to reduce flood risk are encouraged by governments in many countries, but they may face considerable opposition by land managers. Local participative processes are thought to help overcome opposition. This article presents an evaluation of an intensive participative process set up between land managers and governmental agencies following two severe floods in the transboundary Bowmont–Glen catchment in Scotland and England. A combination of interviews and documentary analysis is used. The research demonstrates that the participative process contributed to greater uptake of rural land use change and improved compliance with existing environmental policies. There were nevertheless low levels of social learning amongst participants. Two institutional designs for improving policy implementation are presented.     

Land system change in Italy from 1884 to 2007: Analysing the North–South divergence on the basis of an integrated indicator framework

Over the past centuries, land systems in Italy experienced fundamental shifts, owing to the availability of new energy forms, population surges, and technological progress. The 20th century was characterized by massive productivity increases, accompanied by gradual land abandonment and the return of forest land. We here analyze 120 years of land system change in Italy, applying the human appropriation of net primary production (HANPP) framework, a metric for socio-economic pressures on terrestrial ecosystems. HANPP allows integrating ecological with societal perspectives, by systematically quantifying (a) biomass harvest and (b) the difference between potential productivity of ecosystems and current productivity induced by land use processes, such as land conversion, or land degradation. Besides assessing national trends we calculated HANPP separately for the Italian North and South between 1934 and 2007, in order to scrutinize if high regional discrepancies in terms of natural and socio-economic preconditions translate into diverging land system trajectories. Our results show that national HANPP has been declining from 78% of natural productivity before WWII to 56% in 2007, indicating a declining land -use induced pressure on biomass flows over time. Simultaneously, biomass harvest increased by around 26% due to agricultural intensification, despite shrinking croplands. Although we found a significant difference between the Northern and Southern region in the absolute levels of several land use indicators related to biomass appropriation, the overarching trends of land system change were remarkably similar in both regions. This suggests that underlying drivers of land system change, such as policies aimed at land-use intensification and structural change were equally dominating land system trajectories in the North and South of Italy, not withstanding their socio-ecological divergences.     

Soil is brown gold in the Emilia-Romagna region,Italy

Soil is a natural resource essential to human welfare by virtue of its numerous crucial functions. In the past, soil has been taken for granted because of its widespread, albeit finite, availability. However, now that world's population is projected to exceed ten billion before the end of this century, soil is increasingly perceived as a precious commodity. Consequently, soil is increasingly under pressure by rich private investors and governments within the poorest countries to satisfy appetites for food production and biofuel. A case study is used to explore the plausibility of soil being considered as ‘brown gold’. Based on the comparison of land use maps, we estimated the value in terms of resource from raw material, carbon sink and virtual calories of the productive soil lost during the period 2003–2008 in the Emilia-Romagna Plain, one of the most productive areas of Italy. More than fifteen thousand hectares of cropland underwent land use change – in particular urbanization – over the 6-year period with an implied loss of crop production potential equivalent to the daily calorific requirement of more than 440,000 people. Taking into account that Italy is no longer self-sufficient in food production, such a loss appears to be strategically significant. Perhaps more importantly, urbanization and soil sealing has had negative ramifications on environmental sustainability, on both local and broad scales, with increased consumption of public funds. A logical framework of the socio-economic impact of land use change has been compiled and is presented as a possible example of a policy relevant approach to managing productive soils as a finite resource.     

Land tenure insecurity in post-certification Amhara,Ethiopia

It is generally believed that tenure security has improved due to the programme of land certification. In this paper I argue the opposite. Tenure security concerns three different rights: possession, renting and latent rights. Rights of possession are believed to have improved, but the evidence is weak and conflicting. Land rentals are expanding and farmers face high tenure insecurity. The main problem, though, is latent rights, with great insecurity and increased conflict levels. Despite rapid economic development there is considerable social malaise, an unfortunate agricultural structure, and considerable pressure for land redistribution due to unresolved land tenure issues. The paper is based on the certification literature and primary material from North Shäwa.     

Cropland expansion and grassland loss in the eastern Dakotas: New insights from a farm-level survey

The western Corn Belt region of the United States has become a hotspot for agricultural extensification and consequent land use and land cover changes. The goals of this research were to characterize geographic patterns of grassland loss resulting from cropland expansion in the eastern Dakotas, and to understand how these changes were associated with characteristics of individual farms and farm operators. We collected data on grassland conversion and other land use decisions through a mail survey of farm operators in North and South Dakota. Overall, 40% of respondents converted at least some grassland to cropland between 2004 and 2014, and the total acreage of converted grassland was equivalent to 5.1% of the surveyed farm acreage. Although most converted grassland acres (3.2% of farm acreage) were from land enrolled in the conservation reserve program (CRP), there were also substantial amounts of native grassland conversion (1.0%) and tame grassland conversion (0.9%). The total acreage of grassland conversion was more than four times larger than the acreage enrolled in CRP and other conservation programs. Different types of grassland conversion (e.g., native grassland versus CRP) were concentrated in different parts of the study region, and were spatially disjunct from the areas of highest conservation program enrollment. Larger farms were more likely than smaller farms to expand their cropland acreage and accounted for a disproportionate share of grassland conversion. Younger farm operators, higher levels of farm income, higher proportions of rented croplands, and marginal yields were also associated with cropland expansion and grassland conversion. Although CRP and other land retirement programs will remain important policy mechanisms for conservation in this region, they are not sufficient to maintain current levels of grassland cover and do not provide protection for native grasslands. Alternative conservation strategies and new agricultural policies are thus critically needed to maintain the ecosystem services provided by grasslands.     

How to overcome the implementation gap in ecosystem services? A user-friendly and inclusive tool for improved urban management

One of the main issues with the concept of ecosystem services is its absence on the ground in concrete operational decision-making contexts; that is, an implementation gap. In this study, we investigated if this gap could be overcome through the use of open-source data and free tools, and the adoption of a short-term participatory process. We tested these methods in the context of a project in the urban metropolitan area of Bordeaux (Communauté urbaine de Bordeaux: CUB) in France. The ecosystem services were defined using a participatory approach involving local stakeholders, and then selected scenarios were simulated to test the impact of various development or conservation plans. The study addressed three main questions: (1) Is it possible to adopt a simple methodological approach that overcomes the implementation gap through the development of a user-friendly and inclusive method? (2) What is the added value of a participatory approach? (3) With regards to four scenarios in this territory, what are the ES trends in the selected biophysical and monetary indicators, and will knowledge of these trends help planners to shape a sustainable trajectory for the territory?