城郊休闲农业景观地游憩价值估算——以武汉市石榴红农场为例

研究目的:以石榴红农场为例,对城郊休闲农业景观地的游憩价值进行估算。研究方法:在对样本游客及农庄调查的基础上,应用TCM的两种基本模型ZTCM和ITCM进行估算。研究结果:(1)ITCM和ZTCM两种模型对环境资源游憩效益的估算存在一定差异。本案例中,ZTCM估算的游憩价值界于ITCM线性需求函数和半对数需求函数的估计值之间,其中ITCM线性需求函数的估计值低于ZTCM的估算值,仅是后者的68.81%;而半对数旅游需求函数对游憩效益的估计值则高于ZTCM的估计值,两者的比值为1.55∶1。(2)同一模型(ITCM)中,不同旅游需求函数设定下所估算出的游憩效益显著不同,需求函数的选择直接关系估计值的高低。本研究中,ITCM的半对数旅游需求函数估算出的消费者剩余是4345.4元/人,高于线性需求函数的估算值,是线性需求函数估计值的2.25倍。(3)取估算均值为准,可粗略地估算出石榴红农场2006年总的消费者剩余在5453.33万元,游客人均消费者剩余(consumer surplus,CS)3029.63元,农业景观地年均游憩价值361078元/hm2。研究结论:农业景观地年均游憩效益是传统种植收益的15.7倍,是休闲农场目前土地经营性收入的6倍,农业景观地的游憩价值远远高于其通过市场显现的经济产值,是农地资源价值构成中无法忽略的重要组成部分。     

Testing for convergent validity between travel cost and contingent valuation estimates of recreation values in the Coorong,Australia*

A number of studies valuing recreation have shown that the travel cost method (TCM) generates higher estimates of value than the contingent valuation method (CVM), even though the latter is commonly associated with potential problems of hypothetical and strategic bias. In this study, both methods have been used to estimate the recreational values associated with the Coorong on the Murray River in south‐eastern Australia. Values per adult visitor per recreation day are estimated with the TCM at $149 and with the CVM at $116. A number of methodological and framing issues to explain these value differences are tested. In summary, while no single methodological or framing issue could be identified that would reconcile the difference between TCM and CVM values, it appears likely that there may be a combination of factors that drive the systematic variations in consumer surplus values. The evidence in this study suggests that the most important of these are likely to be the different decision points underpinning data collection and the consideration of substitute sites, strategic responses and the treatment of uncertain responses within the CVM.     

农用地分等在基本农田划分中的应用研究

目前,我国基本农田面积的划分缺乏真正的理论基础和严格的科学论证;基本农田保护的效果、影响和方式等缺乏合理的评价标准,从而影响实际保护工作的可操作性;基于云南省农用地分等成果对农用地的数量、质量及分布特征与规律进行科学量化,并结合分析比较法划分基本农田的数量指标,为实现真正意义上的基本农田数量与质量双重保护提供了一种理论依据和技术参考。     

自然河流和休闲渔业的水景设计在居住小区的应用探析——以芜湖市都宝花园水景应用为例

随着人们生活质量的不断提高和对环境问题的日益重视,人们不再仅仅满足于有树木和草坪的居住环境,需要更为丰富的景观元素。水体造景运用,愈来愈受到人们的喜爱。本文在对水体景观类型、运用原则进行全面阐述的基础上,以芜湖市都宝花园水景应用为例,重点介绍了居住小区自然水景的设计和应用,并对存在的问题和解决的对策加以分析探讨。     

Reshaping the global agricultural landscape: perspectives from Brazil

This article highlights the main changes observed in Brazilian agriculture and analyzes the connections of the observed changes in global agriculture. My approach to the analysis focuses the main drivers of changes, where institutions play a central role. Three driving forces are are considered: first, the effects of global demand for food, fiber, and energy; second, the sustainability debate; and third, the bio‐energy paradigm. Each driver presents both local as well as global effects. The article does not emphasize the impact changes in Brazil had on the global agricultural landscape but argues that the impacts run from local and global changes, which cannot be discussed separately.     

Measuring the functional efficiency of agricultural futures markets

This article presents a method for measuring the functional efficiency of agricultural futures markets in terms of social welfare using a standard futures market structural model. Employing the concept of social surplus, it can be shown that, when futures prices are used to estimate future spot prices, the errors in prediction produce to some degree resource misallocation, which in turn results in welfare losses. Therefore, the social welfare associated with the presence of futures markets can be measured using a Social Loss index. The indicator was calculated for the period 1975–2015 and for several subperiods, which allow us to analyse functional efficiency before and after the 2007–2008 spikes in the prices of agricultural commodities. Futures contracts for 12 products are evaluated. The products are grouped in three different categories: ‘soft products’, ‘livestock’ and ‘grains and oilseeds’. The results indicate that livestock contracts tended to be more efficient than the rest of the contracts during the whole period, but in 2008–2015 their efficiency decreased vis‐á‐vis the rest of the products. Nevertheless, 2008–2015 proved to be the most efficient subperiod, confirming the remarkable development of agricultural futures markets over time.     

Estimating values for recreational fishing at freshwater dams in Queensland*

In this paper, estimates of value for recreational fishing are reported for three major freshwater impoundments in Queensland, Australia, using both travel cost and contingent valuation methods. Policy analysts often require estimates of value when analysing the importance of recreation against other uses of impoundments, or when considering the potential for further investments, such as with fish stocking programs. Different forms of the travel cost method are used to estimate separate consumer surpluses associated with two key subgroups of recreational anglers: frequent and occasional anglers. A contingent valuation study is used to estimate the marginal values associated with a potential improvement in fishing experience. The results of the travel cost analysis provide strong evidence that recreational values vary between different groups of anglers and across sites, while the contingent valuation estimates provide values for additional marginal benefits of recreational angling.     

Public preferences for landscape features: The case of agricultural landscape in mountainous Mediterranean areas

Provision of landscape amenities produced by farmers, in addition to their economic function of producing food and fibre, has contributed to a reassessment of the role of agriculture in society. In this paper, we examine whether agricultural landscape provision really responds to a social demand as is argued by those in favour of multifunctionality. Thus, the aim of the present work is two-fold. First, we evaluate rural landscape preferences of citizens from a range of choices in the mountain area of the Alpujarras (south-eastern Spain), and second, we estimate their willingness to pay (WTP) to enjoy each of the landscape characteristics existing in the area. For the empirical analysis, based on a survey of public preferences due to the good public characteristics of landscape amenities, we applied two stated preference methods: Conjoint Analysis (CA) and Contingent Valuation (CV). Three landscape attributes were considered for this analysis: type of vegetation layer, density of rural buildings, and level of slope. Several levels were also considered for each attribute: abandoned fields, dryland farming, irrigated farming, and natural lands were included for the vegetation layer; three levels (low, intermediate and intense) were considered for the level of slope and three levels (none, little and intense) for rural buildings.     

Conditioning trends shaping the agricultural and rural landscape in Africa

African countries continue to face deepening food crises that have been accentuated by the global food, energy, and financial crises. This situation is part of a long‐term structural problem: decades of under‐investments in agricultural sector and poor policies of support for smallholder farmers who form the bulk of the farming population. The inability of these farmers to achieve a supply response when commodity prices were high and market access was less of a problem suggests that there are multiple sets of binding constraints that continue to limit the potential of agricultural growth to reduce food security and poverty on the continent. This article reviews some of the historical trends that have hampered the performance of the agriculture sector. In addition, it reviews the impacts of more positive trends that could stimulate agricultural growth in Africa that could change the African agricultural landscape. The article however warns that there are more recent global developments and some continental challenges that could prevent or slow agricultural growth. These include the global financial crisis, public sector investments, inequities in global agricultural development policies, rush for agricultural lands by foreign investors, domestic commercial financing markets, climate change, and emerging carbon markets. The article argues that while opportunities for accelerated growth exists for African agriculture, new sets of policy instruments will be needed to support smallholder farmers to access new agricultural technologies, finance, reduce impacts of climate change, and adopt sustainable land use practices that can allow them to benefit from emerging global carbon markets.     

Multifunctionality of agriculture: an inquiry into the complementarity between landscape preservation and food security

Without support, the levels of agricultural public goods suchas food security and landscape preservation would fall shortof demand in high-cost countries. However, as demonstrated byNorway as a case study, the current level of support is disproportionatefrom a public goods perspective, and the policy instrumentsare badly targeted at the public goods in question. Becauseagricultural land is a major component of both food securityand landscape preservation, giving rise to a high degree ofcost complementarity between the public goods, it would be moreefficient to support land-extensive production techniques thanproduction per se.     

从景观生态学的角度看自然风景区旅游资源规划

自然风景区具有重要的生态和环境功能，作为一种旅游资源，对它的开发，规划要在不损害景区自然环境的前提下进行，认为景观生态学可以作为自然风景区旅游资源规划的理论基础之一。探讨了该学科若干基本概念和理论用于自然风景区景观规划的可能性。     

Anthropogenic and topographic correlates of natural vegetation cover within agricultural landscape mosaics in Turkey

Natural vegetation enhances the value of agricultural landscapes for people and wildlife. However, the role of anthropogenic versus topographic factors in driving the extent of natural vegetation cover within agricultural lands at large spatial scales remains unexplored. I assessed the influence of anthropogenic and topographic variables on the extent of agricultural mosaics with high natural vegetation cover in the country of Turkey where a large extent of natural and semi-natural vegetation is maintained by traditional agriculture. GIS layers depicting human land use, elevation, slope, roads and population data were obtained and summarized at two spatial scales, within provinces and for 100 km² grid cells covering the country’s entire agricultural land area. Average farm size was also obtained at province level. Hierarchical Partitioning was conducted to determine the independent effect of anthropogenic and topographic variables on the variation in agriculture with high natural vegetation. Slope had the largest independent effect on the variation in the proportion of agricultural mosaic with high natural vegetation cover. The extent of agricultural and settlement area also explained much of the variation in natural vegetation across both grid cells and provinces. The proportion of natural vegetation increased as human population and road density decreased across grid cells and as average farm size decreased across provinces. These results suggest that while topography is the primary driver of natural vegetation cover within agricultural mosaics in Turkey, the pressures associated with urban development and agricultural industrialization may also influence the cultural and wildlife value of agricultural landscapes.     

Assessment of landscape regeneration of a Natura 2000 site hosting greenhouse farming by using a dashboard of indicators. A case in Sicily through the territorial implementation of a pilot project at farm level

Rural landscapes within Natura 2000 network are particularly sensitive to any anthropic action which could cause the compromise of protected habitats. Agriculture, if conducted with unsustainable techniques, could cause loss of biodiversity and landscape quality. The aim of this study is to propose a dashboard of indicators to assess the landscape and environmental benefits achievable by a landscape transformation based on a sustainable management of the agriculture activity in an area characterized by the presence of intensive greenhouse farming. The method was applied in the southern coast of Sicily, where there is the largest SCI (Site of Community Importance) and SPA (Special Protection Area) site of the Region. Here, the dune system was seamlessly occupied by greenhouses, so endangering habitats that guarantee the survival of endemic species, such as the Leopoldia gussonei. The main dimensional, visual and agro-environmental indicators for assessing the landscape and environmental pressure were identified and valued both in the actual state and after the hypothesized conversion. The results show that the proposed intervention would allow a meaningful landscape improvement combined with a considerable reduction of the pollution of the area.     

农地组织化流转与农业生产效率改进：效应与机制

研究目的：探讨村集体介入的农地组织化流转对农业生产效率的影响效果与作用机制，为打破农地流转困境、实现农业高质量发展提供可资借鉴的经验参考。研究方法：处理效应模型。研究结果：（1)与农户分散流转相比，村集体介入实现的农地组织化流转能够有效促进农业生产效率的提升，且多种检验均表明研究结果稳健；（2)机制分析表明，农地组织化流转促进了流转数量和质量的双重提升，表现为地块规模的扩大和转入期限的延长，并分别通过规模经济效应和地权稳定效应实现农业提质增效；（3)进一步分析表明，农地组织化流转有效降低了化肥施用强度，能够实现农业增效与增绿的协同发展。研究结论：在继续坚持并创新完善土地集体所有制基础上，应稳妥充分发挥村集体在农地流转市场中的组织协调职能，实现农地高效流转与农业高质量发展的有效衔接。     

Measuring agricultural total factor productivity in China: pattern and drivers over the period of 1978‐2016

The Chinese agricultural sector has experienced a substantial increase in total output since dramatic reforms were introduced in 1978. This paper uses the index method to measure agricultural total factor productivity (TFP) for China’s crop and livestock industries, based on the gross output model from 1978 to 2016. We construct production accounts for the industries using input‐output relationships for the 26 main agricultural commodities and commodity groups, which account for over 90 per cent of the total agricultural inputs and outputs. The results show that China’s agricultural TFP grew at a rate of approximately 2.4 per cent a year before 2009, which is comparable to the main OECD countries and is double the world average. TFP growth accounts for approximately 40 per cent of output growth, suggesting that input growth was the main driver of output growth in the past. However, average productivity growth slowed down after 2009 though it has gradually recovered since 2012. The slowdown reflects the emerging challenges to existing farm production practices in Chinese agriculture, suggesting the need for further institutional reform.     

三江平原植被景观异质性分析

利用遥感数据和野外调查数据对三江平原植被进行景观异质性分析,把三江平原植被景观划分为农田、林地、草地、水域、湿地、无植被用地6种景观类型,借助FRAGSTATS景观指数计算软件,根据研究区域特征选取景观异质性指数进行计算;结果表明,景观多样性指数为1.1594,优势度指数为5.4921,聚集度指数为57.6631,表明三江平原植被景观异质性较高.     

农业社会化服务对耕地撂荒的影响研究 ——基于中国家庭大数据库的经验证据

研究目的：探讨农业社会化服务对耕地撂荒的影响机理,利用浙江大学中国家庭大数据,定量估计农业社会化服务对农户耕地撂荒的影响效果,并对其影响机制进行实证检验。研究方法：描述性统计分析、倾向得分匹配法和工具变量法。研究结果：（1）农业社会化服务能显著减少农户耕地撂荒,但这种作用主要在我国粮食主产区和中部地区较为明显;（2）农业社会化服务能促进土地规模经营户转入土地,但没有证据表明其对小农户转出土地有显著抑制效应。研究结论：中国应大力推动和支持农业社会化服务组织发展,降低服务作业成本,健全服务标准和强化合同监管,更好发挥其对减少耕地撂荒的促进作用。鼓励小农户连片作业外包,增强集体行动对提升社会化服务供给能力的作用,以此减少耕地撂荒。     

天鹅山林场森林景观异质性分析

景观空间格局分析是景观生态学研究的核心问题;利用SPOT5数据以及森林资源调查数据在资兴市天鹅山林场开展森林景观异质性分析,对林场森林资源景观分为杉木林、阔叶林、竹林、灌木林、松林、幼林及非林地等7种景观类型,结合Fragstats3.3景观分析软件进行景观格局指数计算,研究结果表明:天鹅山林场一级森林景观斑块总体密度平均值为7.6458块/hm2,在7个森林景观类型中,以竹林的斑块密度最高,其次才是阔叶林、松林、非林地、杉木林和幼林;景观多样性指数为1.5377,均匀度指数为0.7902,优势度指数为0.4802,说明景观异质性较高,景观类型丰富。