农业保险对农业碳生产率的影响研究

[目的]探究农业保险能否实现农业经济发展与碳减排“双促进”,进而提升农业碳生产率。[方法]文章基于2008—2020年中国30个省（市、区,未含香港、澳门、台湾省和西藏地区）的面板数据,构建双向固定效应模型和中介效应模型,实证检验农业保险对农业碳生产率的影响及作用机制。[结果]（1）农业保险有利于提升农业碳生产率,即农业保险发展水平每提高1%,农业碳生产率平均提升0.049%。（2）从作用机制来看,农业保险通过促进农业产业集聚和农业技术进步,从而实现农业碳生产率的提升,中介效应占比分别为39.1%和24.5%。（3）进一步讨论发现,农业保险对农业碳生产率的影响存在农业产值占比的单一门槛效应,门槛值为0.012 5,当农业产值占比低于门槛值时,农业保险对农业碳生产率的作用不明显,而当农业产值占比超过门槛值时,农业保险会对农业碳生产率产生显著的促进作用。[结论]政府应从强化政策支持,提高保障水平;实行差异化补贴,推动规模化生产;完善保险条款,探索创新品种等方面进一步强化农业保险的环境正外部性。     

土地生态系统服务研究进展及趋势展望

研究目的:评述了2000年以来国内外土地生态系统服务研究进展。研究方法:文献调研法。研究结果:自2000年以来,国内外在土地生态系统服务价值评估、权衡与协同分析以及空间流动等研究方面取得了重要研究成果和进展,但在概念和内涵、方法和技术以及应用等方面存在一些问题。研究结论:未来土地生态系统服务研究应该在以下方面深化发展:构建更加完善的生态系统服务研究学科体系、将生态系统服务融入到全球变化研究框架、建立政策—土地利用—生态系统服务之间的复杂联系。土地生态系统服务研究将会为提升人类福祉水平提供更优的决策支持。     

中国森林固碳及提供其他生态服务功能的潜力和挑战

应对气候变化,实现可持续发展,是一项紧迫而又长期的任务。胡锦涛主席在2009年联合国气候变化峰会上宣布将森林碳汇作为应对气候变化的一项重要举措。分析中国扩大森林面积和蓄积目标的重要性,讨论如何挖掘中国森林固碳及提供其它生态服务功能的潜力。     

Ecosystem-based adaptation in cities: An analysis of European urban climate adaptation plans

Ecosystem-based adaptation (EbA) measures have been increasingly promoted in the literature, as well as in policies and practices, for their environmental and socio-economic co-benefits. The recent scientific literature has shown a growing interest to assess climate adaptation plans at the urban level, in recognition of the important role played by urban areas in addressing climate change challenges. However, little information is available on the combination of these two issues, i.e., the actual inclusion of EbA measures in climate adaptation plans at the urban level. This paper addresses this gap by developing a framework to analyze the treatment of EbA in urban level climate planning, and apply it to a sample of climate adaptation plans in Europe. The framework consists of a classification of EbA measures, and a scoring system to evaluate how well they are reflected in different components of the plans. The results suggest that there is in general good awareness in plans of EbA measures, and of their potential role in addressing climate change challenges. However, their treatment in climate adaptation plans at the urban level often lacks sufficient baseline information, as well as convincing implementation actions. The paper concludes by offering recommendations to improve future practice, in terms of enhancing the baseline information to improve the proposal and design of EbA measures, improving the treatment of co-benefits associated to EbA measures, and strengthening coordination with other planning tools. Possible future development of this works include the integration of the proposed EbA classification, and the analysis of a larger sample of territorial plans.     

Is native timber tree intercropping an economically feasible alternative for smallholder farmers in the Philippines?

Integration of trees on upland farms in the Philippines has been slower than expected and desirable from an environmental perspective. Our economic and risk analysis points to current policies as part of the problem. The study compares three domesticated indigenous timber trees (Shorea contorta V., Pterocarpus indicus J., and Vitex parviflora W.) intercropped with maize against a benchmark of the widely used exotic mahogany (Swietenia macrophylla K.). We used a biophysical simulation model (WaNuLCAS 3.1) to represent interaction between trees and crops for a fundamental level of water, nutrient and light capture as the basis for production functions. External conditions affecting systems profitability were accounted for in the Policy Analysis Matrix (PAM). Elements of risk were introduced through Monte Carlo simulation. Study results revealed that from a farmer’s perspective intercropping systems provide similar (within an uncertainty range of + or ? 10%) returns to monocropping scenarios. When net subsidies and taxes are accounted for, social profitability evaluations favour tree intercropping at high tree densities. The net effect of the current bias in price policies towards food production therefore refrains farmers from making decisions to integrate trees on farms; a decision that is actually in the national interest on economic grounds, even without consideration of positive environmental effects.     

Who determines the trade-offs between agricultural production and environmental quality? An evolutionary perspective from rural eastern China

We explore the evolutionary nature of interactions between government policy, farm decision-making and ecosystem services in Shucheng County, Anhui Province, 1950–2015. Analyses of ecological, social and economic trends are complemented by interviews with local farmers. Since the Household Responsibility System started in 1980, there has been a trade-off between rising levels of provisioning services and falling levels of regulating services with evidence that critical thresholds have been passed for water quality. Using a Framework for Ecosystem Service Provision, we argue that farmers have acted only as ecosystem service providers and have not influenced the policies that have brought about the trade-offs. Over the period, ecological degradation is best described as an example of ‘creeping normalcy’ where cumulative conventional actions by individual farmers produce unsustainable losses in regulating services. The Chinese government should act to balance the various ecosystem services through valuation and national policy. In this respect, there is a need for agencies that can provide place-based advice to farmers that will allow them to maintain productivity levels while pursuing restorative actions. Even with new policies, the draw of urban employment, high production costs and an ageing population threaten the viability of farming in these marginal agricultural areas.     

农业社会化服务试点政策对农业绿色发展的影响——基于湖南县域的准自然实验研究

[目的]党的二十大报告明确了要加快推动农业绿色发展,揭示当前国家政策主推的农业社会化服务试点政策在推动农业绿色发展方面的作用。[方法]文章使用2008—2020湖南省县域面板数据,运用交叠DID、PSM-DID和合成DID等模型开展实证考察。[结果]基准回归结果表明,农业社会化服务试点政策的实施有助于推动农业绿色发展,但政策的动态效应显示政策效果的发挥存在一定的滞后性;机制分析表明,农业社会化服务试点政策除了直接降低农业生产过程中的环境类要素投入外,还可以通过促进农业规模经营和促进农业技术进步两条间接路径推动农业绿色发展;进一步异质性分析表明,相较于经济发展水平低、人力资本水平低的地方,经济发展水平和人力资本水平较高的地区政策效果显著;且在劳动力转移程度较高的地区政策绿色发展效应更强。[结论]应加大农业社会化服务政策试点力度,积极培育多种形式的农业服务组织,促进多种形式的适度规模经营,以此推进农业绿色发展。     

中国农业全要素生产率的动态演进及其影响因素分析

[目的]通过测算中国农业全要素生产率,揭示其动态演进趋势及影响因素,从而为推动我国农业供给侧结构性改革,实现农业现代化提供科学的决策依据。[方法]文章使用SBM-Global Malmqusit生产率指数法测算了中国农业全要素生产率,在此基础上利用Kernel核密度估计方法刻画了中国农业TFP增长的动态演进,并通过建立面板数据模型对影响中国农业TFP增长的诸多因素进行了分析。[结果]中国农业全要素生产率增长的主要源泉是技术进步,而技术效率的下降是阻碍其增长的主要原因;核密度估计表明各省份之间的农业相对全要素生产率水平差距不断扩大,技术效率普遍恶化,而技术进步增长速度显著;农业金融发展水平、工业化水平、农业科技水平对中国农业TFP都产生了显著的促进作用,而农业产业结构调整、对外开放水平对中国农业TFP则产生了阻碍作用,农村人力资本则对农业TFP产生的正效应不显著。[结论]提高农业全要素生产率,实现农业现代化.各省份应加强农业科技创新,深化农业科技体制改革,完善农村金融服务体系,推动工业化和农业现代化深度融合,培育新型职业农民等措施。     

农业全要素生产率增长对农业用水强度的影响

目的 探索农业全要素生产率增长对农业用水强度的影响,为实现农业节水增效和可持续发展提供新的经验依据。方法 文章基于2004—2017年中国31省（市、自治区,不含港澳台）面板数据,采用随机前沿函数法、面板回归模型和面板门槛模型探讨了农业全要素生产率对农业用水强度的影响效果、作用方式和异质性。结果 （1）农业全要素生产率增长对农业用水强度具有显著负向影响,具体来说主要通过技术进步降低农业用水强度;（2）农业全要素生产率对农业用水强度的影响具有门槛特征,伴随着农业全要素生产率门槛值的跨越,农业全要素生产率提升对农业用水强度的负向影响程度得到增强,从而带来农业用水强度的阶梯性下降;（3）从水稀缺程度异质性看,农业全要素生产率可以有效降低高度缺水地区和中度缺水地区的农业用水强度,而对低度缺水地区的农业用水强度无显著影响。结论 根据水稀缺程度因地制宜提升农业全要素生产率,使其尽早跨越门槛阈值,将会是实现农业节水增效的关键。     

供给侧结构改革背景下的西南地区农业全要素生产率分析

［目的］探究在制度改革背景下的农业生产力发展水平和地区差异,有利于全面了解农业发展状况,为后期农业政策的制定、调整以及农业发展提供理论基础。［方法］文章利用DEA-Malmquist指数法对我国西南地区5个省（市）农业全要素生产率（TFP）水平变化发展趋势进行分析,并在此基础上对不同地区农业TFP差异变化和发展趋势进行预测。［结果］（1）Malmquist指数分析结果表明,我国西南地区农业TFP呈缓慢增长的趋势。通过对不同地区农业TFP结果进行比较,四川省农业TFP有先逐渐上升后下降的趋势,而技术进步是影响四川省农业TFP增长的原因;（2）重庆市农业TFP也是呈现波动式缓慢增加的趋势,年平均增长率为354%; 贵州省农业TFP近20年来增长速度最快,主要影响因素为技术进步; 云南和广西农业TFP也均呈缓慢增长的趋势,技术效率和技术进步在不同时期对农业TFP的影响有所差异。（3）收敛性分析结果表明,我国西南地区农业TFP差异有减小的趋势,并且不同地区农业TFP水平具有向各自稳定状态发展的可能性。［结论］我国西南地区农业TFP增长与技术进步具有较高的同步性,因此,制约我国西南地区农业全要素生产率增长的关键因素是农业科技进步。在供给侧结构性改革背景下,必须以市场需求为科研导向,加大科技创新投入力度,促进我国西南地区农业的可持续发展。     

秦巴山区生态屏障建设的初步探讨

秦巴山区是长江上游生态屏障的重要组成部分,四川秦巴山区具有丰富的自然和人文资源,是四川北部和东北部重要的生态屏障,提供了重要的生态系统服务,但对四川秦巴山区有限的研究影响了对这一区域生态屏障建设重要性的认识,该区域还是典型的"丰富自然资源与落后经济矛盾体"。对区域、生态系统服务功能和生态屏障的片面认识、区域分割和缺乏系统规划等是该区域生态屏障建设面临的主要问题,解决这些问题是建设四川秦巴山区生态屏障的关键。     

基于生态服务价值的天门土地利用总体规划环境影响评价研究

本研究基于生态系统服务价值理论对天门市2006~2020年土地利用总体规划方案进行环境影响评价。鉴于谢高地等建立的我国生态系统服务功能价值评估体系不适于中小尺度的区域研究,本文根据天门市实际情况修正各土地生态系统单位面积生态服务价值系数,采用Costanza生态系统服务价值计算公式结合ARCGIS 9.3技术得出2005~2020年天门市生态系统服务价值的变化:生态服务总价值量增加7.75亿元;生态服务价值结构变化较小,食物生产、气体调节和保持土壤这三项价值有所减少;空间分布变化主要表现为中心城区城镇生态系统的扩大和周围工矿生态系统的减少。评价结果对天门市生态环境建设具有重要的现实意义。     

生态调节服务产品价值实现的适宜性评价及模式分区 ——以浙江省丽水市为例

研究目的：针对生态调节服务产品价值实现的难点问题,提出生态产品价值实现的适宜性评价技术,为生态产品价值实现模式在国土空间落地提供决策支持。研究方法：利用过程模型方法评价生态调节服务产品的空间分布格局,采用适宜性评价技术分析生态产品开发的适宜性。研究结果：（1）提出了“生态系统服务分类—价值实现途径—适宜性分区”生态产品价值实现的分析框架;（2）从生态系统服务、土地利用和限制因子3个方面建立了生态产品价值实现的适宜性评价指标体系;（3）定量评价了丽水市固碳、释氧、水源涵养、水土保持、污染去除、负氧离子释放、降温调节、增湿调节8种调节服务产品的空间分布格局,生态系统服务表现出空间集聚特征;（4）丽水市生态农业、生态工业、生态康养和生态补偿4种价值实现模式分区面积分别占58%、8%、13%和21%。研究结论：生态调节产品价值实现的适宜性评价和模式分区,将生态产品价值实现机制落实到国土空间上,可为“两山”转化和高质量发展提供决策参考。     

农业社会化服务绿色发展效应的作用路径研究——基于农户要素禀赋的调节作用

[目的]绿色全要素生产率被视为考量绿色发展的重要表征。农业社会化服务是小农户对接现代农业的经验性路径和政策性选择,对提升农业绿色全要素生产率、助推农业农村绿色发展具有重要意义。[方法]文章基于投入产出纬度法、技术优化的Malmquist-Luenberger指数分别测算了样本农户的社会化服务和绿色全要素生产率变动情况,深入探究了微观场域下社会化服务对农业绿色发展的影响路径,以及农户要素禀赋在其间可能的作用,并通过调节效应模型进行实证检验。[结果]（1）研究发现社会化服务对农业生产行为的重塑能力,会随着服务水平的持续提高,引起农业经营活动的空间高效集聚与农业要素的空间优化配置,呈现出农业生产方式的绿色化、规模化、资本化与技术化特征,消除劳动力自由流动的“隐形壁垒”,打破农业技术辐射扩散的“玻璃幕墙”,呈现出双轮驱动的提升模式,共同实现了农户层绿色农业技术效率、绿色农业技术变化的提高。（2）这种影响呈现非线性特点,促进作用大于抑制作用,最终表现为社会化服务的线性正向效果,共同驱动了农户层面绿色全要素生产率的提升。（3）农户的要素禀赋与社会化服务存在互补作用,强化了社会化服务绿色效应的路径依赖,且这种调节影响也存在门槛。农业社会化服务通过农户要素禀赋的调节作用,降低了其跨越门槛值的难度,为之后的社会化服务借助绿色农业技术效率、绿色农业技术变化两条路径,提升绿色发展水平提供了现实保障和长效机制。[结论]研究为更好地发挥农业社会化服务在提升绿色发展方面的作用,而采取不同的政策措施提供了理论依据,未来需要继续深入实施农业农村改革,加快推进现代农业绿色高质量发展。     

Becoming an Agroecologist through Action Education

Action education provides an appropriate set of methods for learning about the complexities of farming and food systems. Agroecology provides the framework to organise learning opportunities for students interested in solving challenges in today's world. Our programmes in agroecology concentrate on discovery and learning. Rather than agroecological theory having primary value, we immerse students in practical phenomena at the farming and food system level, and let these phenomena determine what theory is necessary and relevant. Teachers are converted from lecturers to leaders and catalysts in the learning process. In a learning landscape on campus, on farms, and in communities, we find direction by focusing on how students can become agroecologists. Students will have knowledge of farming and food systems, and the skills necessary to handle complexity and change, to link theory to real life situations, to communicate and facilitate in an effective way, and to be autonomous in their learning. Agroecology and sustainable agriculture are good places for training in these skills. Such skills will be vital for graduates to proactively deal with the challenges of specialisation, high technology, and use of non-renewable resources in modern society, in the quest for strategy to achieve sustainable development.     

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?