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1.
The southern pine beetle (SPB) is among the leading biological agents killing southern pine species in the eastern United States. In light of recognized spatiotemporal autocorrelation in SPB outbreaks, we devise a spatiotemporal block bootstrapping method that can be applied to analyze spatiotemporally dependent infestations. We also identify the relevant risk determinants and evaluate their impacts on the frequency of SPB outbreaks. For example, we find forest type, climate, and natural disasters like storm and forest management are all significantly associated with SPB risks. Using the results of a statistical model, we design a county-level group index insurance plan that generates estimates of actuarially fair premium rates for timber stands containing southern pine species. Given that no government-provided compensation scheme for SPB epidemics currently exists, application of this new insurance product could reduce forest owners losses. Our study offers an approach to analyzing and protecting against risks of other destructive pests affecting the timber sector.  相似文献   
2.
High-speed rail (HSR) and tourism are closely related economic activities because improved mobility is perceived to facilitate tourist behavioral changes. This study examines the influence of HSR on the travel patterns of individual tourists in Taiwan in relation to time, space and carbon emissions. A framework is first provided to discuss how changes in the speed of intercity transportation will affect visitors’ choice of the journey, behavior at destinations and trip quality. In addition, HSR is expected to influence five general aspects of travel decisions relating to mobility and trip emissions, including mode selection, travel distance, length of stay per trip, annual travel frequency and total travel days. In the example of Taiwan, information by onsite sampling of 400 domestic travelers found that HSR had a weak influence on travel distance and length of stay per trip, but was observed to facilitate extended time at each stop, a deeper engagement with the locality, and an approximate 10% reduction in transport carbon emissions through intermodal substitution. These phenomena are in line with the slow travel concept of sustainable tourism consumption.  相似文献   
3.
[目的]揭示耕地后备资源变化规律及其驱动因素是进行耕地后备资源合理保护、开发利用的重要基础,但目前对于耕地后备资源变化及驱动因素的研究较为匮乏。[方法]文章以山东省为例,基于2003年和2015年两期耕地后备资源数据库,在分析耕地后备资源时空变化的基础上,采用空间回归模型分析了其变化的驱动因素。[结果]2003~2015年期间,山东省集中连片耕地后备资源减少了30.81万hm~2,其中可开垦土地减少24.97万hm~2,可复垦土地减少5.84万hm~2。[结论]总人口、文盲率、农民人均纯收入、建设用地扩张速度、第一产业产值占总产值比重等是山东省耕地后备资源变化的显著性驱动因素,并且总人口和建设用地扩张的驱动作用最大,受教育程度和产业结构调整的作用次之,农民人均纯收入变化对耕地后备资源变化的影响最小。"宏观统筹协调,异地代补"是解决"耕地后备资源空间分布不均衡、供需不匹配",实现耕地占补平衡、高效合理的开发利用耕地后备资源的必经之路。但异地代补的数量比例和质量应严格控制,并注重对补充耕地地区的经济补偿和政策倾斜,逐步缩小与发达地区之间的差距。  相似文献   
4.
[目的]明确农药施用与农业经济增长关联状态及其影响因素,为实现"控药减害增收"的目标提供借鉴。[方法]基于2005—2015年数据利用脱钩理论和对数平均分解指数法分解进行分析。[结果]中国农业经济增长伴生大量农药施用,仅少数省域表现出农药施用和农业经济增长扩张绝对脱钩的理想状态,东北西北部分省域农业经济增长则以更大幅度的农药投入增长为代价。中西部地区劳动力规模和技术进步效应是推动农药施用与农业经济增长脱钩的因素;东部地区种植规模变化、劳动力规模和技术进步因素均是推动农药施用和农业经济增长脱钩的因素;东北地区仅劳动力规模效应成为推动脱钩的力量。[结论]推动农药施用与农业经济增长脱钩需要强化农业科技的创新与普及,完善农业生产过程中的技术支撑,推动农业病虫害监测预警,加大对环境友好型低污染农药和肥料的推广度;构建农户施药的多重约束机制,完善农业病虫灾害保险减少农户对生产过程的风险感知,发挥农业合作社对农户施药行为的规制作用,完善产品分级认证和安全准入制度;通过农地合理流转和农业机械化等方式集约利用农业生产资源;因地制宜推动农药施用与农业经济增长脱钩,结合区域资源优势和农业发展阶段有针对性地设计对策措施。  相似文献   
5.
Firms are under constant pressure from various governmental and nongovernmental agencies to switch from conventional environmentally polluting products to green product innovations (GPIs). However, the relevant research pertaining to GPI has been published in a diverse set of journals that vary in their scope and readership and, therefore, the scholarly contribution to the topic remains largely fragmented. This study has utilised a systematic literature review approach to examine the literary corpus on GPI to paint a holistic picture of its different aspects. The content and thematic analysis of 85 studies resulted in the extraction of seven key research themes: organisational capabilities, organisational learning, institutional pressures, barriers, structural changes, benefits of GPI, and methodological choices. This study's findings further highlight the various gaps in the GPI literature and raise some research questions that warrant scholarly investigation in the future. Likewise, our study has important implications for practitioners who are likely to benefit from a holistic understanding of the different aspects of GPI. Similarly, policymakers can use this study's findings to introduce policy interventions, especially in countries where GPI adoption is low.  相似文献   
6.
研究目的:设计土地储备智能决策体系,将土地储备决策环节进行科学化、定量化和模型化,为政府合理开展土地储备提供决策依据。研究方法:遵循科学性、实用性、先进性、开放性原则,以数据为驱动,人工智能为核心,通过基于Hadoop/Spark的大数据处理技术、多源异构数据融合技术、智能决策模型集对多源时空大数据挖掘分析。研究结果:提出了土地储备智能决策体系,研究了一套面向土地储备的决策方法集,实现对现状条件的精准刻画,对土地储备规模、结构、时序等内容的科学决策;在此基础上,研发了智能决策支持平台,将数据资源共享、现状条件评估、智能决策专题等功能集成,构建土地储备智能决策"一张图",并实现平台的自我学习和更新。研究结论:应用于宁波市实例验证,该体系有效地促进了土地储备科学智慧决策,对优化土地资源配置具有参考意义。  相似文献   
7.
随着社会经济的快速发展,市场经济体制在不断地完善,科学技术水平也在不断地上升,这时我国进入了大数据时代。传统的财务管理模式已经无法再适应时代的发展变化,所以企业应该及时转变自身的财务管理模式,更新管理理念。论文针对大数据背景下企业财务管理面临的挑战和变革进行分析,介绍财务部门的主要作用和发展现状,并提出提高财务管理水平的具体方法和策略,希望能够为企业的发展起到一些参考作用。  相似文献   
8.
Price reviews are a potentially costly activity. A significant fraction of unchanged prices may stem from firms not reviewing prices, rather than from obstacles to changing prices per se, such as menu costs. In this paper, we disentangle these two causes of price stickiness by estimating an inflated ordered probit model on a panel of French manufacturing firms. The results point to a low frequency of price reviews, suggestive of the relevance of information costs as a determinant of the observed price stickiness. In view of the “inattentive producers” literature, pointing that the source of price rigidity matters, this is suggestive of a large real effect of monetary policy.  相似文献   
9.
本文基于1993—2017年中国粮食主产区和主销区的面板数据,在比较两个区域农民收入及其结构变化的基础上,使用面板矫正标准误(PCSE)和面板向量自回归(PVAR)模型实证研究并比较主产区和主销区农民收入结构变化对农民种粮积极性的短期和长期影响。结果表明:无论从短期还是从长期来看,对于主产区而言,工资性收入和政策变量对粮播比有显著的负向影响,家庭经营性收入、转移性收入对其有显著正向影响,而财产性收入对其影响不显著。对于主销区而言,家庭经营性收入、转移性收入和财产性收入对粮播比的影响方向与主产区相同,但是工资性收入对其影响与主产区不同,有显著正向影响,政策变量的影响不显著。在长期,工资性收入对主产区和主销区粮播比的影响程度逐渐增加,经营性收入与财产性收入对主产区的影响更大,而转移性收入对主销区的影响更大。因此,在粮食播种面积连续3年下降的背景下,需要进一步优化农业补贴政策,转变粮食生产方式,鼓励主销区增加粮食播种面积,建立多层次农业保险体系。  相似文献   
10.
The semiarid region in the state of Sergipe, Brazil, approximately 11,000 km2, has experienced high deforestation rates in the last decades, which ultimately contribute to global climatic changes. The valuation of ecosystem services of CO2 sequestration can support definition of environmental policies to decrease deforestation in that region. This study aimed to assess land use and land cover changes in the Sergipe semiarid region between 1992 and 2017 by applying remotely sensed data and technics; simulate the land use and land cover changes between 2017 and 2030 by applying a cellular automaton model, by assuming current land use trends (Business as Usual – BAU) as a reference scenario, and a more conservative scenario (Protected Forest – PF), in which was assumed an effective enforcement of the Brazilian Forest Code established in 2012; simulate the carbon stocks by 2017 assuming the BAU and PF scenarios by 2030, and estimate the Carbon balance between the 2030 and 2017 scenarios; and estimate the economic valuation of carbon emission and sequestration by using the InVEST software. The results showed that agriculture (cropped lands) was main driver of the landscape changes in the study area, which increased 14% by 2017, a net increase of 1494.45 km2. The results showed that the total Carbon emissions would reach 736,900 Mg CO2-eq by assuming the BAU scenario, which would increase the cost of opportunity up to US$ 17.7 million and a social carbon cost varying between US$ 10.3 and US$ 30.2 million. The restoration of the permanent preservation areas could contribute to increase Carbon sequestration up to 481,900 Mg CO2-eq by 2030, which is equivalent cost of US$ 11.6 million. The natural landscape in the Sergipe semiarid region was strongly affected by deforestation activities occurred between 1992 and 2017. It requires, therefore, effective actions to support and promote restoration of degraded areas. The forested areas within the Sergipe semiarid region were the most affected type of vegetation because of expansion of agricultural fields soil exposures (Exposed Land). Environmental assessments based on scenarios and economic valuations can provide crucial information to support policy and decision makers to improve strategies for environmental management and conservation.  相似文献   
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