长江经济带旅游生态效率时空演变及其与旅游经济互动响应

运用基于非期望产出的Super-SBM模型测度长江经济带旅游生态效率,综合运用标准差椭圆、重心模型等方法勾勒旅游生态效率时空演变轨迹,借助VAR模型探讨旅游生态效率与旅游经济发展水平间的互动响应关系。结果表明：长江经济带旅游生态效率整体处于中等效率阶段,呈动态上升趋势,且表现出“东部>西部>中部”的空间分布格局;旅游生态效率形成“低低集聚、高高集聚”式的“俱乐部收敛”型“双峰”格局,向西北方向移动趋势明显;东部和中部旅游生态效率与旅游经济发展水平的脉冲响应最终趋于平稳,西部地区响应程度偏弱;旅游经济发展水平对旅游生态效率的贡献率随时间发展趋于升高,旅游生态效率对旅游经济发展水平的贡献程度随时间发展逐步降低。     

市场一体化的工业污染排放机制:长江经济带例证

采用长江经济带2003~2015年105个城市面板数据,利用动态面板系统GMM方法探讨了市场一体化影响长江经济带工业二氧化硫、工业烟尘以及工业废水的实证结果及中间机制.研究表明：长江经济带各类工业污染物排放都具有动态累积效应以及存在路径依赖问题,市场规模加剧了工业污染排放,第三产业结构比例以及技术水平的提升则降低了各类工业污染排放水平,市场一体化存在影响各类工业污染物排放的规模、结构与技术传导路径.具体地,全样本中,市场一体化对各类工业污染排放物都具有技术中介效应,对于除工业烟尘之外的其他工业污染物排放具有市场规模中介效应,但第三产业结构中介效应不显著;分析区域异质性可知,与中下游地区相比,长江经济带上游地区市场一体化水平偏低,导致其对技术进步的促进不显著,缺乏影响各类工业污染物排放的技术中介效应,另外市场一体化对各地区工业烟尘的排放都具有一定的显著中介效应,至少能够从规模、结构以及技术进步层面找到一条显著的传导路径.本文推测,市场一体化对工业污染排放的影响可能受到了经济发展阶段、地区企业所有权属性、产业结构以及交通基础设施建设等潜在因素影响,而且工业烟尘排放量较大的行业是未来降低长江经济带工业污染排放的政策重点.     

长江经济带乡村性的时空分异格局及驱动机制

乡村性是描述乡村地域特征的重要指标,其时空分异可以有效反映乡村发展及转型的基本面。聚焦我国重大国家战略发展区域“长江经济带”,采用乡村性指数测度模型及探索性空间数据分析探究2000年、2005年、2010年及2017年长江经济带县域乡村性的时空分异格局,并运用GWR模型重点分析影响因素的空间异质性。结果表明：（1）2000—2017年,长江经济带县域乡村性总体有所减弱,空间上呈现“东部低、中西部高”的特点;县域乡村性在城市群（圈）、省会及大城市附近呈现较低水平,向外围逐渐升高。（2）乡村性高高集聚主要分布在中西部的传统农区,随时间推移明显缩减;低低集聚则集中在长三角、武汉、长株潭等城市群（圈）地区,且整体格局较为稳定。（3）农业技术、政府支持、资本投入、市场调节因素能促进乡村发展及转型,其中,农业技术的作用最强。自然环境和区位条件则兼具促进和限制作用。这些影响因素对不同地区乡村发展及转型的影响存在差异性,未来制定区域乡村发展策略应针对不同地区分类精准施策。     

Reexamining the Minimum Viable Population Concept for Long‐Lived Species

For decades conservation biologists have proposed general rules of thumb for minimum viable population size (MVP); typically, they range from hundreds to thousands of individuals. These rules have shifted conservation resources away from small and fragmented populations. We examined whether iteroparous, long‐lived species might constitute an exception to general MVP guidelines. On the basis of results from a 10‐year capture‐recapture study in eastern New York (U.S.A.), we developed a comprehensive demographic model for the globally threatened bog turtle (Glyptemys muhlenbergii), which is designated as endangered by the IUCN in 2011. We assessed population viability across a wide range of initial abundances and carrying capacities. Not accounting for inbreeding, our results suggest that bog turtle colonies with as few as 15 breeding females have >90% probability of persisting for >100 years, provided vital rates and environmental variance remain at currently estimated levels. On the basis of our results, we suggest that MVP thresholds may be 1–2 orders of magnitude too high for many long‐lived organisms. Consequently, protection of small and fragmented populations may constitute a viable conservation option for such species, especially in a regional or metapopulation context. Reexaminando el Concepto de Población Mínima Viable para Especies Longevas Resumen     

成渝经济区生态系统服务功能重要性评价

选取了生物多样性保护重要性、水源涵养重要性和土壤保持重要性3个重要生态系统服务功能进行分析评价,综合评价了成渝经济区生态系统服务功能的重要性及其区域分异规律. 结果表明:成渝经济区极重要区面积为19 244.00 km2>/sup>,占区域总面积的9.25%,主要为生物核心栖息地、极重要水源涵养区以及土壤保持极重要区;重要区面积为46 814.76 km2>/sup>,占区域总面积的22.56%;一般重要区面积为141 344.08 km2>/sup>,占区域总面积的68.19%.      

Challenges for a sustainable resource use: Uncertainty,trade, and climate policies

We integrate new challenges to thinking about resource markets and sustainable resource use policies in a general framework. The challenges, emerging from six papers that JEEM publishes in a special issue, are (i) demand uncertainty and stockpiling, (ii) international trade and resource dependence, (iii) deforestation, and (iv) intertemporal effects of climate change policies (“Green Paradox”). We discuss new insights and results on these issues by fitting them into the Hotelling model of non-renewable resource depletion.     

山东半岛蓝色经济区海域生态环境综合评价

海域生态环境评价作为承载力研究的基础,在近海生态管理中得到了广泛关注. 针对海洋生态环境研究中评价指标体系简单、标准相对单一及不利于实际应用等问题,以生态系统为研究视角构建了基于环境因子和生态响应的近海生态环境综合评价指标体系与指数计量方法,根据环境因子指数和生态响应指数在交叉判断矩阵中的位置,将近海生态环境状态分为优、良、中、差和劣5个等级,并将该方法应用于山东半岛蓝色经济区海域评价. 结果表明:研究海域整体环境因子指数为0.41~0.84(平均值为0.67),生态响应指数为0.17~0.75(平均值为0.45),综合评价等级为良,但已非常接近中等级别;其生态环境问题主要表现为溶解无机氮负荷较高、重金属和浮游动物密度负荷过低. 不同海域生态环境状态存在明显差异,25个近岸海域中等级优和良的共占60%,主要分布在山东半岛东部和西南部;海域等级为中和差的各占16%,另有8%海域等级为劣. 该评价模型与方法从生态环境整体性揭示海域存在问题,可为山东半岛蓝色经济区建设提供科学依据.      

辽宁沿海经济带滨海湿地资源的开发与保护研究

辽宁省拥有丰富多样的滨海湿地资源.随着辽宁沿海经济带升级为国家战略,滨海湿地资源将面临不同程度的开发影响.从辽宁滨海湿地资源禀赋与开发现状人手,分析了滨海湿地资源开发与保护中存在的主要问题,探讨了滨海湿地在沿海经济带开发中的重要功能与地位,并提出实现滨海湿地资源可持续开发利用的对策建议.     

成渝地区双城经济圈社区参与自然生态保护监管的思考

近年来,监管成为自然生态保护的重要议题,考虑监管体系的全面性和实用性,社区参与自然生态保护监管是必要和有意义的。本文以成渝地区双城经济圈为研究区,梳理近年四川省与重庆市在生态保护红线、自然保护地、绿化提升及生态保护与修复方面取得的成效,指出生态退化仍未根本改变、行政区划隔断生态保护的连通性、自然生态保护监管能力有待加强等自然生态保护困境。从社区参与的角度,对社区参与自然生态保护的现状、社区参与自然生态保护监管的可行性与必要性进行分析,并从适应新要求新定位、注重操作实施、构建参与流程办法以及系统评价评估和典型区域试点示范方面提出对策建议,以期为成渝地区双城经济圈自然生态保护监管提供决策支撑。     

Assessing combined toxic effects of tetracycline and P25 titanium dioxide nanoparticles using Allium cepa bioassay

• UVA pre-irradiation to TiO₂ NPs enhanced its toxicity toward plant A. cepa. • UVA TiO₂ NPs increased intracellular ROS, resulting in more cell damage. • Cell death enhanced cell permeability and increased uptake of NPs. • Being highly toxic (EC₅₀ = 0.097 µmol/L), TC did not increase ROS generation. • Even at a low dose, TC enhanced the toxic potential of TiO₂ NPs significantly. Usage of titanium dioxide nanoparticles (TiO₂ NPs) and tetracycline (TC) has increased significantly in the present era. This leads to their release and accumulation in the environment. Both the compounds, individually, can have adverse toxic effects on the plants. Their binary mixtures can increase this degree of damage. The present study aimed to evaluate the toxicity of both the contaminants in individual and binary mixtures in Allium cepa. Further, the toxicity of TiO₂ NPs upon UVA pre-irradiation was also measured. Results showed that UVA pre-irradiated NPs (UVA-TiO₂ NPs) had a significant decrease in cell viability than their non-irradiated counterparts (NI-TiO₂), denoting an increase in photocatalytic activity upon UVA pre-irradiation. Very low concentrations of TC (EC₁₀ = 0.016 µmol/L) mixed with TiO₂ NPs significantly increased the toxicity for both UVA-TiO₂ and NI-TiO₂ NPs. Intracellular ROS generation was significantly high for UVA-TiO₂ NPs. However, TC did not have any effects on ROS production. Both the compounds exhibited genotoxic potential in A. cepa. Different chromosomal abnormalities like anaphase bridges, telophase bridges, laggard chromosomes, binucleate cells, etc. were observed. The binary mixture of UVA-TiO₂ NPs and TC showed the highest chromosomal aberrations (64.0%±1.26%) than the mixture with NI-TiO₂ or the individual contaminants. This decreased significantly after recovery (46.8%±1.92%), denoting the self-repair processes. This study proved that UVA-TiO₂ NPs were more toxic and could be enhanced further when mixed with a sub-lethal concentration of TC. This work will help to assess the risk of both compounds in the environment.