城市游憩空间结构优化研究——以大连市为例

鉴于我国城市化的快速发展．城市居民游憩需求与供给的矛盾日益突出。本文选择城市游憩空间结构作为研究对象．综合分析现有的城市游憩空间结构和典型游憩功能区的研究成果，探讨了城市游憩需求的空间结构特征、游憩供给的空间结构特征．分析了城市游憩需求和供给空间结构特征的形成因素,提出理想的城市游憩空间结构模式。通过调研大连市主城区游憩场所的分布情况、使用情况以及大连城市游憩者的游憩需求特征,分析了大连市游憩供给和需求之间的矛盾及城市游憩空间的等级结构和整体结构。     

建立锡山市跨行政区水域边界监控点的必要性和可行性

分析了建立锡山市跨行政区水域边界监控点的必要和可行性，并阐述了建立锡山市排污总量控制体系的重要性，以便提高整个区域的水环境质量。     

IMPACTS OF VISITORS ON SOIL AND VEGETATION OF THE RECREATIONAL AREA “NACIMIENTO DEL RÍO MUNDO” (CASTILLA-LA MANCHA, SPAIN)

This study examines the effects of recreational use on the soil and vegetation at a site of ecological importance (Nacimiento del Río Mundo, Albacete, Spain). The most visited sites showed increased soil compaction of approximately 50%, bare ground increase to 61 ± 10% and a decrease in richness (from 25 ± 2 to 15 ± 2 species), diversity (from 4.0 ± 0.1 to 2.7 ± 0.4) and stratification of plant species (from 80 ± 11 to 21 ± 4%). The most visited sites had 90% less plant species as compared to the least visited. Intense use was associated with the presence of nitrophilous plant and vegetal species with a morphology adapted to heavy trampling. The recreational areas showed a distribution pattern of impact radiating outwards from the most used and degraded point. At the most visited point, Los Chorros (the spring of the river), the impact radiated outwards for about 20 m. A pilot experiment examining the effects of one-year restriction to visitors for access to a formerly impacted area showed a plant cover increase by anthropic and not by native species of 57 percent units.     

旅游踩踏对土壤微生物生物量碳、氮、磷的影响

为了探明旅游活动对张家界国家森林公园土壤微生物活性及多样性的影响,保护土壤生态平衡及合理开发自然保护区提供理论依据,进行了旅游踩踏对土壤微生物生物量碳、氮、磷的影响研究.结果表明,在所设的3个试验区中,0～5cm土壤层的微生物生物量碳、磷受到旅游踩踏的影响最严重,5～15cm土壤层的微生物生物量碳、磷受到旅游踩踏的影响较严重,而15～25cm土壤层的微生物生物量碳、磷受到旅游踩踏的影响最轻,旅游踩踏对所设3个试验区中3个层次土壤的微生物生物量碳、磷的影响均达到了显著水平(p＜0.05).从旅游踩踏对3个土壤层的微生物生物量氮的影响程度来看,0～5cm土壤层的微生物生物量氮受到的影响最严重,5～15cm土壤层的微生物生物量氮受到的影响较严重,而15～25cm土壤层的微生物生物量氮受到的影响最轻,背景区与缓冲区15～25cm土壤层的微生物生物量氮差异没有达到显著水平.说明张家界国家森林公园土壤微生物遭到了旅游踩踏的破坏,抵御外界干扰的能力已受到了旅游踩踏的破坏.     

Congestion at Recreation Areas: Empirical Evidence on Perceptions, Mitigating Behaviour and Management Preferences

Economists have tried to estimate the demand for recreation under conditions of congestion, struggling especially with a model that uses observed rather than stated behaviour to obtain results. This paper reports statistical analyses of data on perceptions, mitigating behaviour and management preferences in order to highlight the difficulties related to empirical analysis of congestion. We offer evidence that may be of assistance to those wishing to construct measures of congestion for use in an observed behaviour model. The results may also be useful to recreation area managers who can implement a quota or permit system or change site entry or access fees to control access to the site they manage.     

INTEGRATED RIVER BASIN OPTIMIZATION: MODELING ECONOMIC AND HYDROLOGIC INTERDEPENDENCE1

ABSTRACT: This paper presents an integrated optimal control model that optimizes economic performance of reservoir management in watersheds in which there are significant economic and hydrologic interdependencies. The model is solved using the General Algebraic Modeling System (GAMS). Results show that application of this model to New Mexico's Rio Chama basin can increase total system benefits over historical benefits by exploiting complementarities between hydroelectricity production, instream recreation, and downstream lake recreation.     

A reflection on four impactful Ambio papers: The biotic perspective: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Climate change impacts

Climate change represents one of the most pressing societal and scientific challenges of our time. While much of the current research on climate change focuses on future prediction, some of the strongest signals of warming can already be seen in Arctic and alpine areas, where temperatures are rising faster than the global average, and in the oceans, where the combination of rising temperatures and acidification due to increased CO₂ concentrations has had catastrophic consequences for sensitive marine organisms inhabiting coral reefs. The scientific papers highlighted as part of this anniversary issue represent some of the most impactful advances in our understanding of the consequences of anthropogenic climate change. Here, we reflect on the legacy of these papers from the biotic perspective.     

Applying the Kuhn–Tucker model to estimate the value of recreational ecosystem services in Sicily

This paper applies the Kuhn–Tucker model to estimate recreation demand of parks in Sicily. We estimate a fixed coefficient specification and a random coefficient specification to take into account heterogeneity across visitors. Estimates suggest a diversity of preferences across the population and that parks with higher level of quality attributes are more likely to be visited. We also simulate two sets of hypothetical policy scenarios to evaluate and compare the recreational value of each park and the welfare impacts of changes in a quality attribute.     

欧盟碳配额现货与期货价格关系及对中国的借鉴

基于欧盟碳市场配额现货与期货的发展经验和对我国统一碳市场建设的借鉴,本文以2005-2012年欧盟碳排放权交易体系(EU ETS)欧盟配额的现货和期货价格为样本研究二者之间的关系。本文运用单位根检验(ADF检验)的方法验证现货与期货价格的序列平稳性,并在序列平稳的前提下基于协整理论研究现货价格与期货价格的长期均衡关系,反映了二者间的静态关系。但短期内这一静态关系并不成立,反而表现出一定的动态性,短期价格的变动能够真实地反映市场需求,对价格的形成起着重要作用,因而采用向量误差修正模型重点研究二者间的短期动态关系。研究表明:1碳现货价格与期货价格间有着不同程度的影响,二者存在长期均衡,但短期内受市场特定因素的影响,二者又有所偏离;2期货价格反应灵敏,偏离均衡后调整速度快于现货,而且期货的滞后期价格对现货价格影响显著,这更加突显了碳期货的价格发现作用;3期货市场涉及了投资者对市场的预期和判断,较现货交易包含了更多的投机性,价格更为灵活,波动频繁,增加了市场风险。最后,根据结论对我国碳市场建设提出一些启示和建议:针对现货与期货价格之间的动态关系,应当积极开发和利用碳期货市场,通过期货的价格发现功能形成合理碳价,同时需要增强期货市场与现货市场的透明度,实现信息的传递与分享,最终实现期货市场对现货市场的补充和完善;为规避期货价格的波动性所带来的风险,需要建立一套完善的风险防控体系,在风险可控的前提下利用期货价格对市场进行预期,及时引导市场价格,形成完善的价格机制,为全国统一碳市场建设提供价格基础。     

遗产旅游地生态移民影响的实证研究——以武陵源风景名胜区为例

生态移民是近年来诸多景区为保护生态环境而采取的重要举措之一。以世界遗产地武陵源风景名胜区为例,通过对安置点居民的问卷调查与实地访谈获取第一手资料,从居民感知的角度分析生态移民给安置区居民所带来的经济、社会文化、资源环境、心理及安置政策等方面的影响及其相关因素。构建生态移民影响的感知差异分析模型,探讨不同基本背景的居民对生态移民影响的感知差异性。结果表明,安置点居民对生态移民的社会文化、资源环境以及心理层面的正面影响比较认可;对于经济影响的感知分歧较大;而对于移民政策的感知十分消极;不同性别、年龄、文化程度、收入水平以及不同旅游业参与程度的居民对生态移民影响的认知态度存在显著差异。在此基础上,指出武陵源生态移民过程中所存在的主要问题及相关政策导向