土地利用演变对国家公园生态系统服务价值的影响——以三江源国家公园为例

研判土地利用演变对国家公园生态系统服务价值的影响，是推进国家公园生态文明体制建设的重要依据。为厘清土地利用演变对生态系统服务价值的影响效应，基于2000-2020年三江源国家公园土地利用数据，首先采用生态系统服务价值修正模型测算生态系统服务价值，继而运用价值变率模型、GIS空间分析方法刻画三江源国家公园生态系统服务价值演变的空间差异特征，最后引入交叉敏感性系数揭示三江源国家公园土地利用演变对生态系统服务价值的影响趋势。结果表明：(1)20年间三江源国家公园的土地利用演变表现为荒漠、草地、水体三地类间的互相转换，变化速率最大的时间段在2015-2020年，集中发生于长江源园区西北部和北部；(2)从时间序列来看，三江源国家公园的生态系统服务价值呈现"趋好"态势，其中，2015-2020年的变化量高达82.42亿元，草地和水体对园区生态环境贡献较大，土地利用类型的演变与生态系统服务价值存在一定的关联；(3)从空间演变来看，三江源国家公园三园区(长江源、黄河源和澜沧江源)的生态系统服务价值从高值到低值依次为：长江源>黄河源>澜沧江源，呈现出从西北向东南递增的分布特征；(4)土地利用类型演变对生态系统服务价值的影响程度从大到小排序为：荒漠与水体>草地与水体>荒漠与草地，土地利用转型跨度愈大，对生态系统服务价值的影响就愈强。研究时段内土地利用演变对生态系统服务价值影响的交叉敏感性系数呈现先升高后降低的特征，表明生态系统服务价值的变化也会反作用于土地利用对生态系统服务价值影响的敏感性。     

黄河流域中上游林草生态调节服务功能价值核算

科学评估林草生态系统服务功能价值，对于掌握流域生态资产储量，推动高质量发展与生态保护具有重要基础性意义。基于多源数据开展林草生态服务功能价值的高分辨率核算及空间格局分析，结果表明：集成运用遥感产品、气象数据以及生态统计调查数据等多源数据，并参考已有生态服务价值评估规范和文献资料，构建的1km×1km像素尺度林草生态系统调节服务功能价值体系，克服了传统统计监测数据在准确度和研究粒度方面的局限，为系统、协同的区域生态治理提供依据；2015年黄河中上游流域林草生态调节服务功能价值为18997.69亿元，其中森林提供11833.11亿元，草地提供7164.58亿元；单位面积林草生态调节服务价值高值区域为青海-甘肃、陕西-山西境内水热条件较好的山地，低值连片区域广布在中部黄土高原，这与森林郁闭度、草地盖度以及区域降水、地形等自然条件有关；在黄河流域生态保护与高质量发展中，应注重以生态服务功能为基础，突破行政区边界限制，建立生态产品价值实现机制，提升区域高质量发展中生态效益的价值权重。     

Bundles of choice: Variety and the creation and manipulation of Kenyan Khat's value

This article examines the enormous variety evident in the ‘social life’ of Kenyan khat (miraa) and the role of this variety in the creation and manipulation of value. The article, after a discussion of the literature on value and its relevance to miraa, describes variables used in distinguishing the many different types of miraa, describes how consumers associate themselves with certain varieties and suggests why some varieties are more valued – culturally and economically – than others. The article then looks at the international trade in miraa, and how value is manipulated as exporters – well positioned to exploit different ‘fields of value’ – blend different varieties together to ensure a decent financial reward. It concludes by emphasising that understanding miraa requires an appreciation of its complex particularity.     

南方丘陵山区生态安全格局构建与优化修复——以瑞金市为例

构建科学合理的生态安全格局、落实生态保护修复与空间优化是促进区域生态系统健康运行和社会经济可持续发展的重要途径。以南方丘陵山区瑞金市为例，综合生态敏感性评价与最小阻力模型，解构瑞金市生态安全格局及其自然生态与社会经济特点，并提出生态保护修复与空间优化方案。结果显示：(1)瑞金市生态源地共有123.22km~2,占总国土面积5%,主要为重要山林地和水域，环绕中部盆地呈卫星状分布；(2)潜在廊道119条，生态节点72个，在周边山地呈闭合网络状，但中部盆地廊道单一、节点密集，网络连通性较低；(3)瑞金市是典型的高原型阻力面，中部盆地城镇发展区、沟域经济延伸带、西部工矿挖采点生态阻力高、源地辐射弱，应生态预警与重点修复。瑞金市生态保护修复与空间优化应宏观统筹、分区推进、精细落实，划分生态修复核心区、生态监测预警区、生态保护缓冲区和生态保护重点区，明确空间管控原则、分区推进生态保护，围绕“源地-廊道-节点”落实生态修复。     

基于易地扶贫搬迁视角的喀斯特生态脆弱区生态系统服务价值的时空演变

易地扶贫搬迁是针对生活在"一方水土养不好一方人"地区贫困人口实施的一项专项扶贫工程，在助力贫困人口实现脱贫的同时，对改善生态脆弱区生态环境具有积极的促进意义。"十三五"期间贵州省易地扶贫搬迁人口约占全国总搬迁人口的1/5，是全国易地扶贫搬迁人口最多的省份，因此，研究选择贵州省县域搬迁人口最多的册亨县为研究区域。基于2009、2015、2020年3期土地利用和易地扶贫搬迁人口数据，研究选用修正当量因子法及耦合协调模型分析易地扶贫搬迁实施前后的生态系统服务价值（ESV）时空演变规律，并探讨了易地扶贫搬迁生态修复成效。结果表明：（1）搬迁后2015-2020年，册亨县ESV增长8.32亿元，增长幅度达到17.97%，比较搬迁前2010-2015年（增幅4.13%）有显著提高。（2）坡妹、冗渡、巧马、丫他、八渡、百口6个乡镇ESV增量占册亨县总增量的82.89%，ESV增量贡献最大。（3）册亨县搬迁力度越大的乡镇其ESV增加越明显，对应的耦合协调水平越高，易地扶贫搬迁与ESV增长有明显的空间相关关系。研究从生态系统服务的角度量化易地扶贫搬迁所产生的生态修复成效，有助于提高易地扶贫搬迁后续工作的科学性和空间针对性。     

Applications of mitochondrial DNA analysis in conservation: a critical review

Patterns of variation in mitochondrial DNA (mtDNA) increasingly are being investigated in threatened or managed species, but not always with clearly defined goals for conservation. In this review I identify uses of mtDNA analysis which fall into two different areas: (i) 'gene conservation' - the identification and management of genetic diversity, and (ii) 'molecular ecology' - the use of mtDNA variation to guide and assist demographic studies of populations. These two classes of application have different conceptual bases, conservation goals and time-frames. Gene conservation makes extensive use of phylogenetic information and is, in general, most relevant to long-term planning. Appropriate uses here include identification of Evolutionarily Significant Units and assessment of conservation priority of taxa or areas from an evolutionary perspective. Less appropriate are inferences about fitness from within-population diversity and about species boundaries. Molecular ecology makes more use of allele frequencies and provides information useful for short-term management of populations. Powerful applications are to identify Management Units and to define and use naturally occurring genetic tags. Estimating demographic parameters, e.g migration rate and population size, from patterns of mtDNA diversity is fraught with difficulty, particularly where populations are fluctuating, and is unlikely to produce quantitative estimates sufficiently accurate to be useful for practical management of contemporary populations. However, through comparative studies, mtDNA analysis can provide qualitative signals of population changes, allowing efficient targeting of resource-intensive ecological studies. Thus, there are some relatively straightforward uses of mtDNA, preferably in conjunction with assays of nuclear variation, that can make a significant contribution to the long-term planning and short-term execution of species recovery plans.     

Does environmental management improve enterprise's value? – An empirical research based on Chinese listed companies

The company's environmental management behaviors can improve the relationship between the company stakeholders, help companies to sustainably develop. But it is more seen as an obligation and cost of the company's environmental protection in developing countries. So what kind of impact the environmental protection have on the value of the company? Taking Chinese listing Corporation as a sample. This paper analyzes the impact of enterprises’ environmental management and its disclosure on corporate value. We conclude that environmental management excluding independent environment report can improve corporate value. In specific environmental management measures, producing environmental friendly products can help environmental friendly products gain recognition and improve corporate value significantly.