黄土丘陵区3种典型天然草地群落土壤呼吸对模拟降雨的响应

土壤呼吸是影响陆地生态系统碳循环的关键生态学过程之一,降雨是土壤呼吸变化的重要驱动因子.为探明黄土丘陵区退耕草地群落土壤呼吸对降雨的短期响应规律,选择白羊草(Bothriochloa ischaemum)、达乌里胡枝子(Lespedeza davurica)、铁杆蒿(Artemisia gmelinii)为优势种的3种草地群落为研究对象,于2014年6月和7月,以未降雨群落为对照,对比测定了2种模拟降雨量(15 mm和50 mm)下连续8 d的土壤呼吸速率及土壤水分和土壤温度等.结果表明:2种模拟降雨量对3种草地群落土壤温度和土壤含水量均具有显著影响(p0.05).50 mm降雨下群落土壤呼吸速率增加量高于15 mm降雨.3种群落土壤呼吸对降雨的响应程度存在明显差异,其中,土壤呼吸速率峰值高低顺序为:白羊草(1.75 g·m~(-2)·h~(-1))铁杆蒿(1.69 g·m~(-2)·h~(-1))达乌里胡枝子(1.12 g·m~(-2)·h~(-1)).0~10 cm土壤含水量与土壤呼吸速率呈显著对数函数关系.3种群落土壤呼吸温度敏感性系数Q_(10)值变化范围是1.31~2.01,且月份和降雨量处理间均存在差异.研究表明,准确评估降雨格局改变背景下退耕草地生态系统碳收支需考虑群落类型的差异.     

艾比湖湿地土地利用/覆被-景观格局和气候变化的生态环境效应研究

借助Arc GIS与ENVI软件,以1998年、2006年和2014年遥感影像Landsat TM/OLI为数据源,得到3期艾比湖湿地自然保护区土地利用/覆被类型图.在空间尺度上将研究区分为3个特定研究单元来分析土地利用/覆被变化特征,并从景观格局和气候变化两个方面来进行生态环境效应研究.通过计算土地利用/覆被类型生态风险指数,从而获得研究区生态安全指数,最终建立艾比湖湿地自然保护区土地利用/覆被类型与生态环境之间的数量关系,并对整体及局部地区进行生态环境质量动态分析.结果表明,水域和其他(裸地和戈壁)是研究区内的优势景观类型.水域的平均斑块面积最大,水域和其他(裸地和戈壁)的最大斑块指数较高,盐碱地和其他(裸地和戈壁)的分维度指数较高,水域和其他(裸地和戈壁)的聚集度指数较大,林草地空间分布离散,破碎化程度高,连通性差.1998—2014年期间多样性指数增加,说明各景观类型所占比例趋于均衡化,作为优势景观类型的湿地对整个景观的控制作用减小,景观异质性增加.1998—2014年间,艾比湖湿地自然保护区总体生态环境指数呈逐步升高趋势,但生态环境质量的改善与恶化同时存在,并在特定研究单元上出现明显的区域分异特征.盐碱地、其他(裸地和戈壁)向湿地及荒漠向其他(裸地和戈壁)的转化是环境改善的主导因素.湿地向水域和其他(裸地和戈壁)的转变是环境恶化的主导因素.据1998—2014年的气象资料,降水量呈下降趋势,降水减少使植物存活率降低,导致植被覆盖率下降,从而影响生态环境的健康发展.另外,在分析驱动机制的基础上,建立了优选多元线性回归方程,结果表明,在景观指数和年径流量中,艾比湖湿地自然保护区生态环境指数的变化与平均斑块面积和分维度指数均呈显著相关.该研究对艾比湖湿地自然保护区土地利用合理规划管理、生态恢复和经济发展政策的制定有着非常重要的意义.     

基于Logistic曲线的城市应急能力评价研究

为科学、合理的对城市应急能力发展现状与发展过程进行评价,运用Logistic曲线模拟替代传统线性曲线分析城市应急能力发展过程,并运用该曲线对传统的线性隶属函数进行改进,提出了基于Logistic曲线的城市应急能力发展现状评价模型和城市应急能力可持续发展过程.运用该模型对广州市火灾应急能力进行实证分析,分析结果显示,20...     

Are soil conservation technologies “win‐win?” A case study of Anjeni in the north‐western Ethiopian highlands

This study measures the impact of fanya juu terraces on the net value of crop income in a high‐rainfall area in the Ethiopian highlands using cross‐sectional multiple plot observations. Using propensity score matching methods we find that the net value of crop income for plots with fanya juu terraces is lower than for plots without fanya juu terraces. This finding makes it difficult to avoid concluding that while the technologies might reduce soil erosion and associated off‐site effects, they do so at the expense of poor farmers in the Ethiopian highlands. Therefore, fanya juu terraces cannot be characterized as a “win‐win” measure to reduce soil erosion. New agricultural technologies need to be profitable to the farmer if they are to be adopted and sustained.     

Ecological niche modeling of customary medicinal plant species used by Australian Aborigines to identify species-rich and culturally valuable areas for conservation

Customary medicinal plant species used by Australian Aborigines are disappearing rapidly with its associated knowledge, due to the loss of habitats. Conservation and protection of these species is important as they represent sources of novel therapeutic phytochemical compounds and are culturally valuable. Information on the spatial distribution and use of customary medicinal plants is often inadequate and fragmented, posing limitations on the identification and conservation of species-rich areas and culturally valuable habitats.In this study, the habitat suitability modeling program, MaxEnt, was used to predict the potential ecological niches of 431 customary medicinal plant species, based on bioclimatic variables. Specimen locality records were obtained from the Global Biodiversity Information Facility (GBIF) data portal and from Australia's Virtual Herbarium (AVH).Ecological niche models of 414 predicted species, which had 30 or more occurrence points, were used to produce maps indicating areas that were ecologically suitable for multiple species (concordance of high predicted ecological suitability) and having cultural values. For the concordance map, individual species niche models were thresholded and summed. To derive a map of culturally valuable areas, customary medicinal uses from Customary Medicinal Knowledgebase (CMKb) (www.biolinfo.org/cmkb) were used to weight individual species models, resulting in a value within each grid cell reflecting its cultural worth.Even though the available information is scarce and fragmented, our approach provides an opportunity to infer areas predicted to be suitable for multiple species (i.e. concordance hotspots) and to estimate the cultural value of a particular geographical area. Our results also indicate that to conserve bio-cultural diversity, comprehensive information and active participation of Aboriginal communities is indispensable.     

鼎湖山南亚热带森林生态系统服务价值动态

以鼎湖山3个南亚热带森林演替典型阶段生态系统为对象,采用我国《森林生态系统服务功能评估规范》（LY/T 1721—2008）标准化计算公式与服务价格,量化揭示南亚热带森林生态系统演替过程中生态系统服务功能价值动态。结果表明：随着演替的进行,南亚热带森林生态系统服务功能总价值不断增大;但各分项服务功能价值则表现出不同的动态规律与变化幅度,从而使得森林生态系统服务结构呈现非线性演化特征。在南亚热带森林生态系统演替的早期阶段,生态系统服务价值的最大组分是涵养水源的功能价值,而中、后期则是保育土壤。人工林营造可以有效增强区域生态系统的水源涵养能力,而保育演替中、后期森林则对于大气CO2收和土壤保育而言尤为重要。     

Study on Human Capital Valve Quantity Model and Investment Featuers

Human capital, the most active and valuable element ofproductivity, is the primary drive and crucial factor in thegrowth and development of modern regional economy.However, because of many different meanings about theconception of human capital and the complexity of itsevaluation, the measure and calculation of human capitalhas become a difficult problem. As yet, there is neither acommon measure means of human capital nor enoughcognition of its investment features.1 HUMAN CAPITAL VALUE …     

VALUING ECOSYSTEM SERVICES OF CHILEAN TEMPERATE RAINFORESTS

The Valdivian Rainforest Ecoregion (35°–48° S) in southern South America is among the ecosystems with highest conservation priority worldwide due to its rich diversity, degree of endemism, and critical conservation status. Temperate rainforests in this vast area are essential as source of biological resources and to maintain different ecosystem services which remain largely unmeasured and unvalued. Consequently, the benefits they provide are not reflected in decision-making regarding forest management and conservation. Based on existing studies and results from ongoing research we describe selected ecosystem services and provide estimates of their economic value. Timber benefits for secondary forests expressed as net present stumpage values were US$ 3742 ha⁻¹ and US$ 3093 ha⁻¹ for sustainable forest management (SFM) and unsustainable harvesting, respectively. Timber benefits for old growth forests␣equaled US$ 4546 ha⁻¹ and US$ 5718 ha⁻¹, for SFM and unsustainable harvesting, respectively, using an 8% discount rate. Annual benefits from recreation were US$ 1.6 ha⁻¹ and US$ 6.3 ha⁻¹ for the two most important national parks located in the study area. The annual value of maintaining soil fertility was US$ 26.3 ha⁻¹ using the replacement cost of nutrient losses due to soil erosion. The annual economic value of water supply for human consumption using the production function method was US$ 235 ha⁻¹. These results provide valuable information on the kind and magnitude of values that could be relevant in decision-making concerning conservation and management of native forests in the Valdivian Rainforest Ecoregion.     

山东苍山MS5.2地震泰安石英倾斜仪异常分析

利用矢量曲线、γ因子等方法识别苍山ＭＳ５．２地震前泰安石英倾斜仪的前兆异常。分析认为：ＳＱ—７０石英倾斜仪反映出一定的地形变异常信息。     

遗产廊道旅游价值评价体系构建及其应用研究——以古运河江苏段为例

遗产廊道是目前保护线性文化遗产的一种新趋势。我国拥有丰富的线性文化遗产，准确地评价其旅游价值，对于有效保护和合理开发利用文化遗产资源，具有重要意义。本文基于遗产廊道自身的特殊性和整体性，尝试从廊道资源条件、区域社会条件、廊道生境条件和旅游保障条件及发展潜力等方面建立遗产廊道旅游价值评价指标体系，旨在从廊道整体效应出发评价其旅游价值。并运用层次分析法（AHP）和德尔非法（Delphi）相结合的方法，确定指标体系各因子的权重。并以古运河江苏段为例进行实证研究。评价结果与古运河江苏段实际情况基本吻合，说明本文构建的评价指标体系具有一定的科学性和可信度。