亚热带喀斯特石漠化土地退化特征研究

喀斯特石漠化退化土地是目前西部地区经济发展、生态恢复与重建工作最为严重的问题之一。喀斯特石漠化是一种严重的土地退化,石漠化土地退化过程中存在社会经济反馈、动力反馈和生物原反馈等多层次反馈结构。由于喀斯特生态系统的独特性和脆弱性,喀斯特石漠化土地具有不同于其它生态脆弱区土地退化的特征,因而将其归纳为土地退化恢复过程的基岩差异性、退化恢复过程与土地利用方式的相关性、退化土地成因的地域差异性、石漠化土地的空间异质性与尺度相关性、恢复过程的土壤—地形决定性、土壤资源的不可再生性,石漠化土地退化的本质是喀斯特生态系统服务功能的下降和丧失,是一种功能性荒漠化。对石漠化土地的特征进行全面深入的探讨,有助于石漠化土地分类治理和生态恢复重建。     

退化土地评价及其生态重建方法研究

本文系统分析了退化土地评价研究的历史和方法，总结了退化土地的主要类型、分布和形成机理，最后概述了退化土地重建领域的研究进展。     

贵州山区石灰土侵蚀及石漠化的地质原因分析

石灰土是广泛分布于亚热带喀斯特山区的一种非地带性土壤，近几十年来，位于西南喀斯特分布中心的贵州石灰土地区石漠化扩张速度明显加快，已经对该地区数千万群众的基本生存条件构成严重威胁。从地质学角度详细分析这一地区石灰土土壤侵蚀和土地石漠化的形成原因，分析结果表明：石灰土本身的矿物学特征和基本理化性质较好，并不是造成土壤侵蚀和石漠化的主要原因。石灰土成土速率慢，土壤允许流失量小；作为土壤营养库的富含有机质和矿质养分的表土层一旦被剥蚀，土壤结构迅速退化，土壤侵蚀愈演愈烈；喀斯特独特的二元结构和地形地貌是石灰土侵蚀的主要影响因子；石灰土与基岩之间缺少风化母质的过渡，岩土界面的土壤侵蚀是石灰土侵蚀的重要特征；这些因素才是导致石灰土地区土地石漠化的主要原因。     

一个值得关注重要案例：贵州省普定县生态重建与可持续发展试点工程

1　生态重建与反击贫困是全社会共同责任中国西南石灰岩地区如何重建生态 ,反击贫困 ,走可持续发展之路 ,是该区域跨世纪的重大课题 ,已引起社会各方面的重视与关注。中国国土经济学研究会一位著名社会学家指出 :“西南石灰岩地区的贫困问题 ,就人与自然的关系而言 ,其实质是生态重建 ;就人与社会的关系而言 ,是社会经济重构。”如果“人增—耕进—林退—土地石化”的恶性循环不能遏制 ,其结果必然是一方水土养活不了一方人的绝对贫困 :如果个人不能被社会所整合 ,仍处于封闭的自然社区之中 ,即使一方水土养活一方人 ,也还处于“丰衣足食”…     

沿海发达地区土地利用研究新进展与方向

土地资源的短缺、质量退化与低效利用．已成为影响沿海发达地区生态安全与可持续发展的重要制约因素，也是土地利用管理与规划决策所面临的现实难题。我国沿海经济发达地区作为人地矛盾激化和经济快速转型背景下特殊的人文生态脆弱区，受到了包括地理学、生态学、经济学和社会学等多学科学者的密切关注，尤其是近10多年来在沿海土地利用变化及其效应研究方面取得了丰硕成果。主要以土地科学研究新方向和沿海地区经济社会发展态势为基本背景．从土地利用类型及其转换格局、驱动力因素辨识与驱动机制、土地利用转换的效应、区域土地可持续利用．以及土地利用优化配置与调控等方面，对沿海地区土地利用研究进行了初步梳理和评述，并指出今后应重视深化沿海发达地区土地利用研究的9个重点问题。     

农村生态资源的生态服务价值评估及时空特征分析

利用Costanza的生态系统服务功能价值核算方法,以省(市)为核算单元,对1989-2007年间中国农村生态资源的生态服务价值进行评估,并分析我国农村生态服务价值的时空分异特征.研究结果表明:①)1989-2007年间中国农村生态资源的生态服务价值呈现先增长后下降的趋势,1996年以后农村生态资源退化较为严重,主要是由耕地和草地的生态服务功能下降造成的农村生态价值中林地和草地所提供的生态价值所占的比重较高,其比重都在40%左右;②农村资源生态服务价值较多的省份主要分布在西部地区,不同地区农村生态服务价值的内部构成差异也很大;③中国农村生态资源的退化普遍存在,农村资源退化不仅分布在生态脆弱的西部地区,并且已经蔓延到部分中部和东部地区,其中江苏、浙江、山东、北京、天津、河北、辽宁、河南、广东等省市主要表现为耕地退化型;福建、江西、湖南、广西、云南等省市主要表现为林地退化型;贵州、西藏、甘肃等省市主要表现为草地退化型,因此,不同区域应实行差别化的管理措施.     

基于最小累积阻力模型的贵阳市景观生态安全格局构建

贵阳市是我国典型的喀斯特地区,水土流失严重,生态环境脆弱。在生态重要性、景观连通性和生态需求分析的基础上进行生态源地识别,根据土地覆被状况、人为干扰程度和夜间灯光数据构建了生态阻力面,基于最小累积阻力模型识别生态廊道网络,在此基础上构建了贵阳市域和市区的景观生态安全格局。结果表明:(1)贵阳市最重要和重要生态斑块总面积5 393.43 km2,主要分布在西部和北部;生态用地斑块的景观连通度总体较高,其中园地最好,林地最差;生态需求较高的区域主要分布在人口密集的城市建成区周边。生态源地占总面积的18.56%,集中分布于北部及西南部红枫湖、百花湖等区域;(2)贵阳市生态廊道总长为933.58 km,其中关键廊道长287.6 km,沿东北向西南方向延伸。现状廊道遍布市域,主要为河流水系;潜在廊道和关键廊道98%都为林地,主要分布于北部和西部生态环境较好的山地丘陵区;(3)市区景观生态安全格局中,生态源地主要集中在百花湖、红枫湖、香纸沟、相思河等风景区,花溪湿地和南明河作为市区关键廊道纵贯南北。最后,在此基础上提出了"保护和建设并重、区县间统一规划的"生态系统管理对策,为贵阳市生态环境建设提供切实可行的科学指导。     

农牧交错带农业生态服务功能的作用及其保护途径

目前全球农业生产覆盖全球25％～30％的土地面积，约50％的可利用土地已经被农业占据。如果农业生态系统．特别是生态脆弱区的系统服务功能得不到恢复与保护．那将会拖全球环境保护的“后腿”。由于中国的国情决定了在生态脆弱区环境保护中必须坚持环境保护与发展农业生产“两手抓“。因此．农业生态系统服务功能的恢复、维持应该成为该地区生态环境保护与建设的重要组成部分。农业生产不仅要提高生态系统服务的产品功能，更要恢复和维持其各种维持生命的间接服务功能。本文在分析农业生态系统服务功能退化表现与影响因素的基础上．提出了针对各项服务功能的恢复与维持对策。     

中国西南喀斯特地区人口、资源、环境与可持续发展

中国西南喀斯特地区人口－资源－环境的矛盾非常突出,贫困与生态恶化的双重压力严重制约区域可持续发展。西部大开发战略为西南喀斯特地区的持续发展和反贫困提供了前所未有的机遇。喀斯特地区可持续发展的首要任务是更新观念,以生态环境重建为切入点,加强基础设施建设,实施科教兴国战略,控制人口数量、提高人口素质;调整产业结构,加大扶贫开发力度,把宏观调控与市场机制相结合,实现跨越式发展。     

关于中国西南石漠化的若干问题

石漠化是西南岩溶山地脆弱生态系统发生的土地退化。根据已有的经验和研究成果,深入探讨了中国西南岩溶山地喀斯特石漠化的科学内涵、成因、发展过程、评价指标及防治机理等。土壤和植被是岩溶环境中最为敏感的自然环境要素,可能是石漠化过程的主要自然成因,而以土地利用为表现形式的强烈人类活动为驱动力;石漠化的发生发展过程即人为过程→生物学过程→加速的地学过程。石漠与石漠化,二者属于完全不同的范畴,不同空间尺度的石漠化评价应有不同的评价指标、标准和石漠化生态基准的多样性,以便为石漠化的演化研究及生态重建起一定的参考作用。鉴于石漠化现象在我国现实中存在的客观性、在理论概念上的模糊性及在生态治理中的急迫性,有必要加强石漠化在不同时空尺度下的驱动机制研究,特别是人类驱动力的研究,加强原生岩溶生态系统和受损岩溶生态系统运行规律的研究。     

Ethnosciences––A step towards the integration of scientific and indigenous forms of knowledge in the management of natural resources for the future

Integration of indigenous knowledge and ethnoscientific approaches into contemporary frameworks for conservation and sustainable management of natural resources will become increasingly important in policies on an international and national level, both in countries that are industrialised and those that have a developing status. We set the scene on how this can be done by exploring the key conditions and dimensions of a dialogue between ȁ8ontologiesȁ9 and the roles, which ethnosciences could play in this process. First, the roles of ethnosciences in the context of sustainable development were analysed, placing emphasis on the implications arising when western sciences aspire to relate to indigenous forms of␣knowledge. Secondly, the contributions of ethnosciences to such an ȁ8inter- ontological dialogueȁ9 were explored, based on an ethnoecological study of the encounter of sciences and indigenous knowledge in the Andes of Bolivia, and reviewed experiences from mangrove systems in Kenya, India and Sri Lanka, and from case-studies in other ecosystems world-wide, incl. Australia, Burkina Faso, Ecuador, Ethiopia, Guatemala, Indonesia, Nepal, Niger, Philippines, Senegal, South-Africa and Tanzania.     

Paradoxical ozone associations could be due to methyl nitrite from combustion of methyl ethers or esters in engine fuels

We review studies of the effects of low ambient ozone concentrations on morbidity that found a negative coefficient for ozone concentration. We call this a Paradoxical Ozone Association (POA). All studies were in regions with methyl ether in gasoline. All but one study carefully controlled for the effects of other criterion pollutants, so the phenomenon cannot be attributed to them. One was in southern California in mid-summer when ozone levels are highest. Because ozone is created by sunlight, the most plausible explanation for a POA would be an ambient pollutant that is rapidly destroyed by sunlight, such as methyl nitrite (MN). A previously published model of engine exhaust chemistry suggested methyl ether in the fuel will create MN in the exhaust. MN is known to be highly toxic, and closely related alkyl nitrites are known to induce respiratory sensitivity in humans. Support for the interpretation comes from many studies, including three linking asthma symptoms to methyl tertiary butyl ether (MTBE) and the observation that a POA has not been seen in regions without ether in gasoline. We also note that studies in southern California show a historical trend from more significant to less significant ozone-health associations. The timing of those changes is consistent with the known timing of the introduction of gasoline oxygenated with MTBE in that region.     

Distributions of personal VOC exposures: a population-based analysis

Information regarding the distribution of volatile organic compound (VOC) concentrations and exposures is scarce, and there have been few, if any, studies using population-based samples from which representative estimates can be derived. This study characterizes distributions of personal exposures to ten different VOCs in the U.S. measured in the 1999-2000 National Health and Nutrition Examination Survey (NHANES). Personal VOC exposures were collected for 669 individuals over 2-3 days, and measurements were weighted to derive national-level statistics. Four common exposure sources were identified using factor analyses: gasoline vapor and vehicle exhaust, methyl tert-butyl ether (MBTE) as a gasoline additive, tap water disinfection products, and household cleaning products. Benzene, toluene, ethyl benzene, xylenes chloroform, and tetrachloroethene were fit to log-normal distributions with reasonably good agreement to observations. 1,4-Dichlorobenzene and trichloroethene were fit to Pareto distributions, and MTBE to Weibull distribution, but agreement was poor. However, distributions that attempt to match all of the VOC exposure data can lead to incorrect conclusions regarding the level and frequency of the higher exposures. Maximum Gumbel distributions gave generally good fits to extrema, however, they could not fully represent the highest exposures of the NHANES measurements. The analysis suggests that complete models for the distribution of VOC exposures require an approach that combines standard and extreme value distributions, and that carefully identifies outliers. This is the first study to provide national-level and representative statistics regarding the VOC exposures, and its results have important implications for risk assessment and probabilistic analyses.     

Long-term increase in climatic dryness in the East-Mediterranean as evidenced for the island of Samos

The Eastern Mediterranean region is among the regions which were predicted to become drier under IPCC climate scenarios. Here, we document a gradual reduction of rainfall and tree growth and the loss of rural springs during the last decades of the twentieth century. Years with severe drought are associated with very low tree growth (dendrochronology) and dry falling of springs as evidenced by interviews with local stakeholders. The paper discusses the consequences of accelerating drought on natural vegetation and agriculture and points at the interaction with fire dynamics and economy, both likely to enhance the drought effect.     

Comparative analysis of the effect of predator odor on morphological and physiological parameters of adult male Campbell hamsters (<Emphasis Type="Italic">Phodopus campbelli</Emphasis>) and dwarf hamsters (<Emphasis Type="Italic">Phodopus sungorus</Emphasis>)

The effect of long-term exposure to natural excretions of the European polecat on the morphological parameters and hormonal status of adult male Campbell hamsters (Phodopus campbelli) and dwarf hamsters (Ph. sungorus) was studied. Exposure to volatile components of natural excreta of a potential predator did not have any significant effect on hamsters. The combined influence of volatile and nonvolatile components of the polecat’s excretions caused physiological stress in Ph. campbelli, while in Ph. sungorus, on the contrary, an increase in thymus weight and the plasma testosterone level was recorded.     

How Do Groups Solve Local Commons Dilemmas? Lessons from Experimental Economics in the Field

The use of experimental settings to observe human behaviour in a controlled environment of incentives, rules and institutions, has been widely used by the behavioural sciences for sometime now, particularly by psychology and economics. In most cases the subjects are college students recruited for one to two hour decision making exercises in which, depending on their choices, they earn cash averaging US$ 20. In such exercises players face a set of feasible actions, rules and incentives (payoffs) involving different forms of social exchange with other people, and that in most cases involve some kind of externalities with incomplete contracts, such as in the case of common-pool resources situations. Depending on the ecological and institutional settings, the resource users face a set of feasible levels of extraction, a set of rules regarding the control or monitoring of individual use, and sometimes ways of imposing material or non-material costs or rewards to those breaking or following the rules. We brought the experimental lab to the field and invited about two hundred users of natural resources in three Colombian rural villages to participate in such decision making exercises and through these and other research instruments we learned about the ways they solve - or fail to - tragedies of the commons with different social institutions. Further, bringing the lab to the field allowed us to explore some of the limitations of existing models about human behaviour and its consequences for designing policies for conserving ecosystems and improving social welfare.     

Quantifying the transfer of radionuclides to food products from domestic farm animals

Databases have been compiled to derive parameter values relevant to the transfer of radionuclides from feedstuffs to domestic animal products to provide a revision to the IAEA Handbook on transfer parameters TRS 364. Significant new data inputs have been incorporated into the databases from an extensive review of Russian language information and inclusion of data published since the early 1990s. Fractional gastrointestinal absorption in adult ruminants presented in the revised handbook are generally similar to those recommended for adult humans by the ICRP. Transfer coefficient values are presented in the handbook for a range of radionuclides to farm animal products. For most animal products, transfer coefficient values for elements additional to those in TRS 364 are provided although many data gaps remain. Transfer coefficients generally vary between species with larger species having lower values than smaller species. It has been suggested that the difference is partly due to the inclusion of dietary dry matter intake in the estimation of transfer coefficient and that whilst dietary intake increases with size nutrient concentrations do not. An alternative approach to quantifying transfer by using concentration ratios (CR), which do not consider dietary intake, has been evaluated. CR values compiled for the handbook vary considerably less between species than transfer coefficient values. The advantage of the CR approach is that values derived for one species could be applied to species for which there are no data. However, transfer coefficients will continue to be used as few studies currently report CR values or give data from which they can be estimated.     

A Dynamic model of Cs accumulation by fish of different age classes

A dynamic model of radionuclide accumulation in fish is developed. In the model, the fish population is represented by a set of discrete age classes. Each age class is characterized by a specific growth rate, diet and activity of metabolic processes. The model describes all known types of size effect in the contamination of fish with radiocaesium. The detailed dynamics of ¹³⁷Cs accumulation by fish are demonstrated using the results of the model's application to ichtiofauna in a water body which has a high level of contamination with radiocaesium — namely, the cooling pond of the Chernobyl NPP.     

Greenwashed sports and environmental activism: Formula 1 and FIFA†

ABSTRACT

Formula 1 motor sport and the Men's World Cup of association football, two major sporting events on our calendars, are indirectly and directly responsible for environmental despoliation. They serve as advertisements for heavy industry, are designed for elite as much as mass consumption, and provide sponsors with dubious social licenses to operate. This occurs through the very mechanisms of the events themselves (engines in Formula 1, tourism in the World Cup) as well as their promotional externalities. I look at greenwashing claims made about these two sporting events and examine counter-discourses, then investigate economic and ecological citizenship. I suggest that a progressive agenda can be forwarded if Greenpeace, which runs campaigns related to these sports, works with its fellow elites, in the case of Formula 1, and with fans in the case of football. Doing so may be more effective than business-as-usual direct action.     

江苏海洋开发的资源环境条件评述

江苏海洋的区位优越，海域广阔，环境条件总体有利，海洋资源种类多，数量大，具有综合开发功能，而且资源和环境的区域组合良好，有利于海洋产业的集约经营和协调发展，但也存在不少限制因素，如深水区离岸较远，海底矿产勘探程度低，自然灾害较多等。应根据实际情况确定本省海洋的开发战略。