全球变化对资源环境及生态系统影响的生态学理论基础

随着全球变化研究的深入,面向社会可持续发展的全球变化风险与应对、全球变化对资源环境要素时空配置与生态系统的影响评估等应用性问题正成为全球变化领域的新趋势.基于生态学范畴,本文重点梳理了资源环境的涵义及其构成要素:资源是自养生物利用无机物制造有机物及能量和物质在生物间传递过程中所消耗的一切实体,包括无机资源(太阳辐射、C...     

Fragile Castles: The Paradox of Research Politics,Scientific Progress,and the Mutation of Medical Knowledge

This paper is based on fieldwork done from 1996-1999 in different locations among village communities from Central Anatolia afflicted with the deadly malignancy of mesothelioma. Medical research has long established the relationship between mesothelioma and the environment; yet in earlier work correlations deduced through my genealogies provide evidence of a possible genetic cofactor causing these cancer deaths. This paper illustrates how medical research becomes an arena for local and global political interests and how the disruption of the doctor-cancer patient relationship impedes medical research. Methods include illness and clinical narratives, kinship charts and pedigrees, and observation of involved doctors and patients in multiple sites and geographical locations. Under focus are the anthropologist's involvement in global biomedical research and her interconnectedness with its political events.     

The effect of sand depth,feeding regime,density, and body mass on the foraging behaviour of a pit‐building antlion

Abstract 1. Pit‐building antlions are small sit‐and‐wait arthropod predators, which dig conical pits in sandy soils. We studied how biotic (conspecific density and feeding regime) and abiotic (sand depth) factors affect pit diameter and depth, while taking into account the larval body mass. 2. Pit diameter increased with larval body mass at a decelerating rate. In addition, larger larvae tended to relocate less frequently than smaller ones. 3. Sand depth positively affected overall pit size, while increasing conspecific density had a weaker but negative effect on pit size. 4. Feeding the antlions resulted in an increase in pit diameter compared with an unfed control group. However, as prey size increased this positive effect diminished. This result suggests that the existence of prey provides information about the quality of the microhabitat, triggering pit extension. However, similarly to the reduction in the foraging effort of saturated predators, antlions provided with large prey invested only little effort in pit enlargement. 5. Antlions were previously shown to be sensitive to prey and conspecific vibrations in the sand. We thus expected the feeding regime of the neighbour to affect antlion behaviour – surrogate of discriminating between local and global shortage of prey. Nevertheless, antlions with fed neighbours (a local prey shortage) did not show different behaviour compared with a control group in which both antlions were unfed (a global prey shortage).     

The sensitivity of soil respiration to soil temperature,moisture, and carbon supply at the global scale

Soil respiration (Rs) is a major pathway by which fixed carbon in the biosphere is returned to the atmosphere, yet there are limits to our ability to predict respiration rates using environmental drivers at the global scale. While temperature, moisture, carbon supply, and other site characteristics are known to regulate soil respiration rates at plot scales within certain biomes, quantitative frameworks for evaluating the relative importance of these factors across different biomes and at the global scale require tests of the relationships between field estimates and global climatic data. This study evaluates the factors driving Rs at the global scale by linking global datasets of soil moisture, soil temperature, primary productivity, and soil carbon estimates with observations of annual Rs from the Global Soil Respiration Database (SRDB). We find that calibrating models with parabolic soil moisture functions can improve predictive power over similar models with asymptotic functions of mean annual precipitation. Soil temperature is comparable with previously reported air temperature observations used in predicting Rs and is the dominant driver of Rs in global models; however, within certain biomes soil moisture and soil carbon emerge as dominant predictors of Rs. We identify regions where typical temperature‐driven responses are further mediated by soil moisture, precipitation, and carbon supply and regions in which environmental controls on high Rs values are difficult to ascertain due to limited field data. Because soil moisture integrates temperature and precipitation dynamics, it can more directly constrain the heterotrophic component of Rs, but global‐scale models tend to smooth its spatial heterogeneity by aggregating factors that increase moisture variability within and across biomes. We compare statistical and mechanistic models that provide independent estimates of global Rs ranging from 83 to 108 Pg yr^?1, but also highlight regions of uncertainty where more observations are required or environmental controls are hard to constrain.     

假基因的发现与研究

随着人类基因组计划的顺利实施,人们分离、鉴定新基因的速度越来越快,对于占人类基因组97%的非表达序列的研究,即对所谓"垃圾"DNA的研究已成为全球范围内关注的热点.现就假基因的发现、命名和分类、特性和分布、产生、作用机理、功能、进化及展望等方面进行论述.     

Global Life Cycle Paper Flows,Recycling Metrics,and Material Efficiency

Despite major improvements in recycling over the last decades, the pulp and paper sector is a significant contributor to global greenhouse gas emissions and other environmental pressures. Further reduction of virgin material requirements and environmental impacts requires a detailed understanding of the global material flows in paper production and consumption. This study constructs a Sankey diagram of global material flows in the paper life cycle, from primary inputs to end‐of‐life waste treatment, based on a review of publicly available data. It then analyzes potential improvements in material flows and discusses recycling and material efficiency metrics. The article argues that the use of the collection rate as a recycling metric does not directly stimulate avoidance of virgin inputs and associated impacts. An alternative metric compares paper for recycling (recovered paper) with total fibrous inputs and indicates that the current rate is at just over half of the technical potential. Material efficiency metrics are found to be more useful if they relate to the reuse potential of wastes. The material balance developed in this research provides a solid basis for further study of global sustainable production and consumption of paper. The conclusions on recycling and efficiency should be considered for improving environmental assessment and stimulating a shift toward resource efficiency and the circular economy.     

The global economic costs of substituting dietary protein from fish with meat,grains and legumes,and dairy

This paper estimates the costs to replace fish by protein from meat, from grains and legumes, or from dairy products. We apply the World Trade Model, an input–output model of the interactions among major world regions based on comparative advantage, to analyze alternative scenarios about protein content and sources in global diets. We find that the substitution of fish by meat or dairy entails several trillion U.S. dollars of additional costs annually, corresponding to increased use of pastureland, cropland, water, and other factors of production. The price of animal products increases steeply as higher‐cost producers need to come online, yielding rents to owners of scarce resources. By contrast, the global economy adjusts at significantly lower costs to the substitution of fish by grains and legumes, but this dietary shift involves substantial modification in the mix of agricultural output and its geographic distribution. There have been few analytic studies able to associate costs and prices directly with specific combinations of dietary options. We provide a flexible economic framework for analyzing alternative scenarios about the present and future production of food. The focus on the provision of protein for the human diet, allowing for substitutions between land‐based and aquatic sources, lays the groundwork for subsequent closer examinations of the potential future contribution of aquaculture and, in a yet broader framework, the impact of the coming generation of large dams on fish habitat and freshwater ecosystems more generally.     

Conservation,protected areas and the global economic system: how debt,trade, exchange rates,inflation and macroeconomic policy affect biological diversity

The main characteristics of the dominant economic system, including the increasing use of markets and money are described. The global system has expanded trade, including international trade, and production tremendously. While this system has the potential to favour nature conservation, in practice the opposite has occurred. Difficulties raised for conservation of biodiversity by short-term economic crises such as deficits in a country's international payments, the adoption of policies for structural economic adjustment, international capital flows, international loans and foreign aid as well as debt-for-nature swaps are discussed. As explained, it is politically difficult in market economies to support nature conservation at the expense of economic growth and as more economies develop and become market economies this problem spreads. Given global interdependence of nations, an important issue is the distribution of net benefits from biodiversity conservation between developed and less developed countries. Possible distributions of benefits and related issues are discussed. In conclusion, the importance of political lobbying by nature conservation groups in developed market economies is emphasised as a means of ensuring correction of market failures. Unfortunately, no economic system is likely to prove satisfactory in itself in conserving biodiversity so political action by conservationists is always required.     

全球环境变化对典型生态系统的影响研究:现状、挑战与发展趋势

随着全球环境变化和人类活动对生态系统影响的日益加深,生态系统结构和功能发生强烈变化,生态系统提供各类资源和服务的能力在显著下降。在这种背景下,全面认识生态系统的结构功能与全球环境变化的关系已成为当前生态学研究的热点之一。本文综述了全球环境变化对典型生态系统(包括森林生态系统、河口湿地生态系统、城市生态系统)影响以及全球环境变化适应的研究现状,分析研究面临的困难及挑战。在此基础上,提出对未来研究发展趋势的展望。在森林生态系统与全球环境变化研究上,未来应重视能更好模拟现实情景的、多因子、长期的全球环境变化控制试验,并注重不同生物地球化学循环之间的耦合作用。在湿地生态系统与全球环境变化研究上,未来应加强氮沉降、硫沉降及盐水入侵对湿地生态系统碳氮循环的影响,明晰滨海湿地的蓝碳功能,加强极端气候和人类干扰影响下湿地生态系统结构和功能变化及恢复力的研究。在城市生态系统与全球环境变化研究上,未来应深化城市生物地球化学循环机制研究,实现城市生态系统的人本需求侧重与转向,并开展典型地区长期、多要素综合响应研究。在全球环境变化适应研究上,未来应构架定量化、跨尺度的适应性评价体系,加强典型区域/部门的适应性研究以及适应策略实施的可行性研究,注重适应与减缓对策的关联研究及实施的风险评估。期望本综述为我国生态系统与全球环境变化研究提供一些参考。     

The carbon balance of tropical, temperate and boreal forests

Forest biomes are major reserves for terrestrial carbon, and major components of global primary productivity. The carbon balance of forests is determined by a number of component processes of carbon acquisition and carbon loss, and a small shift in the magnitude of these processes would have a large impact on the global carbon cycle. In this paper, we discuss the climatic influences on the carbon dynamics of boreal, temperate and tropical forests by presenting a new synthesis of micrometeorological, ecophysiological and forestry data, concentrating on three case-study sites. Historical changes in the carbon balance of each biome are also reviewed, and the evidence for a carbon sink in each forest biome and its likely behaviour under future global change are discussed. We conclude that there have been significant advances in determining the carbon balance of forests, but there are still critical uncertainties remaining, particularly in the behaviour of soil carbon stocks.     

Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity,ecosystem productivity,food security,and human health

The availability of carbon (C) from high levels of atmospheric carbon dioxide (CO₂) and anthropogenic release of nitrogen (N) is increasing, but these increases are not paralleled by increases in levels of phosphorus (P). The current unstoppable changes in the stoichiometries of C and N relative to P have no historical precedent. We describe changes in P and N fluxes over the last five decades that have led to asymmetrical increases in P and N inputs to the biosphere. We identified widespread and rapid changes in N:P ratios in air, soil, water, and organisms and important consequences to the structure, function, and biodiversity of ecosystems. A mass‐balance approach found that the combined limited availability of P and N was likely to reduce C storage by natural ecosystems during the remainder of the 21st Century, and projected crop yields of the Millennium Ecosystem Assessment indicated an increase in nutrient deficiency in developing regions if access to P fertilizer is limited. Imbalances of the N:P ratio would likely negatively affect human health, food security, and global economic and geopolitical stability, with feedbacks and synergistic effects on drivers of global environmental change, such as increasing levels of CO₂, climatic warming, and increasing pollution. We summarize potential solutions for avoiding the negative impacts of global imbalances of N:P ratios on the environment, biodiversity, climate change, food security, and human health.     

扩散对破碎化景观上宿主-寄生种群动态的影响

景观破碎化和扩散是空间种群模型的重要因素,对生物入侵存在着深远的影响。本章将基于偶对近似模型,探讨由局部和全局宿主-寄生相互作用共同决定的扩散模式对破坏性景观上疾病入侵与传播的影响。其中,生境破坏由生境丧失量与生境破碎化程度来描述。模拟结果显示,宿主和病毒的全局扩散对疾病的入侵与种群密度产生不对称效应：病毒的全局扩散对系统产生的影响较宿主的全局扩散更为显著。不同扩散模式下,生境丧失越高或破碎化程度越低,均将越有害于寄生病毒的入侵;同时,生境的破坏程度也显著地影响了入侵阈值对扩散模式的响应机制。本文研究结果暗示,景观破碎化的空间分布格局以及病毒扩散的限制均可作为物种保护与管理中有效的疾病控制策略。该研究结果在一定意义上丰富和发展了寄生感染理论,为物种保护提供了生态学理论依据。     

The global nitrogen cycle: Past, present and future

Food and energy production converts N2 to reactive N species that cascade through environmental reservoirs and in the process impact human and ecosystem health. This presentation will examine the impact of increased N mobilization on the global N cycle by contrasting N distribution in the late-19th century with those of the late-20th century. The presentation will give a general overview of regional differences and will conclude with a projection of the global N cycle for 2050.     

Design-driven, multi-use research agendas to enable applied synthetic biology for global health

Many of the synthetic biological devices, pathways and systems that can be engineered are multi-use, in the sense that they could be used both for commercially-important applications and to help meet global health needs. The on-going development of models and simulation tools for assembling component parts into functionally-complex devices and systems will enable successful engineering with much less trial-and-error experimentation and laboratory infrastructure. As illustrations, I draw upon recent examples from my own work and the broader Keasling research group at the University of California Berkeley and the Joint BioEnergy Institute, of which I was formerly a part. By combining multi-use synthetic biology research agendas with advanced computer-aided design tool creation, it may be possible to more rapidly engineer safe and effective synthetic biology technologies that help address a wide range of global health problems.     

海洋生物技术催生蓝色生物经济

海洋生物技术是20世纪末国际出现的前沿技术,至今发展势头良好,方兴未艾。在全球经济面临转型换代的关键时刻,蓝色经济渐现端倪。探讨了蓝色生物经济的概念和内涵,评述了海洋生物技术研发前沿与重点应用领域,展望了蓝色生物经济的良好市场前景与可持续发展,提出了加快发展我国蓝色生物经济的策略和建议。     

The global nitrogen cycle: Past, present and future

Food and energy production converts N2 to reactive N species that cascade through environmental reservoirs and in the process impact human and ecosystem health. This presentation will examine the impact of increased N mobilization on the global N cycle by contrasting N distribution in the late-19th century with those of the late-20th century. The presentation will give a general overview of regional differences and will conclude with a projection of the global N cycle for 2050.     

The Concept of City Carbon Maps: A Case Study of Melbourne,Australia

Cities are thought to be associated with most of humanity's consumption of natural resources and impacts on the environment. Cities not only constitute major centers of economic activity, knowledge, innovation, and governance—they are also said to be linked to approximately 70% to 80% of global carbon dioxide emissions. This makes cities primary agents of change in a resource‐ and carbon‐constraint world. In order to set meaningful targets, design successful policies, and implement effective mitigation strategies, it is important that greenhouse gas (GHG) emissions accounting for cities is accurate, comparable, comprehensive, and complete. Despite recent developments in the standardization of city GHG accounting, there is still a lack of consistent guidelines regarding out‐of‐boundary emissions, thus hampering efforts to identify mitigation priorities and responsibilities. We introduce a new conceptual framework—based on environmental input‐output analysis—that allows for a consistent and complete reconciliation of direct and indirect GHG emissions from a city. The “city carbon map” shows local, regional, national, and global origins and destinations of flows of embodied emissions. We test the carbon map concept by applying it to the greater metropolitan area of Melbourne, Australia. We discuss the results and limitations of the approach in the light of possible mitigation strategies and policies by different urban stakeholders.     

造林再造林、森林采伐、气候变化、CO2浓度升高、火灾和虫害对森林固碳能力的影响

森林生态系统具有吸收大气CO_2、缓解气候变化的作用。造林再造林作为京都议定书认可的大气CO_2减排途径,是提高森林固碳能力的低成本、有效策略。森林生态系统固碳能力还受森林采伐、气候变化、大气CO_2浓度升高、火灾以及虫害等自然因素和人为因素的强烈影响。综述了全球和区域造林再造林的固碳能力,以及目前较受重视的一些因素(森林采伐、气候变化、大气CO_2浓度升高、火灾以及虫害)对森林生态系统固碳能力的影响。结果表明,全球造林再造林固碳能力为148—2400TgC/a;采伐造成的全球森林碳损失最大为900 TgC/a,其次是火灾为300 TgC/a,虫害造成森林碳释放最小在2—107 TgC/a之间。建议在今后的研究中,应关注固碳措施和多种环境因素对森林生态系统固碳能力,尤其是对森林土壤固碳能力的影响,严格控制森林采伐和火灾发生,以及减少或避免造林再造林活动引起的碳泄漏。     

全球生物经济演进规律与我国生物经济发展对策建议

随着全球资源的日益枯竭,为了应对环境、气候、资源问题以及粮食安全危机,各个国家纷纷探寻能够实现人类社会可持续发展的经济模式——生物经济。我国近日发布了《“十四五”生物经济发展规划》,首次将生物经济上升至国家战略发展高度。生物经济以生命科学和生物技术发展为核心,形成包括生物医药、生物农业、生物制造以及生物能源等新兴产业,是支撑未来可持续发展潜力较大的经济发展模式。概述了全球生物经济的演进规律、各个国家生物经济的发展概况以及我国生物经济的产业发展情况,并在百年未有之大变局叠加新冠疫情的复杂形势下,提出了关于我国未来生物经济发展的相关对策建议。