植物功能性状、功能多样性与生态系统功能: 进展与展望

植物功能性状与生态系统功能是生态学研究的一个重要领域和热点问题。开展植物功能性状与生态系统功能的研究不仅有助于人类更好地应对全球变化情景下生物多样性丧失的生态学后果,而且能为生态恢复实践提供理论基础。近二十年来,该领域的研究迅速发展,并取得了一系列的重要研究成果,增强了人们对植物功能性状-生态系统功能关系的认识和理解。本文首先明确了植物功能性状的概念, 评述了近年来植物功能性状-生态系统功能关系领域的重要研究结果, 尤其是植物功能性状多样性-生态系统功能关系研究现状; 提出了未来植物功能性状与生态系统功能关系研究中应加强植物地上和地下性状之间关系及其与生态系统功能、植物功能性状与生态系统多功能性、不同时空尺度上植物功能性状与生态系统功能, 以及全球变化和消费者的影响等方面。     

生物多样性与生态系统服务关系研究进展

生物多样性与生态系统服务关系是当前生态学研究的热点之一,2005年千年生态系统评估之后如何将两者关系应用到生态系统管理和政策制定中逐渐受到重视。然而,从理论上的两者关系认知到应用上的管理实践仍面临着严峻挑战,梳理已有研究成果有利于更好地指导管理实践。本文基于近年生物多样性与生态系统服务关系的主要研究成果,从生物多样性对生态系统单种服务、多种服务、生态系统服务权衡的影响以及环境变化如何影响这些关系等方面,总结了两者关系的主要研究进展,概述了两者关系在自然保护区管理、森林生态系统管理、退化生态系统恢复和农业生态系统改善等领域中的应用,分析了两者关系研究中依然存在的不足之处,强调未来需加强的研究方向主要包括: 生物多样性不同组分相互作用和多营养级生物多样性相互关系对生态系统服务的影响、环境耦合变化对两者关系的复合效应以及生物多样性改善生态系统服务的实践途径。     

农业生态系统能量分析

农业生态系统的能量分析从能流着手进行农业生态系统的功能量化分析,是农业生态系统重要的研究方法之一。本文简要回顾讨论了农业生态系统能量分析研究的历史和进展。着重讨论了能值分析方法对传统能量分析方法的新发展,分析了农业生态系统能量分析目前存在的问题,并就其进一步发展方向进行了探讨能值分析方法用生产某种能量或物质所直接或间接耗用的太阳能值量来衡量该能量或物质的价值,不仅在概念上而且在算法上都是原有能量分析方法的新发展．发展到能值分析阶段的农业生态系统的能量分析方法亦存有自身的不足之处,如能值转换率的计算过于繁复,能值指标体系缺乏统一性及系统可持续发展的能值综合评价指标缺乏等。这些问题的解决与能值最大功率的明晰化、能值分析与能量及耗散分析的结合、与物质分析及景观结构分析的结合等研究等共同构成了农业生态系统能量分析的几大发展方向。     

《生态学基础》：对生态学从传统向现代的推进——纪念E.P.奥德姆诞辰100周年

2013年是“现代生态学之父”美国生态学家奥德姆诞辰100周年。奥德姆的《生态学基础》一书对生态学从传统向现代转换具有积极的推进作用,主要表现在：提升了生态科学的量化水平,促成了生态系统生态学体系的诞生;倡导了生态学与经济学等社会科学的融合,丰富了生态经济学与生态系统服务功能研究;延展了生态学的应用尺度,为社会的生产变革和绿色运动提供了指导。奥德姆的生态学理论中诸如以能量分析为主导的生态系统分析方法还有待完善、生态系统方面较少考虑进化维度,衡量能量质量高低的能值方法的科学性有改善的空间等,但这都无碍他成为世界上最杰出的生态学家之一。     

生态学的科学概念及其演变与当代生态学学科体系之商榷

生态学既是生物学的分支学科,也是环境科学、地球系统科学的重要组成部分,其研究成果可直接服务于植物、动物、微生物的生物多样性保护、生物资源利用及生物产业管理等应用领域。生态系统概念将经典生态学或者基础生态学研究扩展到了生态系统生态学或者生态系统科学的新阶段,奠定了大尺度及全球生态环境科学研究的理论基础,促进了生物学、地理学及环境科学研究的大融合,推动了自然科学与人文科学和社会经济学的学科交叉。在这一大融合的历史过程中,生态学在不断地汲取不同学科营养的同时,提出了许多科学概念或理论学说,并在相关科学研究中得到应用和发展,形成了以认知生态系统与资源环境及人类社会的互馈关系为核心的当代生态学及生态系统科学体系。本文从生态学思想起源与发展、生态学概念的科学内涵及其扩展等方面综合讨论了当代生态学的科学概念、基础理论及其学科体系,并尝试性地对当代生态学的科学内涵、学科范畴、学科体系进行梳理、考察和分析,提出了基础生态学及应用生态学研究的分支学科体系分类方案,期望与学界共同商榷,为完善和重构当代生态学学科体系提供参考。     

城市生态系统:人与自然复合

随着城市化快速发展,城市生态学进入了空前繁荣时期,一些新理念和新范式引起了广泛关注。从生态系统角度,分析了城市生态系统组分、结构、过程、功能和服务的特点,提出了城市生态系统研究的黑箱范式和结构-过程-功能-服务级联范式。重点分析了人与自然在城市生态系统的组分、结构、过程、功能和服务等方面上的不同角色,探讨了人与自然在城市生态系统组分上镶嵌、结构上融合、过程上耦合、功能上互补和服务上协同的相互作用机制,提出了城市生态系统研究的人与自然共同进化范式,即人类和自然相互作用和适应,推动了城市发展。这将为深入认识和研究城市生态系统提供重要理论支撑。     

生物多样性-生产力关系研究进展——基于文献计量分析

生态系统的结构和功能是生态学研究的核心内容。早期基于野外调查的生态学研究强调生产力表征的环境梯度对生态系统结构的影响,而基于控制试验的生态学研究则强调生态系统结构变化对生态系统功能的影响。围绕这两类研究所支持理论间的争论是当前生态学的前沿、热点和难点,其中最具代表性的科学问题是生物多样性与以生产力为代表的生态系统功能间是否存在一般性关系。为深入了解生物多样性-生产力关系研究脉络,分析其对生态学研究范式与理论发展的影响以及对未来研究方向的启示,以Web of Science核心合集数据库中的相关文献为数据源,结合文献计量分析和文献综述,系统总结了多样性-生产力关系研究进展。结果表明：(1)生物多样性-生产力关系研究推动了生态学研究范式由以样带调查为主的观察性研究向以控制试验为主的实验性研究的转变,促进了全球联网控制试验研究的发展。(2)研究聚焦的生态系统类型由最初的北美普列利草原逐渐向其它草地、灌丛、森林等多样的生态系统过渡,研究结论及其生态学理论的普适性逐渐增强。(3)该研究推动了对生物多样性不同维度(如功能多样性和系统发育多样性)在生态系统中作用的认识,促进了学界对除生产功能外的生态...     

基于能值分析的合肥城市生态系统健康动态评价

随着城市化和城市环境问题的日趋突出,城市生态系统健康评价成为近年来生态学领域研究的热点.本文运用能值分析方法,采用活力、组织结构、恢复力和服务功能维持4个要素,构建了评价城市生态系统健康的能值指标--城市健康能值改良指标,并用于合肥市生态系统的健康评价,然后将评价结果与天津、芜湖、上海、宁波、福州等6座国内城市进行比较...     

生物多样性与生态系统功能:最新的进展与动向

生物多样性与生态系统功能的关系及其内在机制是当前生态学领域的重大科学问题。 2 0 0 2年以来人们不再过多地纠缠于“抽样 -互补之争” ,对这一世纪课题的认识又有了新的进展。 (1)人们开始运用已有的知识揭示更大时间和空间尺度上的物种多样性 -生态系统功能关系。多样性作用机制可能存在着动态变化———“抽样向互补转型” :群落建立初期 ,抽样效应是主要的多样性作用机制 ;随时间推移 ,生态位互补成为主要机制。理论研究则预测 :局域尺度上生态系统功能与物种多样性呈现单峰曲线关系 ,在区域尺度上为单调上升关系 ;(2 )非生物因素与多样性 -生产力的交互关系吸引了许多实验研究。人们发现 :物种多样性 -生产力关系可能会受到资源供给率和环境扰动的修正 ,环境因素可能是多样性 -生产力关系的幕后操纵者 ;(3)人们开始重视营养级相互作用对于多样性 -生态系统功能关系的影响 ,生态位互补和抽样假说开始被扩展运用到消费者营养级上 ;(4 )人们开始认真思考物种共存机制在多样性 -生态系统功能关系的形成中所扮演的角色。理论模型研究表明 ,不同的物种共存机制会导致不同的多样性 -生产力关系     

我国土壤动物群落生态学研究综述

总结了我国土壤动物群落生态学研究的特点,即区域分布集中于中国东部、研究的生态系统类型广泛、研究角度多种多样与应用研究发展迅速。并从土壤动物群落与环境关系、土壤动物群落的组成和多样性、土壤动物群落结构、土壤动物群落功能、土壤动物群落演替与受干扰生态系统的土壤动物群落6个方面综述其最新研究成果。在此基础上指出我国土壤动物群落生态学中有待开拓的研究领域是基础研究、特色区域和生态系统的研究、土地覆盖/土地利用对土壤动物的影响研究、土壤动物多样性及其保护研究、土壤动物在土壤生态系统和陆地生态系统物质循环和能量流动中的作用研究、全球变化响应研究与土壤动物应用研究。     

Emergy and exergy evaluation of a dike-pond project in the drawdown zone (DDZ) of the Three Gorges Reservoir (TGR)

The dike-pond system was a form of ecological engineering that was a component of successional dikes and ponds along the banks of the Pengxi River in the drawdown zone (DDZ) of the Three Gorges Reservoir (TGR). The application of science-based evaluation system was appropriate for the flows of emergy in this agricultural ecosystem. The Emergy Analysis (EmA) has the ability to transform different types of inputs to a common form to allow meaningful comparisons across different systems. This study made use of the emergy analysis that assessed two different types of farming methods in the DDZ of the TGR. One method was planning crops in a dike-pond system (model I), and the other method was conventional agriculture (model II). In addition, the Exergies of both yields of agriculture methods were calculated, and the Exergy and Emergy Density (ED) were combined to explore the quality of these methods. The results showed that the two models relied on different resources. The ED yield of both models were similar, but the emergy investment of model II was greater than that of model I. Model II also used less renewable energy input to the agricultural systems than model I. The agricultural emergy sustainability index (AESI) of model I system (AESI = 2.4 > 1) was greater than that of model II system (AESI = 0.5 < 1), which indicated that the sustainable development of model I was stronger than that of model II in the DDZ of the TGR. The ratio Exergy/Emergy density (R_ex/em) in the two models of different agricultural system were 121.52 × 10⁻³ J/sej (Model I) and 24.19 × 10⁻³ J/sej (model II). Model I was greater than model II, and the result intimated that the model I agricultural system was a new method in the DDZ, but it was older and closer to the steady state than model II. The Emergy and Exergy analysis certifies that model I has a more acceptable and more sustainable development potential and is more stabilized in the DDZ of the TGR.     

顺德产业生态系统能值动态分析

虽然当前的产业生态学研究多集中于生产线、企业和产业生态园尺度,但城市无疑是产业系统基本组合单元,城市区域尺度的产业生态学研究是产业生态学研究尺度上推的必经阶段。我国产业生态系统及城市化进程的空间分布不均,以顺德等为代表的东南沿海市(县)产业生态系统的发展历程对中西部地区有拉动和借鉴的双重作用。以能值理论方法为基础,结合环境经济学和区域经济学方法,从系统开放性、本土性、闭路循环性和经济性4个方面,投入和产出端2个角度,对顺德市产业生态系统改革开放22a的发展动态进行分析研究。结果发现,22a系统能值总用量增加15.65倍,能值密度增加16.31倍,人均能值使用强度增加9.70倍,外部不可更新资源用量增加16.32倍。能值废弃率在20世纪80年代不断上升而在90年代迅速下降,但环境负载率则表现为无规律的波动状态。20世纪90年代,系统能值出口率上升至1978年的4.10倍,但能值交换率小于1。结果表明,改革开放22a,顺德产业生态系统自组织能力明显提高,土地资源利用率不断提高,但系统对周边负熵资源,尤其是不可更新资源的依赖性不断提高,人力资源生产力水平提高相对较慢。20世纪90年代污染物处理产业发展迅速,但在系统资料消耗端的绿色化方面则无显明进展。系统对不可更新资源的利用效率不高,产出商品在市场交换中处于表面繁荣背景下的生态经济不利地位。系统已到了向知识密集型发展道路转变的拐点域。能值理论方法与环境经济学和区域经济学分析的整合可以满足产业生态系统分析评价要求,针对产业生态系统特点,进行多尺度、多方面联立评价,实现系统发展现状、动态与动因的整合分析,对产业生态系统优化点的发现与优化方向的确定有直接的意义。     

Applying cumulative exergy demand (CExD) indicators to the ecoinvent database

Goal, Scope and Background Exergy has been put forward as an indicator for the energetic quality of resources. The exergy of a resource accounts for the minimal work necessary to form the resource or for the maximally obtainable amount of work when bringing the resource’s components to their most common state in the natural environment. Exergy measures are traditionally applied to assess energy efficiency, regarding the exergy losses in a process system. However, the measure can be utilised as an indicator of resource quality demand when considering the specific resources that contain the exergy. Such an exergy measure indicates the required resources and assesses the total exergy removal from nature in order to provide a product, process or service. In the current work, the exergy concept is combined with a large number of life cycle inventory datasets available with ecoinvent data v1.2. The goal was, first, to provide an additional impact category indicator to Life-Cycle Assessment practitioners. Second, this work aims at making a large source of exergy scores available to scientific communities that apply exergy as a primary indicator for energy efficiency and resource quality demand. Methods The indicator Cumulative Exergy Demand (CExD) is introduced to depict total exergy removal from nature to provide a product, summing up the exergy of all resources required. CExD assesses the quality of energy demand and includes the exergy of energy carriers as well as of non-energetic materials. In the current paper, the exergy concept was applied to the resources contained in the ecoinvent database, considering chemical, kinetic, hydro-potential, nuclear, solar-radiative and thermal exergies. The impact category indicator is grouped into the eight resource categories fossil, nuclear, hydropower, biomass, other renewables, water, minerals, and metals. Exergy characterization factors for 112 different resources were included in the calculations. Results CExD was calculated for 2630 ecoinvent product and process systems. The results are presented as average values and for 26 specific groups containing 1197 products, processes and infrastructure units. Depending on the process/product group considered, energetic resources make up between 9% and 100% of the total CExD, with an average contribution of 88%. The exergy of water contributes on the average to 8% the total exergy demand, but to more than 90% in specific process groups. The average contribution of minerals and metal ores is 4%, but shows an average value as high as 38% and 13%, in metallic products and in building materials, respectively. Looking at individual processes, the contribution of the resource categories varies substantially from these average product group values. In comparison to Cumulative Energy Demand (CED) and the abiotic-resource-depletion category of CML 2001 (CML’01), non-energetic resources tend to be weighted more strongly by the CExD method. Discussion Energy and matter used in a society are not destroyed but only transformed. What is consumed and eventually depleted is usable energy and usable matter. Exergy is a measure of such useful energy. Therefore, CExD is a suitable energy based indicator for the quality of resources that are removed from nature. Similar to CED, CExD assesses energy use, but regards the quality of the energy and incorporates non-energetic materials like minerals and metals. However, it can be observed for non-renewable energy-intensive products that CExD is very similar to CED. Since CExD considers energetic and non-energetic resources on the basis of exhaustible exergy, the measure is comparable to resource indicators like the resource use category of Eco-indicator 99 and the resource depletion category of CML 2001. An advantage of CExD in comparison to these methods is that exergy is an inherent property of the resource. Therefore less assumptions and subjective choices need to be made in setting up characterization factors. However, CExD does not coversocietal demand (distinguishing between basic demand and luxury), availability or scarcity of the resource. As a consequence of the different weighting approach, CExD may differ considerably from the resource category indicators in Eco-indicator 99 and CML 2001. Conclusions The current work shows that the exergy concept can be operationalised in product life cycle assessments. CExD is a suitable indicator to assess energy and resource demand. Due to the consideration of the quality of energy and the integration of non-energetic resources, CExD is a more comprehensive indicator than the widely used CED. All of the eight CExD categories proposed are significant contributors to Cumulative Exergy Demand in at least one of the product groups analysed. In product or service assessments and comparative assertions, a careful and concious selection of the appropriate CExD-categories is required based on the energy and resource quality demand concept to be expressed by CExD. Recommendations and Perspectives A differentiation between the exergy of fossil, nuclear, hydro-potential, biomass, other renewables, water and mineral/metal resources is recommended in order to obtain a more detailed picture of resource quality demand and to recognise trade-offs between resource use, for instance energetic and non-energetic raw materials, or nonrenewable and renewable energies. ESS-Submission Editor: Dr. Gerald Rebitzer (Gerald.Rebitzer@alcan.com)     

Macroecology: the organizing forces

The fundamental problem in ecology is the relationship between organisms and the physical world. This question is approached through the study of ecosystems as wholes. Pristine, autonomous Arctic lakes provide an invaluable starting point for such investigations. Studies on these lakes, initiated in 1958, indicate that the dominant fish populations assume a recognizable and repeatable structure, which if not disturbed by external forces, is maintained indefinitely. The observable characteristics are high biomass, large individual size, great age, uniformity of individuals despite great variation in age, and relatively few juveniles. This configuration expresses a state of least specific energy dissipation or least specific entropy production and may be regarded as a standing wave in the energy flow. Similar characteristics were found in the dominant species in a wide range of ecosystems worldwide. A state of least dissipation develops when two energy transport processes interfere with each other in the vicinity of thermodynamic equilibrium. Thus it is postulated that living organisms originated through the agonistic interaction between two energy transport processes within materials, initially occurring in an environment close to thermodynamic equilibrium. These two processes, fundamental to energy transfer, are recognized as the principle of least action and its diametrical opposite, the principle of most action. Each force dominates system behavior in a different time frame: most action in the short-term (ecological time) and least action over the long-term (evolutionary time). Interaction between the countervailing forces provides an understanding of a wide range of emergent ecological generalities such as succession, r- and K-selection, the stability and diversity of ecosystems, and the directionality of evolutionary change.     

Emergy and economic evaluations of four fruit production systems on reclaimed wetlands surrounding the Pearl River Estuary,China

Emergy and economic methods were used to evaluate and compare a traditional tropical fruit cultivation system, for bananas, and three newly introduced fruit cultivation systems, for papaya, guava and wampee, on reclaimed wetlands of the Pearl River Estuary, China. The goal of this study was to apply ecological engineering principles to fruit production system designs to maximize total emergy benefits and sustainability. The evaluations considered input structure, production efficiency, environmental impacts, economic viability and sustainability. The market effects on emergy exchange were assessed both for purchasing the inputs to production and for selling the fruit. These market effects were also considered in the evaluation of sustainability by using the Emergy Index for Sustainable Development (EISD), which was evaluated with and without taking the change in natural capital (i.e., soil organic matter) into consideration. The results showed that all three of the newly introduced systems are much more sustainable than the traditional banana production system. The guava production system had the highest value of the Emergy Sustainability Index (ESI = 0.40). The high price of wampee gave it the highest economic yield/cost ratio (4.87) and EISD (0.73). Emergy and economic evaluations are complementary methods, with emergy analysis shedding more light on environmental support and impacts of the production systems not considered in the market value, and economic analysis focusing on the effects of markets on fruit production. The Emergy Exchange Ratio (EER) was proposed as a bridge between emergy and economic evaluations for specific systems and/or processes.     

Properties of membrane stationary states. 2. The isobaric isothermal ensemble

A multi-state membrane transport system serves as the basic model for a comparison of equilibrium and stationary state distributions of ions within an ensemble of membrane channels. Transition probabilities for intramembrane transitions are developed for consistency with an equilibrium Donnan potential and the magnitude of the flux in the stationary state can be controlled with either the bath concentrations or an externally applied potential. The stationary state distribution and operational thermodynamic parameters for the stationary state are expressed as functions of the ratio (j^net/p) where j^net is the observable net membrane flux and p is a characteristic decay constant for the intramolecular transitions. Both parameters are experimentally accessible so that their time independent ratio serves as an experimental measure of the membrane configuration. When operational thermodynamic parameters are expressed as functions of the ratio (j/p) for systems which obey the condition of detailed balance, the free energy varies quadratically with the ratio while the enthalpy, expressed as an average membrane potential, varies linearly with the ratio. As the system is driven from its equilibrium configuration by the net membrane flux the free energy increases relative to the enthalpy of the membrane. The free energy is localized in the membrane region at the expense of dissipation in the bathing solutions.     

Is a constant low-entropy process at the root of glycolytic oscillations?

We measured temporal oscillations in thermodynamic variables such as temperature, heat flux, and cellular volume in suspensions of non-dividing yeast cells which exhibit temporal glycolytic oscillations. Oscillations in these variables have the same frequency as oscillations in the activity of intracellular metabolites, suggesting strong coupling between them. These results can be interpreted in light of a recently proposed theoretical formalism in which isentropic thermodynamic systems can display coupled oscillations in all extensive and intensive variables, reminiscent of adiabatic waves. This interpretation suggests that oscillations may be a consequence of the requirement of living cells for a constant low-entropy state while simultaneously performing biochemical transformations, i.e., remaining metabolically active. This hypothesis, which is in line with the view of the cellular interior as a highly structured and near equilibrium system where energy inputs can be low and sustain regular oscillatory regimes, calls into question the notion that metabolic processes are essentially dissipative.     

Emergy analysis for the environmental sustainability of an inshore fish farming system

The emergy concept was used to evaluate the environmental sustainability of the rearing process of Gilthead Sea Bream (Sparus aurata) in an inshore fish farming system in Gulf of La Spezia (Italy, Northwestern Mediterranean). Emergy is defined as the available energy of one kind previously used up directly and indirectly to make a product or service. The indices for the examined fish farm calculated from the emergy evaluation were compared with those of three other systems producing fishes: two intensive fish farming systems producing, respectively, salmons (Salmo salar) and tilapia (Tilapia mariae), the third system producing again S. aurata but in a semi-natural extensive manner. The emergy evaluation showed that the rearing of fishes in a sheltered area of Mediterranean Sea imposes a large stress on the environment. The greatest contributions to the emergy needed for production were due to fingerlings purchased and goods and services provided that are two external, non-renewable inputs to the system. The strong dependence of external contributions and the relative inability at exploiting local natural resources affect strongly the level of environmental sustainability of the productive process.     

耗散结构,等级系统理论与生态系统

耗散结构理论与其他热力学概念一起,可以解释生态学中的许多现象。生态系统是耗散系统,用耗散结构理论来分析和讨论生态平衡等问题更为合理、准确。等级系统理论是为理解和研究高度复杂系统而发展起来的系统理论。等级系统理论为研究生态系统的行为和特征提供了客观的、适用的概念构架和实践指南,并为生态系统科学的统一性理论的形成开辟了广阔前景。本文拟就耗散结构理论和等级系统理论的主要内容及其在生态学中的应用作一介绍和讨论。     

耗散结构、等级系统理论与生态系统

耗散结构理论与其他热力学概念一起,可以解释生态学中的许多现象。生态系统是耗散系统,用耗散结构理论来分析和讨论生态平衡等问题更为合理、准确。等级系统理论是为理解和研究高度复杂系统而发展起来的系统理论。等级系统理论为研究生态系统的行为和特征提供了客观的、适用的概念构架和实践指南,并为生态系统科学的统一性理论的形成开辟了广阔前景。本文拟就耗散结构理论和等级系统理论的主要内容及其在生态学中的应用作一介绍和讨论。