Economic land use, ecosystem services and microfounded species dynamics

In an integrated economy–ecosystem model humans choose their land use and leave the residual land as habitat for three species forming a food chain. The size of habitat determines the diversity and abundance of species. That biodiversity generates, in turn, a flow of ecosystem services with public-good characteristics for human consumption. The ecosystem submodel yields (rather than assumes!) population growth functions with each species’ growth depending on the size of habitat. First the relationship between habitat and species growth (sustenance, decline and extinction) is explored. The laissez-faire economy is shown to result in an underprovision of habitat making the case for land use restrictions for nature protection. The optimal land use policy is characterized with full regard of ecosystem dynamics. Finally, labor-augmenting technical change is introduced to generate ever increasing pressure towards further habitat reductions. In the laissez-faire economy the habitat is consequently squeezed to zero in the long-run so that all species are doomed. Social optimality demands, however, to refrain from using all land for economic purposes despite ever growing labor productivity.     

生态系统功能与生态系统服务的概念辨析

"生态系统功能(Ecosystem functions)"和"生态系统服务(Ecosystem services)"已成为生态学中的重要研究领域.针对国内部分研究人员对"生态系统功能"与"生态系统服务(功能)"概念和术语混淆使用的问题,在归纳总结国内外有关的重要研究的基础上,通过分别论述"生态系统功能"与"生态系统服务"的定义和内涵,辨析和阐明了生态系统"功能"与"服务"的区别与关系.生态系统功能是构建系统内生物有机体生理功能的过程,侧重于反映生态系统的自然属性,是维持生态系统服务的基础;生态系统服务是由生态系统功能产生的,是基于人类的需要、利用和偏好,反映了人类对生态系统功能的利用,是生态系统功能满足人类福利的一种表现.因此"生态系统服务功能"这一术语不准确,容易产生误解.     

生态系统服务价值评估的研究进展

生态系统服务价值评估是当前生态经济学和环境经济学的研究焦点。首先回顾了国内外关于生态系统服务功能的概念和分类的研究;其次根据发展历程分析了国外生态系统服务价值的评估研究;然后从全国、区域以及单个生态系统等方面探讨国内生态系统服务价值评估的研究。最后指出现有生态系统服务价值评估研究中的不足及今后发展方向,以期丰富生态系统服务价值评估理论。     

Limits of monetization in protecting ecosystem services

The monetary valuation of ecosystem services is gaining traction in policy and business communities. Several tools and decision‐making processes have been proposed, including criteria to assess the appropriateness of using monetary valuation for biodiversity conservation outcomes. These criteria include measures such as scale, uniqueness, and threat. We used case studies of monetization projects for which the outcomes were measured to explore the limitations and application of these criteria. There was limited evidence of the effectiveness of such schemes. The majority of the schemes were established in areas where the criteria specifically excluded their use in isolation. Thus, although some aspects of monetization may be beneficial for biodiversity conservation, these schemes were not being used appropriately and require some quantitative minimum (or maximum) measurements to be applied through additional policy or governance measures to ensure biodiversity conservation outcomes.     

The dual nature of ecosystem dynamics

Mechanistic simulation modeling has not generally delivered on its promise to turn ecology into more of a “hard” science. Rather, it appears that deeper insights into ecosystem functioning may derive from a new set of metaphysical assumptions about how nature functions. Force laws from physics are fundamentally incompatible with the heterogeneity and uniqueness that characterizes ecosystems. Instead, coherence, selection and centripetality are imparted to ecological systems by concatenations of beneficial processes—a generalized form of autocatalysis. These structure-enhancing configurations of processes are opposed by the ineluctable tendency of structure to decay (as required by the second law of thermodynamics). The dual nature of this agonism can be quantified using information theory, which also can be used to measure the potential of the system for further evolution. The balance point for these countervailing tendencies seems to coincide with the state of maximal potential for the system to evolve. In an ostensible paradox, the same locus seems to attract stable, persistent system configurations.     

基于RS和GIS的武汉市生态系统服务价值变化研究

以武汉市为例,利用从1996年和2001年TM数据中获取的景观数据,估算了武汉市生态服务价值并分析了景观之间的转化所引起的生态服务价值的变化。结果表明:各景观类型中水域景观的生态服务价值贡献系数最大,达到2.869;研究区域生态服务价值总量变化不大,2001年比1996年只下降了3688.79万元,但各景观生态服务价值变动很大,其中库塘生态服务价值增加了2.38亿元,河流的生态服务价值减少了2.33亿元,其变化率分别达到40.74%和-9.16%;由于河湖被占用所造成的生态服务价值损失达到9891.68万元,城市建设占用其它景观类型所带来的生态服务价值损失达到9908.37万元,这说明建设用地的发展对其他自然景观占用已经影响到了武汉市生态系统服务功能发挥。     

水电开发对河流生态系统服务功能影响的价值评估初探

提出了计算“流量”,即计算受水电开发影响的河流生态系统服务功能的价值变化量的评估思路和方法,并以广东省河源市风光水利枢纽工程为案例进行了定量分析。在对河流生态系统服务功能进行分类的基础上,根据河流生态系统服务功能可能受到水电开发影响的现实情况和影响特征,选择适当的生态系统服务功能价值核算的方法和参数,计算受影响的生态系统服务功能的价值变化量。案例研究结果表明,风光水利枢纽工程开发方案引起的河流生态服务功能价值变化的正效益为7 676万元/a,负效益为-3 894万元/a,负效益占到其正效益的一半以上,说明该工程开发对东江河流生态系统的消极负面影响也是不容忽视的,应采取适当的生态补偿措施。     

生态系统服务内涵、价值评估与GIS表达

生态系统服务价值评估是当前生态经济学领域的研究热点,为解决生态系统之于人类的重要性提供了量化的参考,也是生态补偿机制建立的重要依据.近5年国际上SCI论文发表数量以年均40%速度增长,我国研究起步于上世纪90年代末,十年来发展迅速,从对国外研究的简单模仿逐渐转向对评估模型参数的修正及对技术方法的适应性集成与发展.生态系统服务的内涵研究不断推进,在阐释“自然组分-生态过程-生态功能-生态服务.获得利益”关系上呈现多种观点,相应地提出了不同的价值评估指标体系;生态系统服务价值评估以瞬时静态为主,动态评估略显不足;研究对象从大尺度和单一生态系统逐渐转向中尺度区域,评估结果表现形式从单一数值化向基于GIS的空间表达发展.在回顾全球范围生态系统服务评估研究成果的基础上,从研究区域分布与学科特点、内涵及分类、评估方法和GIS技术应用等四大方面进行归纳分析,并从生态系统管理和决策支持需求的角度,指出生态系统评估研究已取得显著进展,但有关生态系统服务的内涵与分类、生态系统服务价值的动态评估及GIS技术的应用研究仍待深入.     

Increasing the impact of collective incentives in payments for ecosystem services

Collective payments for ecosystem services (PES) programs make payments to groups, conditional on specified aggregate land-management outcomes. Such collective contracting may be well suited to settings with communal land tenure or decision-making. Given that collective contracting does not require costly individual-level information on outcomes, it may also facilitate conditioning on additionality (i.e., conditioning payments upon clearly improved outcomes relative to baseline). Yet collective contracting often suffers from free-riding, which undermines group outcomes and may be exacerbated or ameliorated by PES designs. We study impacts of conditioning on additionality within a number of collective PES designs. We use a framed field-laboratory experiment with participants from a new PES program in Mexico. Because social interactions are critical within collective processes, we assess the impacts from conditioning on additionality given: (1) group participation in contract design, and (2) a group coordination mechanism. Conditioning on above-baseline outcomes raised contributions, particularly among initially lower contributors. Group participation in contract design increased impact, as did the coordination mechanism.     

1983-2003年澳门生态系统服务价值的变化

以澳门1983年和2003年的统计数据为基础,在分析澳门土地利用和土地覆盖变化状况的同时,对澳门生态系统服务的价值进行了评估,结果表明,按当前价计算,(1)2003年澳门生态系统服务的价值为1983年的2.5倍;(2)1983年澳门生态系统服务的价值为3.302×106 美元,相当于26.5250×106 MOP(澳门元);2003年澳门生态系统服务的价值为8.3396×106 美元,相当于66.992×106 MOP;(3)将2003年澳门生态系统服务的价值与2003年澳门的年生产总值(GDP)646.54×108 MOP相比,2003年澳门生态系统服务的价值相当于GDP的0.1%,体现了澳门城市经济主导型的特征.由于缺乏对建筑用地服务价值的相关研究数据,该结果是对澳门生态系统服务价值的保守估计;(4)1997年全球年人均生态服务价值为5544.7美元/人,而澳门2002年人均生态服务价值仅为18.9元/人,为全球水平的0.34%,反映澳门辖区生态服务的严重不足.澳门人均生态系统服务价值偏低主要是由于澳门辖区小且无水域(由于澳门地处生态服务价值非常高的珠江口河口区,生态服务并不受行政边界的影响,所以澳门实质上的生态服务价值并不低);(5)澳门1983年至2003年之间填海造地635 hm2,填海使邻近澳门的珠江河口湿地面积减少同样的面积,由于河口潮汐地的生态服务价值高达9990美元/(hm2·a),远高于填海得到的草地和裸地,所以20年中澳门及周边河口区净生态服务价值下降为1.306×106美元.     

Habitat loss, trophic collapse, and the decline of ecosystem services

The provisioning of sustaining goods and services that we obtain from natural ecosystems is a strong economic justification for the conservation of biological diversity. Understanding the relationship between these goods and services and changes in the size, arrangement, and quality of natural habitats is a fundamental challenge of natural resource management. In this paper, we describe a new approach to assessing the implications of habitat loss for loss of ecosystem services by examining how the provision of different ecosystem services is dominated by species from different trophic levels. We then develop a mathematical model that illustrates how declines in habitat quality and quantity lead to sequential losses of trophic diversity. The model suggests that declines in the provisioning of services will initially be slow but will then accelerate as species from higher trophic levels are lost at faster rates. Comparison of these patterns with empirical examples of ecosystem collapse (and assembly) suggest similar patterns occur in natural systems impacted by anthropogenic change. In general, ecosystem goods and services provided by species in the upper trophic levels will be lost before those provided by species lower in the food chain. The decrease in terrestrial food chain length predicted by the model parallels that observed in the oceans following overexploitation. The large area requirements of higher trophic levels make them as susceptible to extinction as they are in marine systems where they are systematically exploited. Whereas the traditional species-area curve suggests that 50% of species are driven extinct by an order-of-magnitude decline in habitat abundance, this magnitude of loss may represent the loss of an entire trophic level and all the ecosystem services performed by the species on this trophic level.     

Caveats to quantifying ecosystem services: fruit abortion blurs benefits from crop pollination.

The recent trend to place monetary values on ecosystem services has led to studies on the economic importance of pollinators for agricultural crops. Several recent studies indicate regional, long-term pollinator declines, and economic consequences have been derived from declining pollination efficiencies. However, use of pollinator services as economic incentives for conservation must consider environmental factors such as drought, pests, and diseases, which can also limit yields. Moreover, "flower excess" is a well-known reproductive strategy of plants as insurance against unpredictable, external factors that limit reproduction. With three case studies on the importance of pollination levels for amounts of harvested fruits of three tropical crops (passion fruit in Brazil, coffee in Ecuador, and cacao in Indonesia) we illustrate how reproductive strategies and environmental stress can obscure initial benefits from improved pollination. By interpreting these results with findings from evolutionary sciences, agronomy, and studies on wild-plant populations, we argue that studies on economic benefits from pollinators should include the total of ecosystem processes that (1) lead to successful pollination and (2) mobilize nutrients and improve plant quality to the extent that crop yields indeed benefit from enhanced pollinator services. Conservation incentives that use quantifications of nature's services to human welfare will benefit from approaches at the ecosystem level that take into account the broad spectrum of biological processes that limit or deliver the service.     

Understanding the functional principles of nature—Proposing another type of ecosystem services

Ecosystem services are usually interpreted as a free of charge “favour” provided to us and our society by nature. In other words, nature supplies us with a functionality that we would otherwise have to pay for. Our cost would be to provide resources either (1) to ensure the necessary inputs to drive our society, or (2) to assist in counteracting, absorbing or remediating unwanted effects that are results of our societal activities. Through ecosystem studies it has been found that a substantial part of the functionality of nature is laid out in all types of components—the compartments of the ecosystems together with the transactional interrelations (flows) and controls between them. Eventually, many so-called indicators have been proposed during the last decades. Such measures are dedicated to tell us about the quality side of ecosystem functionality, e.g. to tell us how well the system performs relatively to a theoretical maximum efficiency possible. As an additional hypothesis, such functions are thought to orient the systems and thus increase through time development, i.e. to be optimised under the given the constraints, through the evolution of the system. Recently is has been pointed out that natural and societal systems share the feature of being complex in their organisation. Meanwhile, it was remarked that societal systems in many ways evolved in opposite direction of how natural evolution would drive an ecosystem. Many philosophers of biology have stated that biological systems posses information and memory functions which improve their long-term capability to survive. This information is believed to be contained in the organisational structures of the system as much as in its gene pool. If we accept such arguments it means that studies of organisation and function of natural systems will provide us with another type of ecosystem services. This would namely give us information about in what direction to drive society in order to achieve a more sustainable system.     

Adapting the adaptive cycle: Hypotheses on the development of ecosystem properties and services

Ecosystems are dynamic complexes. These dynamics can be described by different ecophysiological parameters and systems theoretical concepts like succession, thermodynamics, information/network theory, resilience, adaptability and the orientor concept. In this paper, different indicators and concepts are linked to Holling's adaptive cycle metaphor in order to derive hypotheses on potential system trajectories. The hypotheses focus on an exemplary temperate forest ecosystem experiencing the adaptive cycle's four phases of exploitation, conservation, collapse and reorganization after an initializing fire event. The different properties are correlated to the number of total system connections and show varying trajectories. Additionally, the provision of selected forest ecosystem services during the different phases is hypothesized and compared to three other land use types.     

重要生态功能区典型生态服务及其评估指标体系的构建

科学评估重要生态功能区的生态服务是管理者制定相关政策的基础,对促进重要生态功能区维护区域生态安全、支撑经济社会可持续发展具有重要意义。依据生态服务的空间转移特性,探索提出了重要生态功能区典型生态服务的概念与内涵,并在此基础上综合运用频度分析法、专家咨询法和层次分析法,构建了重要生态功能区水源涵养、土壤保持、防风固沙、生物多样性保护和洪水调蓄等典型生态服务的评估指标体系。结果表明：在指标体系中,影响水源涵养服务的主要是土壤质地和降水量;影响土壤保持服务的主要是植被覆盖度和丰富度指数;影响防风固沙服务的主要是植被覆盖度和大风时速;影响生物多样性服务的主要是植被景观多样性指数;影响洪水调蓄服务的主要是湿地容积和降水量。土壤、植被、地形和气候等生态因子是重要生态功能区典型生态服务产生与发挥的重要基础。     

Nitrogen dynamics in the sediments of a wetland coastal ecosystem of southern India

The study area, Kuttanad Waters is a part of the Cochin estuarine system on the west coast of India. Kuttanad is well known for its agricultural activity and so the major contribution to the inorganic ions of nitrogen will be from fertilisers applied in agriculture. Based on observed salinity the stations have been divided into three zones. The fresh water zones had higher quantities of silt and clay whereas the estuarine zone was more sandy. The chemical speciation scheme applied here distinguishes three forms of ammoniacal nitrogen species: exchangeable, fixed, and organic ammoniacal nitrogen. No significant trends were observed in the seasonal distribution of total, exchangeable, fixed and organic nitrogen. A significant concentration of exchangeable ammonia was observed in the sediment due to their predominantly reducing environment, which restricts nitrification. High NH₄-N concentrations in the pore waters, along with the sedimentary composition leads to a significantly high quantity of fixed NH₄-N. The low values for N org is due to high mineralisation or deamination of organic nitrogen     

Disadvantages and future research directions in valuation of ecosystem services in China

We have reviewed the development, background and valuation history of ecosystem services in China and abroad, and highlight the importance of ecosystem services and the necessity of their valuation at various temporal and spatial scales. Through critical review of the literature, we have elucidated disadvantages in studies of ecosystem services in China, including the lack of a definite purpose for the valuation of ecosystem services, improper emphasis of valuation studies, stifled application of the contingent valuation method, weak power of research panels in the field, and the absence of the participation of government officials. In addition, we discuss some case studies from Western countries which tracked changes in the total economic value (TEV) of ecosystem services across different states of ecological disturbance and evaluated changes in the TEV under different management regimes. These studies may be useful in guiding future research in China. In essence, there are three major aspects involved in the valuation of ecosystem services: improving accuracy of valuation, association of results of valuation with policy and management decisions, and transfer of payments for ecosystem services. We suggest three priorities for future research in China: to develop an ecosystem service valuation model, to enhance the relevance of valuation studies to policy development, and to reward the protectors of ecosystem services.     

Urban ecosystem services: tree diversity and stability of tropospheric ozone removal

Urban forests provide important ecosystem services, such as urban air quality improvement by removing pollutants. While robust evidence exists that plant physiology, abundance, and distribution within cities are basic parameters affecting the magnitude and efficiency of air pollution removal, little is known about effects of plant diversity on the stability of this ecosystem service. Here, by means of a spatial analysis integrating system dynamic modeling and geostatistics, we assessed the effects of tree diversity on the removal of tropospheric ozone (O3) in Rome, Italy, in two years (2003 and 2004) that were very different for climatic conditions and ozone levels. Different tree functional groups showed complementary uptake patterns, related to tree physiology and phenology, maintaining a stable community function across different climatic conditions. Our results, although depending on the city-specific conditions of the studied area, suggest a higher function stability at increasing diversity levels in urban ecosystems. In Rome, such ecosystem services, based on published unitary costs of externalities and of mortality associated with O3, can be prudently valued to roughly US$2 and $3 million/year, respectively.