现阶段中国生态农业可持续发展面临的实践和理论问题探讨

随着全球经济一体化的发展以及中国实施可持续发展和全面建设小康社会的需要,中国生态农业面临着新的机遇和挑战。我国生态农业经过20多年的实践,现已取得了一定进展,并具备了一定的发展基础。目前,全国2000多个县、乡镇先后实施了生态农业建设。然而,当前我国生态农业可持续发展面临着一系列实践和理论问题。在实践方面,存在着思想认识、技术、资金、建设与管理等问题。在科学理论方面则需要解决如生态农业的基本内涵、分类、生态模式的内在过程与机理及其生态服务功能、模式的尺度转换以及生态农业模式变化规律、生态农业安全等问题。因此,加快开展全国生态农业建设规划,加大资金投入和政策扶持力度,加强农业基础设施和社会化服务体系建设,加快农业产业结构调整和优化升级,发展生态产业,全面推动生态农业的产业化、标准化、信息化和现代化发展。是当前生态农业建设面临的重要任务。     

高寒草地生态经济系统价值流、畜群结构、最优控制管理及可持续发展

高寒草地是中国西部青藏高原地区重要的生态系统,该系统直接和该地区少数民族的民生相联系。由于长期过度放牧,该系统已经开始严重退化,而单纯的保护将会与当地畜牧业发展发生冲突。为了能深入地认识高寒草地牧业生态经济系统存在的经济规律,本砑究以甘南合作藏族自治州畜牧业经济为对象,首先从生态经济学角度以货币为计量标度,定量分析了一个以草地牧业为主的高寒牧区生态经济复合系统中单位面积上能流过程和价值流过程,解释该生态经济系统的耦合关系。然后利用线性规划方法,对该系统中的关键问题,即畜群结构进行优化分析并提出优化方案。最后利用最优控制方法,对放牧及刈割强度进行分析,提出合理的放牧强度模式,使高寒草地的经济效益与生态效益达到最佳平衡。利用这3种方法建立起高寒草地生态经济复合系统的可持续发展监督和管理模式,用价值流分析明确系统的价值走向和倍增效应,用线性规划使畜牧业的种内和品种结构达到最优化并使其经济效益最大,利用最优控制方法使畜牧业生产和草地保护有机结合,形成既保护高寒生态系统又改良并发展当地畜牧业的可持续发展模式。     

Exploring the evolution of environmental sex determination, especially in reptiles

Environmental sex determination has been documented in a variety of organisms for many decades and the adaptive significance of this unusual sex-determining mechanism has been clarified empirically in most cases. In contrast, temperature-dependent sex determination (TSD) in amniote vertebrates, first noted 40 years ago in a lizard, has defied a general satisfactory evolutionary explanation despite considerable research effort. After briefly reviewing relevant theory and prior empirical work, we draw attention to recent comparative analyses that illuminate the evolutionary history of TSD in amniote vertebrates and point to clear avenues for future research on this challenging topic. To that end, we then highlight the latest empirical findings in lizards and turtles, as well as promising experimental results from a model organism, that portend an exciting future of progress in finally elucidating the evolutionary cause(s) and significance of TSD.     

广州市生态可持续发展水平对比评价

基于城市自然-经济-社会复合生态系统原理,应用层次分析法、综合指数法,建立城市生态可持续发展水平测度指标体系,并将广州市与北京、上海、深圳市进行对比评价,最后得出各城市生态化水平、生态可持续发展水平及发展特点等结论。广州现状自然生态化水平、生态可持续发展水平低于深圳、略低于北京,高于上海,在国内大城市中属良好水平;经济生态指数低于深圳、略低于上海,高于北京,在国内大城市中也属良好水平;社会生态指数在四城市中最低。指标及其权重的选定考虑了各指标的层次性、代表性,也考虑到指标数据资料易统计、更客观和可比较等原则。     

生态足迹分析应用于区域可持续发展生态评估的缺陷

可持续发展的生态评估是当前国际生态经济学与可持续发展研究的前沿问题之一,生态足迹从生物生产的角度可以定量评估一个国家或地区发展的生态持续性程度,是近年来发展迅速的一种生物物理量衡量方法。尽管生态足迹分析具有指标指示意义明确、评估结果全球可比与模型方法简便、资料易获取、可操作性强等优点,但在理论方法上仍存在不足之处。综合国内外区域生态足迹分析的最新进展,生态足迹分析应用于区域可持续发展生态评估的理论缺陷主要表现为以下6点：①弱可持续性评价,难以完整反映系统的可持续性状态;②静态模型,缺乏预测功能;③长时间序列生态足迹研究的合理性有待商榷;④全球平均生产力的相对性,导致评估结果的非绝对性;⑤过于强调土地的数量,而忽略土地的质量;⑥假定各类生物生产性土地类型的空间互斥性,忽视兼业性。     

Developing the concept of sustainable fisheries

We are approaching the limits to World fish yields, and it is becoming increasingly difficult to sustain the stocks in the face of allocative disputes between fisheries and competing water uses. A new strategy is needed to integrate aquatic ecosystem management into the larger context of Environmentally Sustainable Development. This will need to span jurisdictions and interest sectors in long-range environment-economy planning. It is suggested that this process is impossible within conventional government infrastructures, and that a new movement is needed, involving multi-sector, independent public participation.Based on a Working Paper for the U.N. Seminar on Ecosystems Approach to Water Management. Oslo, Norway, May 1991.     

Marine environmental issues of Southeast Asia: state and development

The seas of Southeast Asia play an important role in the economy of the surrounding countries. The region's constantly expanding coastal population and development has made great demands on marine resources, with growing evidence seen in the further degradation of the marine environment and continued exploitation of living as well as non-living resources. Integrated coastal area management has never been considered in the past while environmental protection measures and policies have largely been at local or national levels. Implementation of regional study programmes less than 10 years ago and ratification of international as well as regional agreements aimed at protecting the marine environment in recent times indicate a more enlightened approach to the problem.     

广西生态环境可持续发展评估

生态足迹是一种度量可持续发展程度的方法,能定量判断一个区域生态环境是否处于可持续发展状况。基于生态足迹方法对2003年广西生态环境的可持续发展状况进行了评估。结果表明,广西2003年生态足迹为1.1378 hm2,可利用的人均生态承载力为0.5753 hm2,对资源的需求已超过其供给能力,人均生态赤字达到0.5625 hm2,生态环境已经处于不可持续发展状态,必须采取相应措施促使生态环境发展向良性和可持续方向转化。     

中国天然林保护、生态恢复与可持续经营的理论与技术

全面总结了近年来中国在天然林保护与生态恢复的理论与技术实践方面所取得的研究进展。高度凝练出了天然林动态干扰与保育技术、典型退化天然林的生态恢复技术和天然林景观恢复与空间经营技术等三方面的创新成果,形成了天然林保护与生态恢复的理论与技术创新体系,对今后天然林保护、生态恢复与可持续经营进行了展望。     

Elasmobranchs in southern Indonesian fisheries: the fisheries, the status of the stocks and management options

The biology of elasmobranchs makes them very vulnerable to fishing pressure and there is increasing international concern over their exploitation. In northern Australia the stocks of some species may be shared with those in southern Indonesia. Indonesia has the highest landings of elasmobranchs worldwide (>100,000 t p.a.) and millions of Indonesian artisanal fishers rely heavily on elasmobranchs taken in target fisheries. They are also taken by industrial trawlers and as bycatch in pelagic tuna fisheries. This paper, resulting from a collaborative project between Australia and Indonesia, summarises the elasmobranch fisheries; the characteristics of the fisheries are outlined, the status of the stocks are assessed, and management options described and discussed. The project focussed on representative markets and fish landing sites in southern Indonesia from 2001 to 2005. Data were from market surveys, the records of the Indonesian Directorate General of Capture Fisheries, and from research cruises. Data from the ongoing tuna monitoring programme showed that shark bycatch from the tuna fleets forms about 11% of shark landings in Indonesia. Yield per recruit and related analyses were used to integrate biological information to indicate the productivity of each species to allow for management policy options and constraints. Research cruise data show that catch rates of elasmobranchs in the Java Sea declined by at least one order of magnitude between 1976 and 1997. The results indicate strongly that many of the shark and ray species in Indonesia are overfished and that the most effective management strategy may need to involve capacity control, such as licencing, gear restrictions and catch limits, together with controls on the fin trade.     

基于生态足迹方法的南京可持续发展研究

20世纪90年代末以来,随着南京城市化进程的加快和城市建成区面积的扩展,城市生态安全问题日益突出。在运用生态足迹方法分析南京市1999—2009年人均生态足迹及生态承载力变化的基础上,采用Mann-kendall法对南京市人均生态足迹突变点进行分析,应用灰色关联模型从经济、社会和生态子系统方面分析不同阶段人均生态足迹变化的原因。研究表明:1999—2009年间南京市人均生态足迹呈增长趋势,人均生态承载力呈减小趋势,单位万元GDP生态足迹和生态多样性指数呈逐年下降趋势,生态经济系统发展能力较好,但生态压力较大。南京市人均生态足迹变化分为1999—2002年的低位增长阶段和2003—2009年高位波动阶段。通过影响南京市生态足迹变化因素分析发现,2003—2009年与1999—2002年相比,经济子系统依然处于主要地位,但影响因素由农业向以三产为主转变,同时生态子系统和社会子系统各因素的影响力提升。据此,提出优化产业结构,控制人口数量,加强基础设施建设,改善居民居住环境,加大城市绿化建设,提高城市污物处理能力,减少污染物排放的南京可持续发展对策。     

An environmental (pre)history of European fishing: past and future archaeological contributions to sustainable fisheries

This paper explores the past and potential contribution of archaeology to marine historical ecology. The primary focus is European fishing of marine and diadromous taxa, with global comparisons highlighting the wider applicability of archaeological approaches. The review illustrates how study of excavated fish bones, otoliths and shells can inform our understanding of: (a) changes in biogeography, including the previous distribution of lost species; (b) long-term fluctuations in the aquatic environment, including climate change; (c) the intensity of exploitation and other anthropogenic effects; (d) trade, commodification and globalisation. These issues are also relevant to inform fisheries conservation and management targets. Equally important, the long (pre)history of European fishing raises awareness of our ecological heritage debt, owed for centuries of wealth, sustenance and well-being, and for which we share collective responsibility. This debt represents both a loss and a reason for optimism, insofar as it is a reservoir of potential to be filled by careful stewardship of our rivers, lakes, seas and oceans.     

河套平原盐碱地生态治理和生态产业发展模式

开展河套平原盐碱地的生态治理对提升该区生态系统稳定性、土地生产力和资源利用效率具有重要战略与现实意义。为此,科技部通过"典型脆弱生态修复与保护研究"专项立项了重点研发计划项目"河套平原盐碱地生态治理关键技术研究与集成示范(2016YFC0501300)"。介绍了该项目的背景与意义、主要思路与研究内容、整体目标,并对项目研究进行了展望。该项目采用"基础理论+核心技术+新型装备+产业技术+模式示范"一体化思路,旨在揭示河套平原土地盐碱化形成规律与盐碱障碍生态消减原理,研发生物适应型与生态导向型盐碱地治理修复关键技术,研制大型排盐控盐工程设备与复合型生态调理制剂产品,创建盐碱地综合治理技术体系和特色生态产业发展模式。     

The use of ecological,fishing and environmental indicators in support of decision making in southern Benguela fisheries

Indicators have been recognised as a useful tool aiding the implementation of an ecosystem approach to fisheries in marine ecosystems. Studies, such as the IndiSeas project (www.indiseas.org), use a suite of indicators as a method of assessing the state and trends of several of the world's marine ecosystems. While it is well known that both fishing and climatic variability influence marine fisheries in the southern Benguela ecosystem there are currently few studies in support of fisheries management that make use of environmental indicators in order to include climatic impacts on marine fish populations. Trends in ecological, fishing and environmental indicators can be utilised in a way that allows an overall ecosystem trend to be determined, and can therefore be used to aid decision support within southern Benguela fisheries. In this study trends in indicators were determined using linear regressions across three time periods, Period 1: 1978–1993, Period 2: 1994–2003 and Period 3: 2004–2010. These time periods were selected based on the timing of regime shifts within the southern Benguela, including changes in upwelling, wind stress and temperature. Each ecological indicator received a score based on the direction and significance of the observed trend with respect to fishing. To account for the impacts of fishing and environmental drivers on ecological indicators, scores were adjusted by predetermined factors, depending on the extent and direction of trends in these indicators. Weightings were applied to correlated ecological indicators to account for their redundancy, and lessen their impact on overall ecosystem score. Mean weighted scores were then used to establish an overall ecosystem score for each time period. Ecosystem classification was determined as follows: 1–1.49 = improving, 1.5–2.49 = possibly improving, 2.5–3.49 = no improvement or deterioration, 3.5–4.49 = possible deterioration, 4.5–5 = deteriorating. The ecosystem was observed to neither deteriorate nor improve across Period 1 or 2 (mean weighted scores: 2.75 and 2.56 respectively), however, during Period 3 a possible improvement was observed (mean weighted score: 1.99). This study shows that the sequential analysis of suites of ecological, fishing and environmental indicators can be used in order to determine ecosystem trends, accounting for both the impacts of fishing and the environment on ecosystem components.     

不同生态调控情景下人工林可持续经营收益研究

在林业碳汇项目设计与作业标准基础上,将中国东北地区典型人工林生长与经营相关多源数据融合,运用系统动力学理论与方法,构建人工林生态经济系统模型,通过设计实施主伐/间伐、营造混交林、补植补造等不同生态调控情景,模拟并预测人工林可持续经营的生态—经济收益,以此掌握人工林生态调控机制,并为人工林可持续经营决策提供参考。模拟结果显示：(1)高初植密度能有效增汇,而低初植密度相比基准情景则减少了碳汇;(2)高主伐率使得木材收益大幅提升,而无主伐限制了木材收益,且从长期来看碳汇收益有限;(3)高密度-无主伐情景下的累计碳汇量最大,高密度-高主伐情景下的木材收益净现值和总收益净现值最大;若以可持续经营为目标,平衡生态收益和经济收益,则高密度-高主伐情景为理想选择,该情景的累计碳汇量相比高密度-无主伐情景损失有限,对应碳汇收益净现值为357.9万元,以5%贴现率计算的木材总收益和累计总收益的净现值分别为1219.35万元和1577.25万元。由此证实了以林业碳汇项目为依托,因地制宜地构建将造林、抚育、采伐、再造林更新于一体的人工林可持续经营项目,平衡发挥森林生态系统的综合功能,可纾解因无法采伐所带来的高...     

Recruitment of migratory Characiforms in the different wetland habitats of Central Amazonia: Subsidies for sustainable fisheries management

By promoting the biological recruitment of relevant natural resources, wetlands offer a major ecosystem service. This study investigates the importance of wetland habitats of the central Amazon basin as sites for spawning and/or initial development of seven of the most important commercial Characiforms fish species. In order to confirm this importance, samples of the eggs, larvae, and juveniles of these fish species were collected during the four seasonal phases of the hydrological cycles of 2010 and 2011, in different aquatic environments of the wetland ecosystem in the central Amazon. The results confirmed that the flooding phase is the most important for the spawning of these species, and that they preferred to use the marginal areas of the central Amazon as spawning grounds. The larvae of these species colonize the confluence zone of the rivers and the mouths of the floodplain channels, principally during the initial stages (pre-flexion) of their ontogenetic development. The channels that connect the lakes to the rivers are the main dispersal route for the larvae, especially those in advanced stages of development (flexion/post-flexion), towards the internal of the wetland habitats, such as the lakes and large mattresses of floating vegetation. The different wetland habitats of this region provide an extremely important ecosystem service, playing a critical role in the recruitment of commercially-valuable fish species, and thus require adequate protection and management to ensure the continuity of fisheries and natural stocks.     

新疆生态经济系统可持续发展空间格局

运用生态足迹模型、生态经济系统发展能力指标、生态压力区分区标准和生态经济系统分区标准分析了1995—2010年新疆生态可持续性和生态经济系统可持续性的时空演变过程。结果表明:(1)1995—2010年间,生态压力指数、生态赤字总体逐年增大,新疆生态环境不可持续性增强;生态经济系统发展能力指数呈快速上涨趋势,生态经济系统发展能力显著提高,万元GDP生态足迹显著下降,资源利用效率有明显的提高。(2)各地州市1995—2010年间区域差异逐渐增大,生态赤字区逐渐增多,生态压力指数逐渐增大,生态环境不可持续性逐渐增强。一直处于高生态压力区的是乌鲁木齐市、克拉玛依市和石河子市,主要是因为它们经济发展水平和城市化水平高,生物资源、能源消费量大。(3)2000年后,各地州市可持续发展状况发生巨大的变化,主要是因为生态足迹的快速增长,生态承载力基本不变,导致生态压力指数增大,生态赤字增加,归根源于西部大开发战略的成效显著,新疆各地州市经济发展和人口快速增长,生物资源能源消费量增多;1995—2010年间,新疆各地州市生态经济系统发展能力和资源利用效率有了显著提高,但是区域差异变大。新疆生态环境和生态经济系统可持续发展面临挑战。     

Exploring the role of environmental enteropathy in malnutrition,infant development and oral vaccine response

Environmental enteropathy (EE) is a poorly defined state of intestinal inflammation without overt diarrhoea that occurs in individuals exposed over time to poor sanitation and hygiene. It is characterized pathologically by small intestine villous blunting and inflammation. In children from low-income countries, it is implicated as a cause of malnutrition, oral vaccine failure and impaired cognitive development. Here we review the search for non-invasive biomarkers to measure EE non-invasively, and assess the current evidence linking EE to malnutrition, vaccine failure and neurocognitive development.     

基于旅游生态足迹模型的西安市旅游可持续发展评估

基于生态足迹模型、结合旅游者的生态消费及结构特征,将旅游生态足迹引入区域旅游可持续发展评估,阐述了旅游生态足迹的概念,并构建了旅游交通、住宿、餐饮、购物、游览等旅游生态足迹计算子模型。以西安市作为实证研究对象,计算分析了2004年西安市游客的旅游生态足迹。研究结果表明:2004年西安市游客的人均旅游生态足迹为0.1194hm2,人均旅游生态承载力为0.0198hm2,人均旅游生态赤字达0.0996hm2,反映出西安市的旅游业处于"不可持续发展状态",因此必须采取有效措施,合理利用生态资源,才能保证旅游业持续发展。