鄱阳湖沙山植物叶片与土壤C∶N、C∶P沿沙化梯度分布特征

在鄱阳湖多宝沙山沿沙化梯度测定了17种常见植物叶片及土壤有机碳(C)、全氮(N)、全磷(P)含量,以阐明沙山常见植物种与土壤C〖DK〗∶N、C〖DK〗∶P分布特征及对沙化的响应,为沙山植被恢复提供基础数据。结果表明：（1）植物叶片C〖DK〗∶N、C〖DK〗∶P分布范围为185～1273、1698～5071,平均值分别为431、3418;土壤0～10、10～30、30～50 cm层C〖DK〗∶N变化范围分别为98～463、24～465和37～450; 相应土层C〖DK〗∶P范围分别为198～759、30～905和47～765。（2）植物C〖DK〗∶N、C〖DK〗∶P对沙化的响应模式一致,均表现出在重度沙化区数值最小;土壤C〖DK〗∶N随沙化程度增加表现出降低趋势,而C〖DK〗∶P则表现出增加趋势,二者对沙化的响应不一致。（3）植物C〖DK〗∶N、C〖DK〗∶P变化主要取决于叶片的N、P含量;土壤C〖DK〗∶N的变化受控于土壤N含量;C〖DK〗∶P变化则决定于土壤有机C含量     

C模式:中国发展循环经济的战略选择

我国循环经济发展到了需要深化的阶段。运用生态效率的概念揭示循环经济的减物质化本质，通过对生态效率进行情景分析，指出适合我国的循环经济发展模式-C模式。C模式也称1.5-2倍数发展战略，该模式将给予我图的GDP增长一个15—20年左右缓冲的阶段，并希望经过15-20年的经济增长方式调整，最终达到一种相对的减物质化阶段。同时指出实现中图循环经济发展的C模式，需要技术和政策的双重保障。在发展循环经济过程中，中国不但要关注传统的渐进式的部门内部的技术变革，还要前瞻性地促进跨部门的技术变革。同时，还要建立基于生命周期分析和现代治理理论的促进循环经济发展的全过程、全方位政策体系。     

Estimating damages from climate-related natural disasters for the Caribbean at 1.5 °C and 2 °C global warming above preindustrial levels

This paper examines historical and future changes in normalised damages resulting from climate-related natural disasters for the Caribbean. Annualised damages of USD824 million are shown to be non-stationary over the historical period 1964 to 2013. Perturbations of (i) sea surface temperatures (SST) in the tropical North Atlantic (TNA) and (ii) the Atlantic multi-decadal oscillation (AMO) appear to be associated with historical damages. Both the TNA and AMO are known modulators of hurricane activity and rainfall amounts in the Caribbean. Indicative future damages are determined using (i) cumulative distribution functions (CDFs) of perturbed climate states and (ii) an artificial neural network (ANN) model of damages using projected TNA values and the state of the AMO derived from an ensemble of five coupled model intercomparison project phase 5 (CMIP5) global climate models (GCMs) run under the RCP 4.5 scenario. Estimates of future damages are determined when global mean surface temperatures (GMST) reach and exceed 1.5 °C above preindustrial levels. Annual normalised damages may potentially increase to at least USD1395 million or close to double for 1.5 °C. At 2 °C, higher damages may occur; however, large uncertainty across all GCMs prohibits the identification of significant difference between 1.5 and 2 °C. Significant differences in damages do, however, exist for at least two of the GCMs for the two climate states. The robustness of the results is discussed in light of a number of issues, including limitations associated with the data.     

基于FY2C卫星数据的藏北高原降水估算研究

如何确切的掌握降水的时空分布,对区域气候、水文和生态应用等至关重要。以藏北高原典型区为研究区,在大量地面实况降水观测数据与对长时间序列FY 2C 影像光谱特征和云图特征分析的基础上,获取卫星降水模拟参数特征集以刻画云降水的发生与发展过程,选用最值归一化方法对不同量纲云图特征参数进行归一化处理。构建基于三层前向型反向传播神经网络的卫星降水估算模型,用于该地域降水估算,并采用多指标体系分析模型的降水模拟精度。结果表明：静止气象卫星红外波段能较精确地揭示云的降水机理,较高时间分辨率遥感图像可以监测云图的变化细节,并获取能够反映云图降水特征的降水模拟参数;人工神经网络能较好地刻画该地域卫星降水特征的非线性规律;三层前向型反向传播神经网络卫星降水估算模型的估算结果与雨量计实测值间的相关性可以达到0.57。模型估算结果系统性的低估偏小,预示着对该地域弱降水强度将有较好的指示性     

基于C5.0决策树算法的元胞自动机土地利用变化模拟模型

C5.0决策树算法可以揭示数据中的结构化信息,建立直观、易于理解的树形结构,可以用于元胞自动机转换规则的获取。提出了基于C5.0决策树算法的元胞自动机模型,分析了模型构建的理论和原理以及实现方法。在此基础上,以杭州市城市用地演变为例,利用C5.0决策树算法从已有的城市用地及其影响因子数据中挖掘出城市用地的演变规则,并将获得的转换规则应用到元胞自动机模型中进行城市用地演变的动态模拟与预测。结果表明：（1）利用C5.0决策树算法获取转换规则可以在较低采样率的前提下保证具有较高的精度;（2）与其它获取元胞自动机转换规则的方法相比,C5.0决策树算法生成的规则清晰明确,很适合用来获取元胞转换规则;（3）基于C5.0决策树算法的元胞自动机模型在模拟城市用地演变方面具有较高的模拟精度,模拟结果可靠.     

Plan C： China＇s Development under the Scarcity of Natural Capital

The critical issue of China＇s modernization is whether it can free itself from the traditional modernization plan based on the relatively abundant natural capital, and innovatively create a developmental model of a large country under the scarcity of natural capital. This is why China is so keen on circular economy and economical use of resources. Focused on this issue, this paper summarizes the theoretical elements of the development under the scarcity of natural capital, points out that Plan C is the strategic choice for China＇s future development, emphasizes that China needs to enhance the new industrialization, new urbanization and new modernization based on the restriction of natural capital, and discusses the technological and mechanistic support required to realize the development under the scarcity of natural capital.     

南京紫金山马尾松树轮δ13C对气候变化响应敏感性的研究

树木年轮宽度指标在气候重建中发挥了重要的作用,可是在温暖湿润的地区,利用树木年轮宽度重建古气候遇到了困难。因此寻找其他代用指标就成为一项急迫而重要的任务。一些研究发现,树轮稳定碳同位素可以发挥重要的作用。但是,是否所有的树种的树轮碳同位素对气候的响应都同样的敏感,还需要通过大量的研究分析工作来验证。为了了解温暖湿润的亚热带季风区马尾松树轮δ13C对气候响应的敏感性,选取了南京紫金山的两个马尾松树盘,进行了树轮δ13C的分析,建立了1939~2002和1955~2002年两个树轮δ13C变化序列。与降水、温度、相对湿度、光照时数、风速等气候指标进行了相关分析。结果表明：（1）马尾松树轮δ13C对于气候的响应是敏感的,可以作为气候变化的代用指标;（2）坡向对于马尾松树轮δ13C对气候的响应敏感性也有一定的影响,树轮δ13C平均值西南坡比东南坡高,西南坡比东南坡对月平均最低和最高温度的响应更敏感;（3）紫金山马尾松树轮δ13C与该地区生长季（尤其是夏、秋季）的月平均气温、月平均最高气温和日照时数呈正相关,而与月平均最低气温、降水量、空气相对湿度呈负相关     

Environmental impact of unleaded gasolines in the bay of Cádiz (Spain)

Given the strategic situation of the José León de Carranza bridge, which spans the Bay of Cádiz (in the SW of Spain) and carries very heavy motor traffic, together with knowledge of the currents and tidal flows in the zone, we have used a technique of radioactive dating of sediments to study the temporal evolution presented by contamination from lead in the sediment column. This has allowed us to observe the environmental impact, in terms of the concentration of Pb in the sea bed sediments, that has been produced in the zone by the introduction of unleaded gasolines as substitutes for traditional automobile fuels that employ organic forms of tetra methyl lead as an antidetonant agent in the fuel.     

Assessing the implications of a 1.5 °C temperature limit for the Jamaican agriculture sector

Despite recent calls to limit future increases in the global average temperature to well below 2 °C, little is known about how different climatic thresholds will impact human society. Future warming trends have significant global food security implications, particularly for small island developing states (SIDS) that are recognized as being among the most vulnerable to global climate change. In the case of the Caribbean, any significant change in the region’s climate is likely to have significant adverse effects on the agriculture sector. This paper explores the potential biophysical impacts of a +?1.5 °C warming scenario on several economically important crops grown in the Caribbean island of Jamaica. Also, it explores differences to a >?2.0 °C warming scenario, which is more likely, if the current policy agreements cannot be complied with by the international community. We use the ECOCROP niche model to estimate how predicted changes in future climate could affect the growing conditions of several commonly cultivated crops from both future scenarios. We then discuss some key policy considerations for Jamaica’s agriculture sector, specifically related to the challenges posed to future adaptation pathways amidst growing climate uncertainty and complexity. Our model results show that even an increase less than +?1.5 °C is expected to have an overall negative impact on crop suitability and a general reduction in the range of crops available to Jamaican farmers. This observation is instructive as increases above the +?1.5 °C threshold would likely lead to even more irreversible and potentially catastrophic changes to the sustainability of Jamaica’s agriculture sector. The paper concludes by outlining some key considerations for future action, paying keen attention to the policy relevance of a +?1.5 °C temperature limit. Given little room for optimism with respect to the imminent changes that SIDS will need to confront in the near future, broad-based policy engagement by stakeholders in these geographies is paramount, irrespective of the climate warming scenario.     

城市湖泊富营养化对水生植物叶片C、N、P化学计量特征的影响

为研究城市湖泊富营养化对水生植物叶片元素组成的影响,在植物生长季,对南京3个湖泊的6种常见水生植物进行碳(C)、氮(N)、磷(P)生态化学计量学研究,并分析驱动水生植物叶片元素变化的关键环境因子。结果表明:(1)水生植物叶片C、N、P含量变化范围分别为397.03～672.70、10.63～39.16及1.15～13.30 mg/g,叶片C/N、C/P及N/P变化范围分别为13.15～50.36、31.39～458.60及1.88～19.06,其中叶片P含量变异最大,叶片C含量变异最小;(2) Spearman相关性分析表明,芦苇(Phragmites australis)、睡莲(Nymphaea tetragona)和金鱼藻(Ceratophyllum demersum)叶片元素组成与湖泊富营养化综合指数具有显著相关性,叶片P含量随湖泊富营养指数升高而增加,叶片C/P及N/P随之减小;(3) RDA分析表明,春季水生植物叶片C、N、P含量及C/N/P变化主要受水体高锰酸盐指数(COD_(Mn))和底泥总有机碳(SOC)含量的共同影响,夏季主要受水体总磷(TP_W)浓度的影响,秋季主要受底泥总磷(TP_S)含量的影响。     

基于C5.0决策树和时序HJ-1A/B CCD数据的神农架林区植被分类

我国神农架林区海拔高、气候复杂,森林类型多样,结构破碎,森林遥感分类难度较大。将2013年时间序列HJ-1A/B CCD遥感影像作为数据源,计算出植被指数(NDVI、DVI、RVI)和主成分第一分量(PC1),使用DEM数据生成地形因子(高程、坡度、坡向),构建植被分类时序因子集。运用C5.0决策树分类法将神农架林区植被细分为七类:针叶林;针阔混交林;落叶阔叶林;常绿和落叶阔叶混交林;常绿阔叶林;灌丛和草甸。结果表明:该方法的总体精度为72.7%,Kappa系数为0.67;在6~8月,针叶林、草甸和灌丛的植被指数明显低于常绿阔叶林、常绿和落叶阔叶混交林、落叶阔叶林和针阔混交林,对分类的贡献较大,称为植被分类的"窗口期"。PC1、NDVI和高程因子对神农架林地的区分度较高,而坡度、坡向和RVI因子对分类帮助不大。作为一种智能分类方法,C5.0决策树分类方法应用于30m分辨率的时间序列HJ-1A/B CCD数据,能够将地貌复杂的神农架林区植被分为七类,提高了类别精度,具有更高的应用价值。     

立地条件和林龄对四川马尾松林C、N、P化学计量特征的影响

为揭示立地类型和林龄对四川省马尾松林生态化学计量特征的影响,以丘陵、山地2个立地类型小区的4个立地类型组、6个立地类型亚组和15个立地类型中不同林龄马尾松人工林为研究对象,分析了各立地类型与林龄内马尾松针叶C、N、P含量及计量比.结果 表明:四川省马尾松针叶平均C、N和P含量分别为524.34±29.09、10.28±0.51和0.99±0.18 g/kg,C∶N、C∶P和N∶P分别为51.08±3.68、543.90±97.40和10.73±2.24,且其均受立地类型与林龄的显著影响(P＜0.05).同一林龄中,针叶C∶N、C∶P和N∶P在丘陵高于山地;C含量、C∶N和C∶P均在砂质黄壤、丘陵坡下部、山地600～1000海拔15°～35°的阳坡中较高.四川省马尾松人工林适宜的立地类型为丘陵砂质黄壤坡下部及山地砂质黄壤600～1000m海拔15°～35°的阳坡,其针叶C储存能力和N、P养分利用效率较高.同一立地类型内,与针叶N、P含量变化趋势相反,马尾松针叶C含量与计量比自幼龄林至近熟林期逐渐下降,可能受N限制,自近熟林至成熟林期逐渐升高,可能受P限制.     

Freshwater stress on small island developing states: population projections and aridity changes at 1.5 and 2 °C

Small island developing states (SIDS) face multiple threats from anthropogenic climate change, including potential changes in freshwater resource availability. Due to a mismatch in spatial scale between SIDS landforms and the horizontal resolution of global climate models (GCMs), SIDS are mostly unaccounted for in GCMs that are used to make future projections of global climate change and its regional impacts. Specific approaches are required to address this gap between broad-scale model projections and regional, policy-relevant outcomes. Here, we apply a recently developed methodology that circumvents the GCM limitation of coarse resolution in order to project future changes in aridity on small islands. These climate projections are combined with independent population projections associated with shared socioeconomic pathways (SSPs) to evaluate overall changes in freshwater stress in SIDS at warming levels of 1.5 and 2 °C above pre-industrial levels. While we find that future population growth will dominate changes in projected freshwater stress especially toward the end of the century, projected changes in aridity are found to compound freshwater stress for the vast majority of SIDS. For several SIDS, particularly across the Caribbean region, a substantial fraction (~?25%) of the large overall freshwater stress projected under 2 °C at 2030 can be avoided by limiting global warming to 1.5 °C. Our findings add to a growing body of literature on the difference in climate impacts between 1.5 and 2 °C and underscore the need for regionally specific analysis.     

Sediment integrative assessment of the Bay of Cádiz (Spain): An ecotoxicological and chemical approach

This study consisted of the sediment toxicity assessment of the Bay of Cádiz based on two endpoints: growth inhibition for Cylindrotheca closterium (benthic microalgae) and fecundity inhibition for Tisbe battagliai (harpacticoid copepod). A new methodology to eliminate (but not as storage technique) the autochthonous biota present in the sediment samples by immersing them in liquid nitrogen (? 196 °C) was also assessed. Sediment toxicity data showed different toxicity levels for both organisms. In general, T. battagliai was more sensitive; however a good correlation (r = 0.75; p  < 0.05) between sediment toxicity results for both species was found. Data in pore water (pH, redox potential, and toxicity for microalgae and copepod) and sediment (pH, redox potential, organic carbon, and metal concentrations) demonstrated that ultra-freezing did not alter sample characteristics; thus, this technique can be adopted as a pre-treatment in whole-sediment toxicity tests in order to avoid misleading results due to presence of autochthonous biota. Multivariate statistical analysis such as cluster and principal component analysis using chemical and ecotoxicological data were employed. Silt and organic matter percentage and lead concentration were found to be the factors that explain about 77% of sediment toxicity in the Bay of Cádiz. Assay methodology determined in this study for both assayed species is considered adequate to be used in sediment toxicity monitoring programs. Results obtained using both species show that the Bay of Cádiz can be considered a moderately polluted zone.     

Management of loss and damage in small island developing states: implications for a 1.5 °C or warmer world

Small island developing states (SIDS) have been identified as some of the most vulnerable countries to the impacts of climate change due to inherent environmental, economic, and demographic characteristics. As SIDS experience impacts of climate change and reach their limits to adaptation, the identification and management of loss and damage is essential. Monitoring and evaluating loss and damage, and implementing effective responses to address these impacts, becomes even more important in a 1.5 °C or warmer world, as impacts from climate change increase. As global agreements on climate change are implemented and mechanisms to manage impacts continue to be negotiated and established, the existing ability of SIDS to monitor and respond to loss and damage must be evaluated to determine gaps that must be addressed in a 1.5 °C or warmer world. This research utilizes interviews with UNFCCC climate change negotiators for SIDS and analysis of Intended Nationally Determined Contributions, to assess the state of loss and damage management in SIDS. The research provides an assessment of loss and damage already being experienced in SIDS, the status of existing mechanisms to actively monitor and evaluate loss and damage, and the existence of policies and mechanisms in SIDS to address loss and damage. Three areas of concern appear to be common for SIDS: lack of data relating to loss and damage, gaps in financial assessments of loss and damage, and a lack of policies or mechanisms targeted at loss and damage. These issues appear to be most acute in relation to slow onset impacts. Cumulatively, these challenges may present difficulties in detection and attribution and in obtaining a holistic understanding of the extent and costs of loss and damage for SIDS.     

Heading for the hills: climate-driven community relocations in the Solomon Islands and Alaska provide insight for a 1.5 °C future

Whilst future air temperature thresholds have become the centrepiece of international climate negotiations, even the most ambitious target of 1.5 °C will result in significant sea-level rise and associated impacts on human populations globally. Of additional concern in Arctic regions is declining sea ice and warming permafrost which can increasingly expose coastal areas to erosion particularly through exposure to wave action due to storm activity. Regional variability over the past two decades provides insight into the coastal and human responses to anticipated future rates of sea-level rise under 1.5 °C scenarios. Exceeding 1.5 °C will generate sea-level rise scenarios beyond that currently experienced and substantially increase the proportion of the global population impacted. Despite these dire challenges, there has been limited analysis of how, where and why communities will relocate inland in response. Here, we present case studies of local responses to coastal erosion driven by sea-level rise and warming in remote indigenous communities of the Solomon Islands and Alaska, USA, respectively. In both the Solomon Islands and the USA, there is no national government agency that has the organisational and technical capacity and resources to facilitate a community-wide relocation. In the Solomon Islands, communities have been able to draw on flexible land tenure regimes to rapidly adapt to coastal erosion through relocations. These relocations have led to ad hoc fragmentation of communities into smaller hamlets. Government-supported relocation initiatives in both countries have been less successful in the short term due to limitations of land tenure, lacking relocation governance framework, financial support and complex planning processes. These experiences from the Solomon Islands and USA demonstrate the urgent need to create a relocation governance framework that protects people’s human rights.     

Sustainable Exploitation of Borassus aethiopum, Elaeis guineensis and Raphia hookeri for the Extraction of Palm Wine in Côte d'Ivoire

In the rural areas of developing countries palms are major sources of many products. One of these is palm wine, which has an important role for nutrition, income and social life. In the Côte d'Ivoire (West Africa), palm wine is extracted from three different species: Borassus aethiopum Mart., Raphia hookeri Mann & Wendland and Elaeis guineensis Jacq. As the extraction methods are destructive, palm stands are locally threatened by extinction. This could have serious consequences not only for the nutritional situation of the population but also for their income. Field visits were conducted in order to assess the degree of sustainability of palm wine extraction in eight villages of Côte d'Ivoire's three major agro-ecozones. Based on the annual palm wine need for consumption and commercialisation and on the availability of palms, a sustainability index was calculated for each palm species in each village. The occurrence of palm trees depends on the vegetation type. B. aethiopum is a typical savanna tree (> 20 palms per hectare) and is almost absent in other vegetation types. In 75% of the villages the exploitation of B. aethiopum is not sustainable. The preferred vegetation type for R. hookeri is the forest along the rivers (> 33 palms per hectare) compared to the other vegetation types of the forest zone (< 5 palms per hectare). Due to the high preference for the palm wine of this species its exploitation is not sustainable in any of the selected villages. The distribution of E. guineensis depends mostly on human activities, the main vegetation types being plantations (34 palms per hectare), fallow land and cultivated fields (15 palms per hectare) and the forest along the rivers (31 palms per hectare). The exploitation of this species is in general sustainable throughout all ecozones with some rare exceptions.     

Can ECOPATH with ECOSIM enhance models of radionuclide flows in food webs? An example for 14C in a coastal food web in the Baltic Sea

In this study it was evaluated whether the ECOPATH with ECOSIM software could be used as a platform to facilitate the construction of models and study of transport and accumulation of radionuclides in aquatic food webs. The evaluation was based upon a food web model of carbon (C) and carbon-14 ((14)C) flow for a coastal area in the Baltic Sea, the ECOPATH, the ECOSIM and the ECOTRACE models. The original carbon flows and assumptions were easily incorporated into the ECOPATH and ECOSIM modelling environment. The new model was also well suited to drive a (14)C flow model (ECOTRACE) for each of the organisms included. ECOTRACE estimated steady-state concentrations of (14)C that were between 73 and 142% of the original flows. The results clearly show that there is great potential for a successful development of this approach for integrating scientific knowledge about food webs and radioecological models for aquatic systems.     

Practical tools for quantitative analysis of coastal vulnerability and sea level rise impacts—application in a Caribbean island and assessment of the 1.5 °C threshold

The quantitative analysis of hurricane impacts on coastal development in the Caribbean is surprisingly infrequent and many tools to assess physical vulnerability to sea level rise (SLR) are insufficient to evaluate risk in coastal areas exposed to wave attack during extreme events. This paper proposes a practical methodology to quantify coastal hazards and evaluate SLR impact scenarios in coastal areas, providing quantitative input for coastal vulnerability analysis. We illustrate the implementation of the proposed methodology with results from a site-specific analysis. We quantify how storm wave impacts penetrate farther inland and reach higher elevations for increasing SLR conditions. We also show that the increase in elevation of storm wave impacts is more than the nominal increase in mean sea level, and that elevation increase may be on the order of up to twice the nominal SLR. By developing design parameters for multiple scenarios, as opposed to the determination of a single SLR value for design established by consensus, this approach generates information that we argue encourages resilient design and embedding future adaptation in coastal design. We discuss how government planners and regulators, as well as real estate developers, lenders, and investors, can improve coastal planning and resilient design of coastal projects by using this approach.     

What are the implications of sea-level rise for a 1.5, 2 and 3 °C rise in global mean temperatures in the Ganges-Brahmaputra-Meghna and other vulnerable deltas?

Even if climate change mitigation is successful, sea levels will keep rising. With subsidence, relative sea-level rise represents a long-term threat to low-lying deltas. A large part of coastal Bangladesh was analysed using the Delta Dynamic Integrated Emulator Model to determine changes in flood depth, area and population affected given sea-level rise equivalent to global mean temperature rises of 1.5, 2.0 and 3.0 °C with respect to pre-industrial for three ensemble members of a modified A1B scenario. Annual climate variability today (with approximately 1.0 °C of warming) is potentially more important, in terms of coastal impacts, than an additional 0.5 °C warming. In coastal Bangladesh, the average depth of flooding in protected areas is projected to double to between 0.07 and 0.09 m when temperatures are projected at 3.0 °C compared with 1.5 °C. In unprotected areas, the depth of flooding is projected to increase by approximately 50% to 0.21–0.27 m, whilst the average area inundated increases 2.5 times (from 5 to 13% of the region) in the same temperature frame. The greatest area of land flooded is projected in the central and north-east regions. In contrast, lower flood depths, less land area flooded and fewer people are projected in the poldered west of the region. Over multi-centennial timescales, climate change mitigation and controlled sedimentation to maintain relative delta height are key to a delta’s survival. With slow rates of sea-level rise, adaptation remains possible, but further support is required. Monitoring of sea-level rise and subsidence in deltas is recommended, together with improved datasets of elevation.