Habitat traits and food availability determine the response of marine invertebrates to ocean acidification

Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long‐term study, we investigated the effects of food availability and elevated pCO₂ (ca. 400, 1000 and 3000 μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO₂ due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO₂ fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20 weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO₂, regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO₂ in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO₂, irrespective of parental treatment. In contrast, elevated pCO₂ had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO₂ over 5 weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO₂ negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO₂ in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried over from adults to their offspring. Our findings indicate that populations from fluctuating pCO₂ environments are more tolerant to elevated pCO₂ than populations from more stable pCO₂ habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO₂ stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus.     

Reconciling Carbon-cycle Concepts, Terminology, and Methods

Recent projections of climatic change have focused a great deal of scientific and public attention on patterns of carbon (C) cycling as well as its controls, particularly the factors that determine whether an ecosystem is a net source or sink of atmospheric carbon dioxide (CO₂). Net ecosystem production (NEP), a central concept in C-cycling research, has been used by scientists to represent two different concepts. We propose that NEP be restricted to just one of its two original definitions—the imbalance between gross primary production (GPP) and ecosystem respiration (ER). We further propose that a new term—net ecosystem carbon balance (NECB)—be applied to the net rate of C accumulation in (or loss from [negative sign]) ecosystems. Net ecosystem carbon balance differs from NEP when C fluxes other than C fixation and respiration occur, or when inorganic C enters or leaves in dissolved form. These fluxes include the leaching loss or lateral transfer of C from the ecosystem; the emission of volatile organic C, methane, and carbon monoxide; and the release of soot and CO₂ from fire. Carbon fluxes in addition to NEP are particularly important determinants of NECB over long time scales. However, even over short time scales, they are important in ecosystems such as streams, estuaries, wetlands, and cities. Recent technological advances have led to a diversity of approaches to the measurement of C fluxes at different temporal and spatial scales. These approaches frequently capture different components of NEP or NECB and can therefore be compared across scales only by carefully specifying the fluxes included in the measurements. By explicitly identifying the fluxes that comprise NECB and other components of the C cycle, such as net ecosystem exchange (NEE) and net biome production (NBP), we can provide a less ambiguous framework for understanding and communicating recent changes in the global C cycle.     

基于IBIS模型的1960-2006年中国陆地生态系统碳收支格局研究

定量评估区域陆地生态系统碳收支是生态系统与全球变化科学研究的重要科学问题之一。利用集成生物圈模型（IBIS）对中国陆地生态系统历史时期（1960-2006年）气候及CO₂浓度变化条件下碳收支时空变异特征和发展趋势进行了模拟分析。结果表明,1960-2006年间,中国陆地生态系统净初级生产力（NPP）总量水平约为2.46 GtC/a,总体呈上升趋势,在东南及西南地区最高,其次是长白山及大小兴安岭地区,西北内陆地区的净初级生产力水平最低;1960-2006年间,中国陆地生态系统净生态系统生产力（NEP）总量水平约为0.11 GtC/a,总体呈上升趋势,绝大部分区域表现为碳汇效应,大兴安岭、小兴安岭、长白山、东南地区及西南部分地区碳汇效应较强,西北内陆区表现出弱碳源效应,温带湿润区、高原温带区和高原寒带区碳汇效应呈显著上升趋势;中国11个气候区,NPP与降水均为正相关,除了中温带湿润区、寒温带湿润区、高原温带和高原寒带外,降水是限制植被生长的主要因子。除了高原寒带外,NEP同样表现出与降水的更强相关性,与气温的相关性较弱。经验证,IBIS模型对于中国陆地生态系统碳收支的模拟结果合理,可以为科学预测生态系统的固碳潜力和制定区域碳管理政策提供科学依据。     

小水电代燃料工程对森林生态服务功能的影响

根据国家林业局发布的《森林生态系统服务功能评估规范》(LY/T 1721—2008),从涵养水源、保育土壤、固碳释氧和积累营养物质功能4个方面进行评价,研究小水电代燃料工程的实施对贵州省麻江县项目区森林生态服务功能的物质量及其价值的影响.结果表明: 小水电代燃料工程对森林生态系统服务功能物质量的增加有显著作用.马尾松和柏木人工林在项目区内涵养水源功能的物质量达20662.04 m³·hm^-2·a^-1,比项目区外增加20.5%,保育土壤量为119.1 t·hm^-2·a^-1,比项目区外增加29.7%,固碳释氧量为220.49 t·hm^-2·a^-1,比项目区外增加40.2%,林木营养积累量达3.49 t·hm^-2·a^-1,比项目区外增加48.5%.小水电代燃料工程对项目区森林生态系统服务功能价值增加额度表现为:固碳释氧功能(7.14 万元·hm^-2·a^-1)>涵养水源功能(6.01万元·hm^-2·a^-1)>林木营养积累功能(1.38万元·hm^-2·a^-1)>保育土壤功能(0.81万元·hm^-2·a^-1).小水电代燃料工程对提高森林生态服务功能价值和实现林区的可持续发展具有重要作用.     

黑河流域中游地区净初级生产力的人类占用

基于Miami模型,对黑河流域中游净初级生产力的人类占用（HANPP）及其与生态系统多样性的关系进行了研究,并对HANPP与生态足迹（EF）指标在可持续发展评估方面的价值进行了比较.结果表明：HANPP的提高将降低生态系统多样性,研究区现状年的平均HANPP率为38.61%,肃州区和甘州区的HANPP已超过生态系统潜在生产能力的极限;结合气候变化和社会经济发展状况进行分析,未来40年黑河流域中游生态系统将面临更大压力.与生态足迹（EF）相比,HANPP更适于从生态系统功能变化角度评估区域发展的可持续性.     

Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland

In high‐latitude regions, carbon dioxide (CO₂) emissions during the winter represent an important component of the annual ecosystem carbon budget; however, the mechanisms that control the winter CO₂ emissions are currently not well understood. It has been suggested that substrate availability from soil labile carbon pools is a main driver of winter CO₂ emissions. In ecosystems that are dominated by annual herbaceous plants, much of the biomass produced during the summer is likely to contribute to the soil labile carbon pool through litter fall and root senescence in the autumn. Thus, the summer carbon uptake in the ecosystem may have a significant influence on the subsequent winter CO₂ emissions. To test this hypothesis, we conducted a plot‐scale shading experiment in a boreal peatland to reduce the gross primary production (GPP) during the growing season. At the growing season peak, vascular plant biomass in the shaded plots was half that in the control plots. During the subsequent winter, the mean CO₂ emission rates were 21% lower in the shaded plots than in the control plots. In addition, long‐term (2001–2012) eddy covariance data from the same site showed a strong correlation between the GPP (particularly the late summer and autumn GPP) and the subsequent winter net ecosystem CO₂ exchange (NEE). In contrast, abiotic factors during the winter could not explain the interannual variation in the cumulative winter NEE. Our study demonstrates the presence of a cross‐seasonal link between the growing season biotic processes and winter CO₂ emissions, which has important implications for predicting winter CO₂ emission dynamics in response to future climate change.     

Effects of biodiversity,stand factors and functional identity on biomass and productivity during the restoration of subtropical forests in Central China

恢复梯度上华中亚热带森林生物多样性、林分因子及功能特性对生物量、生产力的影响 草地群落上进行的控制实验大都发现生物多样性对生态系统功能有显著促进作用。然而,在天然林中,多样性与林分因子、群落功能特性的相对作用大小仍存在争议。本文在森林恢复梯度上,研究这3类因素对生物量和生产力的相对影响。我们在湖北神农架设置了处于不同恢复阶段的24块(600 m²)亚热 带森林样地,计算了林分生物量和生产力。选择5个关键的植物功能性状,并计算了群落的功能多样性(功能丰富度、功能均匀度和功能离散度)和性状的加权平均值(CWM)。使用一般线性模型(GLMs)、变异分离等方法探究林分因子(密度、林龄、群落最大树高等)、功能特性、物种和功能多样性对生物量和生产力的相对重要性。研究结果表明,随着森林恢复,林分生物量和生产力显著增加,群落物种丰富度显著增加,而功能离散度显著降低。变异分离结果表明,多样性对生物量和生产力的单独效应不显著,但可能通过与林分因子和功能特性的协同效应来影响生物量和生产力。总体而言,我们发现林分因子对亚热带森林生物量和生产力的影响最大,功能特性显著影响生产力,但不影响生物量。这些结果说明,在森林经营中,调整林分结构和群落物种特性是提高森林碳储量和固碳潜力的有效途径。     

Entomophagous insects – an introduction

This special issue contains papers presented at the 6th International Entomophagous Insects Conference. Entomophagous insects consume other insects. They are a fundamental component of ecosystems and are extensively used as biocontrol agents. The first article reviews the role of ladybirds in biological control and the second reviews the biological control of stink bugs. The following nine research articles cover the rearing, behavior, life history, and ecology of parasitoid and predator species.     

中国生态退化的主要类型、特征及分布

生态退化是目前全球所面临的主要环境问题,它不仅使自然资源日益枯竭,生物多样性不断减少,而且还严重阻碍社会经济的持续发展,进而威胁人类的生存和发展,因此,生态退化已引起各国政府和学者的重视。本文对中国生态退化的主要类型即：森林生态系统的退化、土地沙漠化和水土流失等重大问题进行分析,详细阐述了各个类型的现状、特征及分布。为我国自然资源的合理利用以及退化生态系统的恢复和重建提供基础资料。     

西安城市生态系统生命力评价

以西安市为案例地, 借助包含生产力、生活势、生态势和生机度的城市生命力指数框架, 运用灰色关联分析模型, 从时间序列上进行城市生态系统生命力评价, 以期从生命力视角对西安市的生态文明建设和可持续发展提供参考。评价结果显示, 基于目标层, 2007—2016年西安城市生命力与参考序列的关联度排序为: R2007年相似文献