外来植物对陆地生态系统氮循环的影响途径

外来植物的引种和入侵已成为一个全球性的重要问题.许多外来植物不仅可以改变陆地生态系统的氮输入、输出,而且还可以通过改变氮素吸收、再利用,凋落物质量,土壤环境,土壤生物等因子影响陆地生态系统内都氮循环.在概述陆地生态系统氮循环基础上,系统综述了外来植物对陆地生态系统氮循环的影响方式和途径以及可能造成的生态后果,并对将来研究方向进行了展望:应更多考虑外来植物影响机制的复杂性、不同养分元素循环的相互作用和新技术手段的应用.     

Biogeochemical cycle of Sulfer in the Calamagrostis angustifolia wetland ecosystem in the Sanjiang Plain, China

To better understand the Sulfur (S) cycle in the wetland ecosystem, the S cycle and its compartmental distribution within an atmosphere-plant-soil system were studied using a compartment model in the Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China. The results showed that the soil was the main S storage and flux hinge in which 97.78% S was accumulated. In the plant subsystem, the root was the main S storage, and it remained at 79.60% of the total S contents, which in the Calamagrostis angustifolia wetland ecosystem showed that the parts above the ground took up 0.75 g S/m², the S re-transferring biomass to the root was 0.24 g S/m², and to the litter was 0.51 g S/m²; the root took up 3.76 g S/m² and the S transferring biomass to the soil took up 3.07 g S/m²; the litter S biomass was 0.75 g S/(m²·a) and the S transferring biomass to the soil was more than 0.52 g S/(m²·a). The emission amount of H2S from the Calamagrostis angustifolia wetland ecosystem to the atmosphere was 1.42 mg S/m², whereas carbonyl sulfide (COS) was absorbed by the Calamagrostis angustifolia wetland from the atmosphere and the absorption amount was 1.83 mg S/m². The S input biomass from the rain to the ecosystem was 4.85mg S/m² during the growing season. The difference between input and output amounts was 5.26 mg S/m², which indicated that S was accumulated in the ecosystem and would lead to wetland acidification in the future.     

三江平原小叶章湿地生态系统硫的生物地球化学循环

以三江平原小叶章湿地生态系统为研究对象,应用分室模型研究了硫在大气-土壤-植物系统各分室中的分布及循环过程。结果表明,在植物-土壤系统内,土壤是主要的贮存库和流通介质,有97.78%的硫贮存在土壤中,且主要以有机硫的形态存在,2.22%的硫贮存在植物中。在植物亚系统中,根是主要的贮库,79.60%的硫贮存在根中。湿地植物地上部分吸收的总S量为0.75gS/m^2;向地下再转移的总S量为0.24gS/m^2,向枯落物S库转移的总S量为0.51gS/m^2;根吸收的总S量为3.76gS/m^2;根向土壤S库转移的总S量为3.07gS/m^2;现存枯落物中的总S量为0.75gS/m^2;枯落物向土壤S库的转移量最低为0.52gS/m^2·a。输入和输出过程的研究表明,小叶章湿地生态系统在生长季（5-9月份）向大气排放H2S的量为1.42mgS/m^2,从大气吸收COS的量为1.83mgS/m^2;通过大气降水输入到生态系统中的硫为4.85mgS/m^2,其差值为5.26mgS/m^2,这表明硫在小叶章湿地生态系统中处于累积状态,湿地存在潜在的酸化趋势。     

Biogeochemical cycle of Sulfer in the Calamagrostis angustifolia wetland ecosystem in the Sanjiang Plain, China

To better understand the Sulfur (S) cycle in the wetland ecosystem, the S cycle and its compartmental distribution within an atmosphere-plant-soil system were studied using a compartment model in the Calamagrostis angustifolia wetland in the Sanjiang Plain, Northeast China. The results showed that the soil was the main S storage and flux hinge in which 97.78% S was accumulated. In the plant subsystem, the root was the main S storage, and it remained at 79.60% of the total S contents, which in the Calamagrostis angustifolia wetland ecosystem showed that the parts above the ground took up 0.75 g S/m², the S re-transferring biomass to the root was 0.24 g S/m², and to the litter was 0.51 g S/m²; the root took up 3.76 g S/m² and the S transferring biomass to the soil took up 3.07 g S/m²; the litter S biomass was 0.75 g S/(m²·a) and the S transferring biomass to the soil was more than 0.52 g S/(m²·a). The emission amount of H2S from the Calamagrostis angustifolia wetland ecosystem to the atmosphere was 1.42 mg S/m², whereas carbonyl sulfide (COS) was absorbed by the Calamagrostis angustifolia wetland from the atmosphere and the absorption amount was 1.83 mg S/m². The S input biomass from the rain to the ecosystem was 4.85mg S/m² during the growing season. The difference between input and output amounts was 5.26 mg S/m², which indicated that S was accumulated in the ecosystem and would lead to wetland acidification in the future.     

东亚地区碳循环研究新进展

近百年来,温室效应的日益加剧,引发了全球温暖化、海平面上升等一系列重大环境问题,碳循环研究因此而受到全球范围的普遍关注和重视.东亚地区因其独特的气候特征,多样化的物种和生态系统,以及活跃的人类活动而成为世界碳循环研究中不可或缺的一部分.在中、日、韩三国联合启动东亚碳循环前沿研究计划(A3 Foresight Program)三周年之际,《中国科学生命科学》(Science China Life Sciences)2010年第7期发表了东亚地区碳循环研究专题,包括14篇述评和研究论文,从区域碳储量及其变化特征,不同地带森林生态系统的碳源汇变化,草地和农田生态系统的碳储量和碳循环研究中的新方法等多个方面系统展示了东亚地区碳循环研究的最新进展.     

Ancient DNA reveals the maternal genetic history of East Asian domestic pigs

Zoo-archaeological and genetic evidence suggest that pigs were domesticated independently in Central China and Eastern Anatolia along with the development of agricultural communities and civilizations. However, the genetic history of domestic pigs, especially in China, has not been fully explored. In this study, we generate 42 complete mitochondrial DNA sequences from ～7500- to 2750-year-old individuals from the Yellow River basin. Our results show that the maternal genetic continuity of East Asian domestic pigs dates back to at least the Early to Middle Neolithic. In contrast, the Near Eastern ancestry in European domestic pigs saw a near-complete genomic replacement by the European wild boar. The majority of East Asian domestic pigs share close haplotypes, and the most recent common ancestor of most branches dates back to less than 20,000 years before present, inferred using new substitution rates of whole mitogenomes or combined protein-coding regions. Two major population expansion events of East Asian domestic pigs coincided with changes in climate, widespread adoption of introduced crops, and the development of agrarian societies. These findings add to our understanding of the maternal genetic composition and help to complete the picture of domestic pig evolutionary history in East Asia.     

Nitrogen budgets for the Republic of Korea and the Yellow Sea region

Growing populations in northeast Asia have greatly altered the nitrogencycle, with increases in agricultural production to feed the population, andwith increases in N emissions and transboundary air pollution. For example,during the 1900's over 50% of the N deposition over Republic of Korea wasimported from abroad. In this paper, we present biogeochemical budgets ofN for the South Korean peninsula (the Republic of Korea) and for the YellowSea region. We quantify N inputs from atmospheric deposition, fertilizers,biological fixation, and imports of food, feed, and products. We quantifyoutputs in riverine export, crop uptake, denitrification, volatilization,runoff, sedimentation and sea water exchange. Calculations were conductedusing mean values from 1994–1997. All of the nitrogen budgets werepositive, with N inputs exceeding outputs. The excess N inputs gave rise toincreases in N storage in landfills and in groundwater. Annual accumulationof N in the Yellow sea, including inputs from South Korea and otherdrainage areas, was 1229 kt yr^–1 with a residence time for N ofapproximately 1.5 years, thus doubling N content in marine waters every 3years during 1994–1997. The human derived N inputs leads to excessiveeutrophication and pollution of the Yellow Sea.     

辽宁省生态系统敏感性评价

根据辽宁主要生态环境问题的形成机制,分析了生态系统敏感性的区域分异规律,并对多种生态环境问题的敏感性进行了综合分析。结果表明,全省处于轻度至高度敏感区域,高度敏感区、中度敏感区、轻度敏感区分别占全省陆域面积的34.00%、62.66%和3.34%。高度敏感区分布在辽东山地丘陵、辽东半岛、辽西低山丘陵、辽西北、柳绕地区和大洼县。辽东山地丘陵、辽东半岛和辽西低山丘陵主要是土壤侵蚀高度敏感。辽西北和柳绕地区主要是土地沙漠化高度敏感。大洼县是土壤盐渍化高度敏感。     

基于生态系统敏感性与生态功能重要性的高原湖泊分区保护研究——以达里湖流域为例

内蒙古高原湖泊流域是我国北方地区重要的涵养水源区域,发挥着防汛抗旱、气候调节、生物多样性维持等多种生态系统功能。近几十年来,全球气候变化加之人类活动加剧,导致内蒙古高原湖泊的数量和面积大幅减少,流域生态系统的损害日益明显,严重威胁到了周边地区的生态安全,保护与治理内蒙古高原湖泊流域已逐渐成为社会各界关注及迫切需要解决的问题。面向内蒙古高原湖泊流域保护和管理需求,以改善和提升流域生态环境质量和生态系统功能为目的,以内蒙古高原湖泊达里湖流域为研究对象,基于流域生态特性和主要生态环境问题,选取水土流失、土壤侵蚀及土地沙化敏感性3个指标评价了流域生态系统敏感性,从水源涵养、土壤保持和生境质量重要性3个方面评价了流域生态系统功能重要性,并在此基础上,通过GIS空间分析技术将流域分为极重要敏感区,一般重要敏感区和低重要敏感区。结合流域内达里诺尔国家级自然保护区的生态重要性与3个区域评价结果,从生态保护角度将流域分为禁止开发区、重点保护区、质量提升区与潜在威胁区4个区域,同时提出针对每个区域特点的保护与管理对策。研究结果对提高高原地区湖泊流域生态环境质量以及对流域实施科学有效的管理提供了科学依据,同时在促进区域乃至全球生态建设和可持续发展方面具有重要的理论与现实意义。     

Law of the Sea Issues Between the United States and East Asian States

The United States is the sole superpower in the contemporary world and its role in the development of the law of the sea cannot be ignored. Although having not yet acceded to the U.N. Convention on the Law of the Sea, the United States has contributed to the development of the international law of the sea in numerous ways, including responding to the so-called excessive maritime claims in East Asia and creating new rules of maritime enforcement. This article assesses this recent U.S. practice.     

Spatial genetic structure and historical demography of East Asian wild boar

Pleistocene climatic fluctuations may have had a profound impact on the evolutionary history of many species. The geographical pattern of European wild boar (Sus scrofa) is clearly studied, and it was greatly influenced by ancient climatic events, especially the Last Glacial Maximum. Previous research on genetic variation has mainly focused on the origin and distribution histories of domestic pigs. However, some questions have not been answered, including those concerning the genetic diversity, geographical pattern and possible historic influence of climate on East Asian wild boar (EAWB). Employing the control region of mtDNA (511 bp), we investigated the contributions of historic climate, which possibly shaped the genetic pattern of wild boar. Given that the level of genetic diversity of wild boars is higher in East Asia than in Europe, 172 haplotypes were detected from 680 individuals. Phylogenetic analysis demonstrated the complex phylogeographic structure of EAWB. Mismatch analysis, neutrality tests and the Bayesian Skyline Plot results all retrieved signals of a rapid population expansion, which might have played an important role in driving the formation of complex spatial genetic structure. Genetic data and species distribution modelling showed that the Last Glacial Maximum had weak effect on the distribution of the EAWB. We suggest that, in shaping spatial genetic structure in East Asian, long-term gene flow and population history played more important roles than Pleistocene climate fluctuations.     

古蛋白质分析在东亚古人类演化中的应用前景

东亚古人类演化是学术界关注的热点科学问题,国内外学者对此进行了多学科的相关研究,取得了很多重要进展,但仍然存在许多尚未解决的问题。古蛋白质分析近年来成为古生物演化领域的又一个前沿和热点方向,取得了一系列重要突破。较之古DNA,古蛋白质的保存优势使其可以在时间上和地域上突破古DNA的限制,在古人类演化领域大有可为。东亚古人类化石丰富且时段大致连续,但更新世或更早时期的分子证据非常缺乏。本文从古蛋白质分析的发展史、研究潜力、难点与挑战以及思考与展望等几方面,对古蛋白质分析在东亚古人类演化研究中的应用前景进行梳理与思考。相信随着更多分子证据的积累,古蛋白质分析可为东亚古人类的演化脉络提供更多关键性的线索,极大地促进人类演化研究。     

The response of soil solution chemistry in European forests to decreasing acid deposition

Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion and agriculture has contributed to the acidification of terrestrial ecosystems in many regions globally. However, in Europe and North America, S deposition has greatly decreased in recent decades due to emissions controls. In this study, we assessed the response of soil solution chemistry in mineral horizons of European forests to these changes. Trends in pH, acid neutralizing capacity (ANC), major ions, total aluminium (Al_tot) and dissolved organic carbon were determined for the period 1995–2012. Plots with at least 10 years of observations from the ICP Forests monitoring network were used. Trends were assessed for the upper mineral soil (10–20 cm, 104 plots) and subsoil (40–80 cm, 162 plots). There was a large decrease in the concentration of sulphate () in soil solution; over a 10‐year period (2000–2010), decreased by 52% at 10–20 cm and 40% at 40–80 cm. Nitrate was unchanged at 10–20 cm but decreased at 40–80 cm. The decrease in acid anions was accompanied by a large and significant decrease in the concentration of the nutrient base cations: calcium, magnesium and potassium (Bc = Ca²⁺ + Mg²⁺ + K⁺) and Al_tot over the entire dataset. The response of soil solution acidity was nonuniform. At 10–20 cm, ANC increased in acid‐sensitive soils (base saturation ≤10%) indicating a recovery, but ANC decreased in soils with base saturation >10%. At 40–80 cm, ANC remained unchanged in acid‐sensitive soils (base saturation ≤20%,  ≤ 4.5) and decreased in better‐buffered soils (base saturation >20%,  > 4.5). In addition, the molar ratio of Bc to Al_tot either did not change or decreased. The results suggest a long‐time lag between emission abatement and changes in soil solution acidity and underline the importance of long‐term monitoring in evaluating ecosystem response to decreases in deposition.     

The bryophyte flora of northern Iturup (north-west Pacific): between the circumboreal and East Asian floristic regions

Introduction. The Kuril Islands Chain demarcates the boundary between the circumpolar and East Asian floras in the amphi-Pacific and is a trans-Oceanic migration route from warm-temperate insular East Asia to north-east Asia and Beringia. This paper reviews the flora of the northern part of Iturup Island in regards to its bryogeography and taxonomic diversity, as well as its relative position among other bryophyte floras of north-east and East Asia.

Methods. The paper uses morphological methods to identify the species composition and detrended correspondence analysis to identify the position of the northern Iturup Island in the system of local floras of the eastern, extra-tropical, Pacific.

Key results. The flora is closely related to the bryophyte floras of the southern Kurils and Hokkaido Island, but has been found to be distinctly distant from the ‘true’ cool-temperate East Asian floras, as well as from the boreal and hemiarctic floras of north-east Asia. Instead, the floras of the south Kurils and northern Hokkaido Island belong to a peculiar intermediate phytogeographic province that cannot be unambiguously placed in either the East Asian or circumboreal floristic regions. The hemiboreal character of the bryophyte flora of northern Iturup Island is in contrast to the general appearance of many of the dominant vegetation communities on the island, which are more characteristic of the hemiarctic.

Conclusion. There is no robust evidence to refer the bryophyte flora of northern Iturup either to the circumboreal or East Asian Floristic Region, the flora belongs to a unique intermediate province between the two regions.     

酸沉降影响下庐山森林生态系统水相硫的分布与动态研究

从1997年7月到1999年8月,在庐山植物园选取针叶林和阔叶林各一片样地,对降雨、透冠水、干流水、渗漏水和地表径流进行了监测.结果表明庐山降雨SO2-4浓度有升高趋势,1998年降雨中SO2-4浓度为4.21±3.48mg/L.林冠对干沉降硫有吸收和截获作用,透冠水和干流水中SO2-4明显高于雨水,针叶林中分别为13.68±17.40mg/L和15.50±25.20mg/L,阔叶林分别为6.18±6.37mg/L和7.35±7.73mg/L,是森林中硫沉降的重要组成部分.针叶林地下水中SO2-4含量与雨水的显著正相关(R2=0.758,n=6),与透冠水和树干流中SO2-4含量之和极显著正相关(R2=0.880,n=8),说明日本柳杉针叶林加重了硫沉降,对土壤中SO2-4有较大影响;阔叶林的相关性都不显著,说明阔叶林虽然对SO2-4在土壤中的输入有所贡献,但相对作用较小.针叶林SO2-4输入高而输出低;阔叶林输入低而输出高,可能处于稳态平衡.针叶林地表径流中SO2-4含量受雨水影响较大,阔叶林中的则可能主要是土壤溶液中保存的SO2-4持续淋洗的结果.     

Determinants of pollen dispersal in the East Asian steppe at different spatial scales

Two sites from the East Asian steppe, the Mu Us Sandland as a regional case and the Anguli Nuur catchment as a local one, were chosen to detect roles of vegetation, climate, landform, and human disturbance on pollen dispersal. 1) Vegetation: The semi-arid steppe vegetation is characterized by Artemisia and Chenopodiaceae pollen under various vegetation conditions; however, no evident correlation between pollen percentages and corresponding plant species cover is found. 2) Climate: Samples under different Mean Annual Precipitations (MAPs) clearly distinguish themselves in the Mu Us Sandland, implying MAP-determined surface pollen spectra in regional scale. 3) Landform: Surface pollen assemblages in the azonal psammophytic vegetation and lowland meadow, show insignificant variance from the zonal steppe vegetation. The azonal halophilous vegetation, mostly distributed in the lowland or near the lake shore, leads to higher than average percentages of Chenopodiaceae pollen. Signal of exotic Pinus pollen is also strengthened in the lowland and lake sediment. 4) Human disturbance: The role of human disturbance on surface pollen assemblages is weak, as shown in the Mu Us Sandland.

This study also provides theoretical bases for quantitative reconstructions of palaeoclimate and palaeovegetation based on fossil pollen spectra from lake sediments and lowland soils in the semi-arid East Asian steppe. We suggest that calibration against locally dispersed pollen taxa is necessary to reliably reconstruct changes in vegetation pattern through time, for example, a factor of 1.75 for the widely used A/C (Artemisia/Chenopodiaceae) ratio is suggested according to the pollen assemblages in the surface layers of the lake sediment vs. slope soil in Anguli Nuur. However, uncertainties also exist for such calibration considering the dynamics of local-scale azonal vegetation.     

恢复东湖水生生态系统途径初探

借鉴国内外其他湖泊的治理经验 ,讨论了如何恢复东湖水生生态系统的一些途径 ,其中探讨了①物理方法 :截污 ,清淤与引水冲污 ;②化学方法 :化学除磷与抑藻或杀藻 ;③生物方法 :用生物量输出氮磷与用生物方法对小型浮游藻类进行控制。     

基于生态系统服务功能和生态敏感性的生态空间划定研究——以南宁市为例

生态空间管制是我国国土空间管制的重要内容。针对目前国内对生态空间认知有差异,对其划定技术方法还处于探索阶段的情况下,以生态系统服务功能和生态敏感性技术评价方法为手段,以广西壮族自治区南宁市为研究对象,开展了基于生态系统服务功能重要性和生态敏感性的生态空间划定方法的探索研究。结果表明:(1)研究区域内主导的生态系统服务功能主要为生物多样性维护功能和水土保持功能,其次为水源涵养功能。生态系统综合服务功能重要性类型以一般重要为主,约占研究区总面积的42.32%。(2)研究区生态敏感性以水土流失敏感性为主,其次为石漠化敏感类型。生态环境综合敏感类型以敏感为主,约占总面积的85.44%。(3)研究区内初步划定生态空间总面积约9325.27 km~2,占研究区总面积的42.19%,占研究区内生态用地面积的76.59%。土地利用类型以林地为主,约占生态空间面积的83.65%。划定的生态空间范围涵盖了绝大部分生态用地。本研究在一定程度上丰富了生态空间的内涵,可为进一步理解和划定生态空间提供参考与借鉴。