大都市区生态源地识别体系构建及国土空间生态修复关键区诊断

构建生态安全格局是保障城市生态安全的必要手段，科学识别生态源地是构建生态安全格局的基础。以高度城市化的大都市区--上海市为研究对象构建生态源地识别体系，探究不同土地利用数据源与指标权重对生态源地识别的影响。在此基础上，基于最小累积阻力模型(MCR)与电路理论构建生态阻力面，识别生态保护与修复优先区域，对已有研究仅关注保护/修复的情况进行补充。结果表明：(1)自然生态本底仍是识别生态源地的重要指标，加入人类需求指标可填补已有研究对高度城市化源地识别针对性和丰富性的不足。生态系统服务格局、生态环境安全格局与环境友好格局权重为5 ∶ 2 ∶ 1时，源地识别效果最佳。(2)上海市生态源地空间和数量分布极不均匀，破碎化是首要问题。上海市现有(2017年)生态源地202个，共920.96 km²，占总面积14.53%，其中微型源地(面积<3 km²)数量高达82.67%。城市化水平影响生态源地分布，外环是源地数量与总面积的分水岭，郊环是源地平均面积的重要界线。(3)上海市以"面(源地)-线(廊道)-点(优先点)"组成生态保护网络，其中生态廊道442条，生态保护优先点306个，重要点线分布集中于中心城区边界。上海市生态修复优先区域325.47 km²，其中障碍点309.78 km²，需优化的非生态斑块95个(15.69 km²)，大都市区的生态修复重点区域应聚焦于城市化扩散的阻力区域，且应多关注生态价值适中的草地与耕地。研究工作可为其他高度城市化区域，以及处于高速城市化发展进程城市的国土空间生态修复关键区识别提供借鉴与参考。     

基于生态安全格局的山水林田湖草生态保护修复优先区识别——以四川省华蓥山区为例

优先区识别,是科学有序推进山水林田湖草生态保护修复工作的重要基础。以山水林田湖草生态保护修复工程之一的四川华蓥山区为例,基于生态系统服务重要性提取生态源地共1392.63 km²,占华蓥山区总面积的35.60%;结合土地覆被类型与地质灾害敏感性构建生态阻力面,并利用最小累积阻力模型与电路模型提取生态廊道共84条,夹点区域0.1 km²,含夹点廊道10条;生态保护优先区主要分布在景观破碎化较为严重的广安区境内,以及华蓥山西南端的夹点廊道。以生态修复模拟方法识别障碍点,确定生态修复优先区93.86 km²,大致分两片。其中,广安区境内受到人类活动干扰的破碎化生态空间,主要生态修复策略为植被恢复与退耕还林;华蓥山、铜锣山、明月山等滑坡、泥石流地质灾害频发区,主要生态修复策略是矿山地质修复与植被恢复。本研究提出生态安全格局构建与生态修复模拟的思路,为山水林田湖草生态保护修复工作提供了可行的定量方法。     

基于供需视角的黄河流域甘肃段生态安全格局识别与优化

利用多源空间数据，计算生态系统服务的高值区，识别生态源地，在计算土地利用程度、地均GDP和人口密度确定生态系统高需求区的基础上，通过夜间灯光数据修正生态阻力面系数，利用最小累积阻力模型提取源地与高需求区之间的生态廊道，以此构建并优化区域生态安全格局。结果表明：(1)黄河流域甘肃段生态源地总面积4.59×10⁴ km²，占研究区总面积的32.1%，集中分布于甘南和陇东中部地区。(2)生态系统服务高需求区总面积2.18×10⁴ km²，占研究区总面积的15.2%，主要集中于陇中及陇东的城市建成区，生态系统服务供应和需求空间匹配度差。(3)生态廊道总长度2908.3 km，整体格局上形成了东西向与南北向两大主要廊道轴线。生态廊道的识别中重点考虑了生态需求空间，提出了基于"两带-三区"的流域生态安全格局优化建议。     

基于水-陆耦合生态系统服务的生态安全格局构建研究——以长三角生态绿色一体化发展示范区为例

快速城市化和国土空间规划大背景下，评估区域生态系统服务、构建生态安全格局是实现城市精细化发展的有效手段。本研究立足生态系统服务供给效能，以长三角生态绿色一体化发展示范区为例，从陆域、水域两个层面进行量化计算，构建水-陆耦合生态系统服务综合评价体系，将高供给区域识别为生态源地，并基于MCR模型和电路理论分别提取廊道和节点，构建区域生态安全格局。研究结果表明：1）分别识别陆域和水域生境斑块面积34.31km²、272.50km²，为江南水乡空间存续和城市绿地空间选址提供了理论依据；2）水-陆耦合度评价得到源地41个，总面积206.79km²，占研究区总面积8.57%，呈现"西北多东南少"的格局；3）提取89条生态廊道和91个生态节点，生态廊道总长度586.35km，呈均匀网状分布，节点包括44个夹点及47个障碍点，主要位于吴江区。通过区域生态安全格局的构建与优先级评价，分级提出国土空间生态保护与修复建议，为我国其他快速城市化地区及都市圈周边区域的国土空间合理布局、土地利用的转化与管理提供参考。     

基于生态安全格局的山水林田湖草生态保护与修复

山水林田湖草生命共同体理论认为：生态要素之间存在普遍联系。在生态安全格局构建中,也应着重维护生态过程的完整性与连通性。以宁波市下辖6个城区为研究区,基于山水林田湖草生命共同体理论构建生态安全格局,以景观连通性评价与栖息地质量评价为基础提取生态源地,确定生态保育区。选取地形、地类因子分别作不同距离的缓冲区分析,对由土地利用类型设定的基础阻力面进行修正,形成综合阻力面。通过最小累积阻力模型识别生态廊道,与生态保育区结合,构建宁波市点-线-面的生态安全格局。研究结果表明：生态源地面积47.24 km²,占研究区总面积的1.30%,生态源地分布较为分散,在东西方向上分布不均衡,生态保育区总面积1191.67 km²,占研究区总面积的32.83%。生态保育区与山地丘陵重合度较高,且植被覆盖度高,生态资源丰富,生态廊道总长度519.32 km。研究区生态廊道呈网状分布,有效的促进物质能量的流动。在阻力面设定中引入邻域分析方法,突出了不同生态要素之间的联系,体现了山水林田湖草生命共同体思想,为该地区生态保护修复提供参考。     

基于主导生态功能的抚河流域国土空间生态安全格局分析

从主导生态功能的角度分析探讨生态安全格局，是明晰流域内生态安全、保护生物多样性的重要途径。以抚河流域为研究对象，采用多源空间数据，根据研究区自然条件和生态状况，基于主导生态功能定量评估水源涵养、水土保持、生物多样性3个生态系统服务功能，结合粒度反推法和热点分析选取生态源地，综合自然条件和人类活动影响因素构建阻力面，运用电路理论构建生态廊道，识别生态修复关键区域，提出生态安全格局优化对策。研究结果表明：（1）抚河流域内有25块生态源地，主要为林草地，共5574.63km²，60条生态廊道，共1126.91km；（2）基于生态安全格局识别生态修复关键区域，包括生态夹点26处、总长度为182.99km，生态障碍点19处、总面积为167.09km²，生态断裂点146处，破碎生态空间3283.79km²；（3）结合生态安全格局和生态修复关键区域，构建"三轴六区"生态安全空间布局优化体系。研究对维护抚河流域的生态安全、实行国土空间生态系统修复具有指导意义。     

基于生态系统服务供需的雄安新区生态网络构建与优化

城市生态网络构建是城市生态系统服务有效发挥作用的保障,构建完善的生态网络对于城市生态格局的优化具有重要的意义。结合雄安新区总体规划,通过雄安新区生态系统服务供给、需求两个层面识别生态源地。基于源地-缓冲区-廊道-节点框架,构建新区生态网络。其中,基于生态源地与城镇用地驱动因子,运用最小累积阻力方法得到累积阻力差,构建新区三生空间布局。根据成本距离分析和路径分析,结合雄安新区规划绿带分布,生成生态廊道,并在廊道与廊道交汇点、重要生态功能与脆弱的关键点以及道路轨道交汇点识别生态节点。得出：（1）新区生态源地主要位于白洋淀、公园绿地与其他绿地,分为水域生态源和林地生态源两类生态源地,面积总共728 km²。城镇源地主要位于新区东部容城县与雄县城区以及一些零星的农村居民点区域,面积为166 km²。（2）在新区三生空间布局下,加强生态廊道的构建,提升生态源地之间、生态源地与城镇源地之间的连通性,新区生态廊道主要依赖河流廊道和林地廊道两种类型。（3）在新区未来生态网络的建设中,需要重点关注河流廊道交汇点、河流廊道与城区的交汇处、交通道路与生态用地交汇处等的生态节点的建设及其生态功能的提升。     

基于生态安全格局的国土空间生态修复关键区域识别——以贺州市为例

国土空间生态修复是落实生态文明建设战略的重要举措。科学识别国土空间生态修复关键区域，合理布局全域生态修复空间是当前国土空间规划面临的难点之一。以广西壮族自治区贺州市为例，从生态保护重要性、景观连通性、生态功能重要区域和自然保护区四个方面识别生态源地，运用电路理论提取生态廊道，构建生态安全格局。通过电流密度诊断生态廊道中的生态"夹点"和生态障碍点，判定生态廊道宽度，识别国土空间生态保护修复关键区域，制定生态修复的空间布局策略。研究结果表明：（1）市域生态源地面积3656.89 km²，呈"东西重，中部轻"的空间分布特征；生态廊道总长度639.50 km，以中部分布为主，关键生态廊道133.96 km。（2）市域生态"夹点"共16处，面积124.24 km²，主要分布在钟山县，亟待保护修复的生态"夹点"8处，面积45.02 km²，零散分布于市域；生态障碍点共32处，面积426.56 km²，主要分布在市域东部和南部，需优先保护修复的生态障碍点6处，面积166.05 km²，集中在平桂区。通过综合分析国土生态修复关键区域土地利用现状和空间分布特征，制定了分级分类的生态修复措施，以期进一步优化生态安全格局，为国土空间生态修复区域识别和国土空间生态修复规划编制提供参考。     

基于景观生态风险评价的涪江流域景观格局优化

以流域为尺度进行景观生态风险评价以及景观格局优化，有利于为流域生态系统服务的提高和人类活动管控提供科学依据。以涪江流域为研究区域，从"自然-社会-景观格局"3个维度选取10个评价因子建立评价指标体系，采取空间主成分分析法（SPCA）对流域景观生态风险进行综合评价，再基于生态风险评价的结果和生态源地利用最小累积阻力模型（MCR）和网络分析等方法实现流域景观格局优化。研究结果表明：①涪江流域景观生态风险等级在空间分布上呈西北部高于东南部地区，主要是受自然和景观格局因子影响较大。②涪江流域所面临的生态风险问题较为严重，生态风险等级为中度及以上的区域面积总和为25596.51 km²，占研究区总面积比例的65.35%。③生态源地以林地和水域为主，面积为11194.28 km²，占流域总面积比例为25.58%。④构建生态廊道共41条，总长度为5229.04 km，其中原有廊道29条，新添廊道12条，提取生态节点53个；利用网络分析形成了以主廊道为"中轴"，构建的生态廊道为"辅助"，提取的生态节点为"枢纽"的较为完整的网络生态结构。对研究区景观格局优化前后的连通度进行对比，优化后的整体景观格局连通度得到较大幅度提升。     

基于形态空间格局分析和最小累积阻力模型的广州市生态网络构建

构建生态网络对改善快速城市化背景下城市生态环境问题具有重要作用.本研究以广州市为研究区,采用形态学空间分析方法(MSPA)和景观指数法,提取景观连通性较好的核心区作为生态源地,并基于最小累积阻力模型(MCR)构建广州市生态廊道网络,通过重力模型和连通性指数定量分析生态网络结构,最后提出生态网络的优化对策.结果表明: 广州市共有10块核心区可作为生态源地,重要廊道有18条,一般廊道有27条,主要分布在研究区东北部;优化后的生态网络增加了5个生态源地和13条规划廊道,其结构指数有所改善;林地是生态廊道的主要组成景观,重要廊道的适宜宽度为60～100 m,规划廊道的适宜宽度为30～60 m.研究结果可为城市生态廊道规划提供科学参考.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.