An assessment of the aquatic and wetland vegetation of the Upper Mississippi River

Illinois, Iowa, Minnesota, Missouri, and Wisconsin have strong botanical traditions that have resulted in a macrophyte literature which documents the identity, taxonomy, floristics, and ecology of aquatic macrophytes and wetland vegetation of the Upper Mississippi River and its floodplain. These findings are reviewed with respect to floristics, vegetation dynamics (patterns, history, production and management), and environmental changes that impact vegetation. Aspects requiring future study are noted to direct subsequent investigations.     

Flowering phenology in the vegetation of Shervaroys,South India

Flowering phenology of 475 herbaceous and 348 arborescent taxa that form the vegetation of Shervaroys (Eastern Ghats: South India) was studied in relation to growth form, altitude and vegetation type. It was found that the majority of the herbaceous taxa flowered following rains while the arborescent taxa bloomed predominantly during the dry period irrespective of altitude and vegetation type.     

中国喀斯特植被分类系统

我国喀斯特地貌分布广泛,是全球喀斯特集中分布区面积最大且岩溶发育最强烈的典型区域。喀斯特植被物种组成独特,生物多样性丰富,群落结构复杂,植被类型极其丰富。该文对已发表的喀斯特植被类型和近期的调查资料进行系统整理,依据《中国植被志》的分类原则,在群系尺度上编制了中国喀斯特植被分类系统,包括3个植被型组、13个植被型和554个群系。探讨了喀斯特植被的分类系统与原有分类系统的衔接,并依据相关资料,对喀斯特生境专性群系进行了识别和判定,以期为喀斯特区域的石漠化治理、植被修复提供科学参考。     

江苏省海滩植被演替的研究

江苏省海滩植被可分为滨海盐土植被、盐沼植被及海滩沙生植被三个基本类型。本文论述了这些植被类型的演替规律。滨海盐土植被与盐沼植被的演替,外因于土壤盐分含量递减与有机质含量的递增;海滩沙生植被的演替,外因于土壤沙颗粒大小及其相应的土壤含水量的变化,所以海滩植被演替为外因动态演替。     

Reconstructing pre-impact vegetation cover in modified landscapes using environmental modelling, historical surveys and remnant vegetation data: a case study in the Fleurieu Peninsula, South Australia

Aim To investigate the application of environmental modelling to reconstructive mapping of pre‐impact vegetation using historical survey records and remnant vegetation data. Location The higher elevation regions of the Fleurieu Peninsula region in South Australia were selected as a case study. The Fleurieu Peninsula is an area typical of many agricultural regions in temperate Australia that have undergone massive environmental transformation since European settlement. Around 9% of the present land cover is remnant vegetation and historical survey records from the ad 1880s exist. It is a region with strong gradients in climate and topography. Methods Records of pre‐impact vegetation distribution made in surveyors’ field notebooks were transcribed into a geographical information system and the spatial and classificatory accuracy of these records was assessed. Maps of remnant vegetation distribution were obtained. Analysis was undertaken to quantify the environmental domains of historical survey record and remnant vegetation data to selected meso‐scaled climatic parameters and topo‐scaled terrain‐related indices at a 20 m resolution. An exploratory analytical procedure was used to quantify the probability of occurrence of vegetation types in environmental domains. Probability models spatially extended to geographical space produce maps of the probability of occurrence of vegetation types. Individual probability maps were combined to produce a pre‐impact vegetation map of the region. Results Surveyors’ field notebook records provide reliable information that is accurately locatable to levels of resolution such that the vegetation data can be spatially correlated with environmental variables generated on 20 m resolution environmental data sets. Historical survey records of vegetation were weakly correlated with the topo‐scaled environmental variables but were correlated with meso‐scaled climate. Remnant vegetation records similarly not only correlated to climate but also displayed stronger relationships with the topo‐scaled environmental variables, particularly slope. Main conclusions A major conclusion of this study is that multiple sources of evidence are required to reconstruct past vegetation patterns in heavily transformed region. Neither the remnant vegetation data nor historical survey records provided adequate data sets on their own to reconstruct the pre‐impact vegetation of the Fleurieu Peninsula. Multiple sources of evidence provide the only means of assessing the environmental and historical representativeness of data sets. The spatial distribution of historical survey records was more environmentally representative than remnant vegetation data, which reflect biases due to land clearance. Historical survey records were also shown to be classificatory and spatially accurate, thus are suitable for quantitative spatial analyses. Analysis of different spatial vegetation data sets in an environmental modelling framework provided a rigorous means of assessing and comparing respective data sets as well as mapping their predicted distributions based on quantitative correlations. The method could be usefully applied to other regions where predictions of pre‐impact vegetation cover are required.     

基于TM遥感影像的陕北黄土区结构化植被因子指数提取

根据结构化植被因子指数的概念,以TM影像为信息源,探讨了利用遥感技术提取陕北黄土区结构化植被因子指数（C_s）的途径与方法.结果表明：在陕北黄土区,C_s能更好地描述植被群落的水土保持效益,其与绿度植被指数（归一化植被指数NDVI、修正土壤调整植被指数MSAVI）和黄度植被指（归一化差异衰败指数NDSVI、归一化耕作指数NDTI）等单一的遥感植被指数虽然均存在良好的相关关系,但用绿度与黄度植被指数相结合可综合反映植被的水土保持功能,能较好地克服单一指数在描述植被控制水土流失中的不足;MSAVI、NDTI分别是基于遥感影像提取C_s较为理想的绿度和黄度植被指数;根据群落结构化植被因子指数与遥感植被指数的关系推算区域尺度上的结构化植被因子指数是可行的,但由于不同地区植物物候期的差异,要使该方法在其他地区适用,仍需开展相应的率定和验证工作.     

湖北省植被分类的研究 Ⅰ.自然植被

本文论述了湖北植被分类的原则、依据,植被分类的单位和命名,并拟订了5级分类系统,以植被型、群系、群丛作为主要分类单位。根据多年来全省野外调查资料分析,湖北植被划分为8个植被型组、13个植被型、66个群系组、152个群系、10个群丛。     

乌兰布和沙漠东北缘荒漠-绿洲过渡带植被地上生物量估算

干旱区荒漠植被地上生物量是植被生长状况评价与荒漠化监测的重要指标。在乌兰布和沙漠东北缘的荒漠-绿洲过渡带选取典型区,基于地面调查数据构建主要植物种的异速生长方程,对样方内的植被地上生物量进行估算;基于样方调查数据和Quick Bird影像数据,分别建立植被指数与人工固沙林和荒漠植被地上生物量的回归模型,并对研究区植被地上生物量进行估算。结果表明:植冠体积V是较好的预测变量,所得荒漠植物异速生长方程精度较高,能够满足样方内荒漠植被地上生物量估算需要;采用RVI对数模型估算人工固沙林地上生物量的效果最好(R~2=0.72,RMSEP=56.15),采用RVI线性模型估算荒漠植被地上生物量的效果最好(R~2=0.82,RMSEP=15.07);研究区内荒漠植被和人工固沙林的单位面积地上生物量分别为90.73g/m~2和105.28g/m~2。该研究可以为荒漠化监测和荒漠植被遥感信息提取提供参考。     

Understanding properly the `potential natural vegetation' concept

This is a response to critical comments concerning the inappropriate use of the potential natural vegetation (PNV) concept made in a recent contribution to the Commentary section of this journal. We consider that the PNV concept has been misinterpreted. PNV has been used extensively in several European countries since the mid‐1950s and was never intended to be used to make a prediction of what vegetation would dominate in an area if human influence were removed. PNV maps express hypothetical assumptions of what corresponds to dominant or natural vegetation in each area. Remnants of the vegetation of the past provided by palaeopalynology and other disciplines provide valuable information for interpreting modern vegetation, but natural changes and anthropogenic influences operating over the last millennia have to be taken into account. Annex I of the Habitats Directive provides a balanced list of habitat types for implementing conservation policies within the European Union.     

《中国植被志》的植被分类系统、植被类型划分及编排体系

植被志(vegegraphy)是基于植被调查资料, 全面记叙植被的群落外貌、种类组成、结构和功能、生境条件, 以及地理分布等特征, 并对同类植被进行归纳和总结的志书。“植被志”的英文译为“vegegraphy”, 是本文的新造词, 它是由“vegetation”的词头“vege-”和英文后缀“-graphy” (记叙之意)组成的合成词。《中国植被志》的研编是一项时间紧迫、内容复杂、工作量浩繁的重大科学工程。它的完成将极大提升中国植被科学和生态学的研究水平, 并为中国植被资源的合理利用、生物多样性保护及生态环境治理等提供不可或缺的基础资料。本文首先简述了植被的基本特征(主要包括外貌特征、种类组成、群落结构以及动态变化等)和国内外植被调查的进展情况, 简要回顾了中国植被分类系统的研究历史, 并对以往的分类系统进行了若干修订。在此基础上, 着重讨论并提出了《中国植被志》卷册编排体系和用于《中国植被志》研编的植被类型划分方案。在对植被分类系统的修订方面, 主要对高级分类单位及相对应的英文名称进行了讨论和修订。按照本文修订的分类系统, 中国植被的分类单位及其对应的英文名称分别是: 植被型组(Vegetation Formation Group)、植被型(Vegetation Formation)和植被亚型(Vegetation Subformation)、群系组(Alliance Group)、群系(Alliance)和亚群系(Suballiance)、群丛组(Association Group)以及群丛(Association)。在植被型组中, 划分为9类: 森林、灌丛、草本植被、荒漠、高山冻原与稀疏植被、沼泽与水生植被、农业植被、城市植被及无植被地段。关于《中国植被志》的卷册编排和“植被类型”划分, 首先按高级分类单位——植被型划分相应的“卷”; 在此框架下, 模糊“植被亚型”、“群系组”和“群系”的概念, 确定“植被类型” (Vegetation type), 并将其作为植被志各卷中的“册”。这样处理不仅保证了研编工作的可操作性, 也保持了同一卷册中特定植被类型的完整性。《中国植被志》编排体系中的“植被类型”的划分很重要, 它是指具有相同建群种及相同优势类群(如种、属)的植被组合, 但它不是严格意义上的植被分类单位。“植被类型”的划分遵循“优势类群及生活型的同一性, 生境条件的相对重要性, 植被特征及用途的差异性, 以及突出植被志的应用性”等原则。按该编排体系, 《中国植被志》将由48卷约110册组成。     

中国北方地区的本底植被

根据现代地植物学和古生态研究结果．恢复、评估了我国北方地区的原生植被和潜在植被状况．并论述它们对生态建设的意义。潜在植被分布表明．温带或亚热带郁闭森林仅可以发育在北方的东南边缘地带,而东北中西部、华北平原大部、黄土高原东南部和青藏高原东缘等地区为郁闭度较低的疏林或森林草原可能发育地带。这些地区是北方农业发展和生态恢复的主要区域;东北西部、内蒙古东南部、陕北、宁夏东南部、陇东南和青海省东中部等地区．潜在地带植被当属温带草原．宜发展牧业．是目前退耕还草的重点区域。在全新世中期,东北地区东北部的原生植被为温带落叶阔叶林;东北的南部、河北东部、山东东部、淮河流域等地生长着暖温带落叶阔叶林;在黄土高原东南部、黄淮平原西部和青藏高原东部边缘等地区,原生森林面积比目前大得多．分别分布着以松属和落叶阔叶树占优势的稀疏森林和以云、冷杉占优势的山地寒温带森林．为这些地区勾勒了未来生态恢复所能达到的理想境界。根据原生植被分布．黄土高原西北部地区同样不适合发展林业．退耕以后所能够恢复的也只能是草,而不是林;再往西北．到了毛乌素沙地西北部及其我国西北内陆的广袤半荒漠、荒漠地带．原生地带植被中从未出现森林．在绝大多数情况下均不宜发展林业。     

《中国植被志》研编内容与规范

植被志是基于植被(或植物群落)调查资料, 全面记叙植被的外貌、物种组成、结构和功能, 以及地理分布和生境条件等特征, 并对同类植被进行归纳和总结的志书。《中国植被志》是第一部对中国植被进行全面记述的志书, 预计完成约48卷110册。在借鉴《中国植被》(1980)(简称“80方案”)植被分类基本原则的基础上,《中国植被志》将对中国植被分类系统的高级分类单位(植被型组、植被型和植被亚型)进行归纳和总结, 对中级和低级分类单位(群系组、群系、亚群系, 群丛组、群丛)进行详细描述。植被高级分类单位的描述具有概括性质, 是在中国植被分类系统中级和低级分类单位描述的基础上, 对其在全球和中国境内的地理分布、自然环境、群落外貌、植被类型及多样性、优势种或共优势种、生物多样性保育价值以及资源现状等进行概述, 并对“80方案”相关内容进行修订和拓展, 将提供对中国植被基本特征客观、准确的记述。在植被中级和低级分类单位中, 群系组描述的内容包括地理分布、自然环境、群落外貌、植被类型以及价值与保育等内容; 群系描述的主要内容包括地理分布、自然环境、生态特征、物种组成、群落结构、群丛组和群丛的分类与描述、优势种的生物学特性、生物量与生产力、植被动态与演替以及价值与保育等方面。作为植被志研编的核心内容, 群丛组和群丛的分类与描述主要基于植被调查资料, 采用数量分类方法, 根据群落结构和物种组成的差异划分出不同的植被类型, 并对其基本特征进行定量描述和归纳。其中, 群落的层片结构、特定植被分类单元的特征种或特征种组的筛选与甄别是植被类型划分的关键环节; 而群落外貌, 群落结构, 物种组成, 各类物种的生长习性、生境的偏适性等是群丛组和群丛描述与归纳的重点内容。该文提出了中国植被中级和低级分类单位的命名方案, 其特点在于植被类型的科学名称中同时体现了植被分类单元特征种或优势种的名称及其所属的高级植被分类单位(植被型组或植被型)的名称, 兼顾了植被名称的规范性与实用性。《中国植被志》的研编工作由文献整编、群落调查、数据分析与整理、文本撰写等环节组成。该文对植被样方的调查与收集, 文献收集与整编, 气候、土壤、地形等相关数据的来源及其整理方法, 植被分类方法, 植被命名, 植被分类单元描述的内容, 植被志章节编写大纲、体裁及撰写等多个规范进行了详细的阐述或示例。     

黑龙江省东部山地湿地主要植被类型及其演替规律的研究

首次系统论述了黑龙江省东部山地湿地植被类型,并在此基础上,对黑龙江省东部山地湿地植被演替规律进行了全面探讨。研究表明：黑龙江省东部山地湿地植被演替与发展过程,经过三个阶段：即富营养沼泽→中营养沼泽→贫营养沼泽。无论是森林沼泽,还是草甸、沼生及水生植被都是如此。     

宁夏近20年来植被覆盖度及其与气温降水的关系

利用1981—2004年的植被指数(NDVI)资料,结合实地植被调查资料,将宁夏植被类型划分4个区域,确定了各地植被指数与覆盖度的关系,分析了宁夏各区域植被覆盖度的年际变化、季节变化、植被覆盖度的面积变化及其与气温和降水量的关系。结果表明:24年来宁夏贺兰山与贺兰山东麓的年植被覆盖度呈下降趋势,中部干旱带植被覆盖度呈上升趋势;近4年来,贺兰山植被状况整体变好;贺兰山东麓植被状况整体变差;中部干旱带的植被状况夏季变差,秋季变好;南部山区的植被覆盖度整体变好。宁夏春夏季降水量是影响植被覆盖度的关键性因子,气温对植被覆盖度的影响不显著。     

中国植被地理学:从传统植被地理学到功能植被地理学

本文回顾总结了我国植被地理学发展的历史，展望了其从传统植被地理学到功能地理学的未来研究趋势。作为研究植被地理分布规律的一门科学，植被地理学在我国经历了与社会经济发展密切相关的四个阶段：早期起步阶段，主要是新中国成立前(1920年代—1949)的植物地理学和植被地理学的零星工作；初期成长阶段，主要是新中国成立后至改革开放前(1949—1980)的传统植被地理学研究；中期迅速发展阶段，主要包括改革开放后至经济迅速发展时期(1980—2000),在全球气候变化国际研究背景下的植被地理学研究；近期转型与拓展阶段，主要是国民经济平稳发展及信息时代(2000—至今),面向全球环境变化的植被地理学研究的纵深发展。经过近百年的发展，在植被综合区划与生态功能区划、中国植被分类系统订正、中国植被图与植被志编纂、古植被地理学、植被地理模拟预测与情景分析、植物功能性状和生态化学计量学的功能植被地理学等6个方面取得了可喜成果。今后，需要在以下4个方面开展更广泛的精细与纵深研究：加强更多精细化的植被地理学研究，编纂新一代中国植被图与中国植被志；深入开展人类干扰的植被地理学研究；以植物性状研究为契机，拓展宏观功能植...     

Monitoring vegetation change caused by trampling: a study in the Cairngorms,Scotland

Summary

A study was made in the Cairngorms, Scotland to make recommendations for a monitoring scheme capable of detecting changes in the vegetation caused by recreational pressure following the development of a funicular railway. Four methods were used in field trials to assess percentage cover of plant species and gravel, rock and bare ground, where appropriate, in two vegetation types (open and closed). The methods used were visual estimates in 50 × 40 cm quadrats (Q), the mean of visual estimates in twenty 10 × 10 cm sub-quadrats of the 50 × 40 cm quadrats (Q₂₀), a modified point intercept method (RL) and photography. Variances between observers and between-quadrats were estimated for the different methods. The sampling design for detecting change was based on a model of variance, constructed from field trial data.

Between-observer and between-quadrat variances were related to mean percentage cover and approximated to a binomial distribution. The between-quadrat variance was larger than observer variance. The Q₂₀ method achieved appreciably better precision than the other methods. Analysis of half of the 10 × 10 cmsub-quadrats (1/2Q₂₀) selected in a checker board design achieved a relative efficiency of 78% compared with the Q₂₀. This result suggests that comparable precision to the Q₂₀ method could be achieved by choosing about 14 sub-quadrats in a larger quadrat, thus saving some time. Variation between quadrats also suggested that the Q₂₀ method was the one of choice for maximising precision. The precision of the photographic method was based on fewer data points, so is less accurate than other estimates.

Minimum sample sizes were estimated for detecting a 10% relative change of a species in open vegetation with 30% cover (i.e. a change from 30% to <27 or to >33% cover). With a 10 % Type II error rate and 5 % Type I error rate the minimum sample sizes were 47 quadrats for Q, 18 for Q ₂₀, 43 for RL, and 23 for the means of ten 10 × 10 cm sub-quadrats in open vegetation.

The most time-efficient field recording appeared to be the use of Q despite the required sample size being 2.6 times higher than that of Q₂₀. The far lower time requirement per quadrat, however, compensated for the higher numbers. The number of quadrats would depend on the specified change in percentage cover and on the statistical significance level used. For example, to detect a 10% absolute change in cover (i.e. from 30% to either <20 % or >40 % cover) at 95 % probability the net effective recording time is estimated at 5 h per vegetation type while to detect a 5 % change at 99 % probability would require c. 25 h. Larger samples may be required for other species or for species with a low initial cover.     

近20年辽宁省植被动态特征及其对气候变化的响应

区域归一化植被指数(NDVI)变化特征对环境容量和生态发展方向有重要指示作用。基于SPOT/VEGETATION NDVI数据和ESA CCI-LC植被分类数据，利用Theil-Sen+Mann-Kendall、变异系数、Hurst指数和相关性分析方法，对辽宁省2000—2019年不同植被类型归一化植被指数时空变化特征和气候因子之间的响应关系进行分析。结果表明：(1)NDVI均值呈现从乔木到草原逐渐降低的趋势，不同植被类型在生长季具有不同的生长习性；(2)各植被类型都呈增加趋势，结合Hurst指数和Sen趋势，辽宁省36.26%的植被将趋于改善，约有61.51%的植被将趋于退化；(3)变异系数结果表明：所有植被类型中以乔木植被最为稳定，草原型植被最不稳定。(4)辽宁省各植被类型NDVI与降水显著正相关，与气温相关性相对较低。结果可为辽宁省生态评价和碳循环研究提供植被覆盖动态参考。     

Floodplain vegetation phenology in the Southeast USA: Optimizing the timing of aerial imagery acquisition

Phenological patterns of wetland vegetation were studied on the Savannah River Site, Aiken, South Carolina, USA, to aid in delineation of wetland vegetation community types and plant species from aerial imagery. Relative phenology patterns were recorded for 16 dominant wetland plant species from May 1984 to June 1985 on the floodplains of three streams. These patterns were identified and compared with aerial photographs acquired in the same season as ground observations. Leafout and leaf senescence varied between and within floodplains. In spite of this variability, vegetation classes and individual species may be distinguished best during the late April leafout period.