塔里木盆地二叠纪孢粉植物群区系性质及塔里木地块演化探讨

塔里木盆地二叠系孢粉分为五个孢粉组合带,即：ＳＱ、ＰＶ、ＡＶ、ＬＰ和ＰＧ带。据对盆地孢粉植物群性质的讨论及其与国内外相关孢粉植物群的对比研究,本文将塔里木地块二叠纪孢粉植物群的演化进程分为三个阶段,即：早二叠世早、中期的欧美区型植物群,早二叠世晚期至晚二叠世早期的安加拉区－欧美区混生型植物群和晚二叠世中、晚期的安加拉区型植物群。古地磁研究结果支持这一推论,即孢粉植物群的演化历史基本反映了塔里木地块的漂移、拼合进程。     

塔里木盆地二叠系孢粉组合及生物地层学*

首次系统地研究了塔里木盆地二叠系孢子花粉，讨论了盆地各地层分区孢粉组合特征，建立了从早二叠世至早三叠世早期的6个孢粉组合带，阐述了各组合带孢粉学特征。依据对盆地二叠纪孢粉植物群组成分子的分析及其与国内外相关孢粉组合的比较研究，将盆地孢粉植物群分为3个发展阶段，即：早二叠世早、中期的欧美型植物群，早二叠世晚期至晚二叠世早期的安加拉欧美混生型植物群和晚二叠世中、晚期的安加拉型植物群。文中还从孢粉地层学角度论述了沙井子组、杜瓦组和普司格组的地质时代以及二叠/三叠系界线等问题。描述孢粉25属33种（含2新种）。     

东海陆架西南部台北坳陷古近纪孢粉植物群的时空分布

详细叙述东海陆架西南部台北坳陷古近纪不同凹陷区各时期孢粉植物群展布情况。区内古近纪孢粉植物群可分为早古新世、晚古新世、早始新世和中始新世4个发育阶段,早古新世孢粉植物群仅见于坳陷西南的局部地区,称Abietineaepollenities/Cedripites-Parcisporites-Momipites leffingwellii组合,晚古新世孢粉植物群分4种类型,椒江凹陷称Taxodiaceaepollenites-Engelhardtioidites-Momipites leffingwellii组合,丽水-福州凹陷称Taxodiacenepollenites-Myricaceoipollenites-Momipites leffingwellii组合,闽江凹陷南部称Taxodiaceaepollenites-Momipites leffingwellii组合,闽江册陷北部称Lygodiumsporites-Cicatricosisporites dorogensis-Tiliaepollenites-Bombacacidites组合。早始新世孢粉植物群具南北差异,北部以海金沙科和椴科孢粉植物发育为特征,南部以海金沙科、椴科和杨海科孢粉植物群发育为特征,以上均指示为湿热的亚热带气候。中始新世本区孢粉植物群比较一致,称Cicatricosisporties dorogensis-Ephedripites(D)-Nitrariadites组合,指示为受到干旱气候影响的亚热带气候。区内缺失渐新统,故无渐新世孢粉记录。     

长江三角洲锦溪地区全新世气候适宜期孢粉组合及其环境意义北大核心CSCD

通过对长江三角洲锦溪地区白莲湖附近人工剖面的孢粉研究,重建该地区7 230cal a BP前后的植被和气候。孢粉植物群反映当时气候略有波动,但整体上与全新世气候适宜期的温暖环境相一致。孢粉自下而上可以细分为4个组合带:Zone 1青冈栎含量丰富,反映温暖气候;Zone 2落叶栎有所增多,气候稍有转凉;Zone 3青冈栎含量再度增高,气候变暖;Zone 4松属和落叶栎明显增多,气候再度转凉。从沟鞭藻和相关孢粉类型的分布分析,除底部12号样品因孢粉含量低而未予考虑外,其它样品都指示沉积时期当地受到海水的影响。其中Zone 1和Zone 2孢粉植物群指示两次海水的进退过程。当前孢粉研究结果很好地反映出长江三角洲地区全新世大暖期的气候变化特征,以及与当时海平面变化的关联。     

长江三角洲锦溪地区全新世气候适宜期孢粉组合及其环境意义

通过对长江三角洲锦溪地区白莲湖附近人工剖面的孢粉研究,重建该地区7 230cal a BP前后的植被和气候。孢粉植物群反映当时气候略有波动,但整体上与全新世气候适宜期的温暖环境相一致。孢粉自下而上可以细分为4个组合带:Zone 1青冈栎含量丰富,反映温暖气候;Zone 2落叶栎有所增多,气候稍有转凉;Zone 3青冈栎含量再度增高,气候变暖;Zone 4松属和落叶栎明显增多,气候再度转凉。从沟鞭藻和相关孢粉类型的分布分析,除底部12号样品因孢粉含量低而未予考虑外,其它样品都指示沉积时期当地受到海水的影响。其中Zone 1和Zone 2孢粉植物群指示两次海水的进退过程。当前孢粉研究结果很好地反映出长江三角洲地区全新世大暖期的气候变化特征,以及与当时海平面变化的关联。     

鄂尔多斯盆地西南部甘肃西峰地区延长组孢粉组合及古气候研究

鄂尔多斯盆地西南部西峰油田中上三叠统延长组长8段和长7段钻井岩心中发现丰富的孢粉化石,分别命名为Aratisporites-Punctatisporites组合和Asseretospora-Walchiites组合,组合特征分别与盆地东南部发现的铜川组孢粉组合和延长组孢粉组合相似,地质时代分别为中三叠世晚期Ladinian期与晚三叠世早期Carnian期。通过孢粉植物群类型地层分布特征及其生态环境讨论,推测盆地区中晚三叠世气候温暖潮湿,雨量充沛,植被茂盛。孢粉植物群所反映的古气候为温带—亚热带暖湿或湿热气候。这是由于本地区当时处于较低的纬度,且濒临大型湖泊,而长8—长7段沉积时期正处于湖泊扩张的鼎盛期。     

宁晋泊晚更新世孢粉组合及其古环境演变

宁晋泊是河北平原南部三大古湖群之一,通过LN42．5m厚沉积剖面的孢粉分析,获得古植物群演替达近20次,反映古气候变化具明显冷暖气候旋回5次以上,其中有2次寒冷期,3次湿暖期。结合6．4m以上~(14)C年龄数据推断计算晚更新世与全新世界线在7．5m,这一界线与孢粉植物群、古气侯与古环境等分异界线非常吻合。因此作者推断宁晋泊的形成、发展与消亡时代相应在晚更新世早期的温暖期,全新世高温期再次复兴,后被河流沉积物所掩埋而消亡形成洼地。     

中国晚三叠世孢粉植物群地理分区

我国晚三叠世孢粉化石十分丰富,经研究划分为南北两个孢粉植物群地理区,南方孢粉植物群自上而下由３个组合带构成：１）Ｍｉｃｒｈｙｓｔｒｄｉｕｍ－Ｚｅｂｒａｓｐｏｒｉｔｅｓ组合带,２）Ａｒａｔｒｉｓｐｏｒｉｔｅｓ－Ｔａｅｎｉａｅｓｐｏｒｉｔｅｓ组合带,３）Ｋｙｒｔｏｍｉｓｐｏｒｉｓ－Ｏｖａｌｉｐｏｌｌｉｓ组合带;北方孢粉植物群由２个组合带构成：１）Ｄｕｐｌｅｘｉｓｐｏｒｉｔｅｓ－Ｐａｒａｔａｅｎｉａｅｓ     

东海陆架西南部台北坳陷新近纪孢粉植物群演替

对东海陆架西南部台北坳陷13口钻井孢粉分析表明,本地区新近纪植物群经历了3个发展阶段,即：1)早中新世早期松科花粉优势期;2)早、中中新世阿丁枫科花粉繁盛期;3)晚中新世至早上新世草本被子植物发展期。各时期孢粉植物群在横向上几乎没有大的区别,表明新近纪整个坳陷内构造与沉积环境及其变迁具有很好的一致性。植物群演替反映古气候从早中新世早期的湿润温凉到早、中中新世的暖湿,最后(晚中新世至早上新世)又趋温凉的变化历程。     

中国早第三纪孢粉植物群纲要

简要地叙述中国大陆及陆架区早第三纪孢粉植物群的纵向演变和横向分异，将纵向演变归纳为６个主要的孢粉植物群发展时期。即：１）早古新世榆科花粉发育期；２）晚古新世正型粉扩展期；３）早始新世榆科－桦科－胡桃科花粉繁盛期；４）中始新世壳外科花粉发育期；５）晚始新世蒺藜科花粉扩展期；６）渐新世松科花粉发育期。据横向地区差异，将中国大陆及陆架区划分为７个早第三纪孢粉植物地理区，为：１）东北暖温带至亚热带湿生孢粉植物区，２）华北暖温带至亚热带中生孢粉植物区，３）西北暖温带至亚热带旱生孢粉植物区，４）中南亚热带中生孢粉植物区，５）东海南部陆架亚热带湿生孢粉植物区，６）南方亚热带、热带中生至湿生孢粉植物区，７）西藏亚热带中生孢粉植物区。对以上各期的孢粉植物区的主要特征和各地理区范围，代表性的孢粉和特征分别进行叙述，并以此对中国早第三纪的主要含孢粉地层列表进行了对比。     

云南干热河谷植被与环境研究进展

特殊的地理位置和独特的地形地貌特征组合形成了典型的干热气候环境, 在云南省亚热带高原山地河谷下部发育了一类特有的植被类型, 即干热河谷植被。干热河谷植被具有非地带性和稀有性, 以及由土地利用变化为主的人为活动干扰导致的脆弱性。本文回顾了干热河谷植被的研究历史, 分别从干热河谷的植物群落学和植物区系学、干热河谷植被与土地的关系以及干热河谷植被保护与恢复三个方面进行了总结。植物群落与区系研究主要集中于群落分类、植被分类、群落特征、人为干扰影响、区系特征、性质和起源; 植被与土地关系研究侧重于土壤特性、土地利用/覆盖变化、土地退化及水土流失状况; 植被保护与恢复的热点在植被恢复目标、植被恢复功能区划、植被恢复引种及筛选及植被恢复效益评价研究。未来在这些区域应注重自然灾害及预防、水电工程建设对植被的影响及其响应等方面的研究, 深入开展大尺度植被时空格局的监测和动态服务功能分析。     

Archaeology, land use, pollen and restoration in the Yazoo Basin (Mississippi, USA)

Increasingly, modern ecologists are realizing that the history of ecological systems is crucially important for understanding the landscape and that human land use has a great impact on the trajectory of ecosystems. The Yazoo Basin of Mississippi (USA) is one area in which palaeoecological and archaeological research has been done, but at a time when interpretations of the results relied on paradigms that gave credence only to climate change as a causal factor in explaining vegetation histories of plant communities. This paper uses knowledge of ecological processes and patterns of plant colonization and succession to make testable expectations for vegetation composition and change related to human action. An existing pollen record from the area is then examined in light of these expectations and reveals evidence that humans were an integral part of the ecosystem in this area, influencing the trajectory of vegetation history over thousands of years.     

种子大小及其命运对植被更新贡献研究进展

种子是种子植物的繁殖体.种子对后代的资源投入将会直接影响后代的适合度进而影响到植被群落的更新.一般较大种子物种在种子萌发和幼苗生长阶段是具有较大优势的;但较小种子物种在逃避被动物采食和形成持久的土壤种子库成为植被更新的后备动力方面具有较大的优势.在不同的选择压力下,不同大小种子在以后的生活史中具有不同的命运,对植被的更新也具有不同的贡献.本文主要从种子大小和种子的传播散布、种子萌发、种子存活以及种子土壤库等方面综述了国外关于种子大小及其以后命运对植被更新贡献的研究结果,并对国内的相关研究提出了一些建议：种子生态学研究需要结合群落特点以及微环境等,开展从种子生产到幼苗更新全过程的系统性研究,为植物物种多样性保育和退化植被恢复方面提出有科学依据的管理措施.     

黄土高原地区不同草地退耕模式水分利用效率的比较

研究了半干旱黄土高原区不同退耕模式下植被恢复的比较,对3种不同人工豆科牧草多年生紫花苜蓿alfalfa(Medicago sativa)、多年生沙打旺erect milkvetch(Astragalus adsurgens)、2年生草木樨sweetclover(Melilotus officinalis))和一种自然撂荒(fallow)进行了实地种植比较。通过3a研究发现:紫花苜蓿是耗水最严重的牧草,水分利用效率仅高于撂荒;沙打旺具有最高的地上总生物量和水分利用效率。紫花苜蓿和沙打旺地块中杂草生物量逐年降低,物种数量最低且没有增加。2年生草木樨地物种数和地上生物量逐年增高,草木樨对暴雨的入渗贮存能力最大,显著高于自然撂荒。草木樨结束生活史后第1年地上总生物量(和撂荒一样全为杂草)是撂荒地的两倍,且略高于紫花苜蓿的地上总生物量,同时物种数量也和物种数目最多的撂荒地没有显著差异(p<0.05)。草木樨显著降低了10～40cm土壤剖面的容重,草木樨结束生活史后残留根系有助于深层土壤水分恢复,水分状况恢复良好且优于紫花苜蓿和沙打旺。可见短期的人工干扰下两年生草木樨的种植有利于促进自然植被的恢复,优于自然撂荒和其他牧草种植的方式,容易推广且实际可行。     

Rivers Through Time: Historical Changes in the Riparian Vegetation of the Semi-Arid,Winter Rainfall Region of South Africa in Response to Climate and Land Use

This paper examines how the riparian vegetation of perennial and ephemeral rivers systems in the semi-arid, winter rainfall region of South Africa has changed over time. Using an environmental history approach we assess the extent of change in plant cover at 32 sites using repeat photographs that cover a time span of 36–113 years. The results indicate that in the majority of sites there has been a significant increase in cover of riparian vegetation in both the channel beds and adjacent floodplain environments. The most important species to have increased in cover across the region is Acacia karroo. We interpret the findings in the context of historical changes in climate and land use practices. Damage to riparian vegetation caused by mega-herbivores probably ceased sometime during the early 19th century as did scouring events related to large floods that occurred at regular intervals from the 15th to early 20th centuries. Extensive cutting of riparian vegetation for charcoal and firewood has also declined over the last 150 years. Changes in the grazing history as well as increased abstraction and dam building along perennial rivers in the region also account for some of the changes observed in riparian vegetation during the second half of the 20th century. Predictions of climate change related to global warming anticipate increased drought events with the subsequent loss of species and habitats in the study area. The evidence presented here suggests that an awareness of the region’s historical ecology should be considered more carefully in the modelling and formulation of future climate change predictions as well as in the understanding of climate change impacts over time frames of decades and centuries.     

Classification of vegetation: Past,present and future

Abstract. This paper is a report on the past, status-quo and perspectives of vegetation classification, still a major occupation of many vegetation scientists. The history of vegetation classification is discussed against a background of several controversial issues such as the problem of continuum vs. discontinuum, naturalness vs. arbitrariness of the nature of plant communities, universality vs. ad hoc character of syntaxonomic schemes, as well as classical versus numerical approaches to data analysis for classification purposes. The development of the methodology of vegetation science and the present image of vegetation classification is documented by a bibliometric analysis of the publication record of four majorjournals: Journal of Vegetation Science, Vegetatio, Phytocoenologia and Tuexenia. This analysis revealed a persisting controversy between traditional and numerical approaches to vegetation classification. A series of important changes in vegetation science (foundation of new journals, change of editorial policy by the established, important meetings) punctuate a period called the ‘Innovation period’. Several trends in the development of methods of vegetation systematics are summarized under the headings formalism, pluralism, functionalism, pragmatism and indeterminism. Some new features, such as the development and improvement of numerical tools, use of large data banks and attempts to summarize the theory of vegetation classification are discussed. The new growth-form system of Barkman initiated a revival of physiognomy-based vegetation classification. Within this framework the use of the character-type concept and the development of new numerical methods for studying the hierarchical structure of character-set types seems to be a promising approach. The achievements of population biology and ecophysiology have affected vegetation science by emphasizing the functionality of species within plant communities. The use of guilds and other functional groups has experienced an increasing interest from vegetation scientists. Applied in vegetation science, fuzzy-set theory has bridged the techniques of classification and ordination of plant communities.     

法瑞学派的发展历史及其对当代植被生态学的影响

法瑞学派也称Braun-Blanquet学派, 盛行于欧洲大陆, 也是当今全球植被科学的一个重要学派。该文对这一学派的发展历史、植被科学理论和野外实践, 以及群落分类系统做了简要介绍。法瑞学派的发展可分为开创(1910-1943年)、发展(1945-1980年)、分化(1980-1990年)和融合(1990年至今)四个时期。法瑞学派重视野外实践, 强调植物群落内的相互关系和动态发展, 强调植物群落主要属性是物种组成, 以及特征种(或鉴别种)在群落分类和评价环境中的重要作用; 制定了一套详细的野外调查方法和样地归类的程序; 建立了以“群丛”为基本等级的一个自下而上、严谨的、正规的植被分类体系; 具有理论上的兼容性和技术上的开放性等优点。这些都为当代植被生态学的发展奠定了坚实的基础。同时, 法瑞学派在特征种界定、群丛定义、样地数据集成与转换、与生态外貌系统连接等方面存在一些尚需改进的地方。最后, 该文概述了法瑞学派在中国的发展历史与现状, 以及目前在中国植被研究中所能发挥的作用。     

History of French-Swiss School of phytosociology and its influences on modern vegetation ecology

法瑞学派也称Braun-Blanquet学派, 盛行于欧洲大陆, 也是当今全球植被科学的一个重要学派。该文对这一学派的发展历史、植被科学理论和野外实践, 以及群落分类系统做了简要介绍。法瑞学派的发展可分为开创(1910-1943年)、发展(1945-1980年)、分化(1980-1990年)和融合(1990年至今)四个时期。法瑞学派重视野外实践, 强调植物群落内的相互关系和动态发展, 强调植物群落主要属性是物种组成, 以及特征种(或鉴别种)在群落分类和评价环境中的重要作用; 制定了一套详细的野外调查方法和样地归类的程序; 建立了以“群丛”为基本等级的一个自下而上、严谨的、正规的植被分类体系; 具有理论上的兼容性和技术上的开放性等优点。这些都为当代植被生态学的发展奠定了坚实的基础。同时, 法瑞学派在特征种界定、群丛定义、样地数据集成与转换、与生态外貌系统连接等方面存在一些尚需改进的地方。最后, 该文概述了法瑞学派在中国的发展历史与现状, 以及目前在中国植被研究中所能发挥的作用。     

Climate and evolutionary history define the phylogenetic diversity of vegetation types in the central region of South America

Oecologia - In South America the biogeographic history has produced different biomes with different vegetation types and distinct floras. As these vegetation types may diverge in evolutionary...     

Reconstruction of local vegetation in ad 915 at an oligotrophic mire in northern Japan from pollen, present-day vegetation and tephra data

The use of data for present-day vegetation, modern and pretephra pollen have, together, allowed reconstruction of the spatial pattern of the vegetation of an oligotrophic mire, Shimo-kenashi Mire, in ad 915. The modern pollen data were compared with the surrounding vegetation, showing that pollen of Ericaceae, Rosaceae (excluding Sanguisorba), Sphagnum and Liliaceae, together with trees and shrubs, which form scrub or thicket, indicate the limits of the mires. Shimo-kenashi Mire was narrower in ad 915 and had more islands and peninsulas of scrub. Subsequently, the mire margin has advanced and the scrub islands and peninsulas have disappeared at some sites. The fact that the mire is spreading implies that conditions are wetter since ad 915, caused by changes in local hydrology. This history of vegetation at the site will contribute to the conservation and management of the mire as trends in vegetational change provide the basic information for conservation strategy.