峨眉山世界遗产地表土孢粉组合及其生态和古环境启示

通过峨眉山40个样点表土孢粉组合及其与植物群落之间关系的分析,结果表明:(1)花粉组合中木本植物含量(83.3%)占绝对优势,松属、杉科、桤木属、蔷薇科、桦属、枫杨属、蒿属、毛茛科和水龙骨科为主要孢粉类型;(2)中山常绿阔叶林花粉组合未能反映植被的群落特征;低山常绿阔叶林间人工次生林和常绿落叶阔叶混交林花粉组合只能反映母体植被的部分组成;针叶林花粉组合基本可以指示母体植被的群落特征;灌丛草甸花粉组合能够较好地反映母体植被的群落组成;针阔混交林花粉组合不仅可以很好地指示群落特征,花粉高含量类型还可以与植物群落优势种很好地对应;(3)主要花粉类型冷杉属、杜鹃花科、蔷薇科、珙桐属、槭属和盐肤木属具低代表性;枫杨属、栲属/柯属、桤木属和杉科花粉具超代表性;(4) DCA表明,通过花粉百分含量,能较好地区分人类扰动植被、阔叶林和针叶林,但常绿阔叶林、常绿落叶阔叶混交林和针阔混交林之间,针叶林和灌丛草甸之间难以区分;(5)利用孢粉学恢复热带亚热带常绿阔叶代表类群樟科群落和第三纪孑遗落叶阔叶属种珙桐群落时,受其主体植物花粉外壁薄,易破碎影响,原生植被优势种缺失;因此,孢粉实验改良和保存环境研究,与其他生物学指标(植物大化石和气孔器)综合分析在重建古植物群落中具有重要意义;(6)植物(如冷杉)花粉含量一定程度上能够指示其林分结构。本研究可为热带亚热带山地及相似地区利用孢粉学进行地质时期气候与环境重建提供理论支持和基础资料,并对植被生态恢复提供实践和参考。     

南海东北部表层孢粉的分布规律及传输模式

为了更好地理解南海东北部陆源物质的传输模式以及南海表层孢粉所指示的植被和环境意义,本研究通过对南海东北部273个表层样点进行孢粉分析,采用百分比组合、绝对浓度指标、与离岸最近距离进行定量对比,来揭示南海东北部表层孢粉传输和分布的基本规律。研究显示,南海东北部表层的孢粉属种主要来源以下植被类型,包括红树林,低地和亚低山常绿阔叶林,次生林,低山常绿阔叶林,中山常绿-落叶阔叶混交林,亚高山针叶林。最常见的乔木花粉包括来自次生林群落的松属;其次为来自于低山常绿阔叶林植被的栎属、栲属、罗汉松属、陆均松属、猕猴桃属、金丝桃属以及杜茎山属等。同时还包含少量的中山常绿-落叶阔叶混交林花粉属种,包括鹅耳枥属、桤木属、栗属、枫香属等。最主要的陆源草本为禾本科,其它常见草本包括蒿属、菊科、藜科等。结果显示,南海东北部的表层孢粉主要来源于珠江输入,大型河流输送区域的孢粉沉积浓度超过没有河流输送区域的50倍以上。松属花粉能够被风力携带远距离传播至深海。在表层洋流没有形成涡旋或环流的情况下,会阻挡并削弱花粉沉积,而孢子能够被海流传输携带,珠江口附近高含量的三缝孢子说明了人类活动对自然森林的破坏和珠江携带的水流搬运沉积。在珠江口东边沉积的孢粉组合显示出良好的植被多样性特征,除了以松属花粉为主的次生林以外,以栲属和常绿栎属为主的低山常绿阔叶林组合,和目前华南地区的原生天然植被一致。珠江输送孢粉沉积的最大范围限于120km以内,若没有大型河流传输陆源物质,花粉浓度则在离岸之后急剧降低。对现代表层孢粉浓度和离岸距离的对比,能够定量估算南海东北部冰期时钻孔孢粉与来源地的实际距离,且为推算出冰期时海岸线迁移的幅度提供了线索。     

云南丽江老君山表土花粉与植被关系的研究

通过云南丽江老君山18个样点山地林下表土花粉组合特征及其与植物群落之间关系的分析,结果发现:(1)花粉组合中木本植物花粉占83.3%,木本植物与草本植物花粉比值(AP/NAP)约为5,以常绿栎类、桦属(Betula)和冷杉属(Abies)为主;(2)针叶常绿落叶阔叶混交林和常绿落叶阔叶混交林的花粉组合与植物群落有较好的对应关系,针叶落叶阔叶混交林花粉组合基本能够反映母体植被特征,针叶林花粉组合未能反映植物群落的数量特征;(3)主要花粉类型中冷杉属、柳属(Salix)和杜鹃花科(Ericaceae)花粉具低代表性;常绿栎类、松属(Pinus)和桦属花粉具超代表性,其花粉产量和散布范围为松属常绿栎类桦属;(4)通过花粉相对含量,DCA分析能较好地区分不同植物群落。该研究成果可为西南地区古植被和古环境重建提供基础数据资料。     

云南省香格里拉地区现代孢粉与植被关系研究

本文对云南省香格里拉地区(海拔3 400～4 700 m)7个植物群系下采集的21个现代苔藓样品进行了孢粉研究,探讨了现代孢粉组合与样点周围植被之间的关系,以及主要孢粉类型的代表性与传播能力。结果表明,香格里拉地区不同植物群系的孢粉组合具有不同的代表性成分与变化特征,能较好地反映当地植被状况。桦木林和黄背栎林的孢粉组合中指示性成分分别是高含量的桦木属和常绿栎类花粉;冷杉林下的样品,除采自仅有稀疏冷杉的冷杉林下的样品外,其他样品的孢粉组合都较好地反映了高含量的冷杉属花粉;杜鹃灌丛和蔷薇灌丛的孢粉组合分别以高含量的杜鹃花科和蔷薇科花粉为特征;在花粉产量低且植被较开阔的流石滩疏生草甸中,孢粉组合以高含量的草本花粉和外来乔木花粉(如松、冷杉等)为主。松属花粉在本研究区各植物群系下所有样品的孢粉组合中均有较高含量,说明松属花粉产量高、传播能力最强,具有超代表性;铁杉属和桤木属花粉也具有较强的传播能力,它们是外来花粉的主要成分,在不同植物群系下其花粉含量的高低与当地植被的郁闭度及当地植被花粉产量有关;桦木属和常绿栎类花粉代表性强,花粉产量高,也具有较强的传播能力;冷杉属花粉具有明显的低代表性,但其传播能力较强;杜鹃花科花粉的代表性较好,但传播能力差,其花粉散布范围基本在有母体植物生长的地方;柳属花粉代表性低,其花粉含量高于1.0%可能指示柳树的存在;单裂缝孢子的蕨类植物在本研究区部分样品中有较高含量,说明单裂缝孢子的蕨类植物比三裂缝孢子的蕨类植物可能更能适应海拔3 400 m以上的高海拔环境。     

中俄黑龙江—阿穆尔跨境地区寒温带表土孢粉研究

文中对黑龙江北部-俄罗斯阿穆尔地区进行了表土孢粉分析,采样点共40个,样点的地理分布覆盖了5种主要的植被类型,分别是落叶针叶林、常绿针叶林、针阔混交林、落叶阔叶林、湿地沼泽。每个样点同时在野外进行了植被类型描述和覆盖度统计。结果表明,该地区寒温带植被的表土花粉组成中,占优势的木本花粉主要有针叶类的Pinus,Larix,Picea和Abies;阔叶类的主要为Betula,Quercus等;草本以Cyperaceae和Artemisia为主,这些组分与植被中的建群植物类型基本一致。花粉的植被代表性R值结果表明,桦木属具有超代表性,松属花粉代表性中等,落叶松和云杉属为低代表性,栎属、槭树属等的代表性与植被覆盖度相近。花粉的联合指数揭示了柏科、柳属、禾本科、落叶松属等指数较高,而松属、蒿属、栎属、桦木属等联合指数中等。通过降趋对应分析将花粉组合分为三组:1)松属、冷杉、云杉、落叶松、柏科;2)鹅耳枥、桤木属、桦木属、栎属;3)菊科、莎草科、蒿属、禾本科,分别代表了针叶林、落叶阔叶林和湿地沼泽等植被类型,说明花粉组合在植被类型上具有一定的指示意义。乔木花粉的气候因子分析表明,一月最低气温值与乔木花粉关系最密切。     

东北长白山垂直林带下现代表土花粉与植被关系

在长白山北坡5个垂直植被带的林下采集29个表土(苔藓)样品进行孢粉分析,同时将其结果作对应分析.结果表明,除个别样品,在长白山垂直植被带的孢粉组合中乔木花粉占优势,其中以松属和桦木属最多,在各植被带均有分布.松属花粉最高含量出现在以红松为主的针阔混交林带的孢粉组合中;桦木属花粉则大量见于亚高山岳桦林带和以栎桦为主的阔叶落叶林带,但前者伴有耐寒、早的小灌丛杜鹃花属花粉,而在后者中则见有大量蕨类孢子.阔叶落叶林带的孢粉组合是以类型多、百分含量高的落叶乔木花粉和大量蕨类孢子为特征.亚高山针叶林带的孢粉组合中出现数量众多的云杉属花粉.在高山苔原带孢粉组合中虽然乔木花粉略占优势,但极少或不见蕨类孢子,与其他植被带比较,草本植物和小灌丛花粉明鲜较多,其中杜鹃属花粉含量在草本中占优势,其中出现苔原带的指示花粉--仙女木属.     

东北长白山垂直林带下现代表土花粉与植被关系

在长白山北坡5个垂直植被带的林下采集29个表土(苔藓)样品进行孢粉分析，同时将其结果作对应分析。结果表明，除个别样品，在长白山垂直植被带的孢粉组合中乔木花粉占优势，其中以松属和桦木属最多，在各植被带均有分布。松属花粉最高含量出现在以红松为主的针阔混交林带的孢粉组合中；桦木属花粉则大量见于亚高山岳桦林带和以栎桦为主的阔叶落叶林带，但前者伴有耐寒、旱的小灌从杜鹃花属花粉，而在后者中则见有大量蕨类孢子。阔叶落叶林带的孢粉组合是以类型多、百分含量高的落叶乔木花粉和大量蕨类饱子为特征。亚高山针叶林带的孢粉组合中出现数量众多的云杉属花粉。在高山苔原带孢粉组合中虽然乔木花粉略占优势，但极少或不见蕨类孢子，与其他植被带比较，草本植物和小灌丛花粉明鲜较多，其中杜鹃属花粉含量在草本中占优势，其中出现苔原带的指示花粉——仙女木属。     

太白山表土花粉和气孔器与植物类型的关系研究

通过陕西太白山13个样点表土花粉组合特征和气孔器及其与植物类型之间关系的分析,结果发现:针阔混交林花粉组合能很好地反映植物类型特征,落叶阔叶林和针叶林花粉组合能较好地与植物类型相对应,高山灌丛草甸花粉组合未能反映植物类型数量特征;主要花粉类型松属、铁杉属和桦属花粉具超代表性,胡桃属和榆属花粉具适宜代表性,落叶松属、冷杉属、杜鹃花科和槭属花粉具低代表性;DCA(Detrended Correspondence Analysis)分析表明,通过花粉数据能够较好区分不同植被类型,结合气孔器特征能够准确反映植被特征。     

江苏宜兴龙池山现代植被表土孢粉的初步研究

江苏宜兴龙池山森林自然保护区表土花粉分析结果表明,表土孢粉植物群主要以栎属(Quercus)、松属(Pinus)、青冈属(Cyclobalanopsis)、栲属(Castanopsis)/柯属(Lithocarpus)、栗属(Castanea)占优势的木本植物组成,混生有枫香属(Liquidambar)、杨梅属(Myrica)、冬青属(Ilex)、女贞属(Ligustrum)、紫树属(Nyssa)、盐肤木属(Rhus)、黄连木属(Pistacia)等亚热带常见植物类型。研究区不同海拔高度的表土孢粉组合特征基本反映了当地现今的植物构成、植被面貌及其垂直分布规律。结合长江三角洲及其周边地区其他代表性表土花粉资料,首次提出以常绿阔叶木本植物与落叶阔叶木本植物含量之比(E/D),并结合重要优势、标志木本植物科属,初步识别和确立各地带性森林植被的表土花粉指标,为这一地区开展第四纪古植被和古气候等孢粉研究提供参考性依据。     

云南泸沽湖及周边山地表层孢粉与植被关系研究

本文对云南泸沽湖周边山地不同植被类型下采集的32个表土样品和36个泸沽湖湖泊表层样品进行了孢粉分析,探讨了不同植被类型内的表土孢粉散布特征,对比分析了山地表土与湖泊表层孢粉分布特征的差异。结果表明,不同山地植被类型的孢粉组合具有不同的代表性成分与变化特征,能够较好地反映相应的植被类型。湖泊表层孢粉研究表明,湖泊内不同位置的孢粉组合差异较小,说明湖泊表层孢粉反映的是区域植被的平均分布状况。对比分析泸沽湖周边山地表土与湖泊表层样品的孢粉组合,两者存在一定的差异,表现为:湖泊表层的孢粉组合中乔木花粉(主要是松属)平均含量比表土高,但波动范围要小;草本花粉平均含量要低,且波动范围也小。这可能是由于乔木植物植株较高,而且有些乔木植物花粉具有气囊,更易借助风力将花粉传播到比较远的湖泊中的原因造成的。冷杉和铁杉花粉在所有样品中含量都相对较低,分别不高于6.5%和3.6%;桦属、桤木属、常绿栎类花粉的最高值出现在有这些母体植物生长的表土样品中,在其他样品中则明显较低。在表土孢粉样品中经常可以见到冷杉的气孔器,但在湖泊表层样品中却没有见到,说明气孔器不易到达湖泊中。该研究是对中国西南表层孢粉研究的有益补充,同时为泸沽湖新生代特别是第四纪化石孢粉解释提供了可靠的参考和依据。     

Succession of secondary forests affected by pine wilt disease in western Japan followed on vegetation maps

Abstract. Succession, changes in the distribution pattern of forest vegetation, and Pinus forest survival following pine wilt disease were clarified based on phytosociological analysis and vegetation maps. Survival of Pinus forests was restricted to the early successional stages, which were located on ridges and the upper part of slopes. Subsequent to pine wilt disease, the succession progressed from early to late substages of Pinus forest, mixed deciduous and evergreen Quercus, to evergreen Quercus forest. Succession occurs in abandoned pine forests which apparently are in a bad state and are vulnerable to attacks by pine wilt disease.     

Late Quaternary vegetation and climatic history of eastern Nepal

The late Quaternary vegetation and climatic history at high altitude in eastern Nepal was studied through stratigraphy, radiocarbon dating and pollen analysis. The Thulo Pokhari lake (27°41′ N, 87°43′ E, ca. 3980 m a.s.l.) is just above the subalpine Abies spectabilis–Betula utilis forest zone and surrounded by Rhododendron scrub. The climate in the studied area is very humid under the influence of the monsoon. Silty sediments suggesting lake conditions prevailed at the lower part of the sediment samples, whereas the upper part consisted mainly of herbaceous peat indicating a mire condition. The pollen record extends back to ca. 11000 yr bp . Although the absence of major changes between the pollen assemblages of the Pleistocene and those in the Holocene was attributed to the situation of the sampling plot above the forest limit, the results suggest the following history. (1) The abundance of Pinus pollen around 11000 yr bp represents expansion of the area unoccupied by late successional trees and/or a drier condition. Significant occurrence of Picea pollen is noteworthy, since this genus is absent in eastern Nepal at present in spite of its wide distribution throughout the neighbouring areas of the Himalayas. (2) The increase in abundance of Quercus pollen and the decline in Pinus pollen in the latest Pleistocene represent climatic amelioration favourable to late successional mesophytes. (3) The climate was most moist and mild in the SP-III, although the absolute age of the pollen zone is not distinct. The percentages of broadleaved trees such as Alnus, Betula, Carpinus and Corylus were increased at the expense of Quercus and coniferous pollen types. Sedimentation was interrupted by lake level decline and/or glacial advance during the period from ca. 11000–1600 yr bp . (4) The increase in abundance of coniferous pollen types such as Pinus, Abies and Tsuga indicates that the climate became drier and cooler, and the present subalpine forest zone composed of A. spectabilis, T. dumosa and Betula utilis was established around 1600 yr bp . The formation of bog or alpine meadow vegetation during the period was shown by the ¹⁴C dates of the peat and the increase in Rosaceae and herbaceous pollen. (5) The increase in abundance of Ericaceae and Alnus pollen in the SP-V indicates that the present alpine Rhododendron scrub zone has been established since ca. 940 yr bp as a result of human influence on the original vegetation. This interpretation is supported by the decline in the proportion of arboreal pollen. Since the age of the initiation of human influence varies with the altitude and region, further study will be necessary to determine the accurate age.     

Modern pollen and vegetation relationships in the mountains of southern California,USA

The relationship between modern pollen assemblages and modern vegetation along two elevational transects within the Transverse and Peninsular Ranges of southern California, USA, is demonstrated using cluster analysis of the pollen data. Cluster analysis separates the Sonora Desert vegetation, Valley grassland/agricultural land and chaparral vegetation types on the San Jacinto Mountains transect. Chaparral is not easily separated on the San Bernardino Mountains transect, probably due to the presence of Quercus dumosa (scrub oak) there. The lower montane Quercus – Pinus (oak – pine) community is distinct from other forest types, and can be subdivided palynologically based upon relative importance of Quercus, Pinus and Cupressaceae [primarily Calocedrus decurrens (incense cedar)] pollen. Subdivisions include Quercus – Pinus – Cupressaceae, Quercus – Cupressaceae – Pinus and Quercus – Pinus assemblages. Higher elevation Pinus – Abies (pine – fir) and Pinus-dominated communities are also differentiated from one another, although the subalpine vegetation type only occurs on the San Bernardino Mountains transect. Though the study area presently straddles a transition between winter-wet and summer-wet climatic regimes, differences between the pollen assemblages in the two mountain ranges are minimal. Pollen assemblages from lower elevations document the effects of human activities, primarily agriculture, on the modern pollen rain of the region, with the occurrence of introduced citrus (Citrus sp.) and shade (Eucalyptus sp.) trees and weedy disturbance indicators (e.g., Brassicaceae).     

贵州施秉喀斯特地区林地土壤甲螨的群落组成及多样性（英文）

【目的】为了解施秉喀斯特地区林地土壤甲螨的分布和群落组成特点,明确中国西南喀斯特地区林地类型对土壤甲螨群落密度、组成和物种多样性的影响,对该区林地土壤甲螨的群落结构及多样性进行了的调查和分析。【方法】2012年8月选取了中国西南施秉喀斯特地区典型生境中的8个样地,每个样地9个取样点,用Berlese-Tullgren装置分离土样24 h。多样性分析采用常见的多样性指数;群落相似性分析采用Jaccard相似性系数(C_J);群落聚类分析分别采用Marczewski Steinhaus 距离(C_ms)和Bray-Curtis距离,应用R 2.11程序进行类平均法聚类。【结果】结果显示,中国西南喀斯特8个样地中土壤甲螨由少数的优势属和数量众多的稀有属组成。其中全菌甲螨属 Perscheloribates (22.48%)和长单翼甲螨属 Protoribates (11.45%)个体数量最为丰富。长单翼甲螨属 Protoribate、上罗甲螨属Epilohmannia、小奥甲螨属 Oppiella、小盾珠甲螨属 Suctobelbella 和盖头甲螨属 Tectocepheus 分布广泛。本区的甲螨组成（属级水平）表现出明显热带和亚热带地区特点。在天然常绿落叶阔叶林中,甲螨的个体数量和种类数较多,但多样性不高,而在人工针叶林中甲螨多样性最高。甲螨群落组成和分布特征多样,异质性高,特别是在天然常绿落叶阔叶林中突出。【结论】研究表明,施秉喀斯特生态系统的不同林分影响甲螨的物种多样性和群落稳定性,天然常绿落叶阔叶混交林是甲螨的“避难所”。     

Vegetation changes around the last glacial maximum and effects of the Aira-Tn ash,at the Itai-Teragatani site,central Japan

On the basis of fossil pollen, plant macrofossils and fossil wood, vegetation existing around the Itai-Teragatani Site between 26000 and 20000 yr ago was reconstructed. On the upland, there were mixed forests of conifers and deciduous broad-leaved trees throughout the studied period. The forests consisted mainly ofPinus subgen.Haploxylon andQuercus subgen.Lepidobalanus, together withTsuga, Cryptomeria andUlmus-Zelkova. In the wetland, there were stands ofBetula andAlnus in grassland consisting of Cyperaceae, Gramineae,Lysichiton, Thalictrum, Sangusiorba, Umbelliferae and Compositae. The vegetation changed three times during the studied period. The first change, which occurred prior to the fall of the Aira-Tn ash, was characterized by an increase inAbies, Pinus subgen.Haploxylon and hygrophytes, and a decrease inCryptomeria andAlnus. This is considered to reflect a cooler climate, and expansion of grassland. The second change was caused by the fall of the Aira-Tn ash, which caused serious damage to the vegetation. Many taxa, except forAlnus, Cyperaceae andLysichiton, decreased or vanished after the ash fall. The third change was the process of recovery after the damage. The regenerated forests differed from those before the ash fall. With the regeneration conifers andArtemisia increased. This seemed to reflect the changes in climate and ground conditions caused by the accumulation of the ash.     

Palaeovegetational reconstruction based on pollen and seeds/fruits from a Bronze Age archaeological site in Tuscany (Italy)

Abstract

A reconstruction of the vegetation surrounding the Bronze Age archaeological site of San Lorenzo a Greve (Florence) based on pollen and seed/fruit records is presented. Pollen analysis suggests the presence of prevailingly open and damp landscapes, typically occurring on alluvial soils. Patches of woodland, mostly formed by deciduous Quercus, Ulmus, Salix, were alternated to the grasslands. Vitis also probably grew in these damp thickets together with Alnus and Hedera. The forests on the hilly slopes included deciduous Quercus, Carpinus betulus, Corylus, Cornus mas, and Sambucus nigra. Where the soil was well drained, Ostrya carpinifolia and Mediterranean evergreen elements such as Q. ilex and Viburnum tinus grew. In the landscape scenario reconstructed by pollen analysis, seeds/fruits indicated the presence of specific plants which produce a low amount of pollen: they are seldom recorded in pollen spectra but their fruits were commonly gathered in prehistory.     

Palaeovegetation of China: a pollen data-based synthesis for the mid-Holocene and last glacial maximum

Pollen data from China for 6000 and 18,000 ¹⁴C yr bp were compiled and used to reconstruct palaeovegetation patterns, using complete taxon lists where possible and a biomization procedure that entailed the assignment of 645 pollen taxa to plant functional types. A set of 658 modern pollen samples spanning all biomes and regions provided a comprehensive test for this procedure and showed convincing agreement between reconstructed biomes and present natural vegetation types, both geographically and in terms of the elevation gradients in mountain regions of north‐eastern and south‐western China. The 6000 ¹⁴C yr bp map confirms earlier studies in showing that the forest biomes in eastern China were systematically shifted northwards and extended westwards during the mid‐Holocene. Tropical rain forest occurred on mainland China at sites characterized today by either tropical seasonal or broadleaved evergreen/warm mixed forest. Broadleaved evergreen/warm mixed forest occurred further north than today, and at higher elevation sites within the modern latitudinal range of this biome. The northern limit of temperate deciduous forest was shifted c. 800 km north relative to today. The 18,000 ¹⁴C yr bp map shows that steppe and even desert vegetation extended to the modern coast of eastern China at the last glacial maximum, replacing today’s temperate deciduous forest. Tropical forests were excluded from China and broadleaved evergreen/warm mixed forest had retreated to tropical latitudes, while taiga extended southwards to c. 43°N.     

Modern pollen assemblages from Reasi (Jammu and Kashmir), India: a tool for interpreting fossil pollen records

Twenty five surface samples/moss cushions were collected for palynological analysis from open areas of Reasi District, Jammu and Kashmir (India). These samples were used to investigate the relationships between extant vegetation and modern pollen spectra, which serve as modern analogue for the reliable ecological interpretation of fossil pollen records. The present vegetation in the region comprises tropical dry deciduous forests and subtropical pine forests with scattered stands of oak. The pollen analysis reveals that Pinus sp. (average 69% in the pollen assemblages), amongst the conifers, dominates the pollen rain, which can be attributed to its high pollen productivity and exceptional pollen dispersal efficiency. Cedrus sp. and Podocarpus sp. pollen contribute with an average of 16 and 5% to the total pollen rain. Other conifers such as Picea sp., Abies sp., Juniperus sp. and Tsuga sp., as well as broad-leaved taxa such as Quercus sp., Alnus sp., Betula sp., Carpinus sp., Corylus sp., Juglans sp., Ulmus sp., Salix sp., Elaeocarpus sp., Mallotus sp. and Aesculus sp., have lower averages of 1 to 4.5% in the total pollen rain which could be either due to their poor pollen dispersal efficiency or to the poor preservation in the samples. Tubuliflorae (average 25%), Poaceae (average 6.26%), Cerealia and other crop plants (average 7.68%) are other prominent taxa in the pollen rain. The nearly complete absence of members of tropical dry deciduous forests in the pollen spectra likely is due to the fact that most species in this vegetation type are not wind pollinated.     

Vegetational and climatic investigations in the Early Miocene lacustrine deposits of the Güvem Basin (Galatean Volcanic Province), NW Central Anatolia, Turkey

The palynological analysis of the Burdigalian (Early Miocene) successions of the Güvem Basin (NW Central Anatoia, Turkey) has been carried out with the aim of reconstructing the palaeovegetation. The pollen spectra indicate a flora dominated by trees such as Quercus deciduous type, Carya, Carpinus, Ulmus/Zelkova, Engelhardia, Quercus ilex type and Pinaceae. Pterocarya, Juglans, Alnus, Salix, Liquidambar and Oleaceae are represented by lower percentages. Herbs and shrubs are represented by minor amounts of Poaceae, Amaranthaceae/Chenopodiaceae, Asteraceae/Asteroideae, Brassicaceae, and the aquatics Potamogeton, Sparganium and Typha. The Burdigalian flora reflects a mixed mesophytic forest with Quercus deciduous type, Quercus ilex type, pine species, Ulmus/Zelkova, Engelhardia, Carya, Carpinus, Pterocarya, etc., sparcely interspersed with open herbaceous areas. This flora reflects a warm-temperate climate. The fluctuations in abundances of broadleaved trees and xerophytes may represent fluctuations of relatively wet and dry periods. The overall composition of the flora of the Güvem Basin reflects cooler conditions compared with other Early Miocene floras in Europe, which is possibly due to intense volcanic activity of the area.