黑龙江嘉荫晚白垩世渔亮子组孢粉地层研究

黑龙江嘉荫县渔亮子组是我国最早发现爬行动物化石的层位,盛产鸭嘴龙等爬行类化石,前人认为,该组在层位上相当于北美晚白垩世马斯特里赫特期Ｅｄｍｏｎｔｏｎ群,ＨｅｌｌＣｒｅｅｋ和Ｌａｎｃｅ组,但孢粉化石资料提示,渔亮子组中的被子植物花粉尚未发展至上述群（组）的阶段,其层位应较之低,大致相当于北美的坎佩尼期ＢｅｌｌｙＲｉｖｅｒ群（组）或相当层位。     

Fossil pollen grains of Asteraceae from the Miocene of Patagonia: Nassauviinae affinity

Fossil pollen grains with morphological features unique in the subtribe Nassauviinae (tribe Mutisieae, Asteraceae) occur in Miocene marine deposits of eastern Patagonia, southern South America. A new morphogenus and two morphospecies are proposed to assemble fossil pollen grains characterized by having a complex bilayered exine structure with delicate columellae, separated by an internal tectum. Subprolate specimens with Trixis exine type (ectosexine thinner than endosexine, straight internal tectum) are referred to Huanilipollis cabrerae. This species is similar to pollen of recent Holocheilus, Jungia, and Proustia. Suboblate specimens with Oxyphyllum exine type (ectosexine and endosexine equally thick, zigzag internal tectum) are referred to Huanilipollis criscii. This species is similar to pollen of recent Triptilion. The spore/pollen sequences in which Nassauviinae pollen types occur suggest a wide range of vegetation types varying from forest dominated during the Early Miocene (Chenque Formation) to virtually xerophytic ones during the Late Miocene (Puerto Madryn Formation). The subtribe Nassauviinae comprises 25 genera and ca. 320 species of vines, shrubs and low trees endemic to America with a wide range of ecological preferences; the nearest living relatives of the fossil types being mostly confined to humid landscapes. The unusual occurrence of these groups during the arid characterized Late Miocene time could be attributed to the complex interplay of the mountain uplift and global circulation patterns. These forcing factors would have created a mosaic of different habitats with both patches of forest and dry-adapted species developing in relatively small regions. This is the first fossil record of Nassauviinae and confirms that this subtribe of Asteraceae was already differentiated in the Miocene.     

Fern spore and pollen airspora profile of Singapore

Monitoring atmospheric fern spore and pollen loads in Singapore was initiated in June 1990. Aside from the more numerous fungal spores, fern spores and pollen grains made up 6.2–8.6% and 4.4–5.4% of the total airspora sampled, respectively. The most frequently encountered fern spores, in descending order, were those of Nephrolepis auriculata, Dicranopteris linearis, Stenochlaena palustris, Asplenium nidus, Pteridium aquilinum, and Dicranopteris curranii. For pollen grains, the most frequently encountered, in descending order, were Elaeis guineensis, Casuarina equisetifolia, Acacia auriculiformis, Kyllingia polyphylla, Podocarpus, and Poaceae pollen grains. Seasonal patterns for individual fern spore or pollen types were discernible despite the relatively uniform tropical climate in Singapore. The fern spore and pollen calendar for the period 1991–1995 was compared to that of 2005–2006 as a follow-up study to keep abreast with the rapidly changing landscape of Singapore. Diurnal patterns showing a late morning to afternoon peak period were seen in fern spores, while the peak period was in the morning for pollen types studied with the exception to oil palm pollen. Additionally, association between fern spore and pollen counts and local meteorological conditions were also analyzed and found to be highly correlated. This study has thus identified the fern spores and pollen airspora components, and determined the calendars, as well as diurnal profiles of the Singapore airspora and provides invaluable information for allergy studies by highlighting the trigger sources present in the environment.     

蕨类植物孢子与种子植物花粉萌发的比较

蕨类植物孢子与种子植物花粉在有性生殖过程中都具有重要的作用。花粉作为种子植物的雄配子体, 通过萌发后极性生长的花粉管将精细胞送到胚囊完成受精作用。蕨类植物孢子作为配子体的原始细胞, 通过不对称的有丝分裂产生一大一小两个细胞, 小细胞萌发出极性生长的假根, 大细胞继续分裂发育为原叶体(配子体)。成熟的花粉和蕨类植物孢子都是代谢高度静止的细胞, 两者的萌发过程不仅都受到各种不同环境因子的影响, 而且在信号转导、极性建立和能量代谢等方面可能有着相似的调控机制。本文综述了蕨类植物孢子和种子植物花粉萌发过程的差异和保守性特征。     

The Seed and Fern Spore Bank of a Recovering African Tropical Forest

Seed banks contribute to forest regeneration after disturbance, but less is known about fern spore banks, particularly in a paleotropical context. We sampled the buried seed and fern spore bank in Mabira Forest, a 300 km² forest in central Uganda, to explore the effect of time since disturbance. Soil cores (5 cm depth) were taken from 39 plots across three different classes of ‘recovery’: (1) not disturbed since 1950; (2) logged between 1950 and 1980; and (3) cleared for agriculture between 1970 and 1990 but reforested since. Plant emergence was monitored in a glasshouse. We predicted that the seed bank would reflect time since disturbance, with more pioneer species in recently disturbed stands, and that the fern spore bank would reflect stand age less closely due to greater dispersal capacity. We recorded a median 752 seeds per square meter, most of which were trees; the most abundant species was the invasive tree Broussonetia papyrifera. The fern spore bank was twice as dense, but 95 percent of fern spores were of one species, Christella parasitica. Tree seed density was significantly affected by time since disturbance with fewer seeds in the older stands. Herb seed density, fern spore density, and species richness for all groups were not significantly affected by time since disturbance. Neither seed bank nor fern spore bank closely resembled the aboveground vegetation. We compared our results to existing literature on seed banks in tropical forests, finding that our densities are relatively high for African forests, but low compared to the Neotropics and Australia.     

Water properties in fern spores: sorption characteristics relating to water affinity, glassy states, and storage stability

Ex situ conservation of ferns may be accomplished by maintaining the viability of stored spores for many years. Storage conditions that maximize spore longevity can be inferred from an understanding of the behaviour of water within fern spores. Water sorption properties were measured in spores of five homosporeous species of ferns and compared with properties of pollen, seeds, and fern leaf tissue. Isotherms were constructed at 5, 25, and 45 degrees C and analysed using different physicochemical models in order to quantify chemical affinity and heat (enthalpy) of sorption of water in fern spores. Fern spores hydrate slowly but dry rapidly at ambient relative humidity. Low Brunauer-Emmet-Teller monolayer values, few water-binding sites according to the D'Arcy-Watt model, and limited solute-solvent compatibility according to the Flory-Huggins model suggest that fern spores have low affinity for water. Despite the low water affinity, fern spores demonstrate relatively high values of sorption enthalpy (DeltaH(sorp)). Parameters associated with binding sites and DeltaH(sorp) decrease with increasing temperature, suggesting temperature- and hydration-dependent changes in volume of spore macromolecules. Collectively, these data may relate to the degree to which cellular structures within fern spores are stabilized during drying and cooling. Water sorption properties within fern spores suggest that storage at subfreezing temperatures will give longevities comparable with those achieved with seeds. However, the window of optimum water contents for fern spores is very narrow and much lower than that measured in seeds, making precise manipulation of water content imperative for achieving maximum longevity.     

蕨类植物孢子与种子植物花粉萌发的比较

蕨类植物孢子与种子植物花粉在有性生殖过程中都具有重要的作用。花粉作为种子植物的雄配子体,通过萌发后极性生长的花粉管将精细胞送到胚囊完成受精作用。蕨类植物孢子作为配子体的原始细胞,通过不对称的有丝分裂产生一大一小两个细胞,小细胞萌发出极性生长的假根,大细胞继续分裂发育为原叶体（配子体）。成熟的花粉和蕨类植物孢子都是代谢高度静止的细胞,两者的萌发过程不仅都受到各种不同环境因子的影响,而且在信号转导、极性建立和能量代谢等方面可能有着相似的调控机制。本文综述了蕨类植物孢子和种子植物花粉萌发过程的差异和保守性特征。     

Airborne pollen grains in Nsukka,Nigeria

A study of the airborne pollen grains in Nsukka, Nigeria, has been carried out at two different sampling heights (1.8?m and 15?m) from February 1993 to January 1994. Twenty‐six plant families (40 genera) were identified at the lower sampling height, whilst thirty‐eight families (58 genera) were identified at the height of 15?m. A total of nine and eighteen fern spore types were observed at 1.80?m and 15?m, respectively. The quantitative results indicate that the number of pollen observed at 15?m sampling height was statistically different (p<0.05) from that observed at the height of 1.80?m. The analysis of airborne pollen grains indicates three different periods: (1) dry season, (2) rainy season, and (3) late rainy season to early dry season/Harmattan. The highest pollen abundance was recorded during the late rainy season – early dry season/Harmattan followed by that of the dry season. The predominant pollen grains and fern spores trapped at both heights include Poaceae, Casuarina equisetifolia, Milicia excelsa, Elaeis guineensis, Celtis integrifolia, Alchornea cordifolia, Amaranthaceae/Chenopodiaceae, Combretaceae/Melastomataceae, Nephrolepis biserrata, Thelypteris totta, and Dryopteris spp.     

Antechiniscus in Australia: Description of Antechiniscus moscali sp. n. and Redescription of Antechiniscus parvisentus (Horning & Schuster, 1983) (Heterotardigrada: Echiniscidae)

Two species of the genus Antechiniscus have been found in Nothofagus forests in Australia. The new species A. moscali sp. n. is described. The New Zealand species A. parvisentus (Horning & Schuster, 1983) is redescribed from type material and from the new material from Australia. The taxonomic status of the two species within the genus is discussed.     

家养食草动物粪便中的花粉及菌孢子类型及其对人类活动的指示意义

考古遗址中动物粪化石中的微体植物遗存是重建过去生态环境以及人类活动的重要材料,然而对于能够指示人类活动的粪化石孢粉组合类型及其特征仍然缺乏清楚的认识。本文研究了山羊(Capra aegagrus)、绵羊(Ovis aries)、牛(Bos taurus)、骆驼(Camelus)、牦牛(Bos grunniens)和马(Equus caballus)等几种中国常见的家养食草类动物粪便中的主要孢粉和真菌孢子类型。通过分析这些动物粪便的花粉组合特征,探讨了花粉和菌孢子等微体植物遗存对生态环境及人类活动的指示意义。花粉种类丰度低、一些特征种属花粉(如禾本科、藜科)含量高是家养食草类动物粪便花粉组合的主要特征,可以用于指示人类的饲养行为。家养食草动物粪便中的粪生真菌孢子类型主要有Sporormiella,Sodaria,Pleospora,Coniochaeta,Thecaphora and Dictyosporium。研究表明真菌孢子的分布主要受到动物活动范围的影响,这使得利用粪生菌孢子(如Sporormiella)并结合其他记录来反映人类的饲养或游牧活动成为可能。     

The origin and evolution of Indomalesian,Australasian and Pacific island biotas: insights from Aglaieae (Meliaceae,Sapindales)

Aim The role of long‐distance dispersal in the Indomalesian, Australasian and Pacific flora is currently hotly debated. The lack of well‐resolved phylogenetic trees for Pacific plants has been a major limitation for biogeographical analysis. Here, we present a well‐resolved phylogenetic tree for the tribe Aglaieae in the mahogany family, Meliaceae, and use it to investigate the origin, evolution and dispersal history of biotas in this area. The subfamily Melioideae, including the tribe Aglaieae (Meliaceae, Sapindales), is a plant group with good representation in the region in terms of biomass and species numbers, wide ecological attributes and known animal vectors. The family has a good fossil record (especially from North America and Europe). Genera and species in the tribe Aglaieae therefore provide an excellent model group for addressing this debate. Location Indomalesia, Australasia, Pacific islands. Methods Results from nuclear internal transcribed spacer ribosomal DNA analyses of 82 taxa, based on sequence alignment guided by secondary structure models, were combined with evidence from fossils and distribution data. We used strict and relaxed molecular clock approaches to estimate divergence times within Aglaieae. Putative ancestral areas were investigated through area‐based and event‐based biogeographical approaches. Information on dispersal routes and their direction was inferred from the investigation of dispersal asymmetries between areas. Results Our study indicates that the crown group of Aglaieae dates back at least to the Late Eocene, with major divergence events occurring during the Oligocene and Miocene. It also suggests that dispersal routes existed during Miocene–Pliocene times from the area including Peninsular Malaysia, Sumatra and Borneo to Wallacea, India and Indochina, and from the area including New Guinea, New Ireland and New Britain further east to the Pacific islands at the peripheries of the distribution range. The origin of the Fijian species dates back to the Pliocene. Main conclusions Dispersal over oceanic water barriers has occurred during geological time and seems to have been a major driving force for divergence events in Aglaieae, with some old Gondwanan land masses (e.g. Australia) colonized only during recent times. Movement from the ancestral area was predominantly towards the east. Extant Fijian species of Aglaia are monophyletic and share morphological features rarely found in species of other areas, suggesting speciation within an endemic clade. Divergence of living taxa from their closest living relatives took place during both the Miocene and the Pliocene, and peaked in the Pliocene. The present‐day distribution of many species in the tribe must therefore have arisen as a result of dispersal rather than vicariance events. Furthermore, colonization from Indomalesia to Australasia and the Pacific has frequently been followed by speciation.     

An 18 million year record of vegetation and climate change in northwestern Canada and Alaska: tectonic and global climatic correlates

We reconstruct long-term vegetation/paleoclimatic trends, spanning the last 18 million years, in Alaska, Yukon and far western Northwest Territories. Twenty-one average percentage spectra for pollen and spores are assembled from eight surface/subsurface sections. The sections are dated independently or by correlation. Pollen and spore ratios indicate the direction of change in vegetation and climatic parameters — growing season temperature (T_est), tree canopy density (C_est) and paludification at study sites (P_est). A global warm peak ca. 15 Ma is shown by the abundance of thermophilous taxa, including Fagus and Quercus. A temperature decline immediately following 15 Ma parallels climatic reconstructions based on marine oxygen isotopes. Subsequent declines correlate to the Messinian event and the onset of late Pliocene-Pleistocene glaciation. After 7 Ma herbs and shrubs become more important elements of the palynological assemblages, suggesting a more continental, colder/drier climate. However, a late Pliocene warm interval is evident. Vegetation/climatic changes during the early to late Miocene show synchrony with, and are most economically attributable to, global events. After 7 Ma, vegetation/climate change is attributed primarily to latest Miocene-to-Pleistocene uplift of the Alaska Range and St. Elias Mts. The continuing influence of global climatic patterns is shown in the late Pliocene warm interval, despite uplift to the south. The opening of the Bering Strait ca. 3 Ma may have moderated the climate in the study area.     

鹤庆深钻孢粉记录揭示的气候变化与西南季风演化

本文在鹤庆深钻孢粉分析的基础上,把各孢粉类型划分成不同的孢粉生态组,结合孢粉多样性指数,系统重建云南鹤庆地区2.78 Ma以来的占气候演化所经历的8个大的阶段,与西南季风在滇西北地区8次大的变化相对应:即在2.729-2.608Ma和0.118Ma-11.83ka BP期间,气候整体湿润,冬、夏季降水的季节性较强,反映西南季风相对较强盛;1.447-0.342Ma期间,气候整体逐渐变湿,冷暖、干湿变化幅度逐渐变大,气候组合特征逐渐变复杂,反映西南季风逐渐增强,其波动幅度也逐渐变大,并于0.991-0.342Ma期间达到最强盛,其波动幅度也最大;而在2.780-2.729Ma、2.608-1.447Ma和0.342-0.118Ma期间,气候普遍相对温暖干旱,西南季风相对较弱.     

Presence of sonneratiaceous pollen in middle miocene sediments, central Japan

Numerous sonneratiaceous pollen grains, found in Middle Miocene sediments of central Japan possess both meridional ridges and polar caps with inter-columellate granules Although the exine architecture of these pollen is similar to that of the living Sonneratia alba, a colpal aperture as observable in these fossil pollen grains is only rarely present in Sonneratia or in the fossil Florschuetzia, which is a form-genus showing affinity with the genus Sonneratia. The fossil pollen is described as Florschuetzia claricolpata sp.n. This new species not only has a distributional significance, but also may strengthen the phylogenetic link between the genera Florschuetzia and Sonneratia.     

Observed relationships between El Niño‐Southern Oscillation,rainfall variability and vegetation and fire history on Halmahera,Maluku, Indonesia

A temporally high‐resolution palynological study of the uppermost section of core MD98‐2180 from Kau Bay, Halmahera, Indonesia, provides a vegetation and fire record covering the last 250 years. The record is compared with the Maluku Rainfall Index, Southern Oscillation Index (SOI) and southern hemisphere winter sea surface temperatures (SST) for the central Pacific Ocean based on instrumental data, as well as reconstructions of the SOI and the central Pacific SST and historically recorded El Niño events. The results show that significant El Niño events are generally associated with increased representation of Dipterocarpaceae pollen, probably reflecting the mass‐flowering of this taxon during El Niño‐Southern Oscillation (ENSO) droughts, and elevated charcoal levels, reflecting a greater incidence of fires during these extremely dry periods, while humid phases show increased fern numbers. Our findings demonstrate that pollen records ‘ecological’ in scale can provide useful additional proxy records of ENSO events.     

Towards a model of postglacial biogeography in shallow marine species along the Patagonian Province: lessons from the limpet Nacella magellanica (Gmelin, 1791)

ABSTRACT: BACKGROUND: Patagonia extends for more than 84,000 km of irregular coasts is an area especially apt to evaluate how historic and contemporary processes influence the distribution and connectivity of shallow marine benthic organisms. The true limpet Nacella magellanica has a wide distribution in this province and represents a suitable model to infer the Quaternary glacial legacy on marine benthic organisms. This species inhabits ice-free rocky ecosystems, has a narrow bathymetric range and consequently should have been severely affected by recurrent glacial cycles during the Quaternary. We performed phylogeographic and demographic analyses of N. magellanica from 14 localities along its distribution in Pacific Patagonia, Atlantic Patagonia, and the Falkland/Malvinas Islands. RESULTS: Mitochondrial (COI) DNA analyses of 357 individuals of N. magellanica revealed an absence of genetic differentiation in the species with a single genetic unit along Pacific Patagonia. However, we detected significant genetic differences among three main groups named Pacific Patagonia, Atlantic Patagonia and Falkland/Malvinas Islands. Migration rate estimations indicated asymmetrical gene flow, primarily from Pacific Patagonia to Atlantic Patagonia (Nem=2.21) and the Falkland/Malvinas Islands (Nem=16.6). Demographic reconstruction in Pacific Patagonia suggests a recent recolonization process (< 10 ka) supported by neutrality tests, mismatch distribution and the median-joining haplotype genealogy. CONCLUSIONS: Absence of genetic structure, a single dominant haplotype, lack of correlation between geographic and genetic distance, high estimated migration rates and the signal of recent demographic growth represent a large body of evidence supporting the hypothesis of rapid postglacial expansion in this species in Pacific Patagonia. This expansion could have been sustained by larval dispersal following the main current system in this area. Lower levels of genetic diversity in inland sea areas suggest that fjords and channels represent the areas most recently colonized by the species. Hence recolonization seems to follow a west to east direction to areas that were progressively deglaciated. Significant genetic differences among Pacific, Atlantic and Falkland/Malvinas Islands populations may be also explained through disparities in their respective glaciological and geological histories. The Falkland/Malvinas Islands, more than representing a glacial refugium for the species, seems to constitute a sink area considering the strong asymmetric gene flow detected from Pacific to Atlantic sectors. These results suggest that historical and contemporary processes represent the main factors shaping the modern biogeography of most shallow marine benthic invertebrates inhabiting the Patagonian Province.     

Fern richness,tree species surrogacy,and fragment complementarity in a Mexican tropical montane cloud forest

We related pteridophytes versus tree species composition to identify surrogate measures of diversity, and complementarity of seven cloud forest fragments. Forest structure, and fern and tree composition were determined in 70 (2 × 50 m) transects. Fern density (10,150–25,080 individuals/ha) differed among sites. We recorded 83 fern species in the transects. Nonparametric richness estimators indicated that more sampling effort was needed to complete fern inventories (14 more species). However, ferns recorded outside of the transects increased richness to 103 species (six more species than predicted). Twenty-eight species were unique and rare due to special habitat requirements (Diplazium expansum, Hymenophyllum hirsutum, Melpomene leptostoma, Terpsichore asplenifolia), or were at a geographical distribution edge (Diplazium plantaginifolium, Lycopodium thyoides, Pecluma consimilis, Polypodium puberulum). Correlations between fern richness and tree richness and density were not significant, but were significant between fern richness and fern density, between epiphytic fern density and tree richness and density. Tree richness is not a good surrogate for fern diversity. Only three species were recorded in all fragments (Polypodium lepidotrichum, P. longepinnulatum, P. plebeium); thus fragments pteridophytes compositions are highly complementary, but more similar for ferns than for trees. A regional conservation approach which includes many small reserves needs to focus supplementarity on patterns of tree and fern species richness.     

The Tertiary history of the northern temperate element in the northern Latin American biota

The time of origin of cool-to-cold-temperate plants of northern affinities in the Latin American biota is unsettled. Two models have been proposed-a Paleogene origin from a once widespread temperate rain forest, and a Neogene origin by introductions from the north which is best supported by new evidence. Fourteen palynofloras of Tertiary age are now available from Mexico and Central America, in addition to numerous others from the southeastern United States and northern South America. Pollen of cool-temperate plants occurs in the Eocene of southeastern United States, but not in northern Mexico, central Panama, or northern South America. In the Miocene this pollen is sparse in deposits from Mexico and Guatemala, rare in Panama, and absent from northern South America. In the Pliocene pollen representing a diverse northern temperate element of ten genera is present in the Pliocene of southeastern Veracruz, Mexico, five in northeastern Guatemala, and two (Myrica, Salix) first appear in northern South America; Alnus and Quercus are added in the Pleistocene. This north-to-south and early-to-late pattern is consistent with the appearance of highlands in southern Central America and northern South America in the Neogene, closure of the isthmian marine portal between 3.5 and 2.5 Ma (million years ago), and the late Cenozoic cooling trend evident in the O/O-based paleotemperature curve.     

Phylogeny, speciation and species turnover. The case of the Mediterranean gastropods of genus Cyclope Risso, 1826

The genus Cyclope Risso, 1826 (family Nassariidae) has appeared in the fossil record since the Pliocene. Although it is still found today, the teleoconch morphology has never undergone modification, despite the fact that the protoconch morphologies of fossils (multispiral) and living forms (paucispiral) are different. They vary in their embryological and larval development and, hence, are two different species: C. migliorinii (Bevilacqua, 1928), the fossil species, and C. neritea (Linnaeus, 1758), the living species. We discuss the morphologic modifications in the evolution of this genus: the speciation that leads to its appearance and the speciation driving the Pliocene species to the living one. The order and the direction of these changes are based on phylogenetic analysis. No intermediate forms have been found showing a gradual morphological change that could have been worked by natural selection. Our analysis takes as the origin of the morphological novelties the genetic modifications in the ontogenetic processes which resulted in rapid and important phenotypic changes. Both speciation processes are sympatric cladogenetic. The changes that determine the appearance of the genus affect only the teleoconch, not the larval development. The modifications that lead from one species to the other, within the genus Cycope, affect the larval development exclusively. This points to a certain disconnection between the development of the embryo-larval phase and the young-adult formation, such that evolutionary processes could have occurred independently in different ontogenetic stages. The influence of larval ecology in relation to extinction of the ancestor and persistence of the derived species is also analysed. We hypothesize that climatic fluctuations may have affected the planktonic larvae of the fossil species, driving it to extinction. The living species, developing without the planktonic phase, would have resisted these climatic changes. We consider that the mechanisms described as drivers of the evolution of this genus can be of more general validity in prosobranch gastropods.     

麂属(Muntiacus)的分类及其系统发育研究

麂属(Muntiacus)是一群中小型草食有蹄类,为东洋界的特有属,是典型的热带、亚热带类群。在我国,麂属的分布仅限于长江流域及其以南各地,为我国南方的重要毛皮兽。 以往对麂属的研究多限于一般的形态分类,对其系统发育尚未深入研究。在种级分类上至今还存在一些混乱现象。本文试图用分支系统学(Cladistics)的方法,对麂属的种级分化进行系统整理,并对其系统发育作一初步探讨。