Madonna dell'Arma (San Remo, Italie) : expression locale de la végétation ligure au cours du Paléolithique moyen

Pollen analysis of Madonna dell’Arma cave inside part (Liguria, Italy) allowed us to reconstitute, at local scale, the Ligurian coastal vegetation between the end of the last interglacial period and the beginning of the pleniglacial. This transition period shows an important representation of arboreal cover and a persistence of thermophilous elements that allowed us to considerate the western Liguria as a periglacial refuge. During the end of the last interglacial, xerophytic, halophytic herbs and shrubs taken over from a Mediterranean pre-forest unit in the first slopes constituted the coastal zone. The nearness of Argentina torrent and the Armea influenced, in the coast, the existence of marshy zones colonized by hygrophilous trees. In the Ligurian lowlands spread out sclerophyllous and mesophilous forests according to altitude. The beginning of the pleniglacial is indicated in the sequence by increases of Pinus, Cupressaceae and Artemisia in the context of a decline in the thermophilous components. This picture of vegetation has become integrated into the multidisciplinary studies of the site and contributed to the elaboration of palaeoclimatic hypothesis similar as those revealed by the fauna.     

Histoire plio-pléistocène des écosystèmes végétaux de Méditerranée sud-occidentale : apport de l’analyse pollinique de deux sondages en mer d’Alboran

The pollen analysis of sediments of two boreholes located in the northeastern Morocco (Nador 1) and in the southeastern Spain (Andalucia G1) has allowed shedding a new light on the vegetation and climate of the North African littoral plains, the Rif Massif and the Betic Range during the Pliocene. The vegetation around the Alboran Sea was open and xeric during the Zanclean, dominated by herbs including subdesertic elements as Calligonum, Lygeum, Nitraria and Neurada. This type of vegetation indicates a dry and hot climate. The southwestern Mediterranean steppes have therefore a climatic character; they existed before the presence and the heavy pressure of Man on the environment. From the Piacenzian, the development, at Andalucia as well as at Nador, of Artemisia and the appearance of some altitude trees such as Cedrus and Cathaya indicate a vegetation change linked to a climatic change. Modifications in the vegetation observed during the same period in northwestern Mediterranean seem to indicate that the vegetation changes observed at Andalucia and Nador are controlled by the appearance of the first arctic glacial-interglacial cycles. The cedar tree appears at Nador only at the end of the Piacenzian, at time of the first cooling, while it has been found punctually in Messinian and early Pliocene sediments of Habibas in Algeria and in Messinian sediments of the Bou Regreg section at Salé in Morocco. The regular presence of Cedar at Bou Regreg during the Messinian, allows supposing that it was present in the Middle Atlas Mountains and that its development was favoured by colder conditions.     

Pollen analysis from two littoral marshes (Bourdim and Garaat El-Ouez) in the El-Kala wet complex (North-East Algeria). Lateglacial and Holocene history of Algerian vegetation

The study of two pollen sequences from El-Kala marshes allowed the reconstruction of the regional vegetation history supported by eight radiocarbon dates. Pollen assemblages from Bourdim site were dominated by local input of Alnus and Salix, while regional vegetation was characterized by scattered Quercus suber forests with a well-developed Erica arborea matorral. While the vegetation dynamics recorded at Bourdim is recent (Late Holocene), the majority of the pollen diagram from Garaat El-Ouez is contemporaneous to the Late Pleniglacial and is characterized by open woodlands with Pinus, Poaceae and several heliophilous herbs. The significant values of Cedrus pollen identified in this period indicate that the region of El-Kala most probably played the role of a refugium for this tree.     

Hommes et environnements au Paléolithique supérieur en Ukraine continentale et en Crimée : introduction

Research, conducted under the ANR project “Mammouths”, on “the end of the mammoth steppe: Man/Environment relationship during late Pleniglacial in Eastern Europe”, is the subject of several contributions, a part of them is published in this volume, under the heading “Humans and environments during Upper Paleolithic in mainland Ukraine and Crimea”, in the French journal L’anthropologie.     

Pugillo Di Licheni Dell'Abissinia E Dell'Eritrea

Abstract

The long pollen sequences from four volcanic lakes of the Lazio région are presented in order to outline the history of flora and vegetation on the Tyrrhenian side of Central Italy during the last hundred thousand years. The four long pollen records correlate satisfactorily with each other and reflect climatic changes at least at regional scale. Particular attention is paid to the development of arboreal vegetation during the last glacial. The local name “Lazio Complex” is given to the seven main fluctuations of trees of the Pleniglacial (from about 60,000 to about 30,000 years B.P.). The history of Zelkova, Abies, Picea, Fagus, Corylus, Ulmus, Carpinus betulus, Tilia in central Italy is outlined.     

Late Holocene palaeoenvironment change in central Tianshan of Xinjiang,northwest China

The northern slopes of central Tianshan Mountains in Xinjiang, northwestern China can provide an ideal database to research palaeoclimate as disturbance by human impact is relatively low and the vegetation zones reflect climatic gradients. In order to establish the correlation between modern climatic factors and surface pollen assemblages and to reconstruct palaeoclimate on the northern slope of central Tianshan Mountains, three Holocene sections in Daxigou, Huashuwozi and Sichanghu located at different elevations and vegetation zones were chosen for study. A total of 80 surface pollen samples in 86 vegetation quadrats were collected for pollen‐vegetation relationship analysis. The Warmth Index (WI) and Moisture Index (MI) were calculated based on averaged modern climate data during 1951 – 2000 at eight weather stations in the study area. Pollen percentages of Picea, Artemisia, Chenopodiaceae, Ephedra, and Tamarix, as well as A/C (Artemisia/Chenopodiaceae) and AP/NAP (arboreal/nonarboreal pollen) ratio were selected as pollen variables and WI and MI were chosen as climatic variables. The relationship between pollen percentages (Picea, Artemisia, Chenopodiaceae and Tamarix), A/C, AP/NAP ratio, WI and MI values were estimated (95% confidence interval) using stepwise multiple linear regression analysis. WI and MI values for the three sections were calculated using these regression equations, and palaeoclimate for the study area could be reconstructed. The results showed periods of both cool‐humid and warm‐dry conditions on the northern slopes of Tianshan Mountain during the late Holocene.     

Upper quaternary vegetational and climatic sequence of the fuquene area (Eastern Cordillera,Colombia)

In this paper the results of a pollen-analytical study of three bore holes of lake deposits in the Fuquene-Valle de Ubaté area, Colombian Cordillera Oriental (5° N; elev. 2,580 m) are given. By means of ¹⁴C dates and comparison with other pollen diagrams and dates from the Eastern Cordillera, it was possible to correlate the local pollen zones and chronostratigraphical units with the European chronostratigraphical sequence. The longest diagram (Fuquene II) represents some 30, 000 years, including part of the Middle Pleniglacial, the Upper Pleniglacial, the Late Glacial and the Holocene.During the Middle Pleniglacial, Polylepis wood was an important constituent of the vegetation. During climatic extremes of the Upper Pleniglacial an open páramo vegetation existed.During the main part of the Upper Pleniglacial (from ca. 21,000 to ca. 13,000 B.P.) the lake level was low and the climate dry. The lake level rose again in the beginning of the Late Glacial, and the area around the lake became forested. At the beginning of the El Abra Stadial (Late Dryas Stadial) there was a marked cooling and the lake became lower once more; this had a great impact on the vegetation which became partly open again. The beginning of the Holocene is marked by a gradual increase of forest elements, especially of Quercus (oak.) Oak forests dominated the area during the greater part of the Holocene. During the “hypithermal”, elements growing today at a lower level, such as Cecropia, Acalypha (and possibly Alchornea), must have been growing in the area, intermixed with the oak forest. At the same time there was a considerable increase of Urticaceae in the undergrowth of these forests. The vegetation zones were probably situated several hundreds of metres higher than they are at the present time.The influence of man on vegetation had started already before the beginning of our era, but there is a sudden increase of this influence (e.g., increase of Dodonaea, decrease of Quercus and Urticaceae) somewhere around 2,000 B.P. Later on, the diagram shows the rapid ultimate decline of the forest elements and an increase of Gramineae. Today nothing is left of the original oak forests and their place is taken by arable land or by secondary plant communities with low brushwood.In the lake sediments, thin layers of volcanic ash were found dated approximately 9,000 B.P., 11,000 B.P., and 21,000 B.P., respectively; a series of three ash-layers was deposited between approximately 22,000 B.P. and 26,000 B.P. and one possibly at approximately 30,000 B.P. These layers have been found in several other sections in the Eastern Cordillera and are the basis for a tephrochronology.     

A 2700-year high resolution pollen record of climate change from varved Sugan Lake in the Qaidam Basin, northeastern Tibetan Plateau

A 2700-year high resolution pollen record from annually-varved Sugan Lake in the Qaidam Basin at 2793 m a.s.l was obtained to examine vegetation and climatic change on the NE Tibetan Plateau. Pollen data shows that Sugan Basin was constantly covered by open desert-steppe vegetation dominated by Chenopodiaceae, Artemisia, Poaceae and Ephedra. However, large variations in Artemisia/Chenopodiaceae (A/C) ratios suggest regional moisture fluctuations over the last 2700 years, including a dry and relatively stable climate prior to 300 AD, relatively wet climate from 300 to 1200 AD with variability during 1100-1200 AD, and unstable climate since 1200 AD with relatively moister climate during 1250-1400 AD and 1700-1800 AD. However, other proxies (varve thickness, Chironomid taxa, isotopes of oxygen in precipitated carbonate) show fresher water when regional moisture was lower inferred from A/C ratio. This inconsistency suggests the possible difference of in-lake lithology/environment and regional moisture change. Fresh water into the lake from ice melting on the surrounding mountains might have contributed to the in-lake lithology and environment variation. The effective moisture changes in the Basin are in opposite phases to snow accumulation records from Dunde ice core (5325 m a.s.l) and to the monsoon intensity inferred from Dongge Cave, suggesting that the regional topography might have played an important role in mediating moisture changes at regional scale. Pollen data from Sugan Lake shows the shift of moisture at 1200 AD, from stable to variable conditions. This event is well correlated with other paleoclimate proxies in China and other parts of the world; however, the mechanisms behind these patterns require further investigation.     

Un nouveau Bovini dans la faune du Pléistocène supérieur d’Algérie

During the study of the Quaternary Maghrebian bovines in 1985, the review of the Bovini (aurochs and buffalos) found in Upper Pleistocene sites of Algeria showed that in comparison with most of the African bovine assemblage the attribution of genus Pelorovis to the species antiquus was inappropriate. The biometric and cladistic data revealed a close kinship with genus Syncerus. Later, other authors’conclusions confirmed its relevance. The antique buffalo of the Aterian site of the Phacochoeri has all the characteristics of genus Syncerus, but is different in that it shows a certain number of specific characteristics described in this article.     

Macrauchenia patachonica Owen (Mammalia, Litopterna) de la région de São Raimundo Nonato (Piauí, Nordeste brésilien) et la diversité des Macraucheniidae pléistocènes

The São Raimundo Nonato (Piauí, Northeastern Brazil) area yielded about 50 Macraucheniidae remains. The study of this material and of other fossils from Northeastern Brazil (Paraíba, Pernambuco, Rio Grande do Norte) shows a great similarity to Macrauchenia patachonica as it was defined in Argentina, which is the most abundant of the three species pertaining to the genus. Thus the taxon Xenorhinotherium bahiense created in 1988 by Cartelle et Lessa for a material discovered in the Bahia State and assigned to use for all the Quaternary Litopterns from tropical Brazil appears to be no more than a junior synonym of it. M. patachonica seems to have occupied very varied biotopes from sea level up to a high of 4000 m, and from the cold Southern Patagonia to the Equatorial Venezuela. The species lived from the Middle Pleistocene up to the beginning of the Holocene.     

Reliability of pollen ratios for environmental reconstructions on the Tibetan Plateau

Aim Pollen ratios are widely used to gain palaeovegetation and palaeoclimatic information from fossil pollen spectra, although their applicability has seldom been tested with modern pollen data. I used a data set of 113 lake‐surface sediments from the eastern Tibetan Plateau to test the reliability of several pollen ratios. Location The lake‐surface pollen spectra cover a wide range of vegetation types (temperate desert, temperate steppe, alpine desert, alpine steppe, high‐alpine meadow, sub‐alpine shrub, coniferous and mixed forest) and climatic conditions (mean July temperature, T_July: 4.0–17.4°C; mean annual precipitation, P_ann: 104–670 mm). Methods Lake‐surface sediments were analysed palynologically, and several pollen ratios were calculated. These ratios were interpreted with respect to vegetation and climatic conditions. Results The arboreal pollen sum (AP) was highest in samples from forested areas and was significantly correlated with P_ann (r² = 0.44). In non‐forested areas, samples from large lakes and from lakes surrounded by sparse vegetation had increased AP values, suggesting that AP is a useful vegetation density indicator. Artemisia/Chenopodiaceae (A/C) ratios were lowest in desert areas and were positively correlated with P_ann (r² = 0.25). The aridity pollen index was inappropriate for inferring (palaeo‐)climatic information from samples on the eastern Tibetan Plateau as it had no significant correlation with the environmental factors. Artemisia/Cyperaceae (A/Cy) ratios had a significant correlation with T_July (r² = 0.23), but only a weak correlation with P_ann, which indicates that the A/Cy ratio is applicable as a temperature indicator. Furthermore, it is a valuable tool for the differentiation of high‐alpine meadow from steppe vegetation. Main conclusions AP sum, A/C ratio and A/Cy ratio are useful tools for qualitative and semi‐quantitative palaeoenvironmental reconstruction on the Tibetan Plateau; however, the results obtained should not be interpreted quantitatively.     

Modern pollen samples from alpine vegetation on the Tibetan Plateau

• 1 A set of 316 modern surface pollen samples, sampling all the alpine vegetation types that occur on the Tibetan Plateau, has been compiled and analysed. Between 82 and 92% of the pollen present in these samples is derived from only 28 major taxa. These 28 taxa include examples of both tree (AP) and herb (NAP) pollen types.
• 2 Most of the modern surface pollen samples accurately reflect the composition of the modern vegetation in the sampling region. However, airborne dust‐trap pollen samples do not provide a reliable assessment of the modern vegetation. Dust‐trap samples contain much higher percentages of tree pollen than non‐dust‐trap samples, and many of the taxa present are exotic. In the extremely windy environments of the Tibetan Plateau, contamination of dust‐trap samples by long‐distance transport of exotic pollen is a serious problem.
• 3 The most characteristic vegetation types present on the Tibetan Plateau are alpine meadows, steppe and desert. Non‐arboreal pollen (NAP) therefore dominates the pollen samples in most regions. Percentages of arboreal pollen (AP) are high in samples from the southern and eastern Tibetan Plateau, where alpine forests are an important component of the vegetation. The relative importance of forest and non‐forest vegetation across the Plateau clearly follows climatic gradients: forests occur on the southern and eastern margins of the Plateau, supported by the penetration of moisture‐bearing airmasses associated with the Indian and Pacific summer monsoons; open, treeless vegetation is dominant in the interior and northern margins of the Plateau, far from these moisture sources.
• 4 The different types of non‐forest vegetation are characterized by different modern pollen assemblages. Thus, alpine deserts are characterized by high percentages of Chenopodiaceae and Artemisia, with Ephedra and Nitraria. Alpine meadows are characterized by high percentages of Cyperaceae and Artemisia, with Ranunculaceae and Polygonaceae. Alpine steppe is characterized by high abundances of Artemisia, with Compositae, Cruciferae and Chenopodiaceae. Although Artemisia is a common component of all non‐forest vegetation types on the Tibetan Plateau, the presence of other taxa makes it possible to discriminate between the different vegetation types.
• 5 The good agreement between modern vegetation and modern surface pollen samples across the Tibetan Plateau provides a measure of the reliability of using pollen data to reconstruct past vegetation patterns in non‐forested areas.

     

Évolution des grands Carnivores au Plio Pléistocène en Afrique et en Europe occidentale

This paper provides an overview of current knowledge of Plio Pleistocene Carnivora from Africa and Europe. In Plio Pleistocene times, many genera extend their ranges in Africa and Eurasia but their evolution are quite distinct in the two continents. In Africa, the modern carnivoran guild of sub saharian Africa originated in the early Pleistocene when took place extinction of archaic species. The north African fossil record is far from complete until the middle Pleistocene. In the middle and late Pleistocene, the modern carnivoran guild is associated with other elements: the simian jackal Canis simensis and two species of ursids Ursus arctos and Ursus deningeri which evolved towards Ursus spelaeus. Western European carnivore faunas show due to migration a constant turn-over of the species. Among felids, Panthera schaubi described by Viret (1954) and attributed to the genus Puma by Hemmer et al. (2004), is morphologically close to the snow leopard Panthera (Uncia) uncia. Canis etruscus is the sister group pf the clade including wolf and coyote and Canis arnensis is close to the African jackals. Ursus deningeri appears in the early Pleistocene together with two arctoid forms Ursus rodei and Ursus dolinensis that may be synonymous to Ursus arctos. The genus Hyaena is present in Europe in the middle and late Pleistocene.     

黄河三角洲滨海草甸与土壤因子的关系

黄河三角洲滨海草甸群落的分布和变化与土壤因子密切相关。于2010年6月对黄河三角洲的草甸植被进行了样方调查,并对土壤进行了取样分析。在所调查的67个草本样方中,共出现52种植物。利用典范对应分析(CCA)分析了9种土壤因子与草甸群落分布的关系,结果显示,前两轴总共解释了物种-环境关系方差的46.4%,土壤含水率和电导率对群落分布的影响最大。双向指示种分析(TWINSPAN)将67个样方分为7种群落类型,将其标示在CCA排序图上后,沿第一轴分成三大类群:盐地碱蓬群落→芦苇-盐地碱蓬群落→其他草甸群落,这反映了黄河三角洲滨海草甸群落在盐分梯度上的演替规律。相关分析显示,物种多样性指数与土壤电导率、速效钾和速效磷呈极显著负相关(P<0.01),与pH值呈显著正相关(P<0.05)。解释了黄河三角洲滨海草甸群落与土壤因子的关系和变化规律,对黄河三角洲植被保护和恢复有一定的指导意义。     

The late Pleistocene and Holocene in the Lourdes Basin,Western Pyrénées,France: new pollen analytical and chronological data

In the Lourdes Basin, pollen analytical results and 41 ¹⁴C dates from three sites (four profiles, 538 spectra) have enabled a coherent biostratigraphy to be established from the last Pleniglacial to the present. The end of the Würm Pleniglacial is characterised by a long phase dominated by Poaceae that extended from ca. 20 000 to ca. 15 000 B.P. Another phase with Poaceae, in the context of a treeless environment, is recorded during the late-glacial between the Juniperus optimum (ca. 13 000 B.P.) and the Betula optimum (after ca. 12 500 B.P.). A marked decline in Betula and a rise in Artemisia values suggest a significant cooling of the climate during the Younger Dryas, an event which is now clearly recorded at several sites in southern Europe. The beginning of the Holocene is characterized by the minor role of Pinus and the early arrival of Quercus which achieves an absolute maximum before the arrival of Ulmus and Corylus. A critical assessment of previously published data is made in the light of these new results.     

Vegetation history with implication of climate changes and human impacts over the last 9000 years in the Lake Nanyi area,Anhui Province,East China

Palynological analyses in combination with radiocarbon dating on a Holocene borehole from the Lake Nanyi, Anhui Province, East China demonstrate a well-documented local vegetation evolution since 9000 cal BP, which is the first record of Holocene climate change and human impact in this region. Since 9000 cal BP a mixed evergreen and deciduous broad-leaved forest dominated by Cyclobalanopsis and Quercus developed in this area, indicating a warm climate condition with enhanced insolation. A mixed evergreen and deciduous broad-leaved forest was fully developed between 6600–4500 cal BP, which corresponds to the Holocene Climate Optimum with the strong influence of East Asian summer monsoon (EASM). After 3000 cal BP the broad-leaved forest decreased rapidly, while land herbs and ferns increased. It seems that the climate condition in East China was similar to the present after Holocene Climate Optimum. Pollen results show a potential interface between environment changes and human activities. Pollen diagram demonstrates that human impacts on the natural vegetation remained weak at the early stage but significantly enhanced upwards. The distinctive fluctuations of the pollen contents among AP (trees and shrubs), and the possible agriculture indicators might infer the potential human behaviors for environment changes. Due to the enlargement of organized farming and increase in population, natural forest was eventually replaced by farmland since 3000 cal BP. This study would increase our knowledge of Holocene vegetation transition related to the monsoon dynamics on a long timescale in East China and provide an environmental background for more detailed studies on cultural developments in the middle and lower reaches of the Yangtze River region.     

Les industries lithiques préoldowayennes du début du Pléistocène inférieur du site de Dmanissi en Géorgie

The lithic industry discovered at the Dmanissi site, in Georgia is dated to between 1.81 and 1.7 Myrs and is in association with a rich faunal assemblage composed of large Quaternary vertebrates, as well as several hominid fossils attributed to Homo georgicus, and attests to the human presence on the border of Europe at the beginning of the Lower Pleistocene. The material taken into account in this study was excavated from 1991 to 1999 and comprises 4446 lithic pieces coming from Beds I through VI of the site. The assemblage is very homogenous from the base to the top of the deposits and shows no significative evolutionary tendencies. The lithic material includes a high proportion of whole pebbles (33.8% of the assemblage) coming from two nearby rivers, the Mashavera and the Pinezaouri. They are essentially of fine and coarse grained volcanic tuff, basalt, but also of rhyolite, granite, quartz, as well as other volcanic and metamorphic rocks. Pebbles used for percussion, shaping or debitage were chosen according to their petrographic nature, their morphology and their size. Whole pebbles with percussion marks situated on their extremities or with isolated removals showing convexe edges, are abundant (1.3% of the assemblage). Other pebbles showing percussion marks on a flat face, were used as anvils. Broken pebbles and pebble fragments are very numerous (30.4% of the assemblage). These often show percussion marks on their cortical surfaces. Fractures are generally related to violent percussion as the pebbles were used for striking instruments, or as they were intentionally broken. Some fractures may have been caused accidentally during flaking. Pebble tools represent 4.8% of the lithic assemblage and 10% of the industry, excluding whole and fractured pebbles. These include essentially the primary choppers (pebbles with isolated concave removal negatives) (6% of the industry and 60.1% of the pebble tools), choppers showing continuous cutting edges without a point (2.1% of the industry and 21.2% of the pebble tools). Chopping-tools are very rare (0.8% of the industry and 8.7% of the pebble tools). Although choppers without pointed cutting edges were made using very few removals (3.3 on average), they usually present a regular cutting edge and seem relatively standardised. Cores are well represented (5% of the industry, excluding whole and broken pebbles). They are characterized by a low degree of exploitation and by a frequence of cortical striking platforms. Cored knapped on a single face are most frequent, representing nearly half of the pieces (42.3%), while bifacial cores are present in smaller proportions (34.2%) and multifacial cores are rare (6.3%). Non-modified flakes are very numerous and usually of small size and intentional retouch is absent. On the other hand, the cuttingedges of many the pieces; broken pebbles, pebble tools, cores and flakes, show irregular micro-retouch and irregular retouch such as isolated notches or with continuous or overlapping configuration, sometimes associated with localised crush marks which appear to have been caused by intensive use and heavy working of the pieces. A total of 31.3% of the non-modified flakes show irregular retouch on their cutting edges. One of the main characteristics of the Dmanissi industry appears therefore to be the obtaining of flakes, most often of small size, to be used without modification. The technological and typological characteristics of the lithic industry from Dmanissi allow to attribute the assemblage to a "Pre-Oldowayen" cultural horizon (Lumley de et al., 2004), characterized by the absence of small retouched tools, which appears in East Africa from 2.55 Myrs ago. This cultural horizon is present at the border of Europe, at Dmanissi, around 1.81 Myrs ago and in Western Europe, on the shores of the Mediterranean, at Barranco León about 1.3 Myrs ago and at Fuente Nueva 3 about 1.2 Myrs ago. The lithic industry from the Dmanissi site seems anterior to the Oldowan cultural horizon, characterized by the presence of standardized small retouched tools, which appears in East Africa around 1.8 Myrs ago and emerges in Mediterranean Europe around 800?000 years ago.     

Pléistocène moyen et inférieur dans le Latium (Italie centrale)

Explorations and diggings of the Italian Institute of Human Palaeontology in Latium from 1950 to 2005, have brought out the following composite sequence: (1) for upper-middle Pleistocene of northern Latium: Travertine, gravels Acheulian-Mousterian transition, Riss. Homo (femur), Elephas antiquus, Hippopotamus, Bubalus murrensis, with upper Acheulian artefacts. (2) In middle Latium, middle Pleistocene: Volcanoclastic K-Ar 360 Ky. Below: Lower Acheulian complex and bone artefacts. Homo, Inuus, Elephas antiquus, Ursus deningeri, Dama clactoniana. Volcanic ash with Zelkowa, Buxus: caucasian flora. Hot pyroclastic flow about 15 m (50 feet) thick between 520 and 530 Ky. Limno-tuffite with Taxodiacea flora Lower-middle Pleistocene choppers artefacts below volcanic limit of 700 Ky. Southern Latium, lower Pleistocene: travertine reed Phragmites fragments. Ceprano hominid calvarium 800-900 Ky old. Gravel with chopper artefacts. Red sand with Unio shells. Lower palaeolithic gravelly sand, with very rough choppers artefacts, at Arce, Colle Marino, Colle Pece localities; at Castro dei Volsci chopper, assemblage is more evolved. Unconformity. Yellow sand layer with middle Villafranchian Anancus arvernensis and Mammuthus meridionalis fauna.     

黄土高原水土保持林对土壤水分的影响

黄土高原植被恢复的限制因素主要是土壤水分,植被与土壤水分关系的研究对黄土高原植被恢复具有重要意义.2008年7月1日至2009年10月31日间采用EnviroSMART土壤水分定位监测系统以每30min监测1次的频度,对晋西黄土区刺槐人工林地、油松人工林地、次生林地的土壤水分变化进行了研究.研究得出:次生林地0-150 cm土层中平均蓄水量为331.95mm,刺槐人工林地为233.85 mm,有整地措施的油松人工林地为314.85mm,刺槐人工林比次生林多消耗的98.10mm土壤水分主要来源于80 cm以下土层.次生林主要消耗0-80 cm土层的水分,而人工林不但对0-80 cm土层水分的消耗量大于次生林,对深层土壤的消耗也较次生林大,这将有可能导致人工林地深层土壤的“干化”.在土壤水分减少期(11-1月)刺槐人工林土壤水分的日均损耗量为0.86mm、油松人工林为0.82 mm、次生林为0.84 mm.土壤水分缓慢恢复期(2-5月)刺槐人工林地土壤水分的恢复速度0.90mm/d,油松人工林地为0.53 mm/d、次生林地为0.79 mm/d.土壤水分剧烈变化期(5-10月)刺槐人工林地土壤水分含量的极差为95.71mm,油松人工林地为179.1mm,次生林地为72.03mm.在干旱少雨的黄土高原进行植被恢复时,应多采取封山育林等方式,依靠自然力量形成能够与当地土壤水资源相协调的次生林,是防止人工植被过度耗水形成“干化层”、保障水土保持植被持续发挥生态服务功能的关键.     

A survey of modern pollen and vegetation along an altitudinal transect in southern Georgia, Caucasus region

This paper describes the pollen representation of vegetation patterns along an altitudinal transect in the South Caucasus region. Surface sediments from eight small- to medium-sized lakes and wetlands were analysed for modern pollen, and the results analysed numerically using detrended correspondence analysis (DCA) and dichotomised ordination (TWINSPAN). Pollen spectra from the semidesert region have a clear palynological signal characterised by an abundance of Chenopodiaceae. Differentiation of oak forest, upper tree-line and subalpine communities is more difficult: all are dominated by arboreal pollen (AP) types. The authors propose a number of indicator pollen types and pollen threshold values that may assist in detecting tree-line variations and deforestation events in Holocene pollen diagrams.