Pollen evidence for an Eocene to Miocene elevation of central southern Tibet predating the rise of the High Himalaya

Quantifying the elevation history of the 2000 km-wide Tibetan Plateau to an average elevation of 5 km is important for understanding key aspects of Cenozoic global climate change, collision tectonics and the evolution of the Asian monsoon, yet quantitative measures of Cenozoic surface height change across Tibet remain few and are sometimes contradictory. Here we report the first exploratory application of a modified Co-existence Approach (CoA) using previously published fossil pollen records to reconstruct quantitatively the Cenozoic minimum palaeoaltitudes of Gangdise-Nyainqentanglha Area of the Tibetan Plateau. GCM simulations were used to adjust Eocene and Miocene raw CoA values for secular climate change and changes in palaeolatitude. This modelled correction increased the CoA-derived altitudes by 895 ± 96 m to give a minimum overall Eocene altitude of 3295-3495 m. The Miocene correction factor of 481 ± 25 m gave an overall minimum altitude estimate of 3000-3150 m. For the Holocene CoA returns four equally likely elevations of 4800-4950 m, 3800-3900 m, 3000-3100 m and 2900-3000 m. The first of these is indistinguishable from the present day regional average while the others suggest significant upslope pollen transport. Both the Eocene and Miocene palynologically-derived height estimates are consistent with suggestions of significant core plateau elevation by the Eocene, but are likely to underestimate the true palaeoelevation due to pre-Himalayan upslope pollen transport.     

Cretaceous and Paleogene boundary strata in southern Tibet and their implication for the India-Eurasia collision

Recent stratigraphic studies in southern Tibet provide new information about the timing of the initial collision between the India and Eurasia continental blocks. The stratigraphic and paleontological evidence document dramatic changes in sedimentary facies and microfauna content across the Cretaceous-Paleogene (K/Pg) boundary. In the Zhongba and Gamba areas in southern Tibet, the K/Pg boundary is marked by a major disconformity, separating platform carbonates from overlying terrigenous conglomerates and sandstones. The stratigraphy of the boundary sequences has recently been improved with the recognition of three foraminiferal assemblages. They are: Maastrichtian Orbitoides-Omphalocyclus , Danian Rotalia-Smoutina-Lockhartia and Thanetian Miscellanea-Daviesina microfaunal assemblages. The K/Pg boundary at the Gamba area is placed between the Orbitoides-Omphalocyclus and Rotalia-Smoutina-Lockhartia faunas. In Tingri, Cretaceous Globotruncana and tertiary Globigerina-Globorotalia microfauna demark the position of the K/Pg boundary. The occurrence of terrigenous sandstones and boulder-size conglomerates in the early Paleocene is compelling evidence for tectonic uplift and emergence of the southern margin of the Lhasa block and of the northern margin of the Indian plate. Therefore, supported by biostratigraphic evidence, we argue that the uplift is caused by the onset of continental collision during the earliest Danian. Progressing plate collision resulted in deformation and fragmentation of the Paleocene carbonate platform and deposition of limestone breccias, which we consider as further evidence for tectonic compression as a result of early continental collision during the Thanetian, earlier than indicated by previous studies in the Himalayas. It is the change in the sedimentary facies and depositional environment that provides the earliest evidence and dating of the initiation of the collision process. From studies of sedimentary strata in southern Tibet, the collision of the India and Lhasa continental blocks was initiated at ~K/Pg boundary time (~65Ma). If that is the case, than the major lithofacies changes at the K/Pg boundary observed in the western Tethys, mostly referred to as intrinsic to the eustatic sea level change, has been driven by continental convergence and collision of the Indian and Eurasian plates.     

Vegetation, climate and palaeoaltitude reconstructions of the Eastern Alps during the Miocene based on pollen records from Austria, Central Europe

Aim To reconstruct the flora, vegetation, climate and palaeoaltitude during the Miocene (23.03–5.33 Ma) in Central Europe. Location Six outcrop sections located in different basins of the Central Paratethys in Austria. Methods Pollen analysis was used for the reconstruction of the vegetation and climate. The altitude of the Eastern Alps that are adjacent to the Alpine Foreland and Vienna basins has been estimated using a new quantification method based on pollen data. This method uses biogeographical and climatological criteria such as the composition of the modern vegetation belts in the European mountains and Miocene annual temperature estimates obtained from fossil pollen data. Results Pollen changes from Early to Late Miocene have been observed. The vegetation during the Burdigalian and Langhian (20.43–13.65 Ma) was dominated by thermophilous elements such as evergreen trees, typical of a present‐day evergreen rain forest at low altitudes (i.e. south‐eastern China). During the Serravallian and Tortonian (13.65–7.25 Ma) several thermophilous elements strongly decreased, and some disappeared from the Central European region. This kind of vegetation was progressively substituted by one enriched in deciduous and mesothermic plants. Middle‐altitude (Cathaya, Cedrus and Tsuga) and high‐altitude (Abies and Picea) conifers increased considerably during the Langhian and later on during the Serravallian and Tortonian. Main conclusions Pollen changes are related to climatic changes and to the uplift of the Alpine massifs. The vegetation during the Burdigalian and Langhian reflects the Miocene climatic optimum. The decrease in thermophilous plants during the Serravallian and Tortonian can be interpreted as a climatic cooling and can be correlated with global and regional climatic changes. This study shows that the palaeoaltitude of the eastern part of the Eastern Alps during the Burdigalian was not high enough for Abies and Picea to form a forest. Therefore, we inferred that the summits of most of the mountains would have been less than 1800 m. The substantial increase of middle‐ and high‐altitude conifers in the pollen spectra suggests that the uplift rate increased during the Langhian in this region. Based on higher palaeoaltitude estimations for the pollen floras from the studied sections of Austria, we infer that the uplift of the easternmost part of the Alpine chain continued during the Serravallian and Tortonian.     

Geological setting of Pliocene rifting and deposition in the Afar Depression of Ethiopia

Tectonic extension of the Afar amounts to 10–30 km since 1–2 Ma and to 40–60 km since 3–5 Ma ago, or rougly 1–2 cm per year. Active faulting, volcanism, and development of the Pliocene and younger Afar grabens with their rich hominid and other vertebratefaunas, have been controlled by ENE and WNW oriented lineaments or ancient zones of structural weakness. These lineaments also controlled the alignment of the Gulf of Aden and Red Sea, respectively.Crustal stresses resulting from the late Miocene (Messinian) salinity crisis in the Mediterranean basin may have triggered renewed tectonic movements along certain pre-existing lineaments such as the Levant Shear. Separation of Africa from Arabia (and hence the inception of Afar) was controlled by tectonic events far removed from NE Africa, including possible Miocene fusion of the Indo-Arabian plates.During the early Pliocene, the Ethiopian uplands were far lower (possibly by 1000 m) and the southern Afar-Middle Awash region was higher, so that topographic and climatic contrasts between plain and plateau were less pronounced and the Afar climate was less arid than today.There was a major change from lacustrine to fluviatile deposition in the Middle Awash valley soon after 4·0–3·8 Ma ago, caused by extensional tectonics. Within the topographic constraints imposed by volcano-tectonic activity, regional climatic oscillations have controlled the detailed pattern of Pliocene (and later) sedimentation in Afar.     

Available data point to a 4‐km‐high Tibetan Plateau by 40 Ma,but 100 molecular‐clock papers have linked supposed recent uplift to young node ages

The aims of this study were to synthesize data on the orogeny of the Tibetan Plateau (TP), with a focus on its elevation since the collision of the Eurasian and Indian plates, and to review the arguments in 100 phylogeny‐cum‐biogeography papers that have linked young inferred divergence times to recent TP uplift phases. I surveyed the literature on the geological history of the TP, focusing on different types of data used to infer its past height. I also tabulated the supposed TP history (and supporting references) in papers since 1998. Since the early 1990s, evidence from tectonics, isotopes, fossils and climate simulations increasingly indicates that the TP has been 4–5 km high since the mid‐Eocene. The data also indicate that the Indian summer monsoon, South‐east Asian summer monsoon, and Central Asian winter monsoon arose at different times and are unrelated to Tibetan uplift. A growing number of studies by biologists, however, are linking node ages between 0.5 and 15 Ma to specific (author‐dependent) uplift phases of the TP citing geological papers that are outdated or miscited. Biogeography of the TP thus currently appears to be in a self‐created bubble that encloses hundreds of authors and referees. Our understanding of the biogeography of Tibet requires up‐to‐date interpretation of its geological history and more fieldwork on local ecological habitat diversity, the plateau's history during the Pleistocene and the distribution of possible refugia.     

Phased evolution of the south–north hydrographic gradient in the South China Sea since the middle Miocene

The hydrography of the South China Sea (SCS) is characterized by a south–north (S–N) thermocline gradient in the upper water column from the northern margin of the western Pacific warm Pool (WPWP) to the sea area largely controlled by the East Asian monsoon. Here we examine the records of planktonic foraminifers from Ocean Drilling Program (ODP) Sites 1143 and 1146 in the southern and northern parts of the SCS, respectively, that identify three stages of evolution of the S–N hydrographic gradient in the SCS since the middle Miocene: first, the S–N thermocline gradient possibly occurred in the SCS for the first time during the period 11.510.6 Ma, reflected by an opposite change in the relative abundance of deep-dwelling planktonic foraminiferal species in the south and north; next, the S–N thermocline gradient weakened or even disappeared during the period 10.64.0 Ma, indicated by similar changes in the relative abundance of deep-dwelling species in the south and north; last, the S–N thermocline gradient substantially increased from about 4.03.2 Ma, marked by a major increase in abundance of deep-dwelling species in the northern SCS and a decrease in the southern SCS. Based on the results of oceanic and coupled ocean–atmosphere model experiments and previous studies on planktonic foraminifers in the Pacific Ocean, it is inferred that the initial WPWP was probably formed during the period of 11.510.6 Ma in response to the closure of the Indonesian seaway; The WPWP then weakened or became extremely unstable, before developing its present expression about 4.0–3.2 Ma, induced by the emergence of the Isthmus of Panama. Our observations and model experiments support the argument that the stages in evolution of the WPWP are linked to tectonic changes in ocean gateways.     

中国晚新近纪哺乳动物群落与东亚环境变化

根据已有的中国晚新近纪哺乳动物化石记录,综合新近研究成果,初步探讨中国晚新近纪哺乳动物群落演变进程及其对于气候与环境变化的响应。结果表明,自中中新世晚期至晚中新世(约13 Ma至7-8 Ma),中国北方哺乳动物群落组成上没有明显的分异;而在其后的晚中新世晚期发生了较为明显的区域性分化,分化为东部地区以适应潮湿的较为封闭的动物群落与西部地区适应干旱的开阔环境的群落,这种分异可能与东亚夏季风的加强密切相关; 青藏高原及其周边地区化石类群的扩散与交流资料也表明由青藏高原隆升而形成的地理阻隔也可能发生在该时期;上新世哺乳动物群落演化表现出对于持续的干旱化气候背景的适应,而晚上新世某些类群的分异与主导地位的确立与该时期气候环境背景的剧烈震荡相一致。由于化石资料的不完整,时段分布的不均一,以及地理分布区域的局限,全面认识中国晚新近纪哺乳动物群落组成以及与环境变化的关系尚有很长的一段历程。     

Altitudinal variations in seedling and sapling density and age structure of timberline tree species in the Sergyemla Mountains, southeast Tibet

The growth situation of seedlings of treeline species can be used as an indicator for the upper or lower shift of treeline under global climate change, since any advance of a treeline would require seedling survival above the current treeline elevation. We investigated seedling and sapling density of two dominant conifers Abies georgei var. smithii and Sabina saltuaria at lower, middle and upper altitude of two contrasting slopes in Sergyemla Mountain, southeast Tibet. Seedling and sapling age structure of A. georgei var. smithii was analyzed further. Seedling density of both species, as well as sapling density of S. saltuaria, showed a declining trend as elevation increased. Sapling density of A. georgei var. smithii was somewhat higher at middle altitude than other positions. The frequency of old-aged A. georgei var. smithii seedlings/saplings (age >10 year) was the lowest at the highest altitude and tended to increase with the declining elevation. The results indicate that the higher density of seedling and sapling in high-altitude might be attributed to better soil moisture availability and solar insolation than in the mid- and low-altitudes during the growth season. Yet confined by other environmental factors, A. georgei var. smithii seedlings in high-altitude suffer from lower survival rate and lower possibility to grow tall compared with those in mid- and low-altitudes.     

Vegetation and climate reconstructions on different time scales in China: a review of Chinese palynological research

This paper reviews vegetation and climate reconstructions for different time scales based on palynological studies in China. It discusses examples of significant developments in palynological research topics within China: (1) Modern pollen—a modern pollen database (East Asia Surface Pollen Database) has been established through the collaboration of Chinese palynologists. Based on these data, modern pollen distributions and their quantitative relationship with vegetation and climate have been thoroughly studied. (2) Pre-Quaternary vegetation and climate dynamics—scientists have mapped pollen and palaeobotanical data from the Palaeogene. The vegetation distributions confirm a north–south zonal pattern during the Palaeogene that changed to an east–west monsoonal pattern during the Miocene and Pliocene. These results provide key evidence for understanding monsoon evolution. (3) Late-Quaternary vegetation—biome reconstructions based on fossil pollen data show spatial and temporal changes in vegetation since the Last Glacial Maximum, permitting a better understanding of climate change across China. (4) Quantitative climate reconstructions—some reconstructions have successfully detected Holocene climate variability thereby providing insights into monsoon history. At present, there are no comprehensive spatial reconstructions. Major possible future developments should focus on: (1) long-term vegetation reconstructions from lakes to study Asian monsoon dynamics at orbital scales; (2) quantitative reconstructions of vegetation and climate change to help stronger integration with palaeoclimate models and dynamic vegetation models; (3) land-cover and land-use change across China over the last 6,000 years to understand human impacts and provide empirical data for climate modellers; and (4) integration of pollen data with vegetation and climate modelling to understand the CO₂-vegetation relationship and climate dynamics.     

Stratigraphy and palaeoenvironmental implications of Pleistocene and Holocene aeolian sediments in the Lhasa area,southern Tibet (China)

Along the middle and lower reaches of the Kyichu River and its tributaries (Lhasa area, southern Tibet), a multidisciplinary study was carried out in order to investigate the areal distribution, sedimentological properties, ages and palaeoenvironmental implications of aeolian deposits including intercalated palaeosols. This research was initiated to investigate to what extent southern Tibet is influenced by past human activity, as even recent evaluations perceive the present treeless desertic environment as natural. Fifteen profiles were recorded at an altitude of 3540–4580 m a.s.l. with subsequent sedimentological, geochronological (OSL, AMS ¹⁴C) and palaeobotanical (charcoal) analyses. Sediment properties of both loesses and aeolian sands reveal an origin from aeolian sorting of nearby fluvial deposits. The calculated ages are the oldest obtained thus far on aeolian sediments from southern and interior Tibet, revealing natural aeolian sedimentation before and around the Last Glacial Maximum (c. 20 ka). However, a distinct portion of Late Holocene sandy aeolian sediments also occurs. Both the evidence for the aeolian dynamics (widespread Pleistocene loess and aeolian sand deposition, local Late Holocene aeolian sand deposition, modern reactivation of widespread Pleistocene aeolian sands) and the palaeobotanical findings (Late Holocene vegetation change from a tree-bearing to a widely treeless landscape) provide evidence that the Lhasa area was strongly influenced by human activity since at least the Late Neolithic (c. 4200 cal yrs BP). Thus the present-day desertic environment might not primarily be a result of the semiarid climate or the high-altitude conditions, but rather of activities of the humans and their collateral effects. However, once established, this semi-natural ecosystem persisted, controlled by strong grazing, firewood extraction, erosion and harsh edaphic conditions, preventing the recovery of trees.     

Climate Change-Induced Range Expansion of a Subterranean Rodent: Implications for Rangeland Management in Qinghai-Tibetan Plateau

Disturbances, both human-induced and natural, may re-shape ecosystems by influencing their composition, structure, and functional processes. Plateau zokor (Eospalax baileyi) is a typical subterranean rodent endemic to Qinghai-Tibetan Plateau (QTP), which are considered ecosystem engineers influencing the alpine ecosystem function. It is also regarded as a pest aggravating the degradation of overgrazed grassland and subject to regular control in QTP since 1950s. Climate change has been predicted in this region but little research exists exploring its impact on such subterranean rodent populations. Using plateau zokor as a model, through maximum entropy niche-based modeling (Maxent) and sustainable habitat models, we investigate zokor habitat dynamics driven by the future climate scenarios. Our models project that zokor suitable habitat will increase by 6.25% in 2050 in QTP. The predication indicated more threats in terms of grassland degradation as zokor suitable habitat will increase in 2050. Distribution of zokors will shift much more in their southern range with lower elevation compare to northern range with higher elevation. The estimated distance of shift ranges from 1 km to 94 km from current distribution. Grassland management should take into account such predictions in order to design mitigation measures to prevent further grassland degradation in QTP under climate change scenarios.     

Occurrence of Christella (Thelypteridaceae) in Southwest China and its indications of the paleoenvironment of the Qinghai–Tibetan Plateau and adjacent areas

The uplift of the Qinghai–Tibetan Plateau dramatically changed the regional topography and climate, profoundly impacting the distribution of many plant lineages. Plant responses to environmental changes are particularly prominent in lineages that require ecological factors differentiated from those present before the uplift of the QTP. Two fossil occurrences of Christella H. Lév., Fl. Kouy–Tchéou (Thelypteridaceae), a fern genus now distributed mainly at low elevations of the pantropics with warm and moist habitats, are described based on fossilized Cenozoic leaf fronds recovered from SW China: late Paleocene Christella nervosa (J. R. Tao) C. L. Xu, T. Su & Z. K. Zhou comb. nov. found in Liuqu, southern Tibet and middle Miocene Christella sp. recovered from the Jinggu Basin in western Yunnan. The frond fossils from both sites share key morphological characteristics that diagnose these fossils as Christella. After detailed comparisons, we further clarified Christella papilio (C. Hope) Holttum, a species distributed in warm, humid habitats at altitudes no more than 1300?m, as the nearest living relative of C. nervosa. This finding suggested that southern Tibet had not reached its present elevation during the late Paleocene (ca. 56 Ma). We propose that the uplift, accompanied by severe cooling and aridification after the late Paleocene, caused the disappearance of Christella in southern Tibet, whereas paleoenvironmental conditions enabled the genus to survive in Yunnan. Our study provides the first example of distributional constraints of ferns in SW China in response to paleoenvironmental changes in the Qinghai–Tibetan Plateau and nearby areas.     

Miocene pollen record of KC-1 core in the Qaidam Basin,NE Tibetan Plateau and implications for evolution of the East Asian monsoon

Thick Cenozoic deposits in the Qaidam Basin provide great potential for understanding the tectonic history, paleoclimatic changes, and evolution of the East Asian Monsoon. This study examines the pollen record from the KC-1 core for the interval covering the later Early to Late Miocene (18–5 Ma). Thermophilic taxa percentages are high between 18 and 14 Ma and decrease after this time, a pattern which fits well with the Middle Miocene Climatic Optimum (MMCO) between 18 and 14 Ma and global climatic cooling after 14 Ma. During the same period, xerophytic taxa percentages gradually increase and those of the conifers gradually decrease, suggesting an aridification process in the Qaidam region driven by the gradual strengthening of the East Asian winter monsoon (EAWM) and weakening of the East Asian summer monsoon (EASM). The global climate cooling process appears to have driven the climatic development of the Qaidam Basin region throughout the Miocene, but the uplift of the Tibetan Plateau also contributed.     

云南禄丰古猿生活时期的古气候初步研究

本文通过对云南禄丰古猿化石地点的沉积物进行综合分析,提出古猿生活时期的气候变迁。即石灰坝组一段为干燥而凉爽气候;二段为温暖较湿润的气候;三段为湿热的南亚热带—热带气候;四段为古猿生活时期,已转变成干湿相间的南亚热带—热带季风气候。庙山坡组(五段),初期气候—度变得相当干燥而炎热、到后期又逐渐为干温气候。     

Cyprininae phylogeny revealed independent origins of the Tibetan Plateau endemic polyploid cyprinids and their diversifications related to the Neogene uplift of the plateau

Origin and diversification of the Tibetan polyploid cyprinids (schizothoracins) may help us to explore relationships between diversification of the cyprinids and the Tibetan Plateau uplift. Cyprininae phylogeny was analyzed using mitochondrial and nuclear DNA sequences to trace origins of polyploidy and diversifications of schizothoracins. Ancestral states reconstruction for ploidy levels indicated that the Cyprininae was diploid origin and the schizothoracin clades tetraploid origins. There were two diversification rate shifts along with diversification of the cyprinine fishes in response to the Tibetan uplift. The unusual diversification shifts were located to branches subtending the clades of Tibetan polyploid cyprinids. Our analyses suggested that (i) phylogeny of Cyprininae recovered two independent origins of the Tibetan polyploidy schizothoracins; (ii) diversifications of the schizothoracins were closely related to the Neogene uplift of the Tibetan plateau in the following ways: the relatively ancient Late Oligocene-Middle Miocene adaptive radiation may be associated with the uplift of the southern Tibet and Himalaya; the Middle Miocene-Early Pleistocene lineage-specific diversification broadly coincident with major phase of the Neogene Tibetan uplift; and the most recent Pleistocene diversification shift in Schizothorax closely coincident with the successive Kunlun-Huanghe and Gonghe movements of the Tibetan uplift and the glaciation-induced climate oscillations on the plateau.     

Comparative phylogeography and evolutionary history of schizothoracine fishes in the Changtang Plateau and their implications for the lake level and Pleistocene climate fluctuations

The water level oscillation of endorheic lakes and extent change of glaciers associated with the Asian monsoon are known as prominent representatives of climatic and environmental events in the Tibetan Plateau during the Quaternary. However, details process in spatial and temporal changes are still debated. We use the schizothoracines as a palaeoclimatic proxy to test two hypotheses concerning the evolution of Quaternary glaciations and lakes of the Changtang Plateau: (1) the Tibetan glaciations generally tended to decrease since the middle Pleistocene; (2) the lakes expansion was driven by summer monsoon rainfall. Based on a wide range‐wide sampling throughout in the Changtang Plateau and its adjacent drainages, we constructed phylogeny and demographic histories of schizothoracines in the Changtang Plateau. Our results showed that the populations of the exorheic rivers and lakes in southern Tibet possessed higher genetic variability, earlier coalescent and expansion times than those of the endorheic lakes in the Changtang Plateau. Population expansions are highly consistent with phases of strong summer monsoon and high lake level during interglacial stages. The maximum growth rate intervals showed three pulses from 64.7 to 54.8, 39.6 to 31.0, and 14.9 to 2.4 kya respectively. The significant positive correlations were found between regional precipitation and genetic diversity, as well as coalescence time of populations in the endorheic lakes. We suggested that the demographic history of the schizothoracines reflects the spatial and temporal changes in climate and lake level, in particular, in regional precipitation gradients associated with changes of the South Asian monsoon, and supports the climatic hypothesis of a general diminishing tend in Tibetan glaciations in the Tibetan Plateau since the middle Pleistocene.     

Hemoglobin concentration of pastoral nomads permanently resident at 4,850-5,450 meters in Tibet

This paper presents data on the hemoglobin concentration of a sample of 103 pastoral nomads who are lifelong residents of Phala, at 4,850-5,450 m, on the northern plateau of the Tibet Autonomous Region of the Peoples' Republic of China. This native population resides at the highest altitude of which we are aware and is thus exposed to the most extreme chronic hypoxic stress. However, they do not exhibit the most pronounced physiological adaptations, i.e., hemoglobin concentrations exceeding those found in all other high-altitude populations. Adult male and female mean hemoglobin concentrations of 18.2 and 16.7 gm/dl, respectively, were found. These data, in conjunction with earlier studies of ethnic Tibetans living at 3,400 m, demonstrate a pattern of increasing hemoglobin concentration (erythrocytosis) at increasing altitude of residence in the Himalayas and Tibet. At the same time, however, the hemoglobin concentration is lower than that found among Andean highlanders. These new data raise the possibility of quantitative population differences in hematological adaptation to high altitude hypoxia.     

Altitudinal variations in seedling and sapling density and age structure of timberline tree species in the Sergyemla Mountains, southeast Tibet

The growth situation of seedlings of treeline species can be used as an indicator for the upper or lower shift of treeline under global climate change, since any advance of a treeline would require seedling survival above the current treeline elevation. We investigated seedling and sapling density of two dominant conifers Abies georgei var. smithii and Sabina saltuaria at lower, middle and upper altitude of two contrasting slopes in Sergyemla Mountain, southeast Tibet. Seedling and sapling age structure of A. georgei var. smithii was analyzed further. Seedling density of both species, as well as sapling density of S. saltuaria, showed a declining trend as elevation increased. Sapling density of A. georgei var. smithii was somewhat higher at middle altitude than other positions. The frequency of old-aged A. georgei var. smithii seedlings/saplings (age >10 year) was the lowest at the highest altitude and tended to increase with the declining elevation. The results indicate that the higher density of seedling and sapling in high-altitude might be attributed to better soil moisture availability and solar insolation than in the mid- and low-altitudes during the growth season. Yet confined by other environmental factors, A. georgei var. smithii seedlings in high-altitude suffer from lower survival rate and lower possibility to grow tall compared with those in mid- and low-altitudes.     

Latitude and altitude differentially shape life history trajectories between the sexes in non-anadromous brown trout

We used two different approaches involving two organizational levels and spatial scales to explore altitudinal and latitudinal variation in life histories of non-anadromous brown trout Salmo trutta. First, we studied the factors influencing the maturation of individuals from populations in northern Spain. Second, we explored the effects of altitude (range 40–1,340 m) and latitude (range 40.6–61.7°N) on longevity, maximum length, length and age at maturity, and fecundity, comparing Spanish and Norwegian populations. Individual maturation was determined by length, age, and sex, and at a given size and age individuals were more likely to mature at higher altitudes. Brown trout lived longer but attained smaller sizes at higher latitudes. Both males and females matured at an older age with increasing latitude, but latitude affected their life-history strategies differentially. Males matured at smaller sizes with increasing latitude and altitude, which may indicate that their maturation threshold depends on the growth potentiality of the river since they compete with other males from the same population. The opposite effects were detected in females. Since female fecundity increases strongly with size there may be a size below which maturation has strong fitness costs. Brown trout are extraordinarily plastic, allowing persistence in a wide variety of environments. In the context of climate change, latitudinally based studies are important to predict potential effects of climate change, especially at the southern edge of species distribution.     

Eriocaulon gopalakrishnanum sp. nov. (Eriocaulaceae) from the Western Ghats,India

Eriocaulon gopalakrishnanum K. Rashmi & G. Krishnakumar sp. nov. is described and illustrated from the low altitude monsoon vegetation in the coastal lateritic plateau of the Western Ghat region of Kerala, India. The new species is distinct in the leaves and spathe being papillose, a character not displayed by any other species from this region.