Quantitative reconstruction of palaeoclimate from the Middle Miocene Shanwang flora, eastern China

The fossil leaf flora from the Shanwang Formation, Linqu County, Shandong Province, eastern China, is diverse, abundant, well preserved and discretely spaced, all of which make it suitable for the recognition and application of leaf physiognomic characters. This article is the first study of Chinese Tertiary floras using the CLAMP (Climate Leaf Analysis Multivariate Program) approach. Numerous bedding planes yield leaf assemblages through over 20 m thickness of diatomaceous shales within the Middle Miocene Shanwang Formation. The diatomaceous shales, containing abundant fossils, have been divided into 19 units. A working platform (3×3 m) in the Diatomite Quarry of Shanwang was studied for about 3 months in 1998 and as many fossils as possible were recorded layer by layer. This collecting method, used for the first time in the history of Shanwang research, enabled us to record the presence or absence of megafossils in distinct units so that we could investigate leaf physiognomic characteristics and palaeoclimate for each time interval. Leaf fossils from six units (5, 6, 7, 13, 15 and 16) have been used to estimate palaeoclimate parameters of the Shanwang area using the CLAMP 3B dataset. The predicted climate is that of a lakeside setting, at over 1000 m above sea level and within the 17–15-Ma time interval. Meteorological factors have been estimated using the CLAMP approach, including mean annual temperature (MAT; 9.5–11.2°C), warmest month mean temperature (20.2–22.5°C), growing season length (5.9–6.8 months), mean growing season precipitation (83–165 cm) and relative humidity (73–79%). MAT estimates from leaf margin analysis (LMA) range from 12.5 to 15.2°C, which are a maximum of 4° higher than those from our CLAMP analyses and from previous results of LMA studies of the Shanwang flora (10–13°C). Nearest living relatives (NLR) of other biota (pollen, fish, insects, diatoms, microthyriaceous fungi, etc.) indicate warm and moist temperate to subtropical conditions in the Shanwang area during the Miocene. CLAMP predictions are similar to the climate predicted from NLRs although the MAT prediction is a few degrees cooler. The fact that the Shanwang leaf flora is from a lacustrine sequence may have biased the CLAMP analysis towards cooler (and possibly wetter) climates. The modern Yangtze River valley is a reasonable environmental analogue for the Shanwang Middle Miocene, though Shanwang may have had cooler summers, cooler MAT and less seasonality in rainfall. The climate was essentially constant during deposition of the sequence studied, with possible minor variations in precipitation.     

Early Miocene cricetids (Rodentia) from the Junggar basin (Xinjiang, China) and their biochronological implications

Among the 14 small mammal species from the early Miocene locality of the northern area of the Junggar basin (northern Xinjiang, China), four species are cricetids (Rodentia): unnamed species of Cricetodon and Eumyarion, and two new species, Karydomys debruijni nov. sp. and Megacricetodon beijiangensis nov. sp. Some aspects of the morphology of Cricetodon sp. are shared by Eucricetodon from the late Oligocene, suggesting that these specimens could be of intermediate form between Eucricetodon and Cricetodon. One tooth of Eumyarion sp. was found, making its determination uncertain, but its morphology is clearly differentiated from the one of Cricetodon sp. The species K. debruijni nov. sp. is established based on its primitive features compared to the species known in Europe and Anatolia, and its specific association of characters compared to Karydomys dzerzhinskii. M. beijiangensis nov. sp. shows many plesiomorphic features compared to the species already described in the middle Miocene of China. Based on both the whole assemblage of rodents and the species of cricetids, the biochronologic position and the age of the locality are discussed. The locality appears to be biochronologically very close to the fauna from the Chul’adyr Formation in Aktau Mountains, but we propose an age slightly older than the one proposed for this fauna, probably equivalent to the MN3 biozone in Europe.     

Hominoid dental variability and species number at the late Miocene site of Lufeng,China

The large hominoid sample from the late Miocene site of Lufeng, China, has been variously claimed to contain either one or two species, but very few metric data in support of either position have been published. We calculate coefficients of variation for the dental remains both for the two presumed species and for the pooled sample as a whole using the summary statistics published by Wu & Oxnard (Wu & Oxnard: American Journal of Primatology 5:303–344, 1983a, Nature 306:258–260, 1983b). These are compared to the same measures of single-sex and combined-sex samples of extant hominoids. We also present metric characterizations of male and female canines of extant great apes, with which we evaluate the gender composition of the Lufeng canine sample. In a two-species alternative, the two presumed species have measures of variability and canine representation that are more compatible with single-sex samples representing males and females, respectively. The pooled dental sample has measures of variability within the ranges of single species of extant great apes. We conclude there is a single large hominoid species represented at Lufeng that is highly sexually dimorphic. The phylogenetic relationships of this species are briefly considered. It is generally primitive in craniodental morhpology and is unlikely to be a member of the Sivapithecus-Pongo clade.     

New fossil leaves and fruits of Lauraceae from the Middle Miocene of Fujian,southeastern China differentiated using a cluster analysis

The fossil record of Lauraceae can be traced back to the Early Cretaceous of eastern Asia based on fossil flowers. Here, we refer a number of new occurrences of leaf and fruit fossils of Lauraceae from the Middle Miocene of Zhangpu, Fujian, China, to seven species. These data provide evidence supporting the fact that a diverse subtropical, or tropical, Lauraceae-dominated evergreen forest surrounded this region 15 million years ago (Mya). The Lauraceae fossils presented in this paper provide evidence for the evolution of this group as well as new materials that enable the study of the Fujian Province Neogene flora. The fossils described in this paper fill in the gaps in studies about Lauraceae pollen in the Middle Miocene from Fotan, Fujian, China. In addition, these fossils also enrich the Middle Miocene fossil records of Lauraceae in eastern Asia, especially improving the study of the macrostructures and reproductive organs of fossil Lauraceae from southern China. The similarity between fossil and modern fruits shows that during the Middle Miocene the fruit morphological of Lauraceae have changed very little. We also identify families where the fossils we report belong to their closest relatives and can be used to reconstruct the paleoenvironment of Fujian in the Middle Miocene.     

Integrated network reconstruction,visualization and analysis using YANAsquare

Background  

Modeling of metabolic networks includes tasks such as network assembly, network overview, calculation of metabolic fluxes and testing the robustness of the network.     

Areoana analysis of the cell structure,using an example of reconstruction of leaf morphogenesis in paleozoic mosses of the order protosphagnales

Late Paleozoic protosphagnalean mosses are characterized by cell dimorphism similar to that of the extant genus Sphagnum. The difference between them is the fact that the protosphagnalean dimorphism appears at the latest stages of leaf development. Before the last three divisions of leaf cells, the leaf areolation is identical in structure to bryalean mosses with uniform cells. In young leaves of protosphagnalean mosses, cell areolation is also uniform. Dimorphism is observed only occasionally in a part of individual leaves of protosphagnalean mosses and it also appears in the course of the last three cell divisions. A hypothesis for the origin of sphagnaceous mosses from Protosphagnales as a result of anaboly is proposed, supporting the idea of Neuburg that the latter are ancestral to the former. The diversity of cell dimorphism in various genera of protosphagnalean mosses shows the same triad/tetrad-block pattern, differing mostly in quantitative characters of cell proportions.     

Spatial structure and dynamics of breeding bird populations at a distribution margin,southern California

Aim Local‐scale processes at species distribution margins can affect larger‐scale distribution dynamics, but are rarely studied. The objective of this research was to elucidate the nature of distribution limits by studying the comparative structure, dynamics and environmental associations of breeding bird populations at their distribution margin. We hypothesized that climate is principally responsible for setting distribution limits, whereas biotic habitat features are more strongly associated with distribution patterns within the range. Location Southern California, USA. Methods During 2005–2007 we studied the distribution patterns of breeding birds in three study areas, each spanning a low‐elevation (200–1800 m) desert scrub‐to‐chaparral gradient. We used logistic regression with hierarchical partitioning to assess the independent effects of environmental variables (e.g. climate versus habitat) on distributions. We tested for shifts in the relative importance of these environmental variables in determining distribution limits versus within‐range patterns, and we also compared higher‐ and lower‐elevation groups of species. Results Distribution patterns were highly variable among species, but were remarkably static over the three study areas and 3‐year study period. Across species, habitat floristic variables performed relatively well at explaining distribution patterns. For higher‐elevation species (chaparral birds), climate was relatively important in setting their lower distribution limits, and there was a shift to a greater importance of biotic habitat (mainly habitat structural variables) for determining within‐range patterns. Relationships were more mixed for lower‐elevation species (desert scrub birds), but with respect to distribution limits, biotic habitat variables tended to be more important relative to climate than we observed for chaparral birds. Main conclusions Along this warm, arid elevational gradient, higher‐elevation chaparral birds are more limited by climate at their lower margin than are lower‐elevation desert birds at their upper margin, suggesting that climate plays a strong role (relative to other values) in excluding non‐desert birds from desert. However, given the strong differences among species, predictive distribution models will need to be individually tailored, and for most species biotic habitat variables were of greater importance than climate in determining limits. This research highlights the usefulness of studying environmental relationships at distribution margins and the importance of considering biotic relationships in forecasting distribution shifts under changing climates.     

59卷3期封面

Cover illustration: Firmiana sinomiocenica; Shanwang Basin, Shandong Province, Early Miocene. Courtesy of Wang Zi-xi and Shi Gong-le; Shi Gong-le, the photographer.     

黄河流域鸟类多样性现状、分布格局及保护空缺

黄河流域幅员辽阔, 多样的地理气候、植被类型及人类活动塑造了多样化的生物多样性格局。本研究以IUCN与国际鸟盟发布的鸟类分布图层为基础, 同时收集了黄河流域2009-2019年的鸟类实地观测记录, 包括观鸟记录、GBIF数据库、红外相机监测及其他实地调查的鸟类数据, 共得到35,026条鸟类实地观测有效记录。汇总结果显示, 黄河流域记录有鸟类物种662种, 占中国鸟类物种总数的45.81%。这些鸟类分属于23目83科, 其中雀形目物种数最多(384种, 占本目全国鸟种总数的46.83%), 其次为鸻形目(67种, 占50.00%)和雁形目(39种, 占72.22%)。黄河流域受威胁鸟类共计121种, 其中有37种和52种分别在IUCN红色名录和《中国脊椎动物红色名录》中被列为受威胁物种(即评估级别为极危、濒危或易危), 22种和73种被分别列为国家I级和II级重点保护野生动物。这些受威胁鸟种多为地栖性、体型大、营养级高或具有长距离迁徙习性的物种。黄河流域鸟类整体物种多样性由南向北递减, 以黄河上中游四川、甘肃、陕西的高原与山地内鸟种最为丰富, 而受威胁鸟类物种多样性热点区则在黄河中下游, 下游黄河三角洲及邻近平原区为受威胁鸟类最主要集中分布区。黄河流域内48个国家级自然保护区共覆盖鸟种数504种(占黄河流域鸟类总种数的76.13%), 其中受威胁鸟种92种(占黄河流域受威胁鸟种数的76.03%)。区域内国家级自然保护区大多分布在黄河上游, 对黄河下游的受威胁物种覆盖程度较低, 保护空缺较严重。对此, 我们建议着重加强中下游自然保护区建设与能力提升, 增加对中下游受威胁鸟种的保护力度, 在保护策略上应当积极探索高强度土地利用下的多样化保护机制。     

豚草条纹萤叶甲各虫态的空间分布型

豚草条纹萤叶甲Ophraella communa LeSage是恶性入侵豚草(Ambrosia artemisiifolia L.)的天敌,用频次分布拟合和多种聚集指数测度等方法对该叶甲的成虫、幼虫和蛹、卵的空间分布型进行研究。结果表明,豚草条纹萤叶甲卵、幼虫+蛹、成虫的空间分布符合负二项分布,种群个体的空间分布为聚集分布。用几种衡量聚集度的指标,对上述各虫态分布的聚集程度进行测定;然后计算出各虫态田间最适理论抽样数。     

中国毛葡萄和刺葡萄分布的气候适宜性

毛葡萄和刺葡萄是起源于中国且用于葡萄酒酿造的两大野生葡萄品种。本研究基于已有中国毛葡萄和刺葡萄的气候影响因子研究成果,利用最大熵原理从充分性与必要性方面确定了影响中国毛葡萄和刺葡萄种植分布的主导气候因子,并基于这些因子综合作用反映的毛葡萄和刺葡萄种植分布的存在概率分析了中国毛葡萄和刺葡萄分布区的气候适宜性。结果表明: 影响中国毛葡萄、刺葡萄分布的主导气候因子是年日照时数、开花期5月降水量、年极端最低气温、最冷月平均气温。中国毛葡萄、刺葡萄气候高适宜区分布在湖南西部和南部、广西中北部、贵州东南部、重庆中部。气候高适宜区、适宜区、低适宜区面积分别占研究区域总面积的2%、14%和16%。毛葡萄、刺葡萄气候适宜及以上区域的年日照时数阈值为1200～1800 h,年极端最低气温-8 ℃以上,最冷月平均气温阈值为2～13 ℃,5月降水量为110～320 mm。     

A new Middle Miocene tarsier from Thailand and the reconstruction of its orbital morphology using a geometric-morphometric method

Tarsius is an extant genus of primates endemic to the islands of Southeast Asia that is characterized by enormously enlarged orbits reflecting its nocturnal activity pattern. Tarsiers play a pivotal role in reconstructing primate phylogeny, because they appear to comprise, along with Anthropoidea, one of only two extant haplorhine clades. Their fossils are extremely rare. Here, we describe a new species of Tarsius from the Middle Miocene of Thailand. We reconstructed aspects of its orbital morphology using a geometric-morphometric method. The result shows that the new species of Tarsius had a very large orbit (falling within the range of variation of modern Tarsius) with a high degree of frontation and a low degree of convergence. Its relatively divergent lower premolar roots suggest a longer mesial tooth row and therefore a longer muzzle than in extant species. The new species documents a previous unknown Miocene group of Tarsius, indicating greater taxonomic diversity and morphological complexity during tarsier evolution. The current restriction of tarsiers to offshore islands in Southeast Asia appears to be a relatively recent phenomenon.     

汉中地区汉水流域水生维管植物种类及地理分布

经野外调查,采集标本与鉴定分析,汉中地区汉水流域共有水生维管植物69种,包括蕨类植物3种,种子植物66种,分别隶属于32科48属。其中挺水植物41种,浮水及浮叶植物11种,沉水植物17种。66种种子植物分别隶属于46属,有7种地理分布类型,其中以世界分布类型成分居多,共21属,占本地区水生种子植物总属数的45．7％;热带分布类型成分13属,占28．3％,温带分布类型12属,占26．0％。调查分析发现8种6该区域的新分布种,即：竹叶眼子菜,南方眼子菜,小茨藻,大茨藻,水毛花,穗花狐尾藻,有梗石龙尾的狸藻;新记录属4个,即：茨藻属,狐尾藻属,石龙尾属和狸藻属;新记录科2个,即;茨藻科和小二仙草科。     

延河流域植物叶性状间关系及其在不同植被带的表达

以延河流域不同植被带的地带性植物群落为研究对象,对群落优势种和主要伴生种的6种叶片性状进行测定,分析这些性状及其关系随环境梯度的变化,以了解该区域植物对环境变化的适应策略.结果表明: 植物比叶面积(SLA)与叶组织密度(LTD)、叶片单位面积氮和磷含量均呈显著负相关,与单位质量叶片磷含量呈显著正相关;各性状间的尺度关系和生存对策在不同植被带不同,典型草原带和森林草原带植物LTD SLA的尺度依赖关系比森林带植物的强,而森林带植物叶片单位〖JP2〗面积N、P含量与SLA、LTD间的尺度关系较草原带更明显,植物对环境的适应策略发生了位移.在干旱贫瘠的草原带和森林草原带,植物以防御和抗胁迫策略为主,而在环境条件相对湿润、富养的森林带,植物以快速生长和资源优化配置策略为主.     

Particle-verification for single-particle, reference-based reconstruction using multivariate data analysis and classification

As collection of electron microscopy data for single-particle reconstruction becomes more efficient, due to electronic image capture, one of the principal limiting steps in a reconstruction remains particle-verification, which is especially costly in terms of user input. Recently, some algorithms have been developed to window particles automatically, but the resulting particle sets typically need to be verified manually. Here we describe a procedure to speed up verification of windowed particles using multivariate data analysis and classification. In this procedure, the particle set is subjected to multi-reference alignment before the verification. The aligned particles are first binned according to orientation and are binned further by K-means classification. Rather than selection of particles individually, an entire class of particles can be selected, with an option to remove outliers. Since particles in the same class present the same view, distinction between good and bad images becomes more straightforward. We have also developed a graphical interface, written in Python/Tkinter, to facilitate this implementation of particle-verification. For the demonstration of the particle-verification scheme presented here, electron micrographs of ribosomes are used.     

Nitrogen-utilization efficiency in rice: an analysis at leaf,shoot, and whole-plant level

Plant and Soil - If rice has a higher nitrogen use efficiency for dry matter production (NUE) and grain yield (NUEGY) than wild annuals, we may question whether the higher NUE is due to a higher...