Withdrawn food rate for larvae of Siberian moth on conifers of Siberia

Experimental evaluation of the mass of food withdrawn by larvae of the Siberian moth during their development on larch, cedar pine, fir, spruce, and common pine was carried out. The obtained dependences between the masses of larvae and food withdrawn by them can be directly used to determine the withdrawn food rate of Siberian moth on each of the Siberian conifer species.     

Tumulduria incomperta and the case for Tommotian trilobites

The enigmatic fossil Tumulduria incomperta Missanhevsky 1969 from the basal Tommotian Stage at 'Dvortsy' on the Aldan River, Siberian Platform, is reinvestigated in light of the report (Fedorov et al. 1979, Dokl. AN SSSR 249) of trilobite remains from the same beds. Comparisons of these supposed trilobites with old and new collections from 'Dvortsy' leave no doubt that they are identical to Tumulduria incomperta. Tumulduria is represented by phosphatic plates with a crude bilateral symmetry, consisting of a central longitudinal rounded ridge flanked by flat lateral portions. They are built of growth lamellae overlapping each other along the axis of symmetry. The surface carries prominent transverse folds and lamellar terminations. There is considerable morphological variation, and the similarity of some specimens to trilobites is only superficial. Tumulduria is interpreted as a bilaterally symmetrical metazoan with a dorsal protective plate; it probably represents a short-lived group that left no descendants.     

Microatoll microbialites of Lake Clifton,Western Australia: Morphological analogues ofCryptozoön proliferum Hall,the first formally-named stromatolite

Summary The Linnaean nameCryptozo?n proliferum Hall was proposed in 1883 for a previously undescribed life-form preserved in spectacular exposures of Cambrian limestones in New York State, USA. It is now recognised that these are exposures of stromatolitic microbialites, laminated organosedimentary structures formed from interaction between a benthic microbial community (BMC) and the environment. Microbialites are neither fossil organisms nor trace fossils. These complex structures are the products of dissipative, self-organising systems involving a BMC, the external environment and the accreting microbialite. Functionally analogous BMCs of different species compositions may build similar structures in similar environments in quite separate periods. The type exposures ofCryptozo?n proliferum show objects composed of complex, concentric rings, up to a metre in diameter, that have grown laterally without any restriction other than that provided by neighbouring structures. They are not the relicts of domes truncated by penecontemporaneous erosion or Pleistocene glaciation, but depositional forms in which upward growth was restricted. Analogous modern structures occur on a reef platform along the north east shore of hyposaline Lake Clifton, Western Australia. These are tabular thrombolitic microbialites that vary lakeward across the reef platform from low, compound structures to discrete, concentric structures up to 50 cm high. The Lake Clifton forms are, in turn, morphological analogues of microatolls found on coral reef platforms. Coral microatolls are coral colonies with flat, dead tops and living perimeters in which upward growth is constrained by the sea surface. In shallow water they form circular rims of laterally growing coral around a dead centre. In deeper water they form coral heads that develop flat tops on reaching sea level. It is concluded that both the tabular microbialites of Lake Clifton and the type exposures ofCryptozo?n proliferum are analogous to coral microatolls in both form and origin-structures that have been able to grow laterally, but in which upward growth is restricted by subaerial exposure. Similar microatoll microbialites have been described from other modern environments, including Great Salt Lake, Utah, USA and Stocking Island, Exuma Cays, Bahamas. Ancient examples may include some of the “tufa” deposits of the Basal Purbeck Formation in Dorset, UK, as well as the coalesced domal bioherms of the Upper Cambrian Arrinthrunga Formation of the Georgina Basin, Central Australia, and the “washbowl” structures described from the B?tsfjord Formation of the Varanger Peninsula, north Norway. Progress towards a reliable interpretation of ancient microbialites depends on an understanding of modern environments in which analogous structures are forming. This study of microatolls has demonstrated that other sessile life forms may create colonial ecomorphs that, used cautiously, can serve as analogues for understanding the factors controlling the growth and form of microbialites. The surprising lack of pre-Pleistocene examples of microatolls recorded to date has simply been due to their lack of recognition in the geological record. They occur in sequences from the Proterozoic onwards, and provide powerful environmental indicators of ancient reef platforms on which biological growth was adjusted to contemporary sea level.     

关于石片台面的分类

本文分析了中国旧石器时代常见的石片台面的主要类型,提出两种世人不太注意的类型:有疤台面和刃状台面。     

Siberian species of the riihimakiensis-group in the genusChironomus (Diptera,Chironomidae). 1. Karyotypes and morphology

Karyotypes and morphology of three species with close relations toC. riihimakiensis Wülker 1971 are described from material of Tuva and Altai in Siberia. Only one of them could be reared to the male adult and was namedC. tuvanicus n.sp.     

基于学习通平台的生物化学线上教学模式的探索与实践

为适应新型冠状病毒肺炎时期线上教学的需求,本文结合生物化学课程特点,对生物化学线上教学模式进行了探索与实践。依托学习通平台创建网络课程,整合、优化线上教学资源,利用学习通同步课堂实时互动,及时进行形成性评价及反馈,保证教学质量。在此总结线上教学经验,希望为生物化学线上教学提供参考。     

扎龙湿地白鹤春季停歇地昼间行为时间分配及活动规律

在2004年4～5月,采用瞬时扫描取样法对扎龙国家级自然保护区林甸芦苇沼泽区的野生白鹤(Grusleucogeranus)在春季迁徙停歇地的昼间各种行为进行了研究。结果表明,在整个观察时期内白鹤各种行为具有较强的规律性,活动时间分配比例为:觅食31%、游走27%、静栖19%、警戒17%、修饰6%。白鹤觅食行为在一天中有两个高峰,分别为早晨和黄昏;游走行为基本上与觅食行为呈正相变化,并且几乎每个游走高峰及低潮相应地伴随着觅食的高峰和低潮;由于渔民清晨下苇塘收鱼和放牧,在5:30～6:30和6:30～7:30两个时间段警戒行为比例最高;静栖行为基本与游走及觅食行为呈负相关,对比发现,静栖行为比例低于觅食行为,与笼养鹤类的情况存在一定的差异,原因可能是食物丰富度影响了野生状态下行为的时间分配;修饰行为所占比例较小,是由于修饰行为是非主要行为,其发生是随机的。天气状况对白鹤数量变化有一定影响,阴雨和大风天气,白鹤数量明显减少,鹤群转移。与正常天气情况相比,阴雨和大风对白鹤觅食、静栖和游走行为时间分配影响显著(P阴雨=0·000<0·05,P大风=0·000<0·05),觅食时间缩短,游走行为减少,静栖时间变长。     

小兴安岭地区原麝冬季食性研究

2004 年2 ～3 月和2004 年11 月至2005 年1 月在黑龙江省通河县龙口林场,对原麝冬季的食性进行了研究。采用粪便显微组织学分析技术分析原麝冬季采食植物的种类组成和比例,并测定了主要取食的9 种木本植物及苔藓和蕨类植物的营养成分。研究结果表明,原麝冬季取食的植物共计46 科66 种,其中兴安杜鹃、光萼溲疏、五角槭、羊胡子苔草分别占32.7%、7.8%、5.81%、5.56%, 是原麝冬季主要取食的植物种类,占取食植物的51.9% 。木本植物枝叶是原麝冬季的主要食物,在冬季食物组成中所占百分比最高, 达75.0% 。对草本植物、蕨类、苔藓、地衣的取食量均较小。冬季原麝比较喜欢采食蛋白含量高的植物,采食部位主要为植物木质化较低的当年枝顶端部分。藓类主要出现在1 ～3 月份的食物中。     

镜泊湖岩溶台地不同植被类型土壤微生物群落特征

为了探讨不同演替阶段植被类型土壤微生物群落特征,分别选取镜泊湖岩溶台地草本、矮灌木、高灌木、小乔木与灌木混生(简称混生)群落、落叶阔叶林及针阔混交林6种典型植被类型,进行植物群落调查和对土壤微生物生物量、群落结构和多样性指标、土壤物理化学性质的测定。结果表明：从土壤微生物量、土壤微生物群落组成、土壤微生物代谢动力学过程和代谢功能多样性的角度来看,各种植被类型土壤微生物群落具有明显的差异。演替前期的草本群落土壤微生物量碳氮、细菌生物量、真菌生物量,代谢活性及丰富度指数均最低,但Shannon-Wiener多样性指数和均匀度指数显著(P<0.05)高于其他植被类型。矮灌木土壤微生物群落组成显著受植被类型的影响。高灌木群落和混生(小乔木与灌木混生)群落具有极强的相似性, 但在碳源利用类型上两者表现出一定的差异。落叶阔叶林代谢活性最高,碳源利用能力最强,能利用BIOLOG微孔板中的所有31种碳源,这与其具有较高的微生物量碳氮和细菌生物量一致,其代谢功能丰富度最高。演替后期的针阔混交林下的土壤pH最低,真菌比例升高,在碳源丰富的条件下具有极强的竞争优势(仅次于落叶阔叶林),但在碳源贫瘠的条件下其利用碳源能力较弱(仅高于草本)。植被可能主要通过土壤全磷和有机质影响土壤微生物代谢功能多样性。     

Firmicutes is an Important Component of Microbial Communities in Water-Injected and Pristine Oil Reservoirs,Western Siberia,Russia

The dominant microbial components of fluids from wells in pristine and water-injected, high-temperature, Western Siberian oil fields, were analyzed by PCR-DGGE. Particular emphasis was placed on sulphate-reducing organisms, due to their ecological and industrial importance. Bacterial phylotypes obtained from the non-water-injected Stolbovoye oil field were more diverse than those from the Samotlor field, which is subject to secondary oil recovery by reinjection of recycled production water. The majority of phylotypes from both sites were related to Firmicutes. The low similarity to their closest relatives indicates unique bacterial communities in deep underground production waters and crude oil. Archaeal phylotypes detected only in the Samotlor samples were represented by Methanosarcinales and Methanobacteriales.