贵阳次生林不同演替阶段土壤微生物生物量与反硝化酶活性的研究

土壤营养元素赋存状态和微生物活性是喀斯特地区生态恢复的关键质量指标,温室气体N2O的排放是全球变暖的重要因子。研究了雨季贵阳不同演替阶段森林表层土壤（0～10cm）微生物生物量（SMB）、反硝化酶活性（DEA）、无机氮（N）库和N转化特征,并与玉米地、茂兰喀斯特原始森林土壤做了对比分析。结果表明,微生物群落对土壤水分条件响应强烈,土壤有效N的增加有助于微生物群落的增长,土壤N转化速率越快,微生物N同化作用越低。人为干扰（火烧和农业活动）会增加或降低土壤SMB、增加潜在的气态N流失。总的来说,不同演替阶段土壤SMB、DEA和土壤N库均有显著差异,随植被恢复土壤SMB呈上升趋势,温室气体N2O的排放量呈下降趋势,气态N流失形态从N2O转变为N2,N循环过程趋于优化,表明自发演替是退化喀斯特森林恢复的可靠方式。     

The relationship between soil geochemistry and die back of montane forests in Sri Lanka: a case study

Tropical montane forests of Sri Lanka form a unique ecosystem with more than 50% of endemic plant species. It has been noted that trees, belonging to different size and age classes of these forest, have been dying due to a yet unknown factor. This phenomenon was first observed in the Horton Plains National Park, which is a high plateau, composed of tropical montane forests. Later dying of forests were observed at several areas including Hakgala montane forest. Physical parameters trace nutrients as well as toxic element concentrations in soils, were studied in order to identify the possible geochemical factors behind the forest die back. Systematic soil sampling was carried out covering the entire Horton Plains National Park and random samples were collected from Hakgala montane forest. Samples were analyzed for available Fe, Mn, Zn, Cu, Ni, Cd, Al and Pb using standard colorimetric and atomic absorption spectrometric procedures. Physical parameters such as pH, moisture content, and conductivity of the samples were also measured. Among extractable micro-nutrients Cu and Zn, and Ni show no deficiency or excess levels. However, the recorded available high concentrations of Fe, Mn and Al can be toxic to certain montane plant species. Acidic moist soil of the area may enhance the toxic effects of these elements. Possible source of these elements should be the underground lithology of the area. According to the results obtained, there is a relationship between forest die back and high Pb concentrations. The same phenomenon was also observed in the Hakgala forest. The distribution pattern of Pb in the Horton Plains coincides well with the die back distribution pattern. The observed Pb values at Horton Plains and Hakgala are almost similar to values observed at Pannipitiya and Dombagaskanda locations, which are located close to main roads carrying heavy traffic. It is quite possible therefore, that Pb toxicity may be a significant factor behind the forest die back even though other factors should not be completely ruled out at this juncture. Strong monsoon winds, bringing Pb from the polluted southwestern part of the country, can be the most possible source of soil Pb. Further studies however are indeed necessary to confirm the conclusion.     

云南祥云红土坡墓地出土人骨颅面特征研究——兼谈“昆明”族属问题

红土坡墓地是滇西洱海地区青铜时代晚期的一处重要墓地。对红土坡墓地出土的3例颅骨标本进行性状观察、测量分析等综合研究,其颅面特征可以概括为长颅型、正颅型结合狭颅型,中等眶型和较阔的鼻型,中等面宽,偏低的面高,中等偏大的上面部扁平度。红土坡居民应属于亚洲蒙古人种范畴,与南亚类型在眶鼻和上面部形态上表现出更多的一致性。在与古代人群的对比中,与楚雄元谋磨盘山组最为相似,颅型方面皆为长颅型、正颅型,在眶型、鼻型、面宽、面高和面部扁平度等方面也非常接近;其次为华南地区的佛山河宕组和闽侯昙石山组。在综合分析的基础上,进一步探讨了云南地区古代居民颅面特征中"北方因素"的出现,以及红土坡居民所代表的"昆明"人的族属问题。

     

Subduction zones: Their diversity,mechanism and human impacts

Subduction is not only the counterpart process to seafloor spreading in the plate tectonic regime, but is also the major driving mechanism of plate motions. Various features characteristic to subduction zones are reviewed from a geotectonic viewpoint, and their impacts on human soeciety are considered. The features of subduction zones are difficult to explain by a single model. The importance of recognizing the existence of two basic and contrasted modes in subduction, controlled by the strength of coupling between subducting and overriding plates, is demonstrated. The two modes are High Stress Chilean-type subduction and Low Stress Mariana-type subduction. Collision and accretion of buoyant features on seafloor, an inevitable consequence of subduction, is important in the evolution of continents.     

滇西地区前侏罗系地层问题

滇西地区属三江印支造山带,前侏罗系地层问题可分为两类:一是变质岩地区常见的,如把 S_n(n≥1)当成 S_0等;二是造山带地区特有的,如因未认识蛇绿混杂、重力滑塌和化石再沉积等而曲解化石的地层和相指示意义,一个群里包括了一系列叠置的构造岩片中的不同时代、不同建造背景的岩石等。造山带常是一构造大拼盘,因而其地层工作需要新的理论武装:造山带地层学。     

云南墨江志留纪地层及其笔石序列

云南墨江志留纪地层从下到上包括漫波组和水箐组。根据在水箐组中发现的大量笔石,从下到上共识别出Colonograptuspraedeubeli带、C.ludensis带、Lobograptusprogenitor带、L.scanicus带和Saetograptusfritschilinearis带等5个笔石带,并将各带与捷克、中亚、加拿大和我国广西等地的相应笔石带进行了详细对比。研究表明水箐组的时代应属文洛克世晚期—罗德洛世中期,其层位应在文洛克世早期的漫波组之上。     

中国晚新生代食肉目演替及其古生态意义

本研究系统回顾了中国晚新生代食肉目的演化以及食肉目动物群的演替关系。以属、族或亚科为单位,探讨了我国新近纪和第四纪时期食肉目13个科成员的地史分布和相关类群的生态习性。根据食肉目亚科一级别的演替规律,探讨了中国晚新生代的气候环境变化,支持以下观点：在早中新世气候相对温和,食肉目组成上包含较多的古老、不擅长奔跑的类型;中中新世开始气候趋于干旱化,出现一些四肢修长、擅长在开阔地区追击猎物的类型;晚中新世时期华北气候强烈干旱化,出现了大量以鬣狗科为代表的适应开阔环境的属种,但一些林地组分依然存在,指示这个时期的环境并非典型的草原,依然有较多树木存在;上新世时期华北气候再次变得温暖湿润,鬣狗科大量灭绝,灵猫科等东洋界分子北上;第四纪时期随着冰期的到来,华北再次变成以开阔环境主导,而华南地区一直较为稳定,为温暖湿润的森林环境主导。

     

Nine thousand years of upper montane soil/vegetation dynamics from the summit of Caratuva Peak,Southern Brazil

Biodiversity loss, climate change, and increased freshwater consumption are some of the main environmental problems on Earth. Mountain ecosystems can reduce these threats by providing several positive influences, such as the maintenance of biodiversity, water regulation, and carbon storage, amongst others. The knowledge of the history of these environments and their response to climate change is very important for management, conservation, and environmental monitoring programs. The genesis of the soil organic matter of the current upper montane vegetation remains unclear and seems to be quite variable depending on location. Some upper montane sites in the very extensive coastal Sea Mountain Range present considerable organic matter from the late Pleistocene and other from only the Holocene. Our study was carried out on three soil profiles (two cores in grassland and one in forest) on the Caratuva Peak of the Serra do Ibitiraquire (a sub-range of Sea Mountain Range – Serra do Mar) in Southern Brazil. The δ¹³C isotopic analyses of organic matter in soil horizons were conducted to detect whether C₃ or C₄ plants dominated the past communities. Complementarily, we performed a pollen analysis and ¹⁴C dating of the humin fraction to obtain the age of the studied horizons. Except for a short and probably drier period (between 6000 and 4500 cal yr BP), C₃ plants, including ombrophilous grasses and trees, have dominated the highlands of the Caratuva Peak (Pico Caratuva), as well as the other uppermost summits of the Serra do Ibitiraquire, since around 9000 cal yr BP. The Caratuva region represents a landscape of high altitude grasslands (campos de altitude altomontanos or campos altomontanos) and upper montane rain/cloud forests with soils that most likely contain some organic matter from the late Pleistocene, as has been reported in Southern and Southeastern Brazil for other sites. However, our results indicate that the studied deposits (near the summit) are from the early to late Holocene, when somewhat wetter and warmer conditions (since around 9000 cal yr BP) enabled a stronger colonization of the ridge of Pico Caratuva by mainly C₃ plants, especially grassland species. However, at the same time, even near the summit, the soil core from the forest site already presented the current physiognomy (or a shrubby/elfin or successional forest), indicating that the colonization of the neighboring uppermost saddles and valleys were probably populated mainly by upper montane forest species.     

云南白牛厂银多金属矿床成因

对云南白牛厂超大型银多金属矿床的地质、地球化学特征及矿床形成的长期性及多阶段性的研究认为:白牛厂银多金属矿床是热水沉积—叠生成因矿床,早期呈现寒武纪的热水同生沉积成矿作用,晚期为燕山期花岗岩浆热液成矿作用。该矿床是热水沉积成矿作用与岩浆热液成矿作用叠加成矿的产物。     

滇西金宝山铂钯矿床元素地球化学

金宝山铂钯矿床位于扬子板块西缘红河断裂东侧,宁蒗-弥渡镁铁-超镁铁岩带内,矿体呈似层状、透镜状产于辉石橄榄岩中。辉石橄榄岩和铂钯矿石均富集LREE,具有弱的Eu负异常和较强的Sr、Ba负异常;与N-MORB相比,辉石橄榄岩具有较低的(Nb/Th)PM比值和较高的(Th/Yb)PM比值,表明金宝山岩体受到了地壳物质混染;通过(Th/Yb)PM-(Nb/Yb)PM图解估算得到地壳混染程度在55%~70%之间,强烈地壳混染表明岩浆中的S达到饱和并使得硫化物发生大规模熔离。而利用硅酸盐岩浆/硫化物的质量比值(R因子)方程进行模拟计算,得到金宝山矿床R因子集中于5000~1000之间,明显大于金川、图拉尔根、白马寨等典型岩浆硫化物矿床,说明金宝山岩体形成时岩浆中的硫化物熔离程度较低。辉石橄榄岩和铂钯矿石的S/Se和Cu/Pd比值也同样反映了硫化物低程度熔离的特征。与Nb、Th等元素含量相对稳定的高场强元素相比,S、Se、Pd等元素在硫化物部分熔解以及热液作用过程中更容易发生迁移。类似于River Valley和Platreef矿床等大型层状PGE矿床,金宝山铂钯矿床的形成是一个两阶段的过程,早阶段在岩浆通道或深部岩浆房中,地壳混染使得硫化物发生强烈熔离并在有限的空间内大量聚集,产生富PGE岩浆;后由于硫化物的部分熔解,岩浆中硫化物熔体富集Se、Pd,亏损S、Fe,岩浆中的S由饱和变为不饱和。晚阶段在浅部岩浆房,少量地壳S的加入并未使得S饱和从而发生硫化物大规模熔离。金宝山岩体具有较低的Cu/Pd、Cu/Pt比值,即出现Cu/Pd比值较低的岩体也可能有较大的成矿潜力,这与传统意义上所认为的具有较高Cu/Pd、Cu/Pt比值的矿体不同。     

Karren of Mushroom Mountain (Junzi Shan) in the Eastern Yunnan Ridge, Yunnan, China: Karstological and Tourist Attraction

<正>Mushroom Mountain karren with predominantly flat tops that formed along the stylolites and bedding planes dictated the special features of this karst landscape.Their features and rock relief clearly reflect the geological conditions and development.The subsoil karren with conical tops dissected by subsoil rock relief were exposed from beneath the soil.Below tree vegetation,the subsoil karren are to a great extent covered by moss and lichen,under which they acquire their characteristic shape.On the bare surface they were reshaped by rainwater that carves flutes and solution pans.The old cave that opens below the top of one of the cones reveals the period before its dissection into hills and cones when this part of the karst aquifer was still deep under the water table.     

The Cretaceous volcanic succession around the Songliao Basin,NE China: relationship between volcanism and sedimentation

With volume ratio of 8:1:1.5 amongst acidic, intermediate and basaltic rocks, the Cretaceous volcanics around the Songliao Basin are a series of high‐K or medium‐K, peraluminous or metaluminous, calc‐alkaline rocks, lacking typical basalts and peralkaline members of typical rift‐related types. Their eruption ages range between 133 and 127 Ma, 124 and 122 Ma and 117 and 113 Ma respectively. They are high in total (Rare earth element) REE contents (96.1–326 ppm), enriched in LREE and depleted in HREE (LREE/HREE = 4.6–13.8), with negative Eu and Ce anomalies (Eu/Eu* = 0.04–0.88; Ce/Ce* = 0.60–0.97). They have enriched large‐ion lithophile elements (e.g. K, Ba, Th) and depleted high field strength elements (e.g. Nb, Ti and Y), suggesting a subduction‐related tectonic setting. The volcanic activities migrated from south to north, forming a successively northward‐stepping volcanic series and showing a feature significantly different from the overlying sedimentary sequence striking northeast. Thus, an overlap basin model was proposed. Accompanied by opening of the basin, the volcanogenic succession was formed at the block‐faulting stage (131–113 Ma) owing to the closure of the Mongolia–Okhotsk ocean in the Jurassic and early Cretaceous, while the overlying sedimentary sequence was unconformably deposited at the spreading stage (Albian–Maastrichtian) owing to the oblique subduction of the Pacific plate under the Eurasian plate. The volcanic succession constitutes the lower unit of basin filling and is the forerunner of further basin spreading. Copyright © 2002 John Wiley & Sons, Ltd.     

云南西双版纳埃洛石特征研究

采用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶红外吸收光谱(FT-IR)、X荧光光谱分析(XRF)、电子探针,等现代测试手段,对西双版纳-2μm粒级埃洛石的矿物学特征进行了系统的研究。研究结果表明:该矿床中同时存在10?-埃洛石和7?-埃洛石,以10?-埃洛石为主。埃洛石管的平均长度为约1.25μm,平均外径约0.16μm,内径为15~40 nm,管状结构形态较好,具有天然纳米多孔晶体材料性质。加热后10?-埃洛石中结构水较容易脱除,导致10?-埃洛石转变为7?-埃洛石,但7?-埃洛石的结构水较难脱除,在400℃仍有残留。     

Late-Quaternary dynamics of temperate forests: Applications of paleoecology to issues of global environmental change

Paleoecological evidence recently summarized from 162 fossil-pollen sites in eastern North America provides new insights concerning the nature and rate of response of temperate forest ecosystems to late Pleistocene and Holocene environmental changes. Across this subcontinental region (25°N to 60°N; 50°W to 100°W), temperate forests have changed in composition, location and area occupied in adjustment to major episodes of climatic cooling and warming during glacial-interglacial cycles of the Quaternary. Forest taxa have migrated differentially, reflecting their individualistic life-history characteristics, dispersal and competitive abilities, and tolerance thresholds to environmental changes, as well as the geographic distribution of corridors and barriers to plant migration. Gradient analysis and ecological ordination of paleovegetational data illustrate that: (1) both positions and breadth of major vegetational ecotones have shifted latitudinally over the past 20 ka; (2) good modern analogues exist for certain full-glacial warm-temperate and boreal forests; (3) during the transition from Pleistocene to Holocene conditions, mixed conifer-northern hardwoods forests, spreading across newly deglaciated terrain, lacked good analogues within the modern vegetation; and (4) most cool-temperate deciduous forest communities north of 35°N developed in the Holocene.Forest clearance and cultivation by Native Americans along principal riverways resulted in a transformation from natural to cultural landscapes during the mid- and late Holocene intervals. Fragmentation of temperate forests accelerated with the onset of EuroAmerican settlement and technologic developments after the Industrial Revolution.     

Enigmatic ribbon-like fossil from Early Cambrian of Yunnan,China

During the Late Neoproterozoic and Early Cambrian, a series of paleogeographic and paleoecological events occurred associated with deglaciations and the evolution of life. The appearance of fossils representing diverse phyla, novel body plans and complex ecologies in Ediacaran and Cambrian sedimentary successions has sparked diverse hypotheses about potential drivers for the radiation of early animals during this interval. Recently, new macroscopic fossils of carbonaceous compressions with unique features have been found in Anning, Yunnan, China. The fossils’ bodies are ribbon-shaped and bilaterally symmetric, with dense longitudinal features and transversal features. The fossils occur 0.68 m below a bentonite interlayer which has been dated 535.2 ± 1.7 Ma by Ri-xiang Zhu and his team in 2009. The relatively simply morphology of these fossils, coupled with a lack of preserved internal structures challenge efforts taxonomically identify the precursor organism and definitively ally it to a living group. However, the symmetry and unusual features of the body are analogous to members of Platyzoa. The presence of ribbon-shaped fossils in the Zhongyicun Member in Anning indicates that these organisms were at least a locally significant component of Cambrian seafloor ecosystems, and may hold important implications for our understanding of the early evolution of Bilateria.     

云南峨眉山高钛和低钛玄武岩的岩石成因

峨眉山玄武岩主要的岩石类型是低钛玄武岩和高钛玄武岩,并有少量的苦橄岩。它们不同程度地富集大离子亲石元素和轻稀土元素,相对亏损重稀土元素,稀土元素分馏明显或比较明显,相容元素（Co、V、Cr、Ni）显著亏损。低钛玄武岩浆受到陆壳物质的明显混染,高钛玄武岩浆也受到混染,但混染程度弱于低钛玄武岩浆。同化混染对Sr同位素和大离子亲石元素的影响程度大于对稀土元素和Nd同位素的影响程度。混染物是下地壳变质岩,也有少量上地壳物质。未受混染的样品具有适度亏损的Nd、Sr同位素。高钛玄武岩在岩浆演化过程中主要分离结晶相/堆晶相是单斜辉石,并有少量的斜长石。低钛玄武岩中,单斜辉石和斜长石的分离结晶作用是最主要的因素。低钛玄武岩的主体部分是在尖晶石稳定域与石榴石稳定域之间的过渡带熔融的;高钛玄武岩的主体部分是在石榴石稳定域内熔融的,极少部分是在尖晶石稳定域内熔融的。     

Preliminary Notes on the Mesozoic Mammals of Lufeng, Yunnan, China

Vertebrate fossils of Yunnan are only previously known by a few tragmentaryfinds belonging to early Tertiary and Plio-Pleistocene age. In October 1938, Mr. M.N. Bien of the Geological Survey of China discovered a rich fossiliferous formationwith two levels of vertebrate remains. Most of the well-preserved fossils were derivedfrom the lower level and contain remains of Dinosaurs which are still under the     

云南首次发现晚侏罗世马门溪龙化石

侏罗纪在全球范围内属于重要的产煤期,然而此时云南、四川中-南部没有煤系出现,反而发育了一套独特的"红色岩系".在这样的环境中生活并繁盛着蜥脚亚目等形形色色的恐龙,与中国北部、东部地区的恐龙类群有明显的差异.马门溪龙在中国主要发现于四川,最近在云南侏罗纪"红层"中发现云南马门溪龙(新种)尚属首次,再次证实禄丰一带存在上侏罗统.该化石产于禄丰川街盆地老长箐-大尖峰剖面,在其下部地层中还分别产出代表中侏罗世的川街龙和早侏罗世的禄丰龙化石.能在同一完整地层剖面上见到不同时段早、中、晚侏罗世3套恐龙动物群,这在国内外都是罕见的.     

New Eusauropod Dinosaur from Yuanmou of Yunnan Province, China

1 Introduction Sauropod dinosaurs were group of gigantic quadrupedal herbivores. This group includes the largest terrestrial animals ever to have existed. More than 120 genera have been proposed, however, many of these are now considered to be of dubious validity. Currently, approximately 100 genera are accepted as valid (Upchurch et al., 2004a). The sauropod dinosaur described herein was collected from Jiangyi (Fig. 1), Yuanmou County of Yunnan Province by the Yunnan Provincial Institute…