黄龙世界自然遗产地岷江冷杉原始林群落结构与植物多样性：生境差异性研究

黄龙世界自然遗产地岷江冷杉林(Abies faxoniana)生境类型多样，群落结构复杂，群落植物种类组成多样性丰富。揭示不同生境的生物多样性及其差异是认识生物多样性格局、形成及维持机制的前提和进行多样性保育的基础。本文采用样方法对黄龙钙化滩生境、阴坡非钙化生境及半阳坡非钙化生境的岷江冷杉原始林植物群落结构及植物多样性进行了研究。结果表明： 黄龙岷江冷杉林具有明显的复层异龄结构，垂直结构明显，乔木、灌木、草本、苔藓层次分明。共发现高等植物386 种，其中维管植物46 科103 属163 种，苔藓植38 科83 属物223 种。各层片结构及物种组成如下: (1)钙化滩生境、阴坡非钙化生境、半阳坡非钙化生境分别发现乔木18 种、13种、8 种。乔木层均可分为两个亚层，第一亚层优势种均为岷江冷杉，第二亚层主要为岷江冷杉异龄树或其它大高位芽物种。钙化滩生境第一亚层除优势种岷江冷杉外混生有巴山冷杉(Abies fargesii)、粗枝云杉(Picea asperata)以及阔叶树种白桦(Betula platyphylla)等，第二亚层主要为岷江冷杉异龄树；阴坡非钙化生境第一亚层除优势种岷江冷杉外间有巴山冷杉和白桦，第二亚层物种主要为川滇长尾槭(Acer caudatum var. prattii)；半阳坡非钙化生境第一亚层除优势种岷江冷杉外混生有巴山冷杉，第二亚层主要为岷江冷杉异龄树。依乔木层优势种的差异，钙化滩生境及半阳坡非钙化生境为岷江冷杉纯林，阴坡非钙化生境为岷江冷杉－川滇长尾槭混交林。不同生境乔木层郁闭度、乔木密度、树高结构、直径结构均存在差异。 (2)钙化滩生境发现灌木41 种，平均盖度为18.49±1.72(％)，平均高度为52.12±4.45(cm)，优势种为直穗小檗(Berberis dasystachya)；阴坡非钙化生境发现灌木30 种，平均盖度为29.33±2.56 (％)，平均高度为119.55±8.01 (cm)，优势种为箭竹 (Fargesia spathacea) 、唐古特忍冬(Lonicera tangutica) 和袋花忍冬(Lonicera saccata)；半阳坡非钙化生境发现灌木29 种，平均盖度为31.35±1.93 (％)，平均高度为107.55±4.24 (cm)，优势种为箭竹(Fargesia spathacea)。不同生境灌木层结构和物种组成多样性差异显著，钙化滩生境的灌木盖度、高度总体上较非钙化的坡地生境低, 钙化滩生境灌木以小型叶的落叶灌木为主，沟两侧非钙化的坡地生境上则发育了丰富箭竹。 (3)钙化滩生境发现草本46 种，平均盖度为7.18±0.79 (％)，平均高度为5.04±0.26(cm)，以山酢浆草(Oxalis griffithii)为优势种；阴坡非钙化生境发现草本物种71 种，平均盖度达29.04±2.31(％)，平均高度为9.08±0.52(cm)，以钝叶楼梯草(Elatostema obtusum)、山酢浆草为优势种；半阳坡非钙化生境草本物种50 种，平均盖度为以8.79±0.82(％)，平均高度为7.67±0.43 (cm)，以扇叶铁线蕨(Adiantum flabellulatum)、双花堇菜(Viola biflora)、华中蛾眉蕨(Lunathyrium shennongense)、山酢浆草为优势种。阴坡非钙化生境草本层片发育良好，多样性最为丰富，盖度和物种丰富度均显著高于钙化滩生境和半阳坡非钙化生境。 (4)钙化滩生境发现苔藓物种140 种，平均盖度达84.25±1.30 (％)，以仰叶星塔藓(Hylocomiastrum umbratum) 等大型藓类为优势种；阴坡非钙化生境发现苔藓物种115 种，平均盖度为79.29±1.64 (％)，以刺叶提灯藓(Mnium spinosum)、大羽藓(Thuidium cymbifolium)、毛尖燕尾藓(Bryhnia trichomitra)等个体较小的物种为优势种；半阳坡非钙化生境发现苔藓物种91 种，平均盖度为60.64±1.93 (％)，也以刺叶提灯藓为优势种。 (5)钙化滩生境、阴坡非钙化生境、半阳坡非钙化生境的物种数分别为234 种、221 种、175 种。乔木层的Shannon-Wiener 指数分别为0.75 ±0.12、1.87±0.12、1.78±0.07（灌木层，0.44±0.08、1.71± 0.15、2.49±0.06；草本层，0.33±0.13、1.31±0.15 、2.15±0.08； 苔藓层1.30±0.11、2.08±0.04、1.73±0.11，）；Pielou 均匀度指数分别为0.45±0.05、0.29±0.06、0.28±0.08（灌木层，0.75±0.03、0.68±0.05、0.52±0.06；草本层，0.68±0.02、0.77±0.02、0.74±0.02；苔藓层，0.40±0.03、0.63±0.02、0.52±0.03）；Simpson's 优势度指数分别为0.63±0.06、0.78±0.04、0.83±0.07（灌木层，0.21±0.03、0.28±0.05、0.45±0.06；草本层，0.25±0.02、0.12±0.01、0.17±0.01；苔藓层，0.45±0.04、0.18±0.01、0.31±0.04）。三种生境间乔木层、草本层的Sorenson 群落相似性系数较低, 灌木层、苔藓层的的Sorenson 群落相似性系数较高。 综上所述，黄龙岷江冷杉林的群落结构、植物多样性在三种生境间存在差异性，这将意味着我们在进行黄龙世界自然遗产地的森林经营管理时要较多地关注岷江冷山林群落在不同生境中的差异性。 There were multiplex habitat types, complicated community structure and abundant species composition in the Huanglong World Natural Heritage Site. Uncovering the differences of biodiversity among different habitats was a precondition to understand the distribution, formation and sustaining mechanism of the biodiversity, and the foundation of biodiversity conservation. In the present study, using plenty of quadrants, we investigated the community structure and the biodiversity of the primitive Abies faxoniana forest in different habitats (travertine bottomland, semi-sunny-slope non-calcified habitat and shady-slope non-calcified habitat) in the Huanglong World Natural Heritage Site. The main results are as follows: All the primitive Abies faxoniana forests in the three habitats were uneven-aged with obvious vertical structure including tree layer, shrub layer, herb layer and bryophyte layer. A total of 386 higher plants including 163 vascular plant species (103 generic, 46 families) and 223 bryophyte species (83 generic, 38 families) were investigated. The structure and species composition of each layer are as follows: (1) There were 18, 13 and 8 tree species in travertine bottomland, shady-slope non-calcified habitat and semi-sunny-slope non-calcified habitat, respectively. The tree layers in all habitats can be divided into two clear sub-layers. The upper tree layers were dominated by Abies faxoniana, and the lower tree layers were dominated by uneven-aged Abies faxoniana or other phanerophytes species. There were Abies fargesii , Picea asperata and Betula platyphylla besides the dominated species (Abies faxoniana) in the upper tree layer in travertine bottomland, and the lower tree layers were dominated by uneven-aged Abies faxoniana; There were Abies fargesii and Betula platyphylla besides the dominated species (Abies faxoniana) in the upper tree layer in shady-slope non-calcified habitat, and the lower tree layers were dominated by Acer caudatum var. prattii; There was Abies fargesii besides the dominated species (Abies faxoniana) in the upper tree layer semi-sunny-slope non-calcified habitat, and the lower tree layers were dominated by uneven-aged Abies faxoniana. According to composition percentage of dominate species in tree layer, both the forest in travertine bottomland and in semi-sunny-slope non-calcified habitat could be ranked as pure forest, and the forest in shady-slope non-calcified habitat could be ranked as mingled forest. There were significant differences in crown density, plant density, height structure and diameter structure among the three habitats. (2) A total of 41 shrub species (average coverage 18.49±1.72％; average height 52.12±4.45 ㎝)were found in travertine bottomland, and the dominate species was Berberis dasystachya; A total of 30 shrub species (average coverage 29.33±2.56 ％;average height 119.55±8.01 ㎝)were found in shady-slope non-calcified habitat, and the dominate species was Fargesia spathacea, Lonicera tangutica and Lonicera saccata. A total of 29 shrub species (average coverage 31.35±1.93％; average height 107.55±4.24 ㎝) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Fargesia spathacea. There were significant differences in structure and species diversity of the shrub layers among the three habitats. The coverage and height of shrub had lower value in travertine bottomland than in two non-calcified habitats. Moreover, travertine bottomland was dominated by deciduous shrub species with microphyll and non-calcified habitats developed abundant Fargesia spathacea species. (3) A total of 46 herb species (average coverage 7.18±0.79％;average height 5.04±0.26 ㎝)were found in travertine bottomland, and the dominate species was Oxalis griffithii; A total of 71 herb species (average coverage 29.04±2.31％;average height 9.08±0.52 ㎝)were found in shady-slope non-calcified habitat, and the dominate species was Elatostema obtusum and Oxalis griffithii. A total of 50 herb species (average coverage 8.79±0.82％;average height 7.67±0.43 ㎝) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Adiantum flabellulatum, Viola biflora, Lunathyrium shennongense and Oxalis griffithii. Herb layers developed well in shady-slope non-calcified habitat and had the higher species richness and coverage than travertine bottomland and semi-sunny-slope non-calcified habitat. (4) A total of 140 bryophyte species (average coverage 84.25±1.30％)were found in travertine bottomland, and the dominate species was big bryophyte species such as Hylocomiastrum umbratum and so on; A total of 115 bryophyte species (average coverage 79.29±1.64％)were found in shady-slope non-calcified habitat, and the dominate species was small bryophyte species such as Mnium spinosum, Thuidium cymbifolium, Bryhnia trichomitra and so on. A total of 91 bryophyte species (average coverage 60.64±1.93％) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Mnium spinosum. (5) There were 234, 221 and 175 plant species in travertine bottomland, shady-slope non-calcified habitat and semi-sunny-slope non-calcified habitat, respectively. Shannon-Wiener index of the tree layer was 0.75 ±0.12, 1.87±0.12 and 1.78±0.07 (the shrub layer, 0.44±0.08, 1.71± 0.15 and 2.49±0.06; the herb layer, 0.33±0.13, 1.31±0.15 and 2.15±0.08; the bryophyte layer, 1.30±0.11, 2.08±0.04 and 1.73±0.11.) for the three habitats, respectively; Pielou index of the tree layer was 0.45±0.05, 0.29±0.06 and 0.28±0.08 (the shrub layer, 0.75±0.03, 0.68±0.05 and 0.52±0.06; the herb layer, 0.68±0.02, 0.77±0.02 and 0.74±0.02; the bryophyte layer, 0.40±0.03, 0.63±0.02 and 0.52±0.03.) for the three habitats, respectively. Simpson's index of the tree layer was 0.63±0.06, 0.78±0.04 and 0.83±0.07 (the shrub layer, 0.21±0.03、0.28±0.05、0.45±0.06; the herb layer, 0.25±0.02, 0.12±0.01 and 0.17±0.01; the bryophyte layer, 0.45±0.04, 0.18±0.01 and 0.31±0.04.) for the three habitats, respectively. There were low Sorenson index both in the tree layer and in the herb layer among the three habitats, whereas, high Sorenson index occurred both in the shrub layer and in the bryophyte layer. To sum up, there were differences both in community structure and plant diversity among the three different habitats, which means that we should pay more attention to habitats heterogeneities of the primitive Abies faxoniana forest when we take action to manage the forest in the Huanglong World Natural Heritage Site.

碳离子辐射大丽花矮化突变体的RAPD分析

大丽花经兰州重离子加速器提供的80MeV/u12C6+离子束辐照后产生矮化突变体,用随机扩增多态性(Random Amplified Polymorphic,RAPD)DNA技术对野生型和突变体进行检测分析。结果表明,在所用的25条引物中,1.80×108/cm2剂量辐照后有18条引物扩增出现多态性片断,扩增条带多态率19.57%;1.08×108/cm2剂量辐照后仅有6条引物扩增出现多态性片断,扩增条带多态率5.76%。用Jaccard公式对扩增产物进行统计分析,结果表明,两种剂量C6+辐照后与对照相似性系数分别为0.65和0.92。高剂量辐射后DNA易发生突变,在品种改良和诱变育种中相对较高剂量的选择可能更为有效。

Lipid biomarkers in the Zoige-Hongyuan peat deposit: Indicators of Holocene climate changes in West China

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CO_2干扰对红松和长白赤松幼苗土壤微生物量C的影响

以不同浓度CO2(700、500μm o l/m o l)处理的红松和长白赤松幼苗土壤为研究对象,在2003年的7~9月的中旬采样,对0~10 cm层土壤微生物生物量C受高浓度CO2影响进行了研究。结果表明,700μm o l/m o l CO2对红松幼苗土壤微生物生物量C起着极显著(p<0.01)抑制效应,其作用大于500μm o l/m o l CO2处理;受高浓度CO2处理的长白赤松幼苗土壤微生物生物量C表现出了与红松土壤微生物生物量C相似的变化规律。此外,500μm o l/m o l CO2条件对红松和长白赤松幼苗土壤微生物生物量C的影响存在着不稳定性。

长白山阔叶红松林昆虫多样性研究

通过季节性观察 ,系统地研究了长白山阔叶红松林昆虫类群及其多样性 .结果表明 ,长白山阔叶红松林已知的森林昆虫 2 6目 131科 116 2属 196 0种 ,其中森林害虫 11目 10 5科 881种、重要森林害虫6 38种 ;森林昆虫群落中植食性昆虫类群总数所占比重最大 ,天敌昆虫群落中以捕食性类群总数所占比重最大 .植食类群、寄生性类群和捕食类群全年的均匀度指数分别为 0 884、0 830和 0 80 6 .各类群间季节变动系数的大小顺序为捕食类群 >寄生性类群 >植食类群 .

黄土高原水土流失区人口、粮食发展模式与有关政策探讨

本文以西部大开发战略为指导，采用整体、系统、宏观、多维的思路，由综合研究到单项研究再到分区研究，由理论到实例，由定性到定量，由质量到数量，对黄土高原水土流失区做了系统全面的研究，以1949～1995年资料为基础，剖析了黄土高原水土流失区人口、粮食发展模式在发展过程中存在的难点和焦点问题，针对该区的自然条件与农业生产中的优势与问题，提出了技术体系，讨论了有关政策问题。

美国的土壤侵蚀与防治

<正> 美国是世界农业大国,除遇特大自然灾害外,农业生产一直保持长期稳定发展的态势.1990年谷物的生产量达到3.13亿t,预测到2000年谷物产量可达4.53亿t,1985～2000年谷物平均增长速度为1.8%.美国的农业生产之所以能取得如此辉煌的成就有多种原因,其中政府重视土壤保护是最主要的原因之一.80年代初期,美国的农业科学家皮门特尔就曾向全世界发出警告,指出土壤侵蚀已成为全世界第一号环境问题,呼吁人们注意土壤侵蚀给农业生产带来的严重危害.而当时的美国同样面临着土壤侵蚀的严峻形势.深入的研究表明,土壤侵蚀恶性发展的根本原因不在气候变异、水旱等自然灾害,造成土壤侵蚀的根本原因来自人类对自然界的干扰,其中包括不合理的土地利用、滥砍滥伐、破坏森

大气沉降核素~(7)Be在黄土高原地被物中的分布初探

7Be具有环境微粒示踪价值,在示踪土壤侵蚀研究中有一定的应用,但是有关地被覆盖物对7Be截留吸收的研究目前还相当少,这直接影响了示踪结果的准确性、示踪模型的建立及应用。本文对不同地被物中的7Be含量进行了分析,结果表明:春季末地表不同地被覆盖物中干枯植物的7Be含量最大,半分解物次之,活植物中含量最少。在整个植物生长期内,植物体7Be累积含量呈增长趋势,尤其在秋季增加更为突出;不同植物中7Be含量差异性很大,变异系数达0.6;从总体上看,不同类型植物中7Be的平均含量分布趋势是草本>半灌木及小灌木>种植作物;和其它同类植物种相比,不同作物种中7Be含量的变异系数相对较大,为0.47。

沙地云杉新种的鉴定及其对我国北方生态环境建设意义

在浩瀚无垠的小腾格里沙地东部边缘，生态环境非常脆弱地区、分布着大面积的原始云杉天然林，是世界上非常罕见特殊的森林生态系统类型．但是长期以来，这种云杉究竞是哪一种？在我国植物分类学上一直是个争论性问题．我国著名树木分类学家郑万钧教授在《中国植物志》第七...

内蒙古呼伦贝尔市饮茶型氟铝联合中毒研究

目的探讨饮茶型氟中毒是否为砖茶型氟铝联合中毒。方法对饮茶型氟中毒病区进行饮水、砖茶、奶茶、主食、副食及牧民发、血、尿氟铝水平检测,对饮茶型氟中毒病区儿童和成人进行临床检查和拍摄X线片,同时对成人进行血液生物化学检查,以饮水型病区及非病区居民为对照组。结果呼伦贝尔市饮茶型病区饮水、主食、副食氟铝水平均在正常范围,砖茶氟铝水平分别为(541.3±48.8)、(4351±724)mg/kg,奶茶氟铝水平分别为(3.83±0.73)、(4.28±1.56)mg/L。饮水型病区饮水氟铝水平分别为(3.68±1.05)、(0.45±0.25)mg/L。饮茶型病区牧民氟总摄入量96.15%、铝总摄入量89.60%来源于砖茶。儿童氟斑牙检出率饮茶型病区为25.24%,饮水型病区为63.17%,饮茶型病区非常显著低于饮水型病区(P<0.01);成人氟中毒检出率饮茶型病区为42.61%,饮水型病区为28.83%,饮茶型病区显著高于饮水型病区(P<0.01)。结论呼伦贝尔市饮茶型氟中毒发病机理较为复杂,可能是砖茶型氟铝联合中毒。

The rheological behavior and dynamic mechanical properties of syndiotactic 1,2-polybutadiene

The rheological behavior and the dynamic mechanical properties of syndiotactic 1,2-polybutadiene (sPB) were investigated by a rotational rheometer (MCR-300) and a dynamic mechanical analyzer (DMA-242C). Rheological behavior of sPB-830, a sPB with crystalline degree of 20.1% and syndiotactic content of 65.1%, showed that storage modulus (G ') and loss modulus (G '') decreased, and the zero shear viscosity (eta(0)) decreased slightly with increasing temperature when measuring temperatures were lower than 160 degrees C. However, G ' and G '' increased at the end region of relaxation curves with increasing temperature and)10 increased with increasing temperature as the measuring temperatures were higher than 160 degrees C. Furthermore, critical crosslinked reaction temperature was detected at about 160 degrees C for sPB-830. The crosslinked reaction was not detected when test temperature was lower than 150 degrees C for measuring the dynamic mechanical properties of sample. The relationship between processing temperature and crosslinked reaction was proposed for the sPB-830 sample.

Polypropylene as a carbon source for the synthesis of multi-walled carbon nanotubes via catalytic combustion

Multi-walled carbon nanotubes (MWCNTs) were efficiently synthesized by catalytic combustion of polypropylene (PP) using nickel compounds (such as Ni2O3, NiO, Ni(OH)(2) and NiCO3 (.) 2Ni(OH)(2)) as catalysts in the presence of organic-modified montmorillonite (OMMT) at 630-830 degrees C. Morphologies of the sample undergoing different combustion times were observed to investigate actual process producing MWCNTs by this method. The obtained MWCNTs were characterized by X-ray diffraction (XRD), transmission electron microscope and Raman spectroscopy. The yield of MWCNTs was affected by the composition of PP mixtures with OMMT and nickel compounds and the combustion temperature. The proton acidic sites from the degraded OMMT layers due to the Hoffman reaction of the modifiers at high temperature played an important role in the catalytic degradation of PP to supply carbon sources that are easy to be catalyzed by nickel catalyst for the growth of MWCNTs. The XRD measurements demonstrated that the nickel compounds were in situ reduced into the Ni(0) state with the aid of hydrogen gas and/or hydrocarbons in the degradation products of PP, and the Ni(O) was really the active site for the growth of MWCNTs. The combination of nickel compounds with OMMT was a key factor to efficiently synthesize MWCNTs via catalytic combustion of PP.

Heterojunction ambipolar organic transistors fabricated by a two-step vacuum-deposition process

Ambipolar organic field-effect transistors (OFETs) are produced, based on organic heterojunctions fabricated by a two-step vacuum-deposition process. Copper phthalocyanine (CuPc) deposited at a high temperature (250 degrees C) acts as the first (p-type component) layer, and hexadecafluorophthalocyaninatocopper (F16CuPc) deposited at room temperature (25 degrees C) acts as the second (n-type component) layer. A heterojunction with an interpenetrating network is obtained as the active layer for the OFETs. These heterojunction devices display significant ambipolar charge transport with symmetric electron and hole mobilities of the order of 10(-4) cm(2) V-1 s(-1) in air. Conductive channels are at the interface between the F16CuPc and CuPc domains in the interpenetrating networks. Electrons are transported in the F16CuPc regions, and holes in the CuPc regions. The molecular arrangement in the heterojunction is well ordered, resulting in a balance of the two carrier densities responsible for the ambipolar electrical characteristics. The thin-film morphology of the organic heterojunction with its interpenetrating network structure can be controlled well by the vacuum-deposition process.

Polydispersity of ethylene sequence length in metallocene ethylene/alpha-olefin copolymers. II. Influence on crystallization and melting behavior

In this work, crystallization and melting behavior of metallocene ethylene/alpha-olefin copolymers were investigated by differential scanning calorimetry (DSC) and atomic force microscopy (AFM). The results indicated that the crystallization and melting temperatures for all the samples were directly related to the long ethylene sequences instead of the average sequence length (ASL), whereas the crystallization enthalpy and crystallinity were directly related to ASL, that is, both parameters decreased with a decreasing ASL. Multiple melting peaks were analyzed by thermal analysis. Three phenomena contributed to the multiple melting behaviors after isothermal crystallization, that is, the melting of crystals formed during quenching, the melting-recrystallization process, and the coexistence of different crystal morphologies. Two types of crystal morphologies could coexist in samples having a high comonomer content after isothermal crystallization. They were the chain-folded lamellae formed by long ethylene sequences and the bundlelike crystals formed by short ethylene sequences. The coexistence phenomenon was further proved by the AFM morphological observation.