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1.
应用样方调查法,分析了湖北神农架自然保护区川金丝猴栖息地植被乔木层物种多样性和群落结构随海拔梯度的变化。结果如下:(1)调查样方160个,总面积64000m^2,共记录木本植物37科123属289种,其中乔木25科90属198种,灌木7科29属84种,木质藤本5科4属7种。优势科主要有蔷薇科、忍冬科、樟科、壳斗科和杜鹃花科等。(2)根据不同海拔乔木层物种组成的差异,该区植被类型可分为落阔叶林(1900~2100m)、针阔叶混交林(2200~2400m)和暗针叶林(2500~2600m)3种。(3)随着海拔升高,多样性指数(Shannon—Wie—ner指数)在3种植被类型中旱下降趋势;均匀度指数(Pielou指数)在针阔叶混交林和暗针叶林中呈下降趋势,在落叶阔叶林中变化不明显。(4)随着海拔升高,各乔木层所占比例,乔木l层(〉20m)逐渐减小,乔木Ⅱ层(10~20m)无明显变化,乔木Ⅲ层(〈10m)呈上升趋势。(5)以树高替代年龄,分析了9种优势乔木村种的种群年龄结构,结果表明该区植被的乔木层呈现稳定增长趋势。  相似文献   

2.
幕阜山地处中亚热带-北亚热带过渡地带,物种资源丰富.通过对其典型样地的调查,分别采用Shannon-Wiener指数、Simpson指数和Pielou均匀度指数作为测度指标,研究了幕阜山地区森林群落结构及其物种多样性特征.结果表明,该地区主要有21个森林群落类型.其中常绿阔叶林中,物种丰富度指数与多样性指数在群落梯度上的总体趋势均为灌木层相对高于乔木层,乔木层相对高于草本层;在落叶阔叶林中,其丰富度指数的趋势为灌木层>草本层和乔木层,而在草本层与乔木层间是波动的,多样性指数的趋势为灌木层>草本层>乔木层;在针叶林中,物种丰富度、多样性指数表现的总趋势基本一致,即灌木层的丰富度相对较高,其次为草本层,乔木层的相对较小.在其他群落类型中,多样性指数、均匀度指数在乔木层、灌木层和草本层则表现出多样化的趋势;另外,从总体上看,各种指数在海拔梯度上并未表现出明显的规律性.  相似文献   

3.
常绿阔叶林是福建梅花山国家级自然保护区地带性植被。采用样带与典型群落调查法对区内的常绿阔叶林14400m2样地展开调查,并对植物多样性海拔梯度格局进行分析,结果表明:(1) 群落植物物种丰富度、Gleason丰富度指数、Simpson指数、Shannon Wiener指数和Pielou均匀度指数的均值分别为64.42、10.75、5.75、3.50、0.58,且这5种指数在各样带间差异极为显著,并随海拔的升高均呈单峰曲线变化,峰值出现在海拔700m~900m。(2) 群落各层次的植物物种丰富度、Shannon Wiener指数均呈现灌木层(包括幼树和层间植物)〉乔木层〉草本层的特征。乔木、灌木层物种丰富度与乔木层Shannon Wiener指数在海拔梯度上的样带间差异极显著,变化趋势与群落相似;灌木层与草本层Shannon Wiener指数以及草本层物种丰富度随海拔梯度变化不明显。因此,梅花山自然保护区常绿阔叶林植物物种多样性的海拔梯度格局呈现单峰分布,并支持中间高度膨胀模式(mid domain model)。  相似文献   

4.
甘肃小陇山锐齿栎群落生物多样性特征分析   总被引:26,自引:0,他引:26  
生物多样性是当前群落生态学研究的一个重要方面。为此,选择了地处我国南北交界的秦岭西段北坡——甘肃小陇山的锐齿栎群落作为研究对象,经过大量野外实地调查和室内数据分析,认为:(1)研究区锐齿栎群落乔木层物种多样性测度结果为:平均物种多样性指数H=1.483,平均均匀度指数Jsw=0.67,平均丰富度指数R=9。这与亚热带常绿阔叶林和暖温带阔叶落叶林相比较,具有明显的过渡性特征;(2)乔木层物种多样性沿海拔梯度在阴、阳坡存在两种不同的分布模式。在阳坡,物种多样性沿海拔梯度呈直线上升分布模式;在阴坡,物种多样性对海拔梯度呈不很敏感的分布模式,对阴、阳坡进行对比,阴坡多样性、均匀度和丰富度均大于阳坡,优势度相反;(3)经过采伐干扰,恢复20年后,与保护区相比,乔木层物种丰富度有所增大,多样性和优势度有所降低,均匀度没有产生明显变化。  相似文献   

5.
采用样方法对陕南秦巴山区药用植物群落物种多样性进行了研究。结果显示,该地区药用植物共计105科268属361种,其中药用裸子植物5科6属7种,药用被子植物92科254属344种,药用蕨类植物7科8属10种;含1属的科、含2~5属的科和含1种的属的药用植物数量较多,所占比例较高;该地区各植被类型的物种多样性变化各具特点,其中,物种丰富度指数(S)、Shannon-Wiener多样性指数(H)及Simpson多样性指数(D)表现为:乔木层最小、灌木层较大、草本层最大,但Pielou物种均匀度指数(J)的变化较为复杂;药用植物群落总的物种丰富度、乔木层物种丰富度和草本层物种丰富度均随海拔的升高表现出先升高后下降的趋势,且物种丰富度最大值出现在海拔1000~1200 m的山地常绿落叶阔叶林和温性针阔混交林的过渡区域,但灌木层物种丰富度与海拔之间无相关关系。本研究结果为阐明山地物种多样性的分布格局提供了基础资料,也为该区域药用植物的保护和管理提供参考。  相似文献   

6.
浙江丽水太山山地常绿阔叶林的物种多样性   总被引:4,自引:0,他引:4  
朱圣潮 《生态学杂志》2006,25(5):482-486
通过样方调查,应用物种多样性指数和群落均匀度等指标对分布在浙江丽水太山山地的常绿阔叶林的物种多样性进行了研究。结果表明,常绿阔叶林群落乔木种类较为单一,物种多样性和均匀性在群落不同层次中差别较大,灌木层的物种数量和物种多样性指数最大,乔木层次之,草本层最小,灌木层-乔木层-草本层的物种多样性依此递减。根据分布生境,群落结构和种类组成,可将该山地常绿阔叶林分为3个类型(群系),即木荷甜槠林、青冈石栎林和褐叶青冈林。  相似文献   

7.
格氏栲自然保护区常绿阔叶林群落特征   总被引:4,自引:1,他引:4  
宋育红  张新文  周斌 《生态科学》2005,24(3):228-232
在11000m2样地调查材料的基础上,分析了福建三明格氏栲自然保护区常绿阔叶林群落的种类组成、乔木种群的重要值、群落外貌、物种多样性、水平结构和垂直结构特征。该群落计有维管植物223种,隶属于80个科159属,其中单种属占总属数的80.5%,包括藤本在内的高位芽植物占总种数的85.2%。重要值高的乔木种群是格氏栲、木荷、米槠、马尾松、刮槠和山黄皮。主要乔木种群均服从聚集分布。群落垂直结构复杂,可分为乔木层、灌木层和草本层。生活型谱和物种多样性指数介于南亚热带季风常绿阔叶林和中亚热带常绿阔叶林之间。  相似文献   

8.
浙江天童山区灌丛群落的物种多样性及其与演替的关系   总被引:21,自引:1,他引:20  
张光富 《生物多样性》2000,8(3):271-276
根据浙江天童山区灌丛群落的样地调查数据,采用Shannon-Wiener多样性指数、Simpson指数和群落均匀度指数研究了灌丛群落的物种多样性,并与当地的常绿阔叶林进行了比较。结果表明:这3种指标能够有效地表征亚热带灌丛群落的组成结构特征。天童灌丛群落灌木层的物种多样性指数 SW 高于常绿阔叶林中乔木层,而低于常绿阔叶林中灌木层。灌丛群落灌木层的生态优势度 SN 低于常绿阔叶林中乔木层,但高于常绿阔叶林中灌木层。灌丛群落灌木层的群落均匀度 PW 比常绿阔叶林中乔木层的和灌水层的都低。此外,文中还就本区灌丛群落物种多样性的特点,讨论了加速其进展演替的恢复措施。  相似文献   

9.
利用福建黄岗山东南坡30个样方和西北坡13个样方的资料,研究该地区乔木物种丰富度的垂直变化;东南坡共记录到乔木物种151种,隶属于42科73属;西北坡102种,隶属于32科54属。两坡面的乔木树种组成相差不大。物种丰富度随海拔的变化趋势是:随海拔升高,科、属、种的数量呈下降的趋势;东南坡科、属、种的数量在海拔800—1000m达到最大值,西北坡在海拔1500—1600m达到最大值。东南坡乔木物种Shannon—Wiener指数(H’)与海拔呈负相关;西北坡在海拔1200—1800m范围内H’高于东南坡;Screnson指数(IAc)在不同植被类型交替时出现上下波动,从常绿阔叶林向针阔混交林转化时,物种更替强烈,Screnson指数明显下降。乔木物种生长特征的分析表明,最大树高(Hmax)和最大胸径(DBHmax)出现在中海拔,在相同海拔范围内西北坡的Hmax和DBHmax高于东南坡;东南坡Hmax和DBHmax的峰值出现在海拔800—900m,西北坡出现在海拔1800m。东南坡立木密度在海拔1500m处达最高值,而西北坡立木密度变化不明显,仅在海拔1900m以上明显下降。将全部乔木种划分为常绿阔叶、针叶和落叶阔叶等三种生活型,分析不同生活型的生长特征发现,常绿阔叶种类的胸高断面积和(total basal area,TBA)在低海拔占比例大;针叶种类沿海拔出现两个峰值,与分布两种不同针叶林种类有关;落叶阔叶林的TBA在各海拔段均占一定比例,但在西北坡的比例要高于东南坡。两坡三种生活型的TBA沿海拔梯度变化特征基本上相似。  相似文献   

10.
朱华 《植物生态学报》2021,45(3):224-241
云南具有极其丰富的生物多样性和以常绿阔叶林为优势的植被类型。该研究利用6个基于样方层面的1 hm2样地资料, 以及通过对整个植被类型的植物区系的调查, 对云南常绿阔叶林植被型的3个植被亚型(季风常绿阔叶林、半湿润常绿阔叶林和中山湿性常绿阔叶林)的生态外貌特征、植物区系组成及其生物地理演化进行了研究。在样方层面, 尽管这3个常绿阔叶林在树种组成上优势种均为壳斗科、樟科和山茶科植物, 但它们在种类组成、多样性、生态外貌和生物地理特征上呈现多样化。分布在南部及西南部的季风常绿阔叶林物种组成极其丰富, 具有热带森林的生态外貌, 并以热带亚洲分布种为优势种。主要分布在云南高原的半湿润常绿阔叶林和云南中部和北部山地的中山湿性常绿阔叶林具有亚热带常绿阔叶林的生态外貌特征和以中国-喜马拉雅及中国特有种占优势, 是中国西南独特的植被类型。在植被亚型层面, 这3个常绿阔叶林的植物区系(包括所有生活型的种子植物)中种数最多的科, 按地理成分均为世界分布型的科, 含种数较少的科则为其他各种分布型的科。半湿润常绿阔叶林和中山湿性常绿阔叶林的植物区系, 热带分布属分别占总属数的44.91%和44.04%, 温带分布属占46.29%和48.19%, 其中北温带分布属比例最高, 分别为18.36%和19.95%。季风常绿阔叶林植物区系则显示了不同的地理成分格局: 热带分布属占总属数的78.05%, 并以热带亚洲分布属占最高比例。通过对这3个常绿阔叶林的比较发现, 半湿润常绿阔叶林和中山湿性常绿阔叶林除生态外貌特征有一定区别外, 在植物区系组成和地理成分上很接近, 它们在种的组成上, 与季风常绿阔叶林的类似性仅为17.1%和15.4%。季风常绿阔叶林因其在植物区系和生态外貌上与后二者区别明显, 建议在云南植被分类上划分一个独立的植被型, 它是东南亚低山常绿阔叶林分布在中国西南部热带北缘山地的一个植被类型。结合云南的地质历史和古植物学资料, 认为云南的常绿阔叶林及其植物区系受晚中新世以来的地质历史事件深刻影响。半湿润常绿阔叶林是中国西南独特而特有种丰富的植被类型, 由于严重的人为干扰破坏, 现已片段化或成为萌生灌丛状, 应给予优先保护。  相似文献   

11.
Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.  相似文献   

12.
The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.  相似文献   

13.
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.  相似文献   

14.
The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γj in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γj are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO3 (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li+ are: Cs+ (1.38), Rb+ (1.32), K+ (1.31), Na+ (1.16), TMA+ (0.53), TEA+ (0.45), TBA+ (0.03), Cl (0.19), glutamate (0.04), and NO3− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.  相似文献   

15.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.  相似文献   

16.
17.
The aim of this report has been to present results concerning analytical quality controls of Hg analysis of fish and sediment, analyses of Fe, Ca, total-P, K, pH, alkalinity, conductivity, colour and hardness (Ca + Mg) of lake water samples. Despite the fact that these are standard parameters in many regular water control programs, there are major differences in the reliability with which these parameters can be determined. The focus here is on an overall inter-laboratory comparison between the parameters. Six laboratories have been involved in the analysis. Selected results: pH gives the lowest (average) relative standard deviation (error), about 2 %; conductivity gives an error of about 5–7 %; alkalinity yields an average error of as much as 13–25 %, which is the largest among the parameters studied here; colour also gives a high error, 9–15 %; hardness gives a relative standard deviation of about 6–7 %. Of the other parameters (i. e., Hg, Fe, Ca and P), Hg gives the best reliability and Fe and P the lowest. To have knowledge of the reliability of the analytical data is of paramount importance in most control programs and research projects.  相似文献   

18.
We investigated the uptake of inorganic elements (Be, Na, Mg, K, Ca, Sc, Mn, Co, Zn, Se, Rb, Sr, Y, Zr, Ce, Pm, Gd, and Hf) and the effect of Ca on their uptake in carrots (Daucus carota cv. U.S. harumakigosun) by the radioactive multitracer technique. The experimental results suggested that Na, Mg, K, and Rb competed for the functional groups outside the cells in roots with Ca but not for the transporter-binding sites on the plasma membrrane of the root cortex cells. In contrast, Y, Ce, Pm, and Gd competed with Ca for the transporters on the plasma membrane. The selectivity, which was defined as the value obtained by dividing the concentration ratio of an elemental pair, K/Na, Rb/Na, Be/Sr, and Mg/Sr, in the presence of 0.2 and 2 ppm Ca by that of the corresponding elemental pair in the absence of Ca in the solution was estimated. The selectivity of K and Rb in roots was increased in the presence of Ca. The selectivity of Be in roots was not affected, whereas the selectivity of Mg was increased by Ca. These observations suggest that the presence of Ca in the uptake solution enhances the selectivity in the uptake of metabolically important elements against unwanted elements.  相似文献   

19.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.  相似文献   

20.
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.  相似文献   

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