南极地区苔藓剖面中地球化学元素的营养运移特征

对采自南极的苔藓剖面上各层苔藓的地球化学元素含量进行分析,得到以下的初步结论：地球化学元素在苔藓剖面上的分布具有很强的继承性;不同地球化学元素在苔藓剖面上的分布特征不同,这与元素在苔藓中的营养特征有关,研究发现元素Ca在苔藓体内,异常活跃,它极易被累积在新鲜苔藓体内,Zn也是苔藓易吸收的元素;地球化学元素在老新苔藓中的转移能力不同;底层苔藓的元素转移能力很低,中层苔藓中元素维持在基本平衡的状态,上层苔藓中元素的转移系数较大。     

长白山阔叶红松林主要树种光合作用的光响应曲线

以叶片光合作用观测资料为基础,利用直角双曲线与非直角双曲线两种方法对长白山阔叶红松林的主要建群树种红松(Pinus koraiensis)、紫椴(Tilia amurensis)、蒙古栎(Quercus mongolica)、水曲柳(Fraxinus mandshurica)光合作用的光响应曲线进行了拟合.结果表明,两种方法拟合结果不同,直角双曲线方法简单,但非直角双曲线的拟合结果更符合生理意义.由直角双曲线拟合得出4个树种的初始量子效率α、最大净光合作用速率P_max以及暗呼吸R_d大于非直角双曲线的拟合结果,而光补偿点L_cp随树种不同而有差异.两种方法得出4个树种的α、R_d大小顺序相同,分别是：α为水曲柳＞紫椴＞蒙古栎＞红松;R_d为水曲柳＞蒙古栎＞紫椴＞红松,但由两种方法得出的P_max、L_cp值大小顺序有差异.     

超富集植物短毛蓼对锰的富集特征

通过野外调查和营养液培养试验,研究了锰在短毛蓼体内的富集特征和对其生长的影响.在锰含量高达2.5×105mg/kg的锰矿废弃地上短毛蓼生长良好,叶锰含量高达1.66×104mg/kg.营养液培养条件下,随着生长介质中Mn浓度的升高,短毛蓼根、茎、叶中的Mn含量逐渐增加,当锰供应水平为1.000mmol/L时,叶锰含量超过10000mg/kg;当锰供应水平为20 000mmol/L时,短毛蓼仍能生长,根、茎和叶3部分的锰含量均达到最大值,分别为9923,18112mg/kg和55750mg/kg.在所有锰供应水平下,短毛蓼茎和叶中的锰含量都比根部的高.结果表明,短毛蓼是一种锰超富集植物,这一发现为锰污染土壤的植物修复和探讨锰在植物体内的超富集机理提供了一种新的种质资源.     

珍稀濒危植物迁地保护策略中植物营养问题的探讨

营养缺乏、过量或不平衡都会直接导致植物生长繁殖障碍甚至死亡,通过改良土壤或补充矿质元素来解决这些问题是植物营养学研究的主要内容。这一学科的研究范围已经从传统人工生态系统发展到自然生态系统中。但总的来说,这一学科还没有真正渗透到珍稀濒危物种的迁地保护领域中来。中国各植物园目前正在开展大规模的珍稀濒危植物迁地保护工作,但人们都只重视了物种的引入,却忽视了它们在迁地保护过程中业已存在和可预见的生长繁殖障碍,对迁地保护植物的研究很少涉及其生长繁殖所需的营养条件。针对这一现状,本文提出了目前应开展的几项工作:(1)明确优先开展植物营养学研究的物种范围;(2)物种原产地土壤与植物化学元素背景值的分析;(3)迁地保护物种营养状况动态监测与营养诊断。该研究思路的提出,无论是从植物营养学与植物保育学的学科交叉角度,还是从珍稀濒危物种迁地保护保育策略的理论探索与解决实际问题的角度,都具有十分重要的意义。     

贵州牛角塘铅锌矿区优势植物的重金属富集特征

为筛选适合贵州喀斯特地区重金属污染土壤修复治理以及矿区生态复垦的植物材料,该研究在贵州牛角塘铅锌矿区采集30种优势植物及其根系土壤,测定其地上部、地下部和根系土壤的Cd、Cu、Ni、Pb、Zn含量,计算植物对重金属的富集和转运系数,并通过聚类分析综合评估植物的应用潜力.结果表明:(1)千里光、鬼针草地上部Cd含量高达4...     

5种湿地植物对土壤重金属的富集转运特征

选择芦苇、水葱、千屈菜、扁秆藨草、长苞香蒲5种湿地植物进行盆栽实验,比较它们对土壤中的5种重金属镉、铬、汞、铅、锌的富集特性,分析重金属在各植物体和土壤中的动态分布,以评价所测植物对土壤中重金属的综合富集能力,为利用植物修复金属污染土壤提供理论依据和技术支持。结果表明:(1)种植湿地植物对土壤重金属的富集效果显著高于无植物对照,且随着处理时间的延长,土壤中重金属镉、铬、汞、铅、锌的含量均呈下降趋势。(2)湿地植物对重金属镉、铬、汞、铅、锌的富集效果差异显著,其中水葱根部对重金属镉的富集系数最大,芦苇根部对重金属铬、汞、铅、锌的富集系数均最大,千屈菜、扁秆藨草和长苞香蒲根部对5种重金属的富集系数均较小;芦苇地上部分对金属镉的富集系数最大,千屈菜地上部分对金属铬、汞、铅的富集系数均最大,水葱地上部分对金属锌的富集系数最大。(3)5种湿地植物对重金属镉、铬、汞、铅、锌的转移系数差异显著,其中扁秆藨草对土壤中镉、铬、铅、锌的转移系数均为最大,对铬和锌的转移系数均大于1,长苞香蒲对铬的转移系数大于1,仅次于扁秆藨草。其他3种植物对5种重金属的转移系数均小于1。研究表明,5种湿地植物对重金属Cd、Cr、Hg、Pb、Zn都有富集和转移的能力,但不同植物对不同重金属的富集效果不同。     

入侵植物假苍耳对土壤中铜、铅重金属污染的富集特征

通过室内盆栽试验研究入侵植物假苍耳(Iva xanthifolia)在营养生长阶段对铜、铅的耐性及富集特征。实验结果表明,在1~16 mg·L^-1的添加铜处理及0.5~14 mg·L^-1的添加铅处理条件下,假苍耳对铜、铅两种单一金属均有很强的耐性及富集作用,重金属在植物体地上部和地下部的富集量分别为607.59、137.20,404.38、34.53 mg·kg^-1,对应的富集系数为11.39、4.18,转运系数4.43、11.71,且重金属在植物体内的分布规律均表现为：茎部＞叶片＞根部,地上部分的积累量远大于地下部分。对叶色、株高及生物量等特征的观察表明假苍耳的生长未受到抑制,符合超富集植物的基本特征。与一般超富集植物相比,假苍耳作为一种外来入侵植物,具有生长迅速、植物材料易得,生物量大且分布范围广的优点。     

植物次生代谢物对植食性哺乳动物营养和生理生态特征的影响

植物次生代谢物对植食性哺乳动物的营养和生理生态效应是动植物相互关系研究中的一个重要方面。本文简要介绍了植食性哺乳动物处理植物次生代谢物的一般途径,着重阐述了植物次生代谢物对植食性哺乳动物的营养和生理特征的限制方式,并对决定植食性哺乳动物处理植物次生代谢物能力差异性的相关因素进行了探讨。最后,结合国际上的研究趋势,论述了国内开展此类研究的方向和重点。     

喀喇昆仑、昆仑山地区植物中一些元素的自然含量特征

 本文论述了喀喇昆仑、昆仑山地区87种植物12个元素含量的特征。在含量水平上>10000ppm的元素有K,Ca,800—5000ppm的元素为Na、Mg,Fe、Al,10—100ppm的元素有Ba、Sr、Ti,Mn,V与Be的含量<10ppm。大多数植物Fe、V,Sr的含量高于一般的自然含量。植物中K含量的频数分布呈正态分布,其余元素的频数分布呈对数正态分布。不同植物种元素含量差异较大,Na的变异系数最大,Ca、Mg含量的变异系数最小。同种植物在不同地点元素含量有较大差异,不同植物种差异也不同。如紫花针茅(Stipa purpurea)>垫状驼绒藜(Ceratoides compacta)>鼠麴凤毛菊(Saussurea gnaphaloides)。植物中元素含量之间的相关分析表明,Fe、Al,V,Ti之间分别达极显著相关水平。用植物中12个元素的资料,对22种植物进行分类和排序,区分出Na,K型植物和Fe,Al,V,Ba型植物。     

内蒙古草原放牧恢复过程地衣生物量分布及其影响因素的研究

1　引　　言在干旱半干旱草原生态系统中,地衣是植物群落中的一个重要组成部分.地衣是真菌和具有光合功能的藻类的共生体,共生光合生物通过光合作用为自身和共生真菌提供碳水化合物,共生真菌为共生光合生物提供物理保护、水和矿物元素[9] .地衣芽枝可通过截获风蚀物质而增加土壤表面粗糙度,有利于积蓄降水和养分[1] ,地衣的共生真菌菌丝可以通过分泌粘质物而改善土壤团粒结构[3 ] .另外,地衣还可有效地分解矿物元素,同时还有较强的固氮功能[9,17] ,地衣不仅影响土壤的理化性状而且对维管植物也有潜在的影响.因此,地衣在草原生态系统中可促进…     

Comparisons of photosynthesis-related traits among understory lichens,mosses and vascular plant leaves in a high-elevation subalpine forest

对比高海拔亚高山森林林下地衣、藓类及维管植物叶片的光合相关性状 在高海拔亚高山森林中,许多地衣和藓类植物欣欣向荣,甚至成为林地表层的优势物种。尽管它们在森林生态系统中承担着不可替代的功能,但我们对其光合作用相关的功能性状水平知之甚少,对相同生境下藓类植物和维管植物的比较研究也较为匮乏。因此,本研究选择中国青藏高原东缘亚高山林下常见的3种地衣、3种藓类和4种维管植物,测定并对比了它们的碳、氮、磷含量及化学计量比、单位面积光合组织干重、叶绿素含量及光合光响应曲线的异同。研究结果表明,林下地衣的氮含量高于藓类植物,二者的氮、磷、叶绿素、光合速率及光合氮利用效率均低于维管植物叶片。不同种类地衣的光合相关性状与其生长环境相符,而林地表层的3种藓类植物和3种草本植物的功能性状在各自功能群中的种间差异均不显著。总之,这些结果表明高海拔亚高山林下地衣和藓类植物的优势与其光合相关性状关系不大,对严酷环境较强的适应能力可能是它们得以繁荣生长的关键。     

Caries prevalences among geochemical regions of Missouri

Our objectives were to determine how the prevalences of caries in elementary school children vary between geochemically defined regions of the state of Missouri and to compare this variation with that found for prehistoric Missouri inhabitants (Hildebolt et al.: Am. J. Phys. Anthropol. 75:1-14, 1988). Caries data on 6,584 school children were used in the study of second and sixth graders drinking optimally and suboptimally fluoridated water. Geochemical regions were based on maps recently published by the United States Geological Survey. Differences in mean caries scores and proportions of children with caries were tested by analysis of covariance, analysis of variance, Student t, and chi-squared tests. We found that caries prevalences do vary between the geochemical regions of the state. In the total sample, however, there were no significant differences between those children drinking optimally fluoridated water and those drinking suboptimally fluoridated water. We conclude that there is variation in caries rates among geochemically defined regions of the state and that geochemical factors associated with young parent materials may be antagonizing the action of fluoride.     

中国石蕊科地衣多样性与区系研究

通过实地调查我国华北、 西南等地区的石蕊科地衣多样性,结合前人的研究资料,从物种多样性、 生境、区系成分等多方面对我国石蕊科地衣进行研究.结果显示,我国石蕊科地衣共有5属107种,其中石蕊属(Cladonia)占优势,有94种,占石蕊科地衣总种数的87.9％.共鉴定出山西省新记录8种,云南省新记录种3种.石蕊科地衣生境...     

Classification and ordination of cryptogamic communities in Wilkes Land,Continental Antarctica

The entirely cryptogamic vegetation of Bailey and Clark Peninsulas, Windmill Islands, Budd Coast, Wilkes Land, Antarctica, is described for the first time. The vegetation of this area is exceptionally well developed and diverse and represents one of the most important botanical sites on the continent. The macroflora comprises three species of moss, one liverwort, three fruticose lichens, four foliose and over 20 crustose lichens; several macroalgae also occur. Seventy stands of relatively homogeneous vegetation were analysed and the percentage cover afforded by every species within 20 quadrats per site was recorded. A subjective classification was developed by visual ordering of the data sets and a hierarchical system erected which incorporates one moss- and one lichen-dominated sub-formation; the former includes two associations and seven sociations, while the latter comprises one association which includes four sociations. The data were then arranged by centroid linkage analysis to produce and objective classification, and subsequently ordinated by principal components analysis to generate groups of stands, the inter-relations of which were interpreted in ecological and environmental terms. The objective classification and ordination strongly support the subjectively derived groupings or sociations. Examples of plant interactions are qualitatively described.     

Multianalysis of trace elements in mosses with inductively coupled plasma-mass spectrometry

As a part of an air-pollution biomonitoring survey, a procedure using inductively coupled plasma-mass spectrometry (ICP-MS) and microwave digestion was developed to achieve a high sample throughput and guarantee the accuracy of the results. This article presents an analytical method to measure 22 trace elements. As, Ba, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Ni, Pb, Rb, Sb, Sr, Th, Tl, U, V, W were analyzed in 563 mosses collected in France. The digestion was performed in polytetrafluoroethylene (PTFE) vessel using the mixture HNO₃-H₂O₂-HF. The data were reprocessed taking into account the drift curve calculated for each element. The detection limits (DL) calculation was based on the standard deviations of the reagent blanks concentrations. The DL varied from one batch to another, because of the heterogeneity of the mosses’ elemental contents. The DL ranged between 0.001 μg/g (Cs, Tl) and 70 μg/g (Fe) and were mainly around 0.01 μg/g (As, Cd, Ce, Co, Hg, La, Mo, Sb, Sr, U, V, W). The detection limits obtained were in agreement with the concentrations observed in the samples, except for Hg and Ni. The reproducibility between duplicates and the analytical precision were near 10%. The procedure was tested with the mosses’ reference materials.     

上海市地面藓类植物生态位研究

在上海市市区和西部郊区主要公园,以及吴泾化工厂和吴淞化工厂,共设立22个样点,调查发现共有7种地面藓类植物.根据Levins公式计算了7种藓类植物的生态位宽度.结果表明,藓类植物种数与生态位宽度符合:N=0.344×e^-0.0377B,R=0.9684.大部分地面藓类植物生态位宽度很窄,68%种类生态位宽度小于0.1,因而在苔藓植物保护中应特别注意对小生境的保护.运用王刚的生态位重叠公式计测了其中重要值大于0.1的39种主要藓类植物的生态位重叠值,应用主坐标排序法和最小生成树法对它们进行分类.结果表明,这39种藓类植物可被分成5个生态类群,与生境有一定关系.     

Ecological and biotechnological aspects of lichens

Lichens and the partners from three different kingdoms are both taxonomically and physiologically a very diverse group, which makes them interesting from both ecological and biotechnological points of view. A lichen is a mutual ecophysiological innovation in many extreme environments in which symbiosis seems to protect the partners. Lichen’s ability to grow in harsh environments can be advantageous, resulting in important ecological niches, or disadvantageous when lichens occupy and cause biodeterioration of cultural monuments. Recently, new candidate compounds for drugs, UVB protection, and antifreeze proteins for frozen foods were discovered. Lichens were also found to have potential in bioplastic degradation and prevention of desertification. Nevertheless, there is still large potential for further industrial screening and research on lichen products. Due to improved culture techniques of isolated symbionts, increased knowledge of their secondary metabolism and improved methods for solubilizing lichen metabolites, the screening and activity tests can be implemented more easily today than in the past.     

Field research on the effects of UV-B filters on terrestrial Antarctic vegetation

Patches of vegetation of six common species growing on Léonie Island (67°35 S, 68°20 W), Antarctic Peninsula region were covered with either UV-B transparent perspex screens or UV-B absorbing screens. Uncovered plots served as a control. Temperature and relative humidity were monitored during the austral summer under and outside the screens. The mean effective PSII quantum efficiency showed significant differences among the species, but not between the UV-B treatments. It was concluded that the temperature and the moisture status of the vegetation obscured any possible influence of UV-B treatment on the tteffective PSII quantum efficiency. he usefulness of various UV-B exclusion and supplementation methods used to study the influence of UV-B in the field is discussed.