80 resultados para Caragana microphylla


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干旱胁迫是全球范围内影响植物生存、生长和分布的重要环境因子。岷江上游干旱河谷区,由于生态环境的脆弱性和长期人类活动的干扰和过度利用,导致植被严重退化,水土流失加剧,山地灾害频繁,干旱化和荒漠化趋势明显。这种趋势若不能遏制,将严重阻碍区域社会经济的快速协调发展,并且威胁成都平原地区的发展和长江中下游地区的生态安全。因而开展干旱河谷生态恢复研究成为解决这些问题的关键。水分匮乏是限制干旱河谷生态恢复的关键因子,在全球气候变化的背景下,干旱胁迫在区域尺度上可能会更加严重,并使干旱河谷的生态环境更加恶化。因此,深入研究干旱河谷乡土植物对干旱胁迫的响应和适应机理,具有非常重要的理论和实践意义。 本论文以岷江上游干旱河谷的三种乡土豆科灌木,白刺花(Sophora davidii)、小马鞍羊蹄甲(Bauhinia faberi var. microphylla)和小雀花(Campylotropics polyantha)理论和实践意义。为研究对象,在人工控制条件下设计了4-5个连续性干旱胁迫处理,系统地研究了灌木幼苗的生长、生物量积累和水分利用效率(WUE)、形态结构和生理过程等对干旱胁迫的反应,揭示了幼苗的干旱适应能力及种间差异。主要研究结论如下: 1) 灌木生长和繁殖对干旱胁迫的反应 在干旱胁迫下,幼苗生长速率显著减小,叶片衰老和脱落比率增大,这些变化随着胁迫强度的增加具有累积效应。叶片比茎对干旱胁迫的反应更敏感。在严重干旱胁迫下,幼苗的有性繁殖被限制,但在中等程度干旱胁迫下,幼苗的有性繁殖能力被提高。 2) 灌木生物量积累及其分配和WUE对干旱胁迫的反应 在干旱胁迫下,灌木各器官的生物量都显著减小,但是生物量的分配侧重于地下部分,使得根茎比在干旱条件下增大。幼苗的耗水量(WU)随着干旱胁迫的增加而显著减少。白刺花和小马鞍羊蹄甲WUE在干旱胁迫下降低;小雀花的WUE在中等干旱胁迫下升高。 3) 灌木叶片结构特征对干旱胁迫反应 白刺花叶片具有较为典型的旱生型结构,而小马鞍羊蹄甲和小雀花则为中生型结构。在1至2年的干旱胁迫下,灌木叶片结构组成未发生本质性的改变,主要是细胞大小的变化。在中等和严重干旱胁迫下,叶肉组织厚度明显减小;并且气孔和表皮细胞面积也显著减小,气孔和表皮细胞密度显著增大;叶肉细胞层数、P/S值、表皮厚度等无显著变化。 4) 灌木对干旱胁迫的生理响应 气体交换参数和叶片相对含水量(RWC)在中等干旱胁迫下发生了明显的改变,而叶绿素荧光参数和光合色素含量在严重干旱胁迫下才发生显著变化。在干旱胁迫下,净光合作用速率(Pn)、气孔导度(gs)和RWC呈下降趋势,而叶片温度(Tl)呈增加趋势,蒸腾速率(Tr)的变化不明显。除了日最大Pn减小以外,干旱胁迫对气体交换参数的日变化无显著影响,但是对光合-光响应曲线有显著的影响,使有效光合时间缩短。在严重干旱胁迫下光系统受到损害而代谢减弱,PSⅡ中心的内禀光能转换效率(Fv/Fm)、量子产量(Yield)、光化学淬灭参数(qP)显著降低,而非光化学淬灭参数(NPQ)明显增加。气孔限制和非气孔限制对Pn的影响与干旱胁迫强度有关。在中度胁迫下,气孔限制起主导作用,在严重胁迫下非气孔限制起主导作用,40% FC水分条件可能是灌木由气孔限制向非气孔限制的转折点。 5) 灌木对干旱胁迫的适应能力及其种间差异 三种灌木对干旱胁迫具有较好的适应能力,即使在20% FC,幼苗未因干旱胁迫III而死亡;80% FC适宜于幼苗生长。白刺花生长速率慢,耗水量较少,具有较强的耐旱和耐贫瘠能力,并具有干旱忍受机制,能够在较干旱的环境中定居和生长。小马鞍羊蹄甲和小雀花,生长快,水分消耗量较大,尤其是小雀花,对干旱胁迫的忍受能力较弱,具有干旱回避机制,因而适宜于在较为湿润的生境中生长。综合分析表明,生长速率较慢的物种抗旱能力较强,其更适宜于作为干旱地区植被恢复物种。 Drought is often a key factor limiting plant establishment, growth and distribution inmany regions of the world. The harsh environmental conditions and long-termanthropogenic disturbance had resulted in habitat destruction in the dry valley ofMinjiang river, southwest China. Recently, it tended to be more severe on the vegetationdegradation, soil erosion and water loss, natural disaster, as well as desertification, whichimpact on regional booming economy and harmonious development, and would be verydangerous to the environmental security in the middle and lower reaches of Yangzi River.Therefore, ecological restoration in the dry valley is one of the vital tasks in China. Waterdeficit is known to affect adversely vegetation restoration in this place. Moreover, in thecontext of climate change, an increased frequency of drought stress might occur at aregional scale in the dry valleys of Minjiang River. The selection of appropriate plantingspecies for vegetation restoration in regard to regional conditions is an important issue atpresent and in further. The research on responses of indigenous species to drought stresscould provide insights into the improvement of the vegetation restoration in the dry valleys of Minjiang River. In this paper, the responses of three indigenous leguminous shrubs, Sophora davidii,Bauhinia faberi var. microphylla and Campylotropics polyantha, to various soil watersupplies were studied in order to assess drought tolerance of seedlings, and to compare interspecific differences in seedlings’ responses to drought stress. The results were as follows: 1 Growth and reproduction of shrubs in response to drought stress Seedling growth reduced significantly while leaf senescence accelerated underdrought stress, the cumulative responses to prolonged drought were found. The capacityfor reproduction was limited by severe drought stress, and improved by moderate droughtstress. Leaf responses were more sensitive than shoot to various water supplies. 2 WUE, biomass production and its partitioning of shrubs in response to drought stress Drought stress reduced significantly the total dry mass and their components ofseedlings, and altered more biomass allocation to root system, showing higher R/S ratiounder drought. Water use (WU) and water-use efficiency (WUE) of both S. davidii and B.faberi var. microphylla declined strongly with drought stress. The WU C. polyantha ofalso declined with drought stress, but WUE improved under moderate drought stress. 3 Anatomical characteristics and ultrastructures of leaves in response to drought stress There were xeromorphic for S. davidii leaves and mesomorphic for B. faberi var.microphylla and C. polyantha at the all water supplies. The foundational changes in leafstructures were not found with drought stress. However, mesophyll thickness, the areas ofstomatal and epidermis reduced slightly while the densities of stomatal and epidermisincreased under severe drought stress. Variations in these parameters could mainly be duoto cell size. Other structures did not displayed significant changes with drought stress. 4 Physiological responses of shrubs to drought stress The gas exchange parameters and leaf relative water content (RWC) were affectedby moderate stress, while chlorophyll fluorescence and chlorophyll content were onlyaffected by severe stress. Drought stress decreased net photosynthesis rate (Pn), stomatalconductance, light-use efficiency and RWC, and increased leaf temperature. Therespiration rates (Tr) were kept within a narrower range than Pn, resulting in aprogressively increased instantaneous water use effiecency (WUEi) under drought stress.Moreover, drought stress also affected the response curve of Pn to RAR, there was adepression light saturation point (Lsat) and maximum Pn (Pnmax) for moderate andsevere stressed seedling. However, diurnal changes of gas exchange parameters did notdiffer among water supplies although maximum daily Pn declined under severe stress.VISevere stress reduced Fv/Fm, Yield and qP while increased NPQ and chlorophyll content.Photosynthetic activity decreased during drought stress period due to stomatal andnon-stomatal limitations. The relative contribution of these limitations was associatedwith the severity of stress. The limitation to Pn was caused mainly by stomatal limitationunder moderate drought stress, and by the predominance of non-stomatal limitation undersevere stress. In this case, 40% FC water supply may be a non-stomatal limitation 5 Interspecific differences in drought tolerance of shrubs Three shrubs exhibited good performance throughout the experiment process, evenif at 20% FC treatment there were no any seedlings died, 80% FC water supply wassuitable for their establishment and growth. S. davidii minimized their water loss byreducing total leaf area and growth rate, as well as maintained higher RWC and Pncompared to the other two species under drought stress, thus they might be more tolerantto the drought stress than the other two species. On the contrary, it was found that C.polyantha and B. faberi var. microphylla had higher water loss because of their stomatalconductance and higher leaf area ratios. They reduced water loss with shedding theirleaves and changing leaf orientation under drought stress. Based on their responses, thestudied species could be categorized into two: (1) S. davidii with a tolerance mechanismin response to drought stress; (2) C. polyantha and B. faberi var. microphylla withdrought avoidance mechanism. These results indicated that slow-growing shrub speciesare better adapted to drought stress than intermediate or fast-growing species in present orpredicted drought conditions. Therefore, selecting rapid-growing species might leavethese seedlings relatively at a risk of extreme drought.

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岷江上游干旱河谷区水土流失强烈,地质灾害频繁,生态环境十分脆弱,而土壤条件恶劣(水分不足和养分缺乏)是阻碍该区植被恢复的关键因子,因此研究水分和乡土灌木生长对土壤的影响对该区的生态恢复具有指导意义。本文通过定点模拟实验,选取三种优势豆科灌木为研究对象,分别是白刺花(Sophora davidii)、小马鞍羊蹄甲(Bauhinia faberi var. microphylla)和小雀花(Campylotropics polyantha),设置5 个水分梯度,分别为100%、80%、60%、40%和20%田间持水量(FC),对栽种植物与不种植物下土壤理化性质和酶活性进行测定分析,系统比较和研究了不同水分条件和不同乡土灌木生长对干旱河谷区土壤结构、养分循环、酶活性以及微生物量的影响。主要结果如下:1. 无论生长植物与否,土壤的毛管持水量和毛管孔隙度都随着水分含量的减少而降低,最大持水量、总孔隙度和容重变化不大,相应地,土壤中的非毛管孔隙随含水量的减少而升高。各水分条件下,种植植物的毛管持水量和毛管孔隙度低于无植物生长的土壤,非毛管孔隙度相应地高于无植物土壤。土壤含水量在100%-40% FC 时,三种豆科灌木的毛管持水量和毛管孔隙度存在差异,而20% FC 条件下,三种豆科灌木土壤的物理性质基本相同。2. 水分胁迫影响土壤中养分的矿化和积累,主要表现在降低了水溶性碳和铵态氮的含量,中等程度胁迫时(60% FC)促进了有机碳和硝态氮的富集,对速效钾和有效磷没有明显作用。种植豆科灌木后各水分梯度上都增加了有机碳、铵态氮、速效钾和有效磷的积累。增加程度上三种豆科灌木间有一定差异,对于土壤有机碳总量,种植白刺花和小马鞍羊蹄甲明显高于小雀花,同样的情况还出现在铵态氮和速效钾上,但是对于有效磷,种植小雀花后的增加程度则明显高于白刺花和小马鞍羊蹄甲。种植豆科灌木不仅增加了土壤养分的相对含量,也改变了其在水分梯度上的变化趋势及其变化幅度,这种作用主要体现在碳元素和氮元素上。3. 无植物生长时脲酶活性随水分含量的减少而升高,水分胁迫对磷酸酶和过氧化氢酶的作用不显著,蔗糖酶也保持在相对较高的水平。种植植物后,蔗糖酶、磷酸酶活性与无植物时相比有较大幅度的提高,种植白刺花的脲酶活性也升高,其升高的程度在不同水分含量时不同。种植植物还降低了酶活性在水分梯度上的变幅,使之在水分梯度间的差异显著性降低。脲酶活性在指示土壤性质改变方面是较敏感的指标,其它三种酶在不同植物间的差异不明显。4. 在无植物生长时,中等程度的水分胁迫(60% FC)提高了土壤微生物量碳含量,过高或过低的土壤水分均不利于微生物碳的积累。种植小马鞍羊蹄甲后微生物量碳在水分梯度上的变化趋势与无植物生长时一致,而种植白刺花和小雀花后微生物量碳随着水分含量的减少而降低。不同种类植物的微生物量碳在水分梯度上的变化特征也不同,100% FC 条件下三种植物间没有差异,80%和60% FC 条件下小马鞍羊蹄甲显著高于白刺花和小雀花,40%和20% FC 条件下白刺花和小马鞍羊蹄甲也显著高于小雀花,说明不同种类植物随着干旱胁迫程度的加深微生物量碳的降低幅度不同,在极度干旱时,白刺花和小马鞍羊蹄甲土壤依然保持了较高的微生物活性,而小雀花土壤微生物量则明显下降。The dry valley of the upper reaches of the Minjiang River is seriously degradedmountain ecosystem. It was endangered by extremely soil lost and frequentlygeological disaster. Previous studies showed that short of water and nutrients in soilwas the principal limiting factors of vegetation restoration in this area. The typical soiland three dominant leguminous shrubs Sophora davidii, Bauhinia faberi var.microphylla and Campylotropics polyantha in upper reaches of arid Minjiang Rivervalley were considered as experimental material. Two-month old seedlings of eachspecies were exposed to five water supplies (100%, 80%, 60%, 40% and 20% waterfield capacity (FC)) in a temperature and light-controlled greenhouse. Afterthree-month water treatment, soil physiochemical variables and soil microbialactivities were determined by conventional methods. The main results showed that:1. Soil capillary capacity and capillary porosity decreased along water supplyregimes in all treatments, while saturated water capacity, total porosity and bulkdensity kept in a relatively stable level, as a result, the non-capillary porosity andcapacity increased with decrease of water supply. Compared to non-planted soil, theplant-soil systems had a higher non-capillary porosity and capacity, suggestingappropriate oxygen was present in soil to maintain the living of microorganism. Soilof three type shrub species shared the same capillary capacity and capillary porosityunder 20% FC.2. Water soluble carbon and NH4+-N decreased in response to water stress, whiletotal organic carbon and NO3--N promoted by moderate water stress and inhibited by 100% and 20% FC. Total organic carbon, NH4+-N, rapidly available K and availableP increased after the planting of leguminous shrubs in five water supply regimescompared to non-planted soil. For TOC, NH4+-N and rapidly available K, thepromotion effect was higher in S. davidii and B. faberi var. microphylla than C.polyantha planted soil, while available P displayed the opposite side. The planting ofshrubs also reduced the variance of observed traits along water supply gradients.3. Drought stress increased urease activity in non-planted soil, while insignificantdifferences were observed in phosphatase and catalase activity among five watersupply regimes. The planting of leguminous shrubs facilitated the β-glucosidase andphosphatase activity compared to the non-planted soil. It also reduced the variance ofenzyme activity along water supply gradients. Urease was more sensitive to waterstress than other three enzymes.4. Soil water content significantly affected microbial biomass carbon andCmic:Corg. S. davidii and B. faberi var. microphylla showed more drought toleranceability than C. polyantha, attributing not only to their relatively smaller variance ofmicrobial biomass carbon along soil water supply gradients, but also to the highlevel of microbial activity under severe water stress. S. davidii and B. faberi var.microphylla benefited reproduction of soil microorganism at 60%-80% FC, whilesevere drought limited it due to the competition of water and nutrients between plantand soil microorganism.

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运用Levins生态位宽度和Pianka生态位重叠公式,计测分析了科尔沁沙地流动沙丘以及山竹子Hedysarum fruticosum、柠条锦鸡儿Caragana korshinskii、黄柳Salix gordejevii和小叶锦鸡儿C.micro-phylla人工固沙群落内草本植物种群的生态位宽度和生态位重叠。研究结果表明:在不同的生境条件下物种的生态位宽度存在差异,沙蓬Agriophyllum squarrosum在流动沙丘上的生态位宽度最大,狗尾草Setar-ia viridis、毛马唐Digitaria ciliaris分别在山竹子群落和黄柳群落中的生态位宽度最大,烛台虫实Corispermum candelabrum在柠条锦鸡儿群落和小叶锦鸡儿群落中占据着最宽的生态位。各群落中生态位宽的物种对生态位重叠值较大,但有些较窄的生态位物种对之间也出现较大的生态位重叠,这种现象从另外的角度表明各群落内环境资源存在一定的空间异质性。不同固沙群落中相同物种的生态位宽度和生态位重叠的差异在一定程度上反映了各群落内不同的区域环境特征。

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植物根系利用土壤水分深度和耗水量是研究植物与土壤水关系的基础。以柠条为对象,采用中子仪,对撂荒地和柠条林地土壤水分进行长期定位观测和分析。结果表明,2002年内,随着时间推移,柠条利用土壤水分深度从播种时的2cm左右,迅速增加到9月1日的90cm,10月15日的110cm,11月1日的170cm,到11月15日柠条利用土壤水分深度为220cm;除丰水年(2年生)柠条土壤储水量增加了122.8mm外,随着林龄的增加和降雨量等的变化,植物利用土壤水分的深度和耗水量增加,土壤储水量下降。到2004年生长季末,3年生柠条林地100cm土层出现土壤干层,5年生柠条林地剖面60—300cm土层出现土壤干层。此时需要采取措施,控制柠条生长、密度和耗水量,实现土壤水资源的可持续利用。

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该区干旱与水土流失并存 ,降雨量时空分配不均 ,且水热并不同步 (在春夏 ,植物常因缺水而枯死 ) ,致使生态环境建设中恢复植被的难度大。为此 ,采用工程整地措施与灌草立体配置模式 ,发展集流灌草植被 ,调蓄土壤水分 ,促进灌草植被的快速恢复。结果表明 ,在水平阶营造柠条和披碱草 ,在生长初期 0~ 50 0 cm土层含水量可分为 3个明显的层次 ;在生长的第 4年随着灌草根系深扎 ,土壤水分过耗 ,出现明显的干土层 ,分布深度在 1 2 0~ 2 0 0 cm,厚度为 1 0 0 cm。在第 8年干土层扩大到 1 0 0~ 30 0 cm,厚度为 2 0 0 cm。第 1 4年土壤含水量有所回升 ,但幅度不大 ,同第 8年相比 ,仅提高 1 .5~ 2 .0个百分点。水平阶的柠条灌木林随着生长时间的延续 ,其水分贮量变化是否增加 ,仍有待继续研究。该区 0~ 50 0 cm多年土壤贮水量 ,在生长初期 ( 4月份 ) ,1 5年生柠条480 .1 5mm,1 2年生沙棘、山桃分别为 41 4.6mm和 385.4mm,在生长末期 ( 1 0月 ) ,柠条 498.31mm,沙棘 42 3.31 mm,山桃 ...

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应用时空互代方法,以柠条林为例,对黄土丘陵沟壑区不同利用年限人工林土壤养分特征、空间变异及其演变进行了系统的研究。结果表明,该区人工林土壤肥力处于较低水平;人工林表层土壤养分中速效磷和速效钾的空间变异性较大;各环境因子对土壤养分有一定的影响,海拔、坡度和坡向等环境因子与人工林地土壤养分间呈负相关关系,坡位和地形与人工林地土壤养分间呈正相关关系。随着利用年限的增加,人工林土壤养分各指标含量均增加,与利用年限有显著的相关性。有机质、全氮、有效氮和速效磷的增加量不明显,全磷含量保持相对稳定的水平,速效钾经过多年积累有明显的增加。从土壤养分指数模型可以算出该区的人工林土壤有机质、全氮、有效氮约需35a能达到中上等养分水平,速效钾则约需27a才能达到中上等养分水平。

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通过对黄土高原试验示范区的多年定位观测试验 ,并结合调查数据 ,分析了该区灌木林地的土壤水分循环过程 ,大气降水分配特点 ,揭示了灌木林蒸腾耗水特征 ,以及土壤水分动态趋势 ,总结了沙棘、柠条灌木林地土壤水分平衡规律 ,从而为黄土高原绿化、灌木林的合理布局和经营提供了一定的科学依据。

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The distribution and species diversity of plant communities along a 600 km transect through the northeastern Tibetan Plateau (32 degrees 42'-35 degrees 07' N, 101 degrees 02'-97 degrees 38' E) with altitudes from 3255 to 4460 m are described. The transect started from the Youyi Bridge of Banma through Dari, Maqin and Maduo to Zaling Lake. The data from 47 plots along the transect are summarized and analyzed. The mean annual temperature, the mean annual rainfall and the length of growing season decreases from 2.6 to -4.5 degrees C, from 767.2 to 240.1 mm, from 210 to 140 days, respectively, along the transect from the southeastern Banma to northwestern Zaling Lake. The number of vascular plant species recorded in 47 plots is 242 including 2 tree, 34 shrub, 206 herb species. Main vegetation types on the transect from southeast to northwest are: Sabina convallium forest, Picea likiangensis forest, Pyracantha fortuneana + Spiraea alpina shrub, Hippophae neurocarpu shrub, Sibiraea angustata + Polygonum viviparum shrub, Stellera chamaejasme herb meadow, Potentilla fruticosa + Salix obscura + Carex sp. Shrub, Kobresia capillifolia meadow, P. froticosa + Kobresia humilis shrub, Caragana jubata + S. obscura shrub, Kobresia tibetica meadow, Kobresia pygmaea meadow, K. pygmaea + Stipa purpurea steppe meadow, Stipa purpurea steppe. Plant richness and diversity index all showed a decreasing trend with increasing of elevation along transect from southeast to northwest. Detailed information on altitudinal ranges and distribution of the alpine vegetation, vascular flora and environments over the alpine zone at northeastern Tibetan Plateau provides baseline records relevant to future assessment of probable effects of global climate changes.

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Surface pollen assemblages and their relationhips with the modern vegetation and climate provide a foundation for investigating palaeo-environment conditions by fossil pollen analysis. A promising trend of palynology is to link pollen data more closely with ecology. In this study, I summarized the characteristics of surface pollen assemblages and their quantitative relation with the vegetation and climate of the typical ecological regions in northern China, based on surface pollen analysis of 205 sites and investigating of modern vegetation and climate. The primary conclusions are as follows:The differences in surface pollen assemblages for different vegetation regions are obvious. In the forest communities, the arboreal pollen percentages are more than 30%, herbs less than 50% and shrubs less than 10%; total pollen concentrations are more than 106 grains/g. In the steppe communities, arboreal pollen percentages are generally less than 5%; herb pollen percentages are more than 90%, and Artemisia and Chenopodiaceae are dominant in the pollen assemblages; total pollen concentrations range from 103 to 106 grains/g. In the desert communities, arboreal pollen percentages are less than 5%. Although Chenopodiaceae and Artemisia still dominate the pollen assemblages, Ephedra, Tamaricaceae and Nitraria are also significant important in the pollen assemblages; total pollen concentrations are mostly less than 104grains/g. In the sub-alpine or high and cold meadow communities, arboreal pollen percentages are less than 30%. and Cyperaceae is one of the most significant-taxa in the pollen assemblages. In the shrub communities, the pollen assemblages are consistent with the zonal vegetation; shrub pollen percentages are mostly less than 20%, except for Artemisia and Hippophae rhamnoides communities.There are obvious trends for the pollen percentage ratios of Artemisia to Chenopodiaceae (A/C), Pinus to Artemisia (P/A) and arbor to non-arbor (AP/NAP) in the different ecological regions. In the temperate deciduous broad-leaved forest region, the P/A ratios are generally higher than 0.1, the A/C ratios higher than 2 and the AP/NAP ratios higher than 0.3. In the temperate steppe regions, the P/A ratios are generally less than 0.1, the A/C ratios higher than 1 and the AP/NAP ratios less than 0.1. In the temperate desert regions, the P/A ratios are generally less than 0.1, the A/C ratios less than 1, and the AP/NAP ratios less than 0.1.The study on the representation and indication of pollen to vegetation shows that Pinus, Artemisia, Betula, Chenopodiaceae, Ephedra, Selaginella sinensis etc. are over-representative in the pollen assemblages and can only indicate the regional vegetation. Some pollen types, such as Quercus, Carpinus, Picea, Abies, Elaeagus, Larix, Salix, Pterocelis, Juglans, Ulmus, Gleditsia, Cotinus, Oleaceae, Spiraea, Corylus, Ostryopsis, Vites, Tetraena, Caragana, Tamaricaceae, Zygophyllum, Nitraria, Cyperaceae, Sanguisorba etc. are under-representative in the pollen assemblages, and can indicate the plant communities well. Populus, Rosaceae, Saxifranaceae, Gramineae, Leguminosae, Compositae, Caprifoliaceae etc. can not be used as significant indicators to the plants.The study on the relation of pollen percentages with plant covers shows that Pinus pollen percentages are more than 30% where pine trees exist in the surrounding region. The Picea+Abies pollen percentages are higher than 20% where the Picea+Abies trees are dominant in the communities, but less than 5% where the parent plants are sparse or absent. Larix pollen percentages vary from 5% to 20% where the Larix trees are dominant in the communities, but less than 5% where the parent plants are sparse or absent. Betula pollen percentages are higher than 40% where the Betula trees are dominant in the communities" but less than 5% where the parent plants are sparse or absent. Quercus pollen percentages are higher than 10% where the Quercus trees are dominant in the communities, but less than 1% where the parent plants sparse or absent. Carpinus pollen percentages vary from 5% to 15% where the Carpinus trees are dominant in the communities, but less than 1% where the parent plants are sparse or absent. Populus pollen percentages are about 0-5% at pure Populus communities, but cannot be recorded easily where the Populus plants mixed with other trees in the communities. Juglans pollen accounts for 25% to 35% in the forest of Juglans mandshurica, but less than 1% where the parent plants are sparse or absent. Pterocelis pollen percentages are less than 15% where the Pterocelis trees are dominant in the communities, but cannot be recorded easily where the parent plants are sparse or absent. Ulmus pollen percentages are more than 8% at Ulmus communities, but less than 1% where the Ulmus plants mixed with other trees in the communities. Vitex pollen percentages increase along with increasing of parent plant covers, but the maximum values are less than 10 %. Caragana pollen percentages are less than 20 % where the Caragana plant are dominant in the communities, and cannot be recorded easily where the parent plants are sparse or absent. Spiraea pollen percentages are less than 16 % where the Spiraea plant are dominant in the communities, and cannot be recorded easily where the parent plants are sparse or absent.The study on the relation of surface pollen assemblages with the modern climate shows that, in the axis 1 of DCA, surface samples scores have significant correlation with the average annual precipitations, and the highest determination coefficient (R2) is 0.8 for the fitting result of the third degree polynomial functions. In the axis 2 of DCA, the samples scores have significant correlation with the average annual temperatures, average July temperatures and average January temperatures, and the determination coefficient falls in 0.13-0.29 for the fitting result of the third degree polynomial functions with the highest determination coefficient for the average July temperature.The sensitivity of the different pollen taxa to climate change shows that some pollen taxa such as Pinus, Quercus, Carpinus, Juglans, Spiraea, Oleaceae, Gramineae, Tamariaceae and Ephedra are only sensitive to the change in precipitation.

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Live Performance, Szuper Gallery + Curtain Razors Dur: 50 mins NTSC HD 2011 Direction/Conception - Susanne Clausen, Pavlo Kerestey, Michele Sereda Performance Installation - Susanne Clausen, Pavlo Kerestey Performers - Jason Cawood, Susanne Clausen, Blair Fornwald, Morgan Garneau, John Hampton, Pavlo Kerestey, Michele Sereda Cave Video - Susanne Clausen and Pavlo Kerestey Sound scape - Szuper Gallery Voice - Michele Sereda Ballet Band - Billy Hughes, Trent Mailander and Otis Young Music - Dance of the Spirits - Danilo Villalta Technical Direction - Kenneth Young Stage Management - Paul Crepeau Sound Support - Jeff Morton Structural Design Consultant - James Phillips and Caragana Production Design Inc Set Assistants - Rebbeca Donison and Shelby Lowe Headress - Alla Sidorenko Costume consultation - Dean Renwick Documentation, Still - Carey Shaw, Szuper Gallery Documentation, Moving - Gabriel Yahyahkeekoot Administration + PR - Carey Shaw and the Mackenzie Art Gallery Poster Design - Rio Saxon Design Produced by Curtain Razors and Szuper Gallery in collaboration with the Mackenzie Art Gallery with the support of the Canada Council for the Arts, the Saskatchewan Arts Board and the City of Regina Arts Advisory Committee.

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Apocynaceae sensun strictum from the Mucuge Municipal Park, Bahia, Brazil, including the valid publication of two names in Mandevilla Lindl. The flora of Rauvolfioideae and Apocynoideae, which together form Apocynaceae s.s., from the Mucuge Municipal Park, Chapada Diamantina, State of Bahia, Brazil, is presented. Eight species and five genera were recognized. Mandevilla is the most diverse genus, With four species: M. scabra (Hoffmans. ex Roem. & Schult.) K. Schum., M. tenuifolia (J.C. Mikan) Woodson, M. bahiensis (Woodson) M.F. Sales & Kinoshita-Gouvea, and M.microphylla (Stadelm.) M.F. Sales & Kinoshita-Gouvea, the last two are a new status and a new combination, respectively, whose names are being validly published here. The four remaining genera are each represented by one species: Couma rigida Mull. Arg., Stipecoma peltigera (Stadelm.) Mull Arg,, Temnadenia violacea (Veil.) Miers, and Himatanthus bracteatus (A. DC.) Woodson. Identification key, descriptions, comments and illustrations are presented for every species.

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Pós-graduação em Química - IQ

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Ongoing taxonomic work on Mezilaurus has revealed two new species of the genus in Brazil, which are here described and illustrated. The first one, Mezilaurus glabriantha, from the state of Espirito Santo, represents the third endemic species known from the Brazilian Atlantic Forest, and Mezilaurus microphylla occurs in seasonally dry forests from the central Brazilian state of Tocantins. A key to distinguish the extra-Amazonian species of Mezilaurus from Brazil is provided.