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A new species of Festuca (Festuca rivas-martinezii de la Fuente & Ortúñez) is described from the Sierra de Ayllón, Sierra de Guadarrama, Sierra de Gredos and associated chains (northcentral Spain: provinces of Avila, Guadalajara, Madrid and Segovia. Some morphological, anatomical and cytological characters of the taxon are presented.  相似文献   

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Tragopogon cazorlanum (Asteraceae: Lactuceae) is proposed as a new Spanish species with distribution restricted to the Baetic mountains (south-eastern Spain). Its morphological, palynological, chromosomal, biogeographical and ecological features are discussed, as well as its main relationships and differences with reference to other Spanish species of the genus.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 505–511.  相似文献   

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Three new species are described in Biscutella sect. Biscutella from the central-eastern mountains of the Iberian Peninsula: B. bilbilitana Mateo & M.B. Crespo, B. segurae Mateo & M.B. Crespo, and B. conquensis Mateo & M.B. Crespo. They are characterized morphologically, ecologically and chorologically. Data separating them from B. valentina (L.) Heywood, a taxon to which they sometimes have been referred, are also reported.  相似文献   

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The presence of woody bamboos in Argentine archaeological sites led to attempts to identify them. In general, fragments of culm are recovered with nodes, internodes (or parts of them) and occasionally nodes with buds or their vestiges, but without leaves. Epidermal studies were carried out on developed culms of several bamboo genera growing currently in Argentina and neighbouring areas, with the purpose of detecting characters of taxonomic value that will allow identification at generic or species level. The selected characters did indeed facilitate the determination of the archaeological material. Fifteen species of six native genera from America were studied: Aulonemia Goudot, Colanthelia McClure & E. W. Smith, Chusquea Kunth, Guadua Kunth, Merostachys Spreng. and Rhipidocladum McClure. Epidermal cauline anatomy was described and illustrated using scanning electron and light microscopes. An identification key based on cauline epidermis is presented. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 45–55.  相似文献   

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So far only very few simple sequence repeat (SSR) markers developed from grass species have had their primer sequences published. To make more markers available to the scientific community, we isolated and sequenced 256 microsatellite‐containing clones from four genome libraries of a Lolium multiflorum×Festuca glaucescens F1 hybrid following enrichment in (TC)n, (TG)n, or both repeats. In this work, we report the primer sequences of 60 SSRs including preliminary results of polymorphism for mapping.  相似文献   

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ABSTRACT

Festuca gamisansii subsp. aethaliae, endemic to the Isle of Elba (Tuscan Archipelago) is described. The morphological, anatomical, karyological, ecological and chorological characteristics of the species are given. The main characteristics distinguishing F. gamisansii subsp. aethaliae from F. gamisansii subsp. gamisansii occurring in Corsica are also summarized.  相似文献   

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长白山阔叶红松林生态价位分级与生态系统经营对策   总被引:4,自引:3,他引:4  
引入生态价位概念,以长白山阔叶红松林为对象,采用层次分析法进行了生态价位划分.长白山阔叶红松林的生态系统价值评价综合指数由物理环境因素、群落结构组成、干扰状况3方面8个指标构成,包括坡度、土层厚度、土壤母质稳定性、结构盖度指数、物种多样性指数、更新力指数、优势种寿命和干扰度.采用层次分析法取得相应指标的系数;根据综合评价指数分布范围划分了3个生态价位类型,即低生态价位,综合指数1~1.874;中生态价位,综合指数1.874~2.749;高生态价位,综合指数2.749~3.623;对典型样地进行了生态价位分级,分析了各个生态价位类型森林的主要特征,据此提出了相应的生态系统管理对策,即高生态价位阔叶红松林采用封禁保护型自然经营,中生态价位阔叶红松林采用生态修复型半自然经营,低生态价位阔叶红松林采用近自然生态重建型经营。  相似文献   

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  总被引:1,自引:0,他引:1  
Phytoliths are amorphous silicon dioxide (SiO2.nH2O) inclusions abundant in leaves, in-ternodes and glumes in members of Poaceae. They may occur as inclusions filling the entire lumen of the silica cells, bulliform cells and trichomes or may be part of the outer epidermal cell walls. Since phytoliths are resistant to fungal or animal digestive juices, a large quantity of phytoliths accumulate in the soil where grasses grow. Compared with the pollen grains of grasses which tend to be uniform, phytoliths vary in sue and morphology and can be of value in identification at different taxonomic levels and in the dating of past vegetation. The size and shape of phytoliths of about 100 species of grasses from Tamil Nadu, India, have been determined. Silica bodies were observed either after isolation or in cleared leaf blades. Size and shape of phytoliths were determined under a microscope or from micrographs of the specimens. Size and shape can be used to assign the phytoliths to their respective subfamilies and to distinguish some of the grasses at the generic level. Drawings of silica cells and an identification key are provided for 80 species.  相似文献   

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长白山阔叶红松林蒸散量的测算   总被引:9,自引:8,他引:9  
王安志  裴铁璠 《应用生态学报》2002,13(12):1547-1550
2001年7-9月应用水量平衡法对长白山阔叶红松林蒸散量进行了测定,同时应用波文比(BREB)法对其蒸散量进行了估算,两种方法得到的总蒸散量分别为288.18mm和214.94mm,均小于该时段的降雨量301.9mm。通过两种方法分别得出了各月平均日蒸散量,并通过第二种方法计算出每日的蒸散量及每日不同时刻的蒸散速率,从而对水量平衡法和BREB方法测算阔叶红松林蒸散量的可行性及其精度进行了验证。  相似文献   

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不同类型农田土壤对可溶性有机氮、碳的吸附特性   总被引:7,自引:0,他引:7  
研究了陕西关中地区红油土和淋溶褐土耕层土壤对分离的有机肥提取液中可溶性有机氮、碳(SON和SOC)的吸附特性.结果表明:原始物质吸附等温线方程可以反映土壤对可溶性有机氮、碳的吸附特性,土壤吸附SON、SOC的数量与它们各自加入的量呈极显著线性关系.从原始物质吸附等温线方程的分配系数m看,淋溶褐土对SON、SOC的吸附能力强于红油土.红油土对SON、SOC的平均吸附率分别为24.3%和18.8%,淋溶褐土则分别为38.3%和18.6%;两种类型土壤对SON和SOC的吸附能力较低,说明它们在土壤中具有较强的移动性;土壤对SOC的吸附能力弱于SON,说明SOC更易于从土壤中流失.  相似文献   

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长白山阔叶红松林生长季反射率特征   总被引:14,自引:0,他引:14  
关德新  金明淑  徐浩 《应用生态学报》2002,13(12):1544-1546
根据长白山阔叶红松林气象观测塔上太阳总辐射和反射辐射资料 ,计算了 2 0 0 1年 5月 2 2日~10月 14日森林下垫面的每日整点反射率 .结果表明 ,森林的反射率与太阳高度角有关 ,在太阳高度角很小的日出和日落附近反射率较高 ,太阳高度角大于 30°时反射率变化不大 ,反射率的日变化曲线为U形 .森林的反射率与天空状况有关 ,晴天条件下低太阳高度时的反射率高值明显 ,U形曲线突出 ,昙天时曲线两端高值相对较低 ,U形曲线也相对平坦 ,阴天的日变化曲线则没有明显的规律 ,在某范围内波动 .生长季反射率的变化特点为 6月上旬较高 ,6月下旬稍有下降 ,7~ 9月较稳定 ,10月上旬则逐渐下降 ,反映了冠层叶片物候变化特征 .  相似文献   

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刘艳春 《广西植物》2013,(6):734-739
通过标本研究和野外考察发现:被鉴定为二色金茅和滇南金茅的国产标本实际均为四脉金茅,且二色金茅和滇南金茅在国内无分布,国内各植物志中该名称下的类群应归入四脉金茅。另发表一新组合E. quadrinervis var. latifolia(Rendle)Y. C. Liu & H. Peng.; 国内各植物志和各大标本馆在描述和鉴定Microstegium ciliatum时,常与M. fasciculatum混淆,并在各种场合错误引证; 在此澄清二者真正的区别。  相似文献   

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