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1.
黑龙江产十种蕨类植物孢子囊和叶表皮的扫描电镜观察   总被引:3,自引:1,他引:2  
邢怡  党安志  刘保东 《植物研究》2004,24(4):413-418
用扫描电镜对黑龙江产十种不同科属、不同生境的蕨类植物的孢子囊和叶表皮进行了详细观察,结果显示:蕨类植物的孢子囊和叶表皮在扫描电镜下,显示出更为丰富的形态特征,并表现出细致而稳定的异同点,可作为蕨类系统分类的现代手段,能更好的应用于疑难科属的分类研究;十种蕨类植物也都表现出其形态结构与生态生理的高度一致性.  相似文献   

2.
研究了23种固氮与非固氮树种叶部N、P含量的季节变化、输出率以及叶片衰老过程中N、P的输出过程.结果表明,供试树种叶部N、P含量均存在着明显的季节变化,平均变化率为21~23%,最大变化率出现在叶片衰老期.在衰老期内不同树种表现出不同的N、P动态特征.固氮树种表现出低输出率,落叶中N含量是非固氮树种的1.6~3.7倍.固氮树种生长季叶部N含量在2.5%左右.  相似文献   

3.
森林叶凋落物混合分解的研究I.缩微(Microcosm)实验   总被引:3,自引:3,他引:0  
采用缩微实验法 ,初步系统研究了杉木叶凋落物分别与火力楠、红栲和木荷 3个阔叶树种之一的叶凋落物两两混合分解的动态变化 ,以探明凋落物混合分解过程中可能存在的相互作用 .结果表明 ,杉木叶凋落物与 3种阔叶树种叶凋落物两两混合分解时所表现出不同的相互作用形式 :杉木与木荷表现出抑制作用 ,杉木与红栲或火力楠表现为较弱的促进作用 .  相似文献   

4.
采用缩微实验法,初步系统研究了杉木叶凋落物分别与火力楠、红栲和木荷3个阔叶树种之一的叶凋落物两两混合分解的动态变化,以探明凋落物混合分解过程中可能存在的相互作用.结果表明,杉木叶凋落物与3种阔叶树种叶凋落物两两混合分解时所表现出不同的相互作用形式:杉木与木荷表现出抑制作用,杉木与红栲或火力楠表现为较弱的促进作用.  相似文献   

5.
秦岭南坡不同海拔林分凋落叶分解特征   总被引:1,自引:0,他引:1  
采用野外放置凋落物分解袋法,对秦岭南坡林区不同海拔华山松(Pinus armandii)、油松(P.tabulaeformis)、锐齿栎(Quercus aliena var.acuteserrata)和华北落叶松(Larix principis-rupprechtii)凋落叶分解过程中N、P、C、粗脂肪、粗纤维和热值的变化规律进行比较研究.结果表明:(1)处于不同海拔的同一树种新鲜凋落叶的N、P、C、粗脂肪含量及其热值差异不显著(P>0.05).(2)在一年的分解过程中,凋落叶N、P含量表现出逐渐富集的趋势,其中油松凋落叶N、P富集速度最快,分别达到165.60%和189.94%;凋落叶C、粗脂肪含量和热值、C/N、C/P、粗纤维/N在分解中逐渐下降,粗脂肪释放速率达到50.29%~77.82%.(3)分解一年后,不同海拔同一树种凋落叶N、P、C、C/N、C/P含量仍未表现出显著性差异(P>0.05),但不同海拔凋落叶粗脂肪分解表现出极显著差异(P<0.01),其中差距最大的锐齿栎凋落叶低海拔较高海拔粗脂肪释放率高19.38%;不同海拔华北落叶松和锐齿栎凋落叶粗纤维释放速率差异极显著(P<0.01),而不同海拔油松、华山松凋落叶粗纤维释放无显著差异;处于高低海拔的华北落叶松和锐齿栎凋落叶热值分别为17.12和15.68 kJ·g-1、17.74和13.51 kJ·g-1,表现出极显著差异(P<0.01),油松、华山松凋落叶表现出显著差异(P<0.05).研究发现,一年中海拔差异所造成的降水、温度等因素的变化对各树种凋落叶中N、P、C的释放无显著影响,但对凋落叶分解过程中粗脂肪、热值、粗纤维/N的变化影响显著.  相似文献   

6.
胡杨枝芽生长特征及其展叶物候特征   总被引:1,自引:0,他引:1  
郑亚琼  冯梅  李志军 《生态学报》2015,35(4):1198-1207
以5个不同发育阶段的胡杨(Populus euphratica Oliv.)个体为研究对象,观测记录了枝芽展叶物候、枝芽生长特征和叶形变化的空间分布规律。结果表明:不同发育阶段的胡杨个体以及同一个体树冠的不同层次,其枝芽生长及其展叶物候期表现出不同的时空特征。随着树龄的增加和树冠层次的增高(由基向顶),当年新生枝条长度、枝条叶片数和叶形指数逐渐减小,但叶面积和叶片干重逐渐增大。5个不同发育阶段胡杨个体均表现出展叶物候始于树冠顶层,依次向下结束于树冠基部;展叶物候期共性表现在枝芽萌动期均在4月上旬,起始展叶期集中在4月中旬,展叶终期则在5月上旬到下旬;树龄较大的个体其枝芽萌动期、起始展叶期、展叶终期较树龄较小的个体早;其枝芽萌动期到展叶终期的时间进程较树龄较小的个体短;不同发育阶段的个体枝芽萌动期出现的时间较为离散,起始展叶期和展叶终期出现的时间较为集中。相关分析表明,出叶周期与枝条长度、枝条叶片数量和叶形指数呈极显著正相关,与叶面积和叶片干重呈显著负相关。  相似文献   

7.
山西霍山不同功能型植物叶性特征的比较研究   总被引:3,自引:0,他引:3  
选取山西霍山地区30种主要植物(乔木7种、灌木10种、草本植物13种),分别测定了其比叶面积(SLA),单位重量叶氮含量(Nmass)及单位面积叶氮含量(Narea),初步探讨了3种功能型植物的部分叶性特征,并进行了比较分析。结果表明:在霍山地区这个特定的环境下,草本植物的SLA最大,灌木次之,乔木最小;对于Nmass,同样是草本植物最高,灌木次之,乔木最低;而Narea乔木最高,灌木次之,草本最低,表现出在相同环境下,不同功能型植物的叶性特征的差异性。不同功能型植物的SLA与Nmass呈正相关关系,与Narea呈负相关关系,表现出在相同环境下,不同功能型植物叶性关系的相似性。  相似文献   

8.
雌雄异株植物资源分配模式上往往表现出显著的性别二态性,但在叶片光合及功能性状上是否有差异目前仍未有定论,且与发育阶段的关系尚不明确。阐明上述问题,能够进一步了解雌雄异株植物的生理生态特征,并为理解性别对性二态植物生长发育的影响机制提供理论依据。以雌雄异株绒毛白蜡(Fraxinus velutina Torr.)为研究对象,针对不同发育阶段不同性别植株进行光合特征及叶功能性状测定,采用双因素方差分析了不同发育阶段下雌雄植株光合能力及叶功能性状的性别间差异,采用Pearson检验了雌雄植株各叶功能性状之间的相关性,并采用标准化主轴分析(Standardized major axis regression, SMA)分析不同性别植株净光合速率与叶功能性状的相关性。结果表明性别和发育阶段显著影响植物个体的光合能力和叶功能性状。总体而言,雄树在坐果期和果实成熟期均表现出更强的净光合速率(Pn)、更高的比叶面积(SLA)、叶绿素含量(Chl)和叶氮含量(LNC);而雌树在果实膨大期表现出更强Pn、SLA和Chl。雌雄性别内Pn与SLA、Chl和LNC间均呈显著正相关(P<0.05),雄树的S...  相似文献   

9.
海草形态、生长的种间差异及其相关生长关系   总被引:1,自引:0,他引:1  
海草是海洋沉水高等植物,属典型的根茎克隆植物.根状茎直径和分株重分别是其个体大小的第一、二表征指标,个体大小是海草重要的种间识别特征.对海草6个形态构件指标和18个生长指标的综合分析表明:果实大小、单株叶面积、分株重具有显著的种特异性;分株发出的时间差、水平根状茎分枝率、叶年产量、分株寿命和垂直茎分枝率是海草种特异性最强的5个生长动态指标,海草生长动态的差异主要体现在克隆生长能力强弱和分株生活史长短上;大海草趋于游击型克隆构型,而小海草则趋于密集型,但小海草Cymodocea nodosa例外;大海草基株水平扩展能力较小海草差.海草个体大小与生长特征的相关生长关系表明:随个体的增大,海草在有机构件生长上表现出两相邻叶、相邻分株、相邻节发出的时间差延长,分株、叶、茎寿命延长的特点;在克隆生长水平上表现出根状茎节间长变短、延伸速率降低,分枝率和根状茎上年产分株数降低,分枝角度变小和间隔子增大的趋势;在克隆片段水平上表现为生理整合性增强;在种群层面则表现出生物量增大和种群密度降低的特点.因此,海草个体大小对其形态、生长特征、克隆构型、种群密度和生产力起到了决定作用.大小海草不同的形态、生长动态和克隆构型特征导致它们的生存策略及生态功能也不同,这一点可能对海草场修复基础理论研究具有一定的指示作用.  相似文献   

10.
目前关于我国南方红壤侵蚀区生态恢复植被—芒萁(Dicranopteris dichotoma)功能性状(Functional Traits)的研究鲜有报道。以该区域不同植被恢复年限下(包含0年未恢复地、6年、12年、18年、36年以及80年的次生林地)芒萁叶功能性状为研究对象,结合不同植被恢复年限下土壤因子的变化,采用样方调查分析法,探讨随植被恢复年限的增长芒萁叶功能性状的变化规律及其相互关系,以及芒萁叶功能性状对土壤因子的响应。结果表明,芒萁叶功能性状各指标随着植被恢复年限的增加变化差异明显(P0.05),并随植被恢复年限的增长表现出胁迫型、扩展型、竞争型不同功能性状组合;芒萁叶功能性状间的相关性也表现出显著的特征(P0.01);主成分分析(Principal Component Analysis, PCA)表明叶全氮含量、比叶面积和叶全磷含量主成分贡献排名高,可作为芒萁叶功能性状评价的主要指标。通过冗余分析(Redundancy Analysis, RDA)发现,土壤全碳含量、土壤全氮含量、土壤全磷含量对芒萁叶功能性状各项指标影响显著(P0.01)。芒萁伴随着植被恢复年限的增长,叶功能性状表现出不同的组合状况,且受土壤因子变化表现出相应的适应策略,反映了芒萁叶片随土壤因子变化形态可塑性强,作为重要的生态恢复植被有利于南方红壤侵蚀区植被的有效建植与恢复。  相似文献   

11.
西南岩溶地区黄荆和檵木叶片结构对其生态环境的响应   总被引:3,自引:0,他引:3  
应用常规石蜡切片法对生长于桂林毛村岩溶区和非岩溶区的黄荆(Vitex negundo)和檵木(Loropetalumchinense)的解剖特征进行了比较研究,并对两区的黄荆叶片表皮形态进行了扫描电镜观察.结果显示:(1)两地的黄荆叶片背面均有浓密的绒毛,但致密程度有差异,岩溶区黄荆叶片的气孔深藏于绒毛间隙,这种结构可减少水分蒸发,降低因岩溶干旱带来的水分缺失.(2)岩溶区黄荆和檵木的叶片厚度、上下表皮厚度、栅栏组织的厚度以及栅栏组织的致密程度均大于非岩溶区,这些特征有利于减少水分蒸腾.(3)岩溶区黄荆和檵木叶片的维管组织发达程度高于非岩溶区,有利于在蒸腾减小的情况下促进水分运输和营养元素的迁移,说明2种植物叶片结构特征在不同生境区的改变是其长期在岩溶区干旱环境条件下形成的适应性变化.  相似文献   

12.
独叶草叶宏观形态性状的变异式样的初步研究   总被引:2,自引:0,他引:2  
根据独叶草分布区内 8个居群的叶的 8个宏观性状在散点图上的表现 ,探讨了独叶草的形态变异式样。结果表明 ,独叶草在叶宏观性状上表现出了一定的变异性 ,这种变异性表现在不同居群间及由不同居群组成的区域上 ,但在居群间或由不同居群组成的区域间在性状上有不同程度的重叠。  相似文献   

13.
Phytophagous insects can be affected by plant trait-mediated indirect effects of large herbivores, but little is known regarding how these effects change in response to different densities of large herbivores. To assess the response of an insect to plant qualitative change, the response of a woody vine (Aristolochia kaempferi) to browsing by sika deer (Cervus nippon) and utilization of young leaves by a swallowtail butterfly (Byasa alcinous) were investigated across a deer density gradient. Natural and simulated deer browsing stimulated the regrowth of A. kaempferi and improved nutritional and physical quality of leaves. Young leaves were frequently observed in areas with high deer densities. The proportion of young leaves among the leaves selected for oviposition was higher than their proportion of the total number of leaves. In areas with low deer densities, the utilization of young leaves by B. alcinous increased linearly with deer density, whereas in areas with high deer densities, the utilization of young leaves was around 90%.  相似文献   

14.
用紫外分光光度法测定不同产地有柄石韦的总黄酮含量。结果显示,在全草中云南昆明产的有柄石韦总黄酮含量最高,山东济南产的有柄石韦所含黄酮成分最低;有柄石韦叶中总黄酮含量最高,根中最低。  相似文献   

15.
现蕾期苍耳茎的解剖结构以初生结构为主。维管形成层已经形成,但次生结构尚不发达。茎表皮由普通表皮区和色斑区组成。叶的主脉维管组织与茎中维管组织排列方式类似,而不同于大多数双子叶植物。  相似文献   

16.
We investigated the concentration of Aluminium (Al), Cobalt (Co), Chromium (Cr), Copper (Cu), Iron (Fe), Manganese (Mn), Nickel (Ni) and Zinc (Zn) in the root and aboveground organs of four halophyte species (Salicornia europaea, Suaeda maritima, Salsola soda and Halimione portulacoides), as well as in the soil from maritime and inland saline areas. The aim of our research was to evaluate the capability of some halophyte species to absorb different heavy metals and to detect differentiation of heavy metal accumulation within populations from inland and maritime saline areas. Generally, the plant roots had significantly higher concentrations of metals when compared to stems and leaves. Zinc was the only metal with concentrations significantly higher in the leaves than in the root and stem. Populations from maritime saline areas had higher trace root and stem metal concentrations than populations from inland saline areas. Excepting zinc, populations from inland saline areas had higher heavy metal concentrations in the leaves. The factors that affected metal accumulation by halophytes included the percentage of salt in the soil. We also discuss the potential use of these halophytes in phytoremediation.  相似文献   

17.
We studied the socioecology of white-headed langurs (Trachypithecus leucocephalus) from September 1997 to September 1998 in Fusui Precious Animal Reserve, SW Guangxi, China. We collected data on climate, phenology of food plant species, and foods consumed by langurs living in habitats with different levels of human disturbance. Feeding records showed that the most food is from less common plant species. Young leaves were the staple food item in all langur groups, and consumption correlates with availability. Consumption of mature leaves is not significantly correlated with their availability, but the langurs fed on them, and other food items such as fruits and seeds, when the availability of young leaves was low. Langurs in different areas had broadly similar diets, but they varied most in the proportion of supplementary items such as fruit. Groups in more disturbed habitat did not increase the overall proportion of mature leaves in their diet, but instead maintained their intake of young leaves from a greater diversity of species, and incorporated more immature fruit. Conservationists should direct efforts toward protection of rare plant species providing preferred food items, particularly supplementary foods at times when, and in areas where, preferred food items are less available.  相似文献   

18.
Grass leaf shape is a strong indicator of their habitat with linear leaves predominating in open areas and ovate leaves distinguishing forest‐associated grasses. This pattern among extant species suggests that ancestral shifts between forest and open habitats may have coincided with changes in leaf shape or size. We tested relationships between habitat, climate, photosynthetic pathway, and leaf shape and size in a phylogenetic framework to evaluate drivers of leaf shape and size variation over the evolutionary history of the family. We also estimated the ancestral habitat of Poaceae and tested whether forest margins served as transitional zones for shifts between forests and grasslands. We found that grass leaf shape is converging toward different shape optima in the forest understory, forest margins, and open habitats. Leaf size also varies with habitat. Grasses have smaller leaves in open and drier areas, and in areas with high solar irradiance. Direct transitions between linear and ovate leaves are rare as are direct shifts between forest and open habitats. The most likely ancestral habitat of the family was the forest understory and forest margins along with an intermediate leaf shape served as important transitional habitat and morphology, respectively, for subsequent shifts across forest–grassland biome boundaries.  相似文献   

19.
We have studied by kinetic Chl-fluorescence imaging (Chl-FI) Nicotiana benthamiana plants infected with the Italian strain of the pepper mild mottle tobamovirus (PMMoV-I). We have mapped leaf photosynthesis at different points of the fluorescence induction curve as well as at different post-infection times. Images of different fluorescence parameters were obtained to investigate which one could discriminate control from infected leaves in the absence of symptoms. The non-photochemical quenching (NPQ) of excess energy in photosystem II (PSII) seems to be the most adequate chlorophyll fluorescence parameter to assess the effect of tobamoviral infection on the chloroplast. Non-symptomatic mature leaves from inoculated plants displayed a very characteristic time-varying NPQ pattern. In addition, a correlation between NPQ amplification and virus localization by tissue-print was found, suggesting that an increase in the local NPQ values is associated with the areas invaded by the pathogen. Changes in chloroplast ultrastructure in non-symptomatic leaf areas showing different NPQ levels were also investigated. A gradient of ultrastructural modifications was observed among the different areas. The paper is dedicated to the memory of Prof. Dr López Gorgé (1935–2004)  相似文献   

20.
柑桔锈螨种群动态研究   总被引:1,自引:0,他引:1  
在桔柑园中设置观察区和防治区,对桔柑锈螨Phyllocoptruta oleivora Ashmead种群消长动态进行2周年(1999-2000年)观察。了解桔柑诱螨种群消长规律;年度间的种群变化;桔柑叶、果上锈螨群体动态差异;锈螨发生量与锈果率的关系等。提出药物防治的最适时期及方法。  相似文献   

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