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1.
云南箭竹地上部分生物量模型研究   总被引:3,自引:0,他引:3  
对云南省永仁县白马河林场云南箭竹(Fargesia yunnanensis)秆、枝和叶片含水量及生物量进行了调查。结果表明:云南箭竹叶片的含水率最高,秆的最低;在地上部分各器官的生物量分配中,秆所占比例最大,可达60.31%~65.34%,枝次之(19.28%~21.87%),叶(15.11%~1782%)所占比例最少。通过回归分析探讨了云南箭竹各变量的相关性,并对其各器官的生物量及秆高与胸径和地径进行模型拟合。其中秆、枝和叶的生物量与胸径的拟合方程分别是:WC=0.318D1.753,WB=0.135D1.412,WL=0.140D1.216。应用上述相关数学模型估算不同地理种源云南箭竹各器官生物量。通过对胸径、地径和生物量的比较,认为鸡足山的云南箭竹长势最好。  相似文献   

2.
阿尔泰山林区云杉和落叶松生物量分配格局研究   总被引:1,自引:0,他引:1  
【目的】为了分析阿尔泰山地针叶主要树种生物量分配格局,【方法】基于2012、2013年研究区西伯利亚云杉(Picea obovata)和西伯利亚落叶松(Larix sibirica)实测样木,从年龄、径阶、林分郁闭度等角度,分析树木各组分器官生物量比例变化规律。【结果】两树种树干占整株树木地上生物量比例分别为48.1%、61.9%; 云杉枝、叶占地上生物量比例均高于西伯利亚落叶松; 两树种地上总生物量占整株生物量比例分别为79.8%和79.5%,平均根冠比为0.268和0.270。西伯利亚云杉树干生物量随径阶增大而提高,树叶和树根生物量随径阶增大而降低,树枝生物量随径阶变化幅度较小。西伯利亚落叶松树干生物量随径阶增大而提高,但在30 cm以上径阶比例稍有降低,树枝、树叶生物量与树干生物量呈相反变化趋势。两树种树干生物量均随年龄增加而提高,树枝、树叶生物量随年龄增加而降低。西伯利亚云杉树根生物量随年龄增加而降低,西伯利亚落叶松树根生物量随年龄增加呈先降后增的趋势。西伯利亚云杉树干生物量随郁闭度增加而提高,树枝、树叶和树根生物量随郁闭度增加而降低。西伯利亚落叶松总体上随郁闭度增加树干生物量呈先降后升趋势,树枝和树根生物量变化趋势与树干相反,树叶生物量随郁闭度增加而降低,但变化幅度很小。【结论】西伯利亚云杉和落叶松各组织器官生物量比例均呈现树干>树根>树枝>树叶的趋势。随径阶、年龄、郁闭度增大,西伯利亚云杉树干生物量所占比例逐渐提高,树叶比例则逐渐降低,树枝与树根生物量此消彼长。西伯利亚落叶松各器官生物量所占比例在不同径阶、年龄和郁闭度条件下虽有变化,但幅度不大,总体趋势不变。  相似文献   

3.
斑苦竹无性系种群的数量统计   总被引:11,自引:0,他引:11  
应用生命表和生存曲线对缙云山斑苦竹无性系种群的数量进行统计分析,结果表明,①斑苦竹竹笋-幼竹无性系种群的生存曲线介于B型与C型之间,是一条较为平缓的凹形曲线,其死亡率为40%,②斑苦竹无性系种群的年龄结构比较稳定,但已表现出轻度的衰退迹象。③生存曲线呈波状曲折的C型,各龄级竹子构件的死亡率不同,幼龄和老龄竹死亡率较中龄竹子大.  相似文献   

4.
斑苦竹无性系种群能量结构研究   总被引:7,自引:0,他引:7  
引用Harper(1977)的构件结构理论,将四川缙云山的斑苦竹分为构件、分株和无性系种群三个层次,分别研究了它们的能量结构特征,结果表明:斑苦竹各构件单位的平均能值为枝(18.178MJ/kgDW)>秆(17.969MJ/kgDW)>叶(17.583MJ/kgDW)>根茎(17.505MJ/kgDW)>(17.371MJ/kgDW)>根15.380MJ/kgDW);无性系分株的平均能值随着年龄级  相似文献   

5.
以早春类短命植物顶冰花为研究对象,采用全收获法对其生物量进行统计.结果表明:顶冰花的单株生物量平均为0.316 2 g,地下部分较地上部分平均高出37.92%.随着叶长的增大,叶生物量、果生物量、总生物量、地上生物量与地下生物量均显著增加,而花生物量显著减小.有性生殖生长与植株个体大小的关系密切,占总生物量的5.47%~19.42%,平均为11.92%;占营养器官的比例平均为14.41%,表现出随叶长的增大呈先增加后下降再增加的变化趋势.根冠比介于0.93~1.86,平均为1.33,随叶长的增大呈单峰型变化.整体来看,顶冰花的生物量有随生长发育由地上生长转为地下生长,再由地下生长转为地上为主的变化和从营养生长逐渐转向有性生殖的趋势.以叶长为自变量拟合顶冰花地上、地下和全株的4种生物量估测模型,除地下生物量的指数模型外,拟合和验证结果均达到相关建模的精度要求.  相似文献   

6.
过路黄克隆生长对光照强度的反应   总被引:7,自引:0,他引:7  
利用遮阳网产生光照梯度,以研究光照强度对克隆植物过路黄(Lysimachia christinae)形态特征和生物量分配的影响.结果表明:1)匍匐茎节间长度随光照强度的减弱而增大,遮荫明显增加过路黄的分枝角度,分枝强度没有对光强发生显著反应.遮荫使叶柄变长,而根长则变短.2)随光照强度的减弱,叶柄生物量逐渐增大;遮荫降低了叶生物量、根生物量、总生物量、根生物量比和地下生物量/地上生物量.3)在遮荫条件下,一级匍匐茎基部分株的叶生物量和分株总生物量显著大于顶部分株,而根冠比则相反.根的生物量在各分株间无显著差异.在不遮荫条件下,仅匍匐茎基部分株的叶生物量大于顶部分株,其它的生物量指标在各分株间无显著差异.在分株水平,分株的根冠比不受光强的影响.总之,过路黄的克隆生长在基株和分株水平都对光强作出了明显的反应,而且这种反应具有等级性.  相似文献   

7.
神农箭竹(Fargesia murielae (Gamble) Yi)原产于我国神农架地区,1996-2000年,神农箭竹相继开花死亡,现有更新苗由种子繁殖而成,现正处于南实生苗向克隆种群过渡阶段,研究这一过程中生物量在不同龄级克隆体之间的分配,对于提示从生竹类的觅养过程中的生态关系十分重要.研究结果显示神农箭竹更新苗地上部生物量在各龄级中的分配符合指数函数回归方程Y=5.7319 e0.2054x(R2 =0.9833),且各无性系构件因子之间均存在显著相关关系,其中各器官生物量与胸径的拟合模型均达到显著水平;地上部分干重与胸径的最优拟合模型为一元幂函数模型,方程式为W=2.029×D1.674;秆重与胸径的最优拟合模型为指数模型,方程式为W=0.133×e1.202D.  相似文献   

8.
水杉人工林生物量及其制浆性能的研究   总被引:4,自引:0,他引:4  
研究了水杉人工林3种密度林分的地上部分生物量、干物质分配模式、制浆性能和工艺成熟龄。结果表明:(1)不同密度的水杉人工林,其地上部分生物量存在较大差异。10年生前,3种密度林分的生物量生产为2500株·hm-2>1250株·hm-2>625株·hm-2;10~14年间为2500株·hm-2>625株·hm-2>1250株·hm-2。(2)林分村干生物量所占的比例随林龄的增大而递增,枝、叶所占的比例则随林龄的增大而降低。14年生时,3种密度林分树干、枝、叶生物量所占比例分别在65.88%~70.2%,23.3%~24.8%和6.6%~9.4%之间。(3)林龄和密度显著影响林分的净平均生产量。14年生3种密度林分的地上部分年均净生产量分别为5240.4kg·hm-2、4613.3kg·hm-2和6058.7kg·hm-2。(4)水杉的纤维素含量为47.5%左右,平均纤维长为3.175mm,是一种高级造纸原料。(5)不同密度的水杉人工林,工艺成熟龄存在差异,625株·hm-2、1250株·hm-2和2500株·hm-2林分分别约在25~28年、21~24年及17~20年之间。  相似文献   

9.
为探讨巴山木竹地上部分生物量及其分配规律,以深入理解秦岭山系大熊猫对巴山木竹的觅食对策和环境承载力,于2008年11月到2009年4月通过设置样方对陕西佛坪自然保护区三官庙保护站管护范围内巴山木竹的生物量进行了调查.结果表明随着龄级增长,巴山木竹地上生物量呈增长趋势,各器官生物量所占比例大小依次为:茎>枝>叶.在海拔梯度上,以1600-1800m巴山木竹地上生物量最大.通过回归分析显示,巴山木竹竹叶生物量可以通过竹株基茎以幂函数进行较好地拟合.上述研究结果表明,为保护好研究区域内大熊猫的冬居地,应有效控制海拔1600-1800m落叶阔叶和针阔混交林中的人为活动.  相似文献   

10.
研究了藏嵩草构件群体特征及火烧对此特征和草甸群落组成的影响,所得主要结论为:(1)藏嵩草种群的年龄结构属稳定型;(2)随其株丛增大分蘖密度减少,有性枝/无性枝的比例增加;(3)分蘖群体中的分蘖均重与密度关系不符合“恒定最终产量法则”,不发生因分蘖间竞争而致的密度自疏现象;(4)火烧显著提高每株丛地上部生物量,增加无性枝数量、降低有性枝数量;(5)火烧使群落组成显著变化,物种多样性提高.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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