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1.
利用LCPro‐SD便携式光合仪和FieldSpec Pro光谱仪观测了3种典型湿地植被旱柳(Salix matsu‐dana)、柽柳(Tamarix chinensis)和芦苇(Phragm itescommunis)的光合作用日变化及同步光谱,分析了影响光能利用率(LUE)变化的环境和生理因子,探讨了 LUE和光化学指数(PRI)的相关性.研究结果表明:影响芦苇、柽柳和旱柳光合作用变化的生理因子不同,芦苇的 LUE与Pn、PAR和Gs呈负相关;旱柳和柽柳的 LUE与 Pn 和Gs 呈正相关,与 PAR无关.3种植被的 PRI和LUE的相关性为:旱柳(R2=0.9565)>柽柳(R2=0.9515)>芦苇(R2=0.6425),湿地旱柳的相关性为最大,LUE和 PRI相关性受叶面积指数影响较大.  相似文献   

2.
为探讨自然生境下西鄂尔多斯强旱生小灌木绵刺(Potaninia mongolica Maxim)的光合生理生态适应性,通过对绵刺休眠期和生长期叶片光合作用日变化、光合响应曲线、光合色素含量进行测定,研究绵刺净光合速率与生理生态因子的关系.结果表明:(1)休眠期绵刺净光合速率(Pn)日变化呈"双峰"曲线,出现"午休"现象,主要受非气孔限制因素影响.Pn与光照有效辐射(PAR)、胞间CO_2浓度(Ci)存在二次曲线关系,与相对湿度(RH)存在线性关系,与叶片温度(T_(leaf))在一定范围内呈线性关系;生长期绵刺Pn日变化呈典型"单峰"曲线,Pn与PAR、Ci、T_(leaf)之间存在二次曲线关系,与RH呈线性关系.(2)除类胡萝卜素外,处于生长期绵刺的叶绿素a、叶绿素b、叶绿素总量均高于休眠期绵刺叶片色素含量.绵刺的光合特性与生理生态因子存在密切关系.  相似文献   

3.
文章以位于乌鲁木齐市的新疆师范大学昆仑校区校园内夏橡单株作为试验材料,采用LI-6400便携式光合测量系统测定自然条件下秋季夏橡的净光合速率(Pn)以及相关生理生态因子的日变化过程,并通过相关分析、多元逐步回归分析和通径分析探讨其Pn与生理生态因子之间的关系。结果表明:秋季夏橡Pn日变化呈"Λ"型的单峰曲线,没有出现"光合午休"现象;Pn与气孔导度(Gs)、蒸腾速率(Tr)呈极显著的正相关关系,与叶片温度(Tl)、空气温度(Ta)和叶片光合有效辐射(PAR)呈显著相关关系,与大气CO_2浓度(Ca)、空气相对湿度(RH)、和胞间CO_2浓度(Ci)呈不显著负相关关系,且相关性递减;Pn与各生理生态因子之间的多元逐步回归方程为:Pn=-4.660+3.102Tr+0.099RH+11.320Ls(R=0.997);影响秋季夏橡Pn的决定生理生态因子为Tr和Ls,其中Tr为主要决定因子,而RH为限制因子。研究发现,秋季时节夏橡仍具有较高的光合作用,探究秋季夏橡净光合速率与其生理生态因子的关系,为西北干旱区绿洲生态建设和城市绿化植被管理提供一定的理论依据。  相似文献   

4.
以北京园林常用绿化树种国槐(Sophora japonica Linn.)为研究对象,利用Li-6400便携式光合测定仪对世纪坛广场绿地国槐的净光合速率(Pn)以及相关生理生态因子的日变化进行观测.采用相关性分析和通径分析,研究Pn与气孔导度(Gs)、胞间CO2摩尔分数(xi(CO2))、光合有效辐射(PAR)、大气CO2摩尔分数(xa(CO2))、相对湿度(RH)、大气温度(θa)之间的关系.结果表明,8、9月份Pn日变化均呈现典型的"双峰",峰值出现在10:00-12:00,14:00-16:00,且在12:00左右均出现了明显的光合"午休"现象.Gs、PAR与Pn有极显著的相关关系.8、9月份对Pn直接作用最大的因子分别为RH、PAR.  相似文献   

5.
北美冬青光合作用日变化特征及其与生理生态因子的关系   总被引:1,自引:0,他引:1  
为揭示北美冬青光合作用日变化规律及其影响因子,采用美国LI-COR公司生产的LI-6400XT便携式光合测量系统测定了北美冬青叶片光合作用及生理生态因子的日变化过程.结果表明,郑州地区引种的北美冬青,其净光合速率和气孔导度的日变化呈"双峰"型曲线,在11:00和15:00达到峰值,13:00达到最小值,光合作用存在明显的"午休现象".蒸腾速率为"单峰"型,而胞间CO_2浓度呈U型曲线.北美冬青光合作用的各生理生态因子的相关性分析表明,气孔导度与净光合速率显著负相关,对净光合速率起决定作用;蒸腾速率和胞间CO_2浓度对光合作用显著正相关;光合有效辐射、大气温度与净光合速率呈不显著的正相关关系.  相似文献   

6.
在自然条件下使用LI-6400光合仪,分别在夏季和冬季,对深圳地区引进的4个桂花品种(‘日香桂’、‘小叶佛顶珠’、‘晚银桂’、‘万点金’)的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Cond)、光合有效辐射(PAR)、大气温度(Ta)等生理生态因子的日变化进行了测定,并对桂花Pn与各种因子的关系进行了比较分析,结果表明:在夏季,4个桂花品种Pn日变化均呈现不对称的双峰曲线,有明显的光合"午休"现象.在冬季,4个桂花品种Pn日变化均呈现单峰曲线,不存在"午休"现象.胞间CO2浓度(Ci)、Cond、PAR、Ta和叶片水压亏缺(VPD)是影响桂花Pn较大的几个因子,其中Ci和Ta在夏季的影响程度尤为突出,PAR在冬季的影响程度最为明显.  相似文献   

7.
采用LI-6400型便携式光合仪,对桂林岩溶石山龙须藤Bauhinia championii不同季节净光合速率Pn的日变化进行测定。结果表明,龙须藤Pn日变化曲线春季和冬季呈"单峰"型;夏季和秋季呈"双峰"型,都有明显的光合"午休"现象。夏季龙须藤Pn中午降低主要为非气孔限制,而秋季则主要为气孔限制;龙须藤夏季和秋季节有较高生长势,Pn季节变化趋势为夏季秋季春季冬季;建立了Pn与其影响因子的关系模型,回归方程均达极显著水平(P0.01)。统计分析结果显示,在春季,龙须藤Pn主要受气孔导度Gs和胞间CO2浓度Ci的影响;夏季,Pn受光合有效辐射PAR的影响较明显;秋季时,Gs是Pn主要的影响因子;而冬季则由Gs转为Ci和蒸腾速率Tr的共同作用。  相似文献   

8.
采用开顶式生长室(Open-top chambers,OTC)模拟未来气候变暖的方法,研究崇明东滩湿地植物芦苇(Phragmites australis)快速生长期光合特征对模拟增温的响应,并探究其响应机制.结果表明:增温使芦苇的净光合速(Pn)、蒸腾速率(Tr)和气孔导度(Gs)分别降低了11.9%、22.5%和21.7%,但是对胞间CO2浓度(Ci)和水分利用效率(WUE)没有明显影响;此外,非线性拟合芦苇叶片光合响应曲线的结果显示,两种处理下芦苇的光合响应曲线均表现为先迅速增加后渐平缓的趋势,OTC内芦苇的光合响应曲线始终位于对照的下方;同时,增温显著地降低了芦苇的表观量子效率(AQY)和光饱和点(LSP),分别降低了12.1%和22.0%;而芦苇的暗呼吸速率(Rd)和光补偿点(LCP)却显著增加,分别为16.5%和14.9%,但对最大净光合速率(Pmax)无明显影响.增温条件下,芦苇的叶氮含量(Nmass)显著减少,比叶重(LMA)显著增加,但光合氮素利用效率(PNUE)未产生显著的变化.另外,相关性分析的结果显示:LMA与Pmax、PNUE呈现出显著的负相关,与Nmass呈现极显著的负相关.Nmass与PNUE之间呈现极显著正相关,二者均与Pmax显著正相关,其中Nmass与Pmax的相关性则达到了极显著的水平.总之,模拟增温效应对芦苇的光合特征产生了显著的影响.  相似文献   

9.
于2011年7月中旬采用Li-6400便携式光合仪研究了夏季黄葛树净光合速率(Pn)和蒸腾速率(Tr)的日变化规律,探讨了Pn和Tr与主要环境因子的关系.结果表明:黄葛树Pn日变化为双峰型,有明显的"午睡"特征,为气孔限制因素所致;Tr日变化则为单峰型.黄葛树具有较低的光补偿点(LCP)和较高的光饱和点(LSP),分别约为21.33μmol/(m2.s)和1 633.46μmol/(m2.s),表观量子效率(AQY)约为0.034,为典型的阳生植物.相关分析、通径分析和决策系数分析显示:主要环境因子对Pn日变化直接作用大小为叶面温度(tl),空气CO2浓度(Ca),光合有效辐射(PAR)和水气压差(VDP),其中起主要决策作用的因子为PAR,主要限制性因子为Ca和VDP;对Tr日变化直接作用大小为胞间CO2浓度(Ci),光合有效辐射(PAR),空气相对湿度(RH),水气压差(VDP)和叶面温度(tl),其中起主要决策作用的因子为PAR,主要限制性因子为tl和Ci.  相似文献   

10.
蓖麻杂交种光合特性初步研究   总被引:1,自引:0,他引:1  
对大田栽培的347×2129、转1645×1987、27×2129、转4号×1987、转1号×2129、转2号×2129六个蓖麻材料光合特性进行了研究.结果表明:几种供试材料都不存在光合午休现象.蓖麻叶片净光合速率Pn与有效辐射强度PAR的日变化均呈单峰曲线.气孔导度从早上8:00就开始下降.材料347×2129、27×2129的净光合速率Pn显著高于其他6个品种.  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

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