首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 218 毫秒
1.
该文对薇甘菊及其所在群落内19种植物(草本和木本)的叶片透射率、反射率和光合特征指标进行了测定,结果表明:薇甘菊与其它植物透射和反射图谱的变化趋势都比较相近,在各个光学特征指标与光合相关指标的相互关系中,薇甘菊并没有表现出区别于同一群落内其它植物的特征。从平均值来看,200—800nm下叶片反射率和透射率由大到小依次为:薇甘菊〉草本植物〉木本植物,薇甘菊各光学植被指标(SR680、SR750和PRO均低于其它植物的平均值,但是其光合能力(光利用效率、水分利用效率、电子传递速率和净光合速率)与其它植物接近或稍高。而且,薇甘菊夏季叶片反射和透射率明显高于冬季,这有利于散失夏季过多光照和充分利用冬季短缺光照。薇甘菊叶片的上述光学特征,可能是其生长于其它植物表面强光照环境的一种适应性表现,有利于其在入侵地快速生长。  相似文献   

2.
薇甘菊因为其在新生境的强入侵能力而臭名昭著,有关其入侵的光合生理原因主要集中在叶片光合速率研究,而对非同化器官光合特性少见报道.以叶片为对照,对非同化器官花、果、茎、根的光合电子传递速率、PSII光化效率以及不同器官光合碳固定对群落碳平衡的影响进行了研究,发现尽管非同化器官光合电子传导速率均低于叶片,但是其色素利用效率(叶绿素和类胡萝卜素)显著高于叶片.在生殖生长季节,叶片光合能力明显下降的时期内,非同化器官的光合碳固定对薇甘菊生长起到积极作用.把不同器官的光合碳固定量尺度放大到群体水平发现,基于使用红外线CO2分析法和叶绿素荧光方法计算结果表明,单位土地面积上分布的薇甘菊非同化器官(生殖器官、茎和根等)分别占群体总光合能力的19%和49%,说明非同化器官光合在薇甘菊生长和入侵中可能具有的重要作用.尽管薇甘菊叶片为典型C3植物特征,结果发现了茎以及主叶脉内存在类似C4途径的、具有丰富叶绿体的维管束鞘结构.C4途径的光合效率远比C3植物高可能是薇甘菊非同化器官光合叶绿素效率高于叶片的一个原因,尚需要更多的直接生化证据支持.  相似文献   

3.
林业有害植物薇甘菊(Mikania micrantha)的气体交换特性   总被引:8,自引:1,他引:7  
通过对不同条件和状态下的薇甘菊叶片光合能力(Pn)、呼吸(R)、气孔导度(gs)、蒸腾(Tr)、羧化效率(CE)、最大表观量子效率(φ)及水分利用效率(WUE)进行大量测定,并与同一地区(群落)其它对照种进行对比研究,发现薇甘菊具有以下特征:(1)薇甘菊叶片CO2和水分交换参数在上述不同条件下变化范围达数倍至十几倍,显示其强可塑性.种间比较发现,营养及生殖生长季内薇甘菊Pn与当地木本植物相当,稍低于其它藤本植物,远低于草本植物,说明薇甘菊的强入侵能力可能并非依靠单位叶片的强光合能力,而是其它因素,如前所述光合作用在不同生境、不同生长状态下的光合可塑性等;(2)林下生长薇甘菊的光合能力低于林间空地,而林间空地薇甘菊低于林缘(外)生境.对照实验也证明阴生生境薇甘菊光合显著低于阳生生境.说明薇甘菊是强阳性植物,与其它因子(水分)相比,光照条件是影响其光合能力的最重要因素,可以通过改变林分群落结构、增大郁闭度等降低光照措施来进行生态防治;(3)综合所有室内和野外数据进行频率分析发现,各指标均呈现(偏)正态分布.其中Pn集中分布区在2~10 μmol·m-2s-1之间(占所测总数据的70%);gs集中分布在0.05~0.45 mol · m-2s-1之间(73%);Tr的集中分布区为1~5 mmol · m-2s-1(66%);CE分布于0.01~0.05 mol · mol-1之间数据占64%;近半的R分布在集中区域0.5~1.5 μmol · m-2s-1之间,而在0.5~2.5μmol · m-2s-1之间的数据占所测总量的66%;的集中分布区在0.04~ 0.08 mol ·mol-1之间(77%);这些数据为种间比较等统计分析比较工作奠定统计基础;(4)薇甘菊叶片对Pn和WUE的调节具有类似的方式,即光合作用最主要的调节因素是CE,其次是gs,而与φ的相关不显著;WUE主要是由Pn大小控制,Tr的影响相对较小,薇甘菊叶片WUE随gs的变化而保持恒定.上述有关薇甘菊的CO2和水分交换特性的研究,可以为这一入侵物种的防治提供基础数据支撑.  相似文献   

4.
魏巍  侯玉平  彭少麟  陈鹏东  梁希平  张静 《生态学报》2017,37(18):6021-6028
外来植物入侵严重威胁着当地生物多样性和生态系统功能,引发巨大经济损失,已成为日益严重的全球性问题。光是热带和亚热带森林生态系统植物生长最重要的限制性资源之一,对光的捕获和利用直接影响植物在自然生态系统中的生存和适合度。本研究以华南地区危害严重的入侵植物薇甘菊(Mikania micrantha)和飞机草(Chromolaena odorata)为研究对象,对比二者生长、生物量分配及叶片特征对光照强度变化的响应,从而验证假设:外来植物入侵力受有效光辐射的限制,光照是影响不同演替阶段林型具有不同可入侵性的重要原因之一。研究结果表明,3%—60%全光照下两种外来植物均可存活,并显示较灵活的生物量分配策略,可见其对光照具有广适性,为其广泛分布提供生态学基础。低光严重抑制了两种外来植物的生物量积累,这可能是导致演替后期季风林入侵现象少的主要原因之一。对比两种植物叶片特征对光照强度变化的响应,高光下薇甘菊SLA降低,LAR、LARMR减小,叶片变小变厚,有利于植株保持强光下的水分平衡;低光下薇甘菊增加SLA和LAR,叶片变薄变大,增大对光的截获面积,以实现对光强减弱的适应。相比薇甘菊,3种光照处理对飞机草的SLA、LAR、LARMR无显著影响。以上结果提示:(1)光照影响所在群落对外来植物入侵的抵抗力;(2)攀援植物薇甘菊较丛生型草本飞机草对变化的光环境在叶片水平上具有更高的形态可塑性,有效寻觅光资源。  相似文献   

5.
薇甘菊(Mikania micrantha)原产中、南美洲,1919年薇甘菊作为杂草在中国香港出现,目前已广泛侵入中国广东、海南、云南等省区,是世界上最有害的100种外来入侵物种之一。本文以海南重要外来入侵植物薇甘菊(Mikania micrantha)为实验材料,通过温室盆栽实验,研究了克隆整合对异质性光照生境下薇甘菊克隆片段生长的影响。结果表明:在异质性光照下,克隆整合显著提高了低光斑块分株的生物量,但同时降低了高光斑块分株的生物量,对克隆片段总体的生物量积累无显著影响,且这一结果不受资源输送方向的影响;克隆整合降低了异质性光照下克隆分株间根冠比的差异,加大了克隆分株间净光合速率的差异,且倾向于提高生长在高光斑块分株的比叶面积;克隆整合虽然并不能促进薇甘菊匍匐茎克隆片段在异质性光照生境下总体的生长,但可以促进低光斑块下分株的生长,因而,克隆整合可促进薇甘菊从开阔生境向低光生境(森林、杂草群落等)的入侵能力,因此,克隆整合特性是薇甘菊对异质性光照环境的重要适应对策之一。  相似文献   

6.
沙蒿(Artemisia intramongolica)群落是半干旱草原地区沙地的重要植被类型,分别在植物的生长前期、中期、盛期和后期采用便携式光合测定仪和大型同化分析仪测定了沙蒿叶片和沙蒿群落的光合动态。单叶和群落的光合速率日进程类型随气候的不同而异,瞬时光合速率主要决定于光合有效辐射强度(PAR)。土壤干旱大大降低了单叶和群落的光合能力,晴天土壤湿润时气温和空气湿度控制着叶片的光合速率,午间大气湿度降低是光合午休的主要外因。叶片的蒸腾速率与气温呈显著线性相关,植物的光能和水分利用效率也主要取决于PAR和气温,随着PAR和气温的升高利用效率下降。沙蒿叶片光能利用效率在后期也能保持较高水平。沙蒿对土壤干旱和高温具有一定的适应性,在土壤湿润时能迅速提高光合速率,形成较大的生物量。但是沙蒿的蒸腾速率高,水分利用效率低。研究认为,沙蒿通过对土壤干旱和高温的忍耐机制而保持长时间较高的光能利用效率,并在土壤湿润时迅速提高光合能力和积累干物质来适应半干旱的沙地环境,而且依靠高蒸腾速率和强的水分吸收能力来竞争性抑制其他植物的生长。  相似文献   

7.
寄生植物菟丝子防治外来种薇甘菊研究初探   总被引:14,自引:0,他引:14  
利用寄生植物田野菟丝子(Cuscuta campestris Yunker)作为外来杂草薇甘菊(Mikania micrantha H.B.k)的生物防治手段,研究了田野菟丝子对薇甘菊的光合作用及生长的影响。结果表明:田野菟丝子寄生于薇甘菊30d左右,薇甘菊单株叶片数、地上茎长度和生物量开始减少,光合速率、蒸腾速率、气孔导度、叶绿素含量以及叶绿素荧光Fv/Fm也开始降低。经过约2个月时间,以上的几个生长指标和生理指标均显著降低。在野外自然状态下,田野菟丝子由最初撒播面积约0.0l辞,很快发展到20m。左右的大块面积,离侵染源中心的最大扩散距离达到5m以上。田野菟丝子寄生可以严重影响薇甘菊茎叶生长及开花结实,可望成为根本上解决薇甘菊危害的一种生物控制技术,而且也可以缓解药用菟丝子资源匮乏的问题。结合国内外最新进展,提出有关田野菟丝子与其寄主相互关系中亟待解决的几个问题。  相似文献   

8.
以生长于浑善达克沙地上的C3植物白榆(Ulmus pumila)、C4植物沙米(Agriophyllum pungens)和CAM植物钝叶瓦松(Orostachys malacophyllus)3种不同光合途径植物为材料,测定了它们生长期叶片的光合气体交换参数、叶绿素荧光参数和水势,探讨它们对生长环境的生理响应特征.结果表明,白榆和沙米的净光合速率、气孔导度均高于钝叶瓦松,特别是在夏季高温(>40℃)和强光照(>2 100 μmol·m-2·s-1)条件下表现得更加明显.白榆和沙米的光合速率、叶片水势都发生了严重的午休现象,其白天光合速率的降低主要是由于气孔关闭造成的.钝叶瓦松的叶片水势在3种植物中最高,但是白天的光合速率很低;其Fv/Fm值在14:00最低,一天中此时光系统II受伤害最大;CAM物种瓦松的碳固定仅发生在夜间.研究发现,C3植物白榆和C4植物沙米比CAM植物钝叶瓦松对热和高光照有着更强的忍耐力,瓦松固定碳主要发生在生长最快的阶段;CAM植物瓦松为了能够在夏季强光和高温条件下生存,它必须进行高强度的呼吸,仅在早晨和夜间进行碳固定.  相似文献   

9.
外域杂草薇甘菊 (Mikaniamicrantha)具有极强的分枝能力。在枝构件水平上 ,对生长在台湾相思 (Acaciaconfusa)群落和芒草 (Miscanthussinensis)群落中的薇甘菊枝构件的分枝格局和生物量分配的比较分析得出 :1)同芒草群落相比 ,台湾相思群落中薇甘菊各级枝的分枝数、分枝密度和分枝率都低 ,而分枝长度则较长 ;2 )台湾相思群落中薇甘菊以第一级分枝为主 ,而在芒草群落中则以第二级分枝为主 ;3)台湾相思林中薇甘菊枝构件的叶面积率、比叶面积和比茎长及叶片生物量分配显著大于芒草草丛 ;4)两个群落中薇甘菊枝构件的节间长和比叶柄长没有显著差异。这些结果说明薇甘菊枝构件对环境条件变化具不同响应。  相似文献   

10.
环境资源的异质性在自然界中普遍存在。克隆植物能通过克隆整合较好地适应异质性生境。本文以海南外来强入侵性植物薇甘菊为材料,通过温室盆栽试验,研究克隆整合对异质性土壤养分生境下薇甘菊克隆片段生长的影响。结果表明:在养分异质下,克隆整合显著提高了低养分斑块分株的生物量,但同时降低了高养分斑块分株的生物量,对克隆片段总体的生长无显著影响,且这一结果不受资源输送方向的影响。克隆整合对薇甘菊克隆分株的光合速率和比叶面积影响较小,但当近端分株处于高养分条件时,其改变了克隆分株的根冠比。这些结果指示:克隆整合有利于异质性土壤养分条件下薇甘菊对低养分斑块的占领。因此,克隆整合可影响薇甘菊对资源异质性生境的入侵能力,它使薇甘菊能够扩展到低养分斑块,从而提高其入侵扩散能力。  相似文献   

11.
Plant invasion by Neotropical Melastomataceae is prominent in Hawaii. To understand life history traits of four successful invasive Melastomataceae, two shade-intolerant herbs (Arthrostema ciliatum and Tibouchina herbacea) and two shade-tolerant woody species (Clidemia hirta, a shrub, and Miconia calvescens, a tree) were subjected to three light levels and two watering regimes in a greenhouse. Plant height, leaf number and area, biomass allocation, relative growth rate (RGR), carbon assimilation (A), leaf nutrient content, leaf construction costs (CC), specific leaf mass (SLM), and leaf spectral properties were determined at the end of the experimental period. Plant size, total biomass, RGR, A, CC, and SLM decreased, whereas leaf light transmittance and leaf N increased under low light in all species. The effects of water stress were weaker than light-stress effects. Relative growth rate of herbs grown in sun and partial shade (0.046 and 0.033 g g-1 d-1, respectively) was higher than in the woody species (0.027 and 0.020 g g-1 d-1). Woody species allocated more biomass to leaf production than herbs, which allocated more biomass to stem production. Shade increased allocation of biomass to leaves, and water stress increased the root-shoot ratio in all species. Partial shade increased leaf area ratios more in the herbs (140%) than in woody species (68%). Miconia calvescens and C. hirta had higher leaf absorbance (92%) than both herbs (79%). Maximum A under all light treatments was similar in all species, and there was substantial acclimation to the different light levels. Leaf construction cost was higher in the apparently long-lived leaves of the woody species. Relative growth rate, carbon allocation, and SLM showed larger changes to light and water stress than A and related photosynthetic parameters. All species showed responses qualitatively similar to those of other tropical species including the high acclimation potential to light, but the herbs exhibited the largest quantitative responses. When compared with a large group of native species, the four melastomes appear to be better suited to capture and use light, which is consistent with their rapid spread in mesic and disturbed Hawaiian environments.  相似文献   

12.
The relationship between the microclimate within an Oak-Hickory forest and photosynthetic characters of two resident evergreen herbs with contrasting leaf phenologies was investigated on a monthly basis for 1 full year. Heuchera americana has leaf flushes in the spring and fall, with average leaf life spans of 6–7 months. Hexastylis arifolia produces a single cohort of leaves each spring with a leaf life span of 12–13 months. We predicted that among evergreen plants inhabiting a seasonal habitat, a species for which the frequency of leaf turnover is greater than the frequency of seasonal extremes would have a greater annual range in photosynthetic capacity than a species that only produced a single flush of leaves during the year. Photosynthetic parameters, including apparent quantum yield, maximum photosynthetic capacity (Pmax), temperature of maximum photosynthesis, photochemical efficiency of PSII and leaf nitrogen (N) and chlorophyll concentrations, were periodically measured under laboratory conditions in leaves sampled from natural populations of both species. Mature leaves of both species acclimated to changing understory conditions with the mean seasonal differences being significantly greater for Heuchera than for Hexastylis. Area based maximum photosynthetic rates at 25°C were approximately 250% and 100% greater in winter leaves than summer leaves for Heuchera and Hexastylis respectively. Nitrogen concentrations were highest in winter leaves. Chlorophyll concentrations were highest in summer leaves. Low Pmax/N values for these species suggest preferential allocation of leaf nitrogen into non-photosynthetic pools and/or light-harvesting function at the expense of photosynthetic enzymes and electron transport components. Despite the increase in photosynthetic capacity, there was evidence of chronic winter photoinhibition in Hexastylis, but not in Heuchera. Among these ecologically similar species, there appears to be a trade-off between the frequency of leaf production and the balance of photosynthetic acclimation and photoinhibition.  相似文献   

13.
Leaves from 26 species with growth forms from annual herbs to trees were collected from open, intermediate, and shaded understory habitats in Mississippi and Kansas, USA. Leaf optical properties including reflectance, transmittance, and absorptance in visible and near infrared (NIR) wavelengths were measured along with leaf thickness and specific leaf mass (SLM). These leaf properties and internal light scattering have been reported to vary with light availability in studies that have focused on a limited number of species. Our objective was to determine whether these patterns in leaf optics and light availability were consistent when a greater number of species were evaluated. Leaf thickness and SLM varied by tenfold among species sampled, but within-habitat variance was high. Although there was a strong trend toward thicker leaves in open habitats, only SLM was significantly greater in open vs. understory habitats. In contrast, leaf optical properties were strikingly similar among habitats. Reflectance and reflectance/transmittance in the NIR were used to estimate internal light scattering and there were strong relationships (r1 > 0.65) between these optical properties and leaf thickness. We concluded that leaf thickness, which did not vary consistently among habitats, was the best predictor of NIR reflectance and internal light scattering. However, because carbon allocation to leaves was lower in understory species (low SLM) yet gross optical properties were similar among all habitats, the energy investment by shade leaves required to achieve optical equivalence with sun leaves was lower. Differences in leaf longevity and growth form within a habitat may help explain the lack of consistent patterns in leaf optics as the number of species sampled increases.  相似文献   

14.
In many plant species, herbivory is a major determinant of leaf mortality and it can cause a strong reduction in productive potential. Most predation occurs on young, expanding leaves. Thus, a rapid growth of the leaves can reduce the impact of predation. Furthermore, in cold Mediterranean climates the length of the growing season is constrained to a short period in spring and early summer owing both to low winter temperatures and drought stress in early summer. Therefore, a rapid deployment of leaf area and a high photosynthetic capacity during the spring and early summer might have important positive effects on the final carbon balance of the leaf population. Relative growth rates (RGR) of leaf biomass were measured in 19 woody species typical of Central Western Spain with deciduous and evergreen habits. Highly significant differences were detected in the leaf growth rate of the different species. The differences between species, however, did not correlate either with the mean leaf life-span of each of the species or with other leaf traits such as photosynthetic capacity, specific leaf area or nitrogen content. Leaf growth rate was positively correlated with time elapsed between leaf initiation and fruit maturation, so that species with fruit dispersal in spring and early summer in general had lower leaf growth rates than species with autumn fruit shedding. This relationship shows the effects of the concurrence between vegetative and reproductive organs for nutrients and other resources. Nitrogen concentration in the leaves was very high at the time of bud break, and declined during leaf expansion owing to the dilution associated with the increase in structural components. The rate of nitrogen dilution was, thus, positively related to the leaf growth rate. Relative growth rates calculated for nitrogen mass in leaves were very low compared to the growth in total mass. This suggests that most leaf nitrogen is translocated from the plant stores to the leaf biomass before the start of leaf expansion and that the contribution of root uptake during leaf expansion is comparatively low.  相似文献   

15.
A leaf photosynthesis model was constructed based upon the notionthat the leaf photosynthesis is a summation of photosynthesisof each chloroplast under in situ micro-environmental conditions.Intra-leaf light environment was calculated using the valuesof transmittance and reflectance of leaf tissues reported previously.Simulations of light response curves of whole leaf photosynthesiswere carried out for the model leaves with different patternsof gradients in light environment and/or in photosynthetic activities.The results indicate that the higher absorption coefficientof chlorophyll in spongy tissue than in palisade tissue andintra-leaf vertical gradient in photosynthetic activity of thechloroplasts as reported for real dorsiventral leaves are bothadvantageous to the productivity of the leaf because these propertiesraise the efficiency of the light utilization. Intra-leaf light environment, leaf photosynthesis, light utilization, palisade tissue, photosynthetic productivity, spongy tissue  相似文献   

16.
对广东内伶仃岛群落受薇甘菊危害的植物种类分析表明,58种乔木、小乔木和灌木种不同程度地受薇甘菊的影响,约占样地中木本种类的67%;其中受薇甘菊影响最大的主要是小乔木和阳生性灌木.薇甘菊危害与群落类型的关系表现为,由5、6个优势种组成的结构复杂的具有较大郁蔽度的群落受薇甘菊的危害轻微,而仅由2个优势种组成结构简单且郁蔽度很小的群落受薇甘菊的危害较严重.薇甘菊危害与群落结构的相关分析表明,群落垂直高度越大、片层越丰富,群落中薇甘菊的盖度越小;群落物种越丰富,群落密度越大,个体受害比例越小;群落中其他藤本盖度越大,个体受薇甘菊危害的程度越高.  相似文献   

17.
In temperate regions, evergreen species are exposed to large seasonal changes in air temperature and irradiance. They change photosynthetic characteristics of leaves responding to such environmental changes. Recent studies have suggested that photosynthetic acclimation is strongly constrained by leaf anatomy such as leaf thickness, mesophyll and chloroplast surface facing the intercellular space, and the chloroplast volume. We studied how these parameters of leaf anatomy are related with photosynthetic seasonal acclimation. We evaluated differential effects of winter and summer irradiance on leaf anatomy and photosynthesis. Using a broad-leaved evergreen Aucuba japonica , we performed a transfer experiment in which irradiance regimes were changed at the beginning of autumn and of spring. We found that a vacant space on mesophyll surface in summer enabled chloroplast volume to increase in winter. The leaf nitrogen and Rubisco content were higher in winter than in summer. They were correlated significantly with chloroplast volume and with chloroplast surface area facing the intercellular space. Thus, summer leaves were thicker than needed to accommodate mesophyll surface chloroplasts at this time of year but this allowed for increases in mesophyll surface chloroplasts in the winter. It appears that summer leaf anatomical characteristics help facilitate photosynthetic acclimation to winter conditions. Photosynthetic capacity and photosynthetic nitrogen use efficiency were lower in winter than in summer but it appears that these reductions were partially compensated by higher Rubisco contents and mesophyll surface chloroplast area in winter foliage.  相似文献   

18.
Some Optical Properties of Leaves of Eight Temperate Forage Grasses   总被引:1,自引:0,他引:1  
SHEEHY  J. E. 《Annals of botany》1975,39(3):377-386
Two instruments are described for the measurement of the reflectionand transmission of radiation by grass leaves. The first ofthese was used to measure the spatial distribution of reflectedand transmitted light. It was demonstrated that reflection wasinfluenced by the epidermal structure of a leaf, and that theimportance of this layer increased with increasing angle ofincidence. The second instrument was used to compare the reflectance andtransmittance of leaves of different ages taken from eight temperategrasses. There were significant differences between the grassesin leaf transmittance, and generally the young emerging leafhad a greater transmittance than the fully-expanded leaves.The differences in leaf transmittance could be related to differencesin specific leaf weight. There were no significant differencesbetween the species and varieties in leaf reflectance.  相似文献   

19.
This data paper reports spectral reflectance and transmittance data of leaves from 21 terrestrial vascular plant species (seven herbaceous, and 14 broadleaf and long-needle coniferous tree species) and of shoots from one short-needle coniferous tree species. The reflectance spectra of branches of one tree species, of the trunks of 12 tree species and ground surface of one deciduous broad-leaf forest are also reported. Optical measurements and leaf samplings were made at five sites on Honshu Island, Japan, which are typical vegetation types in East Asia, i.e., grassland, paddy field, and deciduous broad-leaf or coniferous forests. The collection and measurements were conducted for main species in each site. To include other common vegetation types in East Asia, such as evergreen broad-leaf or coniferous forests, the sample collection and the measurements were conducted at gardens and an experimental forest. Leaves of ten deciduous species were measured at different phenological stages from leaf expansion to senescence since those species shows significant seasonal changes in spectral reflectance and transmittance of leaves. Leaves at different position in a canopy (e.g., sunlit versus shaded leaves) were also measured for eight of 21 species. The spectral reflectance and transmittance from both adaxial and abaxial sides of the all leaves or needles, expect Picea abies needles. The measurements of the leaves were conducted with a spectroradiometer attached via an optical fiber to an integrating sphere. Two types of integrating spheres were used: a model LI-1800-12 (Li-Cor) and an RTS-3ZC integrating sphere (Analytical Spectral Devices). A leaf clip accessory was also used instead of an integrating sphere for measuring the leaves of two species. All data were measured within the 350–2,500-nm spectral range with 1-nm steps between measurements but the data obtained by LI-1800 is unavailable in 1,650–1,740, 1,890–1,950, and 2,050–2,500 nm because of a large amount of noise. These data are used as input parameters in a radiative transfer model designed to estimate the leaf area index from radiation reflected from a canopy surface.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号