Study on model for remote sensing estimation of maize yield     

Liu Zhaoli  Huang Tieqing  Wan Enpu  Zhang Yangzhen 《中国地理科学(英文版)》1997,8(2):161-167

Through analysis of perpendicular vegetation index (PVI) from combination of visible and near-infrared spectrums reflecting the feature of crop reflectance, we come to the conclusion that the index can better indicate crop instantaneous photosynthesis whereas people generally regard it as the representation of crop leaf area index (LAI). Exploration of crop photosynthesis within a day and its period of duration leads to production of photosynthetic vegetation index (PST) that can reflect the whole crop accumulated photosynthesis, which means the total biomass produced by crop, moreover the method simulating PST is put forward by employment of multi-temporal spectrum parameters. On the basis of the achievements mentioned above, a new comprehensive model for remote sensing estimation of maize yield is established, which can comprehensively show major physiological actions of maize and the course of its yield formation, organically integrate various effective ways of crop yield estimation. It lays a solid foundation for carrying out remote sensing estimation of maize yield on a large scale.  相似文献   

Influence of albumen on aggregation and O2 evolution of protoplasm from Bryopsis hypnoides Lamourou     

李映霞  王广策 《中国海洋湖沼学报》2008,26(4)

The extruded protoplasm from the coenocytic green alga, Bryopsis hypnoides Lamouroux, was able to reform a cell wall and develop further into a mature alga in seawater. In this paper, the influence of albumen on the ability of aggregation and on the photosynthesis of protoplasm was examined. Results show that the protoplasm of B. hypnoides could aggregate in either albumen or chicken egg, which is similar to that in seawater. However unlike in seawater, the aggregation from B. hypnoides in albumen and chicken egg failed to develop into a mature individual. Interestingly, the protoplasm of B. hypnoides could maintain its photosynthetic O2 evolution in albumen and chicken egg, while the time in chicken egg was longer than that in albumen.  相似文献   

Estuarine phytoplankton dynamics and shift of limiting factors: A study in the Changjiang (Yangtze River) Estuary and adjacent area   总被引：5，自引：0，他引：5  

Zhuo-Yi Zhu  Wai-Man Ng  Su-Mei Liu  Jing Zhang  Jay-Chung Chen  Ying Wu 《Estuarine, Coastal and Shelf Science》2009,84(3):393

Environmental factors in estuaries are highly variable in terms of both spatial and temporal dimensions and hence phytoplankton biomass, as well as community structure, is dynamic. Two cruises were carried out in the Changjiang (Yangtze River) Estuary and adjacent area in spring and summer. The result of CHEMTAX calculation suggests that in spring diatoms and chlorophytes contribute equally to phytoplankton biomass, while phytoplankton community structure is mainly composed of diatoms in summer. We encountered blooms in summer with chlorophyll a (CHLa) over 10 μg l⁻¹ off the Changjiang Estuary and they were mainly caused by diatoms (>90%). Based on the HPLC analysis of samples collected, phytoplankton pigments mainly concentrated beyond the front between 122.5°E and 123°E where nutrients and turbidity were best balanced. Euphotic depth (Z_eu, calculated from Secchi disk depth) to surface mixed layer depth (Z_mix) ratio (i.e. Z_eu/Z_mix) were comparable in spring (average value 1.2) and the ratio increased to 5.2 in summer. Variation of the ratio indicates an apparent shift of light and physical conditions from spring to summer. Correspondingly, CHLa was positively related to Z_eu/Z_mix ratio (r² = 0.83) in spring, indicating the light limitation over the whole investigation area. On the other hand, the relationship of CHLa and Z_eu/Z_mix ratio became unclear when Z_eu/Z_mix ratio >3 in summer. This is probably due to the combination of both light limitation before the front and nutrient limitation beyond the front. In addition, evidence was found that light condition can impact the diagnostic pigments in the Changjiang Estuary.  相似文献   

Bicarbonate Daily Variations in a Karst River: the Carbon Sink Effect of Subaquatic Vegetation Photosynthesis   总被引：7，自引：0，他引：7  

ZHANG Cheng  WANG Jinliang  PU Junbing  YAN Jun 《《地质学报》英文版》2012,86(4):973-979

Using the Guancun River, an underground stream-fed river, in Rong’an County of Guangxi, China as a case study, the daily biochemical cycle was examined in this paper based on the data collected a weeklong via high resolution data logger monitoring and high-frequency sampling. Furthermore, the loss of inorganic carbon along its flow path was estimated. Results show that chemical components of the groundwater input are quite stable, showing little change extent; while all of the chemical parameters from two downstream monitoring stations show diel variation over the monitoring period, suggesting that plant activity in the river has a strong influence on water chemistry of the river. The comparison of the input fluxes from the groundwater with the output fluxes of HCO3? estimated at the downstream monitoring station during the high-frequency sampling period shows a strong decrease of HCO3?, indicating that the river is losing inorganic carbon along its flow path. The loss is estimated to be about 1,152 mmol/day/m of HCO3? which represent about 94.9 kg/day of inorganic carbon along the 1,350 m section of the Guancun River. It means that HCO3? entering the river from karst underground stream was either consumed by plants or trapped in the authigenic calcite and thus constitutes a natural sink of carbon for the Guancun karst system.  相似文献   

铜和镁离子对卵圆卡盾藻生长、光合色素和溶血活性的影响          下载免费PDF全文

苟偲钰  叶志林  江天久 《应用海洋学学报》2021,40(3):395-402

本研究探索了不同浓度的铜和镁离子对卵圆卡盾藻(Chattonella ovata)光合色素含量及其溶血活性的影响,并探讨了溶血活性与光合色素间的关系。结果表明,当铜和镁离子浓度分别为7.84μg/dm~3和18.79 g/dm~3时,卵圆卡盾藻达到最佳生长状态。不同浓度的铜离子(3.92、5.88、7.84、9.80μg/dm~3)处理下,高浓度组(9.80μg/dm~3)抑制了卵圆卡盾藻岩藻黄质和硅甲藻黄素的积累。随着镁离子浓度(7.52、11.27、15.03、18.79 g/dm~3)的增加,叶绿素c2和硅甲藻黄素的平均含量增加,而紫黄质、岩藻黄质平均含量变化不显著(p 0.05)。卵圆卡盾藻的溶血活性均随金属离子浓度升高而增强,与叶绿素c2的变化趋势一致。对溶血活性与光合色素进行因子分析,提示溶血毒素与叶绿素c2密切相关,这种毒素可能是叶绿素c2或其类似物。  相似文献   

增强的UV-B辐射对地木耳中抗逆性物质的影响   总被引：1，自引：1，他引：0  

王弋博  曲颖  杨亚军 《冰川冻土》2011,33(3):654-658

实验室条件下模拟兰州地区夏至臭氧层衰减12％、20％和40％时增强的UV-B辐射2.54kJ·m-2·d-1(T1)、4.25 kJ·m-2· d-1 (T2)和8.35 kJ·m-2·d-1(T3),研究了不同强度的UV-B辐射对陆生蓝藻地木耳（Nostoc commune）中的的抗逆性物质光合色素（叶绿素a、类胡...  相似文献   

2009年初夏长江口及毗邻海区表层浮游植物群落结构的色素表征   总被引：1，自引：0，他引：1  

余小青  金海燕  陈建芳  李宏亮  王奎  高生泉  卢勇  庄燕培 《海洋学研究》2011,(3):145-154

2009年6月对东海表层海水光合色素进行了高效液相色谱(HPLC)分析,通过藻类色素化学分类分析软件Chemical Taxonomy(CHEMTAX)获得了不同浮游植物对叶绿素a的贡献,研究了表层浮游植物群落结构的组成.结果表明:表层浮游植物的生物量与群落组成受温度、悬浮物质量浓度、营养盐等环境因素的影响,在水平分布...  相似文献   

Photosynthetic characteristics of sinking microalgae under the sea ice     

《Polar Science》2014,8(4):385-396

The photosynthetic characteristics of sinking a microalgal community were studied to compare with the ice algal community in the sea ice and the phytoplankton community in the water column under the sea ice at the beginning of the light season in the first-year sea ice ecosystem on the Mackenzie Shelf, in the western Canadian Arctic. The phytoplankton community was collected using a water bottle, whereas the sinking algal community was collected using particle collectors, and the ice algal community was obtained by using an ice-core sampler from the bottom portion of ice core. Photosynthesis versus irradiance (P-E) incubation experiments were conducted on deck to obtain the initial slope (α^B) and the maximum photosynthetic rate (P_m^B) of the three algal communities. The α^B and the P_m^B of the light saturation curve, and chlorophyll a (Chl a) specific absorption coefficient (ā_ph*) between the sinking microalgal community and the ice algal community were similar and were distinctly different from the phytoplankton community. The significant linear relationship between α^B and P_m^B, which was obtained among the three groups, may suggest that a photo-acclimation strategy is common for all algal communities under the low light regime of the early season. Although the sinking algal community could be held for the entire duration of deployment at maximum, this community remained photosynthetically active once exposed to light. This response suggests that sinking algal communities can be the seed population, which results in a subsequent phytoplankton bloom under the sea ice or in a surface layer, as well as representing food for the higher trophic level consumers in the Arctic Ocean even before the receding of the sea ice.  相似文献   

枯水期钦州湾浮游植物群落结构组成与分布特征   总被引：5，自引：2，他引：3  

蓝文陆  李天深  郑新庆  施晓峰  黎明民  陆建军  李波 《海洋学报》2014,36(8):122-129

应用浮游植物特征光合色素的分析方法,研究了2011年枯水期钦州湾浮游植物的结构组成与分布特征。结果表明:枯水期含量较高的浮游植物光合色素按含量高低依次为叶绿素a、岩藻黄素、叶绿素b、青绿素和多甲藻素,其他特征光合色素的含量很低。经CHEMTAX对光合色素转化计算,枯水期普遍检出的浮游植物类群为硅藻、青绿藻和甲藻,是枯水期浮游植物的优势类群,其生物量的平均值(±标准差)分别为(2.36±2.38)μg/L、(0.87±0.53)μg/L、(0.13±0.14)μg/L,变化范围为0.18~7.45μg/L、0.10~1.80μg/L和0.02~0.60μg/L。硅藻、青绿藻和甲藻占枯水期浮游植物生物量比例的平均值(±标准差)分别为59%±21%、30%±16%、6%±4%,占比变化范围为29%~96%、1%~53%和0.4%~14%,其他藻类所占比例很低。河口和外湾靠外海域两个区域以硅藻为优势类群,内湾及外湾近岸硅藻和青绿藻共同为优势类群。河流营养盐输入量和比例的不同决定了钦州湾河口海区浮游植物群落结构的差异,大面积贝类养殖导致了内湾至外湾近岸海区硅藻比例的降低,而外湾水温的增加引起暖水性硅藻大量增长成为优势类群,在温度进一步增加和营养盐持续输入等条件下存在会发生硅藻赤潮的风险。  相似文献   

漳江口桐花树叶片光合色素含量和叶绿素荧光参数与盐度的关系     

吴敏兰  ;陈立松  ;吴锦城  ;方志亮 《台湾海峡》2014,(3):326-330

对生长在漳江口红树林湿地国家级自然保护区不同盐度环境中（FZ1：7.95-10.00;FZ2：11.10-15.25;FZ3：15.60-20.08;FZ4：20.58-23.54）优势红树植物桐花树的光合色素含量和叶绿素荧光特征进行了研究,结果表明盐度最低的样地FZ1比其他样地具有更高的叶绿素a、叶绿素b和胡萝卜素含量（p〈0.05）.Fv/Fm、Fv/F0和PIABS表现出同样的规律：FZ1、FZ2较高,尤其FZ1最高,与FZ3、FZ4有极显著水平差异（p〈0.01）.叶绿素荧光诱导动力学曲线（O-J-I-P）起始部分变化不大,其余部分均是FZ3比其他3个样地低.比活性参数ABS/CS、TRo/CS各样地间无显著差异;ETo/RC、RC/CSo是FZ3比其他样地下降,尤其是与FZ1、FZ2有极显著差异.DIo/CS则是FZ3比其他样地高,尤其是与FZ1、FZ2有极显著差异.这些结果表明,在保护区内盐度7.95‰-15.25‰环境中的桐花树叶片光合色素含量较高,光合器官对光能的吸收、转化和利用效率更高.  相似文献