辐射增温效应对水稻叶片温度及光合速率的影响   总被引：1，自引：1，他引：1       下载免费PDF全文

李临颖  吴元中 《应用气象学报》1993,4(2):250-255

根据人工气候箱试验资料，分析了水稻叶片温度随环境温度、辐射强度的变化规律及辐射增温效应对单叶光—光合曲线的影响；由直角双曲型光合模型模拟了辐射增温效应对叶片光合特征的影响。结果表明，环境温度低于光合的生理适宜温度时，辐射增温效应将使叶片温度升高，从而有利于光合能力的提高；反之则相反。  相似文献   

有机锡对海洋微藻的生理效应　Ⅰ.三苯基锡和三丁基锡对光合色素含量的影响   总被引：5，自引：0，他引：5  

高尚德  吴以平  赵心玉 《海洋与湖沼》1994,25(3):259-265

于1991年4月－1992年五月，以金藻和扁藻为材料，用室内一次培养法研究三苯基锡（TPTC）和三丁基锡（TBTC）化合物对光合色素含量的影响。结果表明，两种有机锡对两种藻均有影响，在0．2—0．4μg／L的浓度时有轻微毒性；浓度大于0．5μg／L时，能使光合色素明显减少。对于两种藻叶绿素a72hEC50影响结果：TBTC和TPTC对金藻的均为0．59μg／L；对扁藻的，TBTC是0．87μg／L，而TPTC本出现半效应浓度。对于两种藻的类胡萝卜素72hEC50影响结果：金藻，TPTC是0．57μg／L，TBTC是0．49μg／L；扁藻，TBTC是0．89μg／L，TPTC也未出现半效应浓度。认为，两种有机锡对光合色素有明显的破坏作用。  相似文献   

青岛三种海产红藻的光合和呼吸特性的初步研究     

吴超元  张京浦  温宗存  彭作圣  刘海航 《海洋与湖沼》1996,27(2):207-212

于1981年在青岛近海采集真江食、石花莱和角叉菜样品，用氧电极法测定它们在不同生长季节和发育阶段的光合和呼吸速率，并研究不同温度对其光合和呼吸速率的影响，同时计算出它们的呼吸温度系数。结果表明，3种红藻具有典型的潮间带海藻的光合特性，即高光饱和点为600—1000μE／（m2·s），较高的光补偿点为12－40μE／（m2·s）和较高的光合适温≥25℃。温度对3种红藻的光合和呼吸的影响均很明显，在5，15，25℃下测试，它们的最高光合和呼吸速率都出现在25℃。3种红藻的呼吸温度系数（Q10），在5－15℃较高，为1．4－5．5在15－25℃较低，为1．1－2．7。说明它们在低温下的呼吸受温度变动影响较大。经计算3种红藻在适宜生长温度下的净光合速率：角又菜和真江蒿在15℃分别为4．90O2mg／（g·h）和8．14O2mg／（g·h）；石花菜在25℃为11．87O2mg／（g·h），在3种红藻中最高。这说明，石花菜的光合效率并不象人们预料的那样低，其秋季幼体在25℃，1000μE／（m2·s）光强下，净光合速率达到19．19O2mg／（g·h）。看来在自然界石花菜生长缓慢主要是由于生境中低光照强度和较低水温所致。  相似文献   

An investigation into robust spectral indices for leaf chlorophyll estimation   总被引：2，自引：0，他引：2  

Russell Main  Moses Azong Cho  Renaud Mathieu  Martha M. O’Kennedy  Abel Ramoelo  Susan Koch 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(6):751-761

Quantifying photosynthetic activity at the regional scale can provide important information to resource managers, planners and global ecosystem modelling efforts. With increasing availability of both hyperspectral and narrow band multispectral remote sensing data, new users are faced with a plethora of options when choosing an optical index to relate to their chosen or canopy parameter. The literature base regarding optical indices (particularly chlorophyll indices) is wide ranging and extensive, however it is without much consensus regarding robust indices. The wider spectral community could benefit from studies that apply a variety of published indices to differing sets of species data. The consistency and robustness of 73 published chlorophyll spectral indices have been assessed, using leaf level hyperspectral data collected from three crop species and a variety of savanna tree species. Linear regression between total leaf chlorophyll content and bootstrapping were used to determine the leafpredictive capabilities of the various indices. The indices were then ranked based on the prediction error (the average root mean square error (RMSE)) derived from the bootstrapping process involving 1000 iterative resampling with replacement. The results show two red-edge derivative based indices (red-edge position via linear extrapolation index and the modified red-edge inflection point index) as the most consistent and robust, and that the majority of the top performing indices (in spite of species variability) were simple ratio or normalised difference indices that are based on off-chlorophyll absorption centre wavebands (690–730 nm).  相似文献   

长江口极微型和微微型浮游生物的垂向变化与周日波动     

李云  李道季  张利华  孔定江  方涛 《海洋科学》2011,35(9):24-30

2006年6月12日至22日“东方红2号”考察船夏季航次期间,在长江口3个连续观测站位进行了水样采集,应用流式细胞仪分析了水样中的极微型浮游生物（Femtoplankton）和微微型浮游生物（Picoplankton）。结果显示,原绿球藻（Prochlorococcus）在所有样品中均未检测到;检测到的聚球藻（Synechococcus）和微微型真核浮游植物（Picoeukaryotes）平均丰度达数量级10^5～10^6个／L,异养细菌（Heterotrophic bacteria）和病毒（Viruses）平均丰度达数量级10^8～10^9个／L。在浑浊的长江口水域,极微型和微微型浮游生物的垂向分布特征不同,主要与各站位特有的水动力条件密切相关：浊度是调控微微型真核浮游植物、异养细菌和病毒周日变化的关键因子之一;微微型真核浮游植物成为微微型浮游植物中最重要的组成部分,与异养细菌具有显著的正相关关系。  相似文献   

Spatial and temporal variation of picoplankton distribution in the Yellow Sea, China   总被引：3，自引：0，他引：3  

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Seven surveys were carried out in April, September, October, December 2006 and March, May, August 2007 in the Yellow Sea, China. Variations in the spatial and temporal distribution of Synechococcus, picoeukaryotes and heterotrophic bacteria are quantified using flow cytometry. Synechococcus and heterotrophic bacteria are most abundant from late spring to autumn, while picoeukaryotes concentration is high in spring. Synechococcus and heterotrophic bacteria concentrated high in the northwest part of the Yellow Sea in spring and autumn, while picoeukaryotes distributed evenly over the whole study area except for a small frontal zone in the coastal area on the west (in spring) and central Yellow Sea (in autumn). Under mixing conditions, the vertical distribution of the three picoplankton groups showed a well-mixed pattern. Upon a well-established stratification, the maximum abundance of picoplankton occurred above the mixed layer depth (~30 m). Cell sizes of Synechococcus and picoeukaryotes were estimated by converting forward scatter signals (FSC) from cytometry analysis to cell diameter, showing the results of 0.65–0.82 μm for Synechococcus and 0.85–1.08 μm for picoeukaryotes. The average integrated carbon biomasses ranged 15.26–312.62 mgC/m2 for Synechococcus, 18.54–61.57 mgC/m2 for picoeukaryotes, and 402.63–818.46 mgC/m2 for heterotrophic bacteria. The distribution of Synechococcus and heterotrophic bacteria was temperature dependent, and picoplankton presence was poor in the Yellow Sea Cold Water Mass.  相似文献   

Flower orientation in Pachycereus weberi (Cactaceae): Effects on ovule production, seed production and seed weight     

D.M. Figueroa-Castro  P.L. Valverde 《Journal of Arid Environments》2011,75(11):1214-1217

Few studies have determined the importance of orientation on flower reproductive success. Flower orientation may affect reproduction of Cactaceae; the interception of photosynthetic active radiation (PAR) differs along the different sides of cacti stems, and translocation of resources between cacti ribs does not appear to occur. Therefore, PAR received by each cacti stem face may determine the resources available for reproduction. We examined the reproductive success of Pachycereus weberi flowers with contrasting orientations. Ovule production per ovary, number of seeds per fruit, seed set per fruit and seed weight were used as indicators of reproductive success for flowers facing southeast and northeast. PAR received on opposite stem sides was recorded as an estimator of resource availability for each side. Results showed that flowers facing southwards produced more ovules and seeds and produced heavier seeds. Seed set was not significantly different between flowers with contrasting orientations. The southern stem faces received more PAR than the northern faces. Reproductive success was different for flowers with contrasting orientations, suggesting that there is an association between PAR received on different P. weberi stem faces and floral reproductive success.  相似文献   

The transient oasis: Nutrient-phytoplankton dynamics and particle export in Hawaiian lee cyclones     

Yoshimi M. Rii  Susan L. Brown  Francesco Nencioli  Victor Kuwahara  Tommy Dickey  David M. Karl  Robert R. Bidigare 《Deep Sea Research Part II: Topical Studies in Oceanography》2008,55(10-13):1275

Macronutrients, photosynthetic pigments, and particle export were assessed in two eddies during the E-Flux I and III cruises to investigate linkages between biogeochemical properties and export flux in Hawaiian lee cyclonic eddies. Cyclone Noah (E-Flux I), speculated to be in the ‘decay’ stage, exhibited modest increases in macronutrients and photosynthetic pigments at the eddy center compared to ambient waters. Cyclone Opal (E-Flux III) also exhibited modest increases in macronutrient concentrations, but a 2-fold enhancement in total chlorophyll a (TChl a) concentration within the eddy center. As indicated by fucoxanthin concentrations, the phytoplankton community in the deep chlorophyll maximum (DCM) of Opal was comprised mainly of diatoms. During an 8-day time series in the center of Opal, TChl a concentration and fucoxanthin in the DCM decreased by 50%, which was potentially triggered by silicic acid limitation. Despite the presence of a substantial diatom bloom, Opal did not deliver the expected export of particulate carbon and nitrogen, but rather a large biogenic silica export (4-fold increase relative to export in surrounding waters). Results suggest that controls on the life cycle of a Hawaiian lee cyclone are likely a combination of physical (eddy dynamics), chemical (nutrient limitation), and biological (growth and grazing imbalance) processes. Comparisons between Noah and Opal and previously studied cyclones in the region point to a relationship between the spin-up duration of a cyclone and the resulting biological response. Nonetheless, Hawaiian lee cyclones, which strongly influence the biogeochemistry of areas 100's of km in scale in the subtropical North Pacific Ocean, still remain an enigma.  相似文献   

半干旱雨养农业区灌浆期模拟酸雨对春小麦叶片光合特性及产量的影响   总被引：1，自引：0，他引：1  

姚桃峰  王润元  王鹤龄  赵鸿 《地球科学进展》2010,25(6):638-646

为探明酸雨对春小麦光合特性及产量的影响,用pH为1.5、2.5、3.5、4.5和5.6的模拟酸雨在春小麦灌浆期对其进行喷淋,然后测定不同pH模拟酸雨处理后春小麦叶片的光合参数与春小麦产量。研究结果表明:①随着酸雨pH的下降,春小麦叶片净光合速率下降了9.61%~61.50%,气孔导度下降了7.03%~57.46%,蒸腾速率下降了3.70%~55.44%,胞间CO2浓度上升了27.91%~43.74%,叶绿素相对含量下降了12.12%~41.92%,产量下降了15.50%~37.05%。酸雨对春小麦叶片光合特性的影响随酸雨的氢离子浓度增大而愈显著。②酸雨pH与净光合速率、蒸腾速率、气孔导度、叶绿素相对含量及春小麦最终产量均呈极显著正相关,与胞间CO2浓度呈显著负相关。  相似文献   

三种植物生长激素对光合细菌生长影响的研究   总被引：2，自引：0，他引：2  

刘影  李兰生  李乐 《海洋湖沼通报》2006,(2):57-61

研究了不同浓度的三十烷醇、α-萘乙酸和赤霉素对光合细菌生长的影响。结果表明这三种植物生长激素对光合细菌的生长均有促进作用。其中赤霉素的促生作用最明显,其最佳质量浓度为0.5 mg/L。三十烷醇和α-萘乙酸的最佳质量浓度均是1.0 mg/L。试验表明在增殖培养中,通过添加某些植物生长激素,来促进光合细菌的生长是可行的。  相似文献