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The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon (CO2 and HCO3 ?) by plants. The net photosynthetic CO2 assimilation (P N), the photosynthetic assimilation of CO2 and bicarbonate (P N’), the proportion of increased leaf area (f LA) and the stable carbon isotope composition (δ13C) of Orychophragmus violaceus (Ov) and Brassica juncea (Bj) under three bicarbonate levels (5, 10 and 15 mm NaHCO3) were examined to determine the relationship among P N, P N’ and f LA. P N’, not P N, changed synchronously with f LA. Moreover, the proportions of exogenous bicarbonate and total bicarbonate (including exogenous bicarbonate and dissolved CO2-generated bicarbonate) utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and 13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31 % at 15 mm bicarbonate, respectively. Meanwhile, the proportions of exogenous bicarbonate and total bicarbonate utilised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate, 2.11 % and 3.10 % at 10 mm bicarbonate, and 2.36 % and 3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants. 相似文献
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文章设置饱水及随后失水处理自然生长的5种喀斯特植物叶片,测定其叶绿素荧光参数,分析各植物光合过程的响应特征。结果显示:盐肤木（Rhus chinensis）PSII反应中心活性及电子传递受严重失水影响,而其稳定的光能转化及光化学效率得益于叶绿素浓度的不断增加;构树（Broussonetia papyrifera）和金银花（Lonicera japonica）的叶绿素浓度逐渐升高随后趋于稳定,构树PSII反应中心对失水敏感,其活性及光能转化对随后持续失水逐渐适应。金银花光合结构及PSII反应中心表现稳定;火棘（Pyracantha fortuneana）叶绿素浓度从第4小时开始增加,光合结构趋于稳定,电子传递速率及光能转化逐渐增加;杨梅（Myrica rubra）电子传递速率及光化学效率均较低。 相似文献
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以喀斯特适生植物构树（Broussonetia papyrifera）为研究对象,非喀斯特适生植物桑树（Morus alba）为对照,比较了不同的植物光合作用对露石生境的响应。与无露石生境相比,多露石生境土壤具有较高的水分含量和较多的有机质。分析植物光合作用的光响应曲线和二氧化碳响应曲线、叶绿素荧光参数以及叶片水势（LWP）和碳稳定同位素值（δ13C）的结果表明:不同生境下,两种植物的LWP及δ13C无显著变化;除了初始荧光参数外,同种植物的叶绿素荧光参数差异不显著;不同生境下,构树的呼吸速率和羧化效率无显著变化,而多露石生境土壤生长的桑树的呼吸速率和羧化效率明显要大于无露石生境土壤生长的;在水分亏缺下,构树以牺牲体内碳的方式来维持稳定的羧化效率,进而保持稳定的光合能力;构树比桑树对喀斯特环境有着较强的适应性。 相似文献
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用时间GIS建立地籍信息系统的研究 总被引：12，自引：0，他引：12
时间ＧＩＳ是当前地理信息系统发的重要领域之一，它的应用不仅方便了历史数据的存储，而且使得基于时间的空间数据分析成为可能，改善了传统ＧＩＳ的动态管理，分析和决策支持功能。本文对在地籍信息系统的建立过程中应用这一技术的有关问题进行了研究。用时间标识的方法建立了各种地籍要素的时空数据结构，以数据更新和查询为例研究了时空数据的操作和应用。 相似文献
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Two strains of green microalgae C.reinhardti and C.pyrenoidosa were examined for their biosorption of Mn2+,Fe2+,Co2+,Ni2+,Cu2+,Zn2+,and Cd2+from aqueous multi-metal solutions.A wide range of biosorption capacities can be observed due to different strains of microalgae and different species of trace metals.This characteristic was ascribed to the distinct components and structures of algal cell walls and the different physicochemical properties of trace metals,such as atomic weight and ion density.C.pyrenoidosa showed higher uptake capacities than C.reinhardti and both of them had a preference for the uptake of cadmium over others in the trace metal solution,suggesting they can be a good biomaterial for biosorption of cadmium.Live microalgal cells displayed a more complex sorption process than dead microalgal cells because of cell assimilation. 相似文献
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湖泊沉积物中蛋白质和氨基酸的动态变化 总被引：5，自引：0，他引：5
测定了阿哈湖和百花湖沉积物孔隙水中蛋白质和氨基酸的含量。蛋白质含量分别在0．32－1．71mg/ml和0．22－1．38mg/ml之间，氨基酸含量分别在1．15－5．01μg/ml（以含N量计）和1．41－4．16μg/ml之间。两湖沉积物氨基酸含量逐渐增高，表明扩散作用的存在。随着时间的推移，蛋白质在沉积物各层中得到了很好的保存，说明它的分解比较有限。沉积物孔隙水中氨基酸含量和微生物活动有关，氨基酸在27cm以后的阿哈湖沉积物中明显积累，可能指示微生物活动的减弱。 相似文献
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The Mt. Beigu wetland, which has undergone periodical changes in water level, lies by the Yangtze River, and its dominant plants are Phragmites communis, Phalaris arundinacea and Polygonum lapathifolium. In order to study the distribution characteristics of nitrogen and phosphorus in the ecological system of the Mt. Beigu wetland, the authors measured the contents of total nitrogen and total phosphorus in Phragmites communis, Phalaris arundinacea and Polygonum lapathifolium, and the contents of nitrogen and phosphorus in the wetland soils with different plant species. In addition the authors investigated the influence of various plants on the spatial and seasonal (spring/autumn) distributions of nitrogen and phosphorus in the wetland soil. The contents of nitrogen and phosphoms in Phalaris arundinacea are significantly higher than those of the other two plant species in the same part. Secondary pollution of phosphorus in the wetland results mainly from Phalaris arundinacea. Phragmites com-munis effectively carries away nitrogen and phosphorus in the wetland soil in the wet season. The capacity of Poly-gonum lapathifolium to remove nitrogen is lowest among the 3 species of plants. These findings offer a theoretical foundation for the selection of plant species to restore the ecological environment and for the selection of time and depth for purging silt on the riverside wetland. 相似文献
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Spatial and seasonal variation of salt ions under the influence of halophytes,in a coastal flat in eastern China 总被引：1，自引：0，他引：1
Yanyou Wu Rongcheng Liu Yuguo Zhao Pingping Li Congqiang Liu 《Environmental Geology》2009,57(7):1501-1508
The high salinity of coastal saline field is a key factor limiting the reclamation. Halophytes have been utilized in the reclamation
of saline land. The study area is in Yancheng, China. An analysis of the concentrations of Rb, Cs, Sr, and Ba, the ratio of
Rb/Cs, and Sr/Ba in soils in autumn shows that the soil of this study area has great homogeneity. Artemisia halodendron, Gossypium hirsutum, and Sesbania cannabina were selected as the reclamation plants in the present study. In order to know the spatial-temporal distribution of soil
salinity, the influence of plant-specific vegetation, and the difference of desalination among these halophytes in coastal
flat, the authors analyze the soil-layers and seasonal variation in salt ions. Sodium chloride was accumulated in 0–5 cm topsoil
with no vegetation during the winter and spring. The effect of desalinization of halophytes is significant. Of the three plant
species, Sesbania cannabina has the greatest desalinization. The difference of ions composition of soils covered with various plant species is significant.
It can be concluded that halophytes have better amelioration of coastal soil salinity. Special attention should be paid to
the selection of plant species and measures to plant and cultivate crops in the reclamation of saline land. 相似文献