权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Effects of temporal variations in environmental conditions on phytoplankton in lakes.

环境条件的时间变化对湖泊浮游植物的影响。

基本信息

批准号：
60540419
负责人：
MIYAZAKI Tatsuo
金额：
$ 1.09万
依托单位：
The University of Tsukuba
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60540419/
关键词：
Carbon uptake Diel periodicity Nitrogen uptake Phytoplankton

项目摘要

Phytoplankton in lakes is placed under constantly fluctuating environments. These fluctuations exert on the growth and competition of planktonic algae. In the present research, we examined effects of these fluctuations on photosynthetic activities and nitrogen uptake, and discussed growth of phytoplankton in lakes.First, we measured the activities of uptake of carbon and nitrogen during the mixing period in lake Nakanuma. Uptake of carbon did not occur in the dark, but that of ammonium did. This result was explained as an adaptation of phytoplankton to varying light conditons.Second, we examined the diel change of the uptake activities during stratification and mixing period. Garbon uptake showed maximum activity at noon and did not occur in the night. Ammonium uptake did not cease in the night. Furthermore, ammonium uptake showed a maximum in the evening in the dark incubation. Using the mathematical model, we could explain the results as follows. Phytoplankton may produce and store carbohydrates, and use these for uptake of nutrients in the night or dark. Thus, phytoplankton may grow even in the night or weak light conditions.Week-scale measurements of the uptake of carbon and nitrogen also exhibited the similar results, and thus sustained the above explanation.

湖泊中的浮游植物处于不断波动的环境中。这些波动影响了浮游藻类的生长和竞争。本研究以中沼湖为研究对象，首先测定了中沼湖混合期浮游植物的碳氮吸收活性，并分析了混合期浮游植物的光合活性和氮吸收活性。碳的吸收没有发生在黑暗中，但铵。这一结果可以解释为浮游植物对不同光照条件的适应。第二，研究了层化和混合期浮游植物吸收活性的昼夜变化。碳水化合物的吸收在中午表现出最大的活动，并没有发生在夜间。氨的吸收在夜间没有停止。此外，在黑暗培养中，铵吸收在晚上表现出最大值。利用数学模型，我们可以对结果进行如下解释。浮游植物可以产生和储存碳水化合物，并在夜间或黑暗中利用这些碳水化合物吸收营养。因此，浮游植物即使在夜间或弱光条件下也能生长。对碳和氮吸收的周尺度测量也显示了类似的结果，从而支持了上述解释。