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Experimental analysis on the impact of climatic warming on lake plankton communities.

气候变暖对湖泊浮游生物群落影响的实验分析

基本信息

批准号：
14580567
负责人：
HANAZATO Takayuki
金额：
$ 2.3万
依托单位：
Shinshu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580567/
关键词：
Climatic warming Lake ecosystem Zooplankton Low temperature Food abundance Population dynamics 固体群動態

项目摘要

The winter population dynamics of the cladoceran Daphnia were investigated in Lakes Kizaki, Misuzu and Tamizo, of which two lakes (Misuzu and Tamizo) were covered with ice. It was found that Daphnia survived as free-living individuals during winter in Lakes Kizaki and Misuzu, suggesting that the low water, temperature (<4℃) does not give serious damage to the Daphnia populations. However, the Daphnia individuals had no eggs and therefore the populations had low productivities in winter. Laboratory experiments have shown that low water temperature and low food abundance do not kill Daphnia but suppress their reproduction, but that the Daphnia start reproduction rapidly if temperature and food density increases. This may be a strategy of the Daphnia populat ions to survive winter and competition with other zooplankton species in spring. Climatic warming must increase water temperature in winter. It is considered that the increased lake water temperature in winter due to climatic warming may disturb the Daphnia's strategy.Filed observation in Lake Suwa has demonstrated that the copepods Acanthcyclops and Eodiaptomus show clear seasonal succession : Dominance of the former in spring to that of the latter in summer. In order to assess the impact of temperature on their seasonal succession, zooplankton communities were maintained in mesocosms in the laboratories, where temperatures were controlled, and changes in the zooplankton community structure were analyzed. Acanthcyclops appeared abundantly in the mesocosms with the spring water temperatures while did not with the summer water temperatures. On the other hand, Eodiaptomus became dominant both under the spring and summer water temperatures. The results have suggested that seasonal dynamics of the Acanthcyclops population in Lake Suwa are controlled directly by wafer temperature, while that those of the Eodiaptomus population are done indirectly through biological interactions mediated by temperature.

在木崎湖、三津湖和多沟湖调查了枝水蚤的冬季种群动态，其中两个湖（三津湖和多沟湖）被冰层覆盖。结果表明，在冬季，木崎湖和三津湖的水蚤以自由生活的个体存活，表明低水温（<4℃）对水蚤种群没有造成严重的损害。但是，水蚤个体没有卵，因此种群在冬季的生产力较低。实验室实验表明，低水温和低食物丰度不会杀死水蚤，但会抑制它们的繁殖，但如果温度和食物密度增加，水蚤会迅速开始繁殖。这可能是水蚤越冬和春季与其他浮游动物竞争的一种策略。气候变暖必然使冬季水温升高。冬季气候变暖引起的湖水温度升高可能干扰了水蚤的生存策略，对淳化湖的野外观察表明，桡足类剑水蚤和始镖水蚤具有明显的季节演替，春季前者占优势，夏季后者占优势。为了评估温度对其季节演替的影响，浮游动物群落保持在实验室中的围隔生态系统中，在那里的温度被控制，并在浮游动物群落结构的变化进行了分析。在春季水温较高的围隔中，剑水蚤大量出现，而在夏季水温较低的围隔中，剑水蚤数量较少。春、夏季水温下始镖水蚤均占优势。结果表明，季节动态的水蚤种群在Suwa湖的直接控制晶片温度，而这些Eodiaptomus人口是间接通过温度介导的生物相互作用。