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Studies on relations among ecosystem components for lake ecosystem management

湖泊生态系统管理中生态系统组成之间的关系研究

基本信息

批准号：
09680560
负责人：
TAKAMURA Noriko
金额：
$ 1.98万
依托单位：
National Institute for Environmental Studies
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680560/
关键词：
Lake Ecosystem Interaction Littoral zone Lacustrine sockeye salmon Pond smelt Daphnia Top down

项目摘要

We examined the population dynamics of lacustrine sockeye salmon and pond smelt, and fauna and distribution of benthos in LakeTowada. The lacustrine sockeye salmon showed the scramble type of density-dependence as the population dynamics. Estimated parameters indicated that the survival of salmon juveniles suddenly decrease when released fish increase more than 2 million individuals. Pond smelt did not show density-dependent mortality in their spawner-recruitment relations. Results of stepwise multiple regression analysis showed that the salmon abundance was negatively correlated with Daphnia longispina abundance, and that pond smelt abundance positively correlated with abundance of D. longispina and copepod larvae. These results suggest that salmon would be in competition with pond smelt for the food. We conclude that the population dynamics of lacustrine sockeye salmon is affected by their population density and abundance of pond smelt in the Lake Towada.Fifty-three taxa of benthos were found. The lake basin was divided into 4 parts according to the benthos fauna. 1) littoral zone below 20m depth with a high biodiversity, 2) sublittoral zone between 20-60m depth with 22 taxa of Oligochaeta and chironomids, 3) profundal zone excluding the deepest part Naka-ko with only 4 taxa and 4) Naka-ko profundal zone with 9 taxa of macroinvertebrates. The bottom of the littoral zone changed from cobbles, sand and mud along a transect line from shore to sublittoral zone. The macroinvertebrates communities only in cobbles and sand showed a high biodiversity, mainly composed of lotic species, but those on mud showed a low biodiversity composed of mostly Oligochaeta and Chironomidae. The biomass of macroinvertebrates was highest at 12-15m depth almost, but the peak shifted to the shallower sites during the winter. This phenomenon and the fish distribution in the littoral zone might suggest that the fish predation controls the distribution of the macroinvertebrates community.

我们研究了湖相红鲑鱼和胡瓜鱼的种群动态，以及十和田湖底栖动物的动物群和分布。湖相红鲑鱼的种群动态表现出密度依赖性的争夺型。估计参数表明，当释放的鱼数量超过200万条时，鲑鱼幼鱼的存活率突然下降。池塘公鱼在其产卵鱼招募关系中并未表现出密度依赖性死亡率。逐步多元回归分析结果表明，鲑鱼丰度与长斯溞丰度呈负相关，池塘公公鱼丰度与长斯溞和桡足类幼虫丰度正相关。这些结果表明鲑鱼将与胡瓜鱼争夺食物。我们得出的结论是，十和田湖湖相红鲑鱼的种群动态受到其种群密度和胡公鱼丰度的影响。共发现了 53 个底栖生物类群。湖盆按底栖动物群分为4部分。 1) 20m以下的滨海区，生物多样性高；2) 20-60m深的滨海区，有22个寡毛类和摇蚊类群；3) 深海区，不包括最深的Naka-ko，只有4个类群；4) Naka-ko深海区，有9个大型无脊椎动物类群。滨海带的底部沿着从海岸到亚滨海带的横断线由鹅卵石、沙子和泥浆变化。仅在鹅卵石和沙地中的大型无脊椎动物群落表现出较高的生物多样性，主要由露水物种组成，而在泥地上的大型无脊椎动物群落则表现出较低的生物多样性，主要由少毛类和摇蚊科组成。大型无脊椎动物的生物量几乎在12-15m深度处最高，但在冬季峰值转移到较浅的地方。这种现象和沿岸带的鱼类分布可能表明鱼类的捕食控制了大型无脊椎动物群落的分布。