Comparative study on the grazing-and detritus-food chains in the littoral benthic community of Lakes Baikal (Boreal), Biwa (Temperate) and Malawi (Tropical).

放牧和碎屑食物链的比较沿岸的底部在北方贝加尔湖，温带的琵琶湖，热带湖泊马拉维进行了从2003年至2005年的水下实验，以测试一个假设的自下而上的约束影响进化发展的高生物多样性在这些湖泊。自下而上的制约因素可能很突出，因为放牧食物链中的底栖生物的丰度受到季节性最低产量的限制，主要是指附着藻类，而初级生产者丰度的大幅波动提供了最终被碎屑食物链中的底栖生物利用的资源。这种假说有助于解释，对于我们引用的湖泊，不同的食草食物链生物生活在热带湖泊的沿岸的底部，由于全年水温和光线穿透的合适条件，那里有相对恒定的大型藻类生产;而另一方面，碎屑食物链生物在北方湖泊的沿岸的底部占优势，藻类产量随季节波动，一年中的产量明显最低。本项目期间的实地调查结果（基于DO的初级生产力和呼吸、底栖动物群落及其食物、碎屑量的测量）实际上验证了上述假设。

Comparison of grazing- and detritus-food-chains on the littoral bottom in boreal Lake Baikal, temperate Lake Biwa, and tropical Lakes Malawi was carried out from 2003 to 2005 by the underwater experiment to test a hypothesis on the bottom-up constraint influencing the evolutionary development of high biodiversities in these lakes. The bottom-up constraint may be prominent where the abundance of benthic organisms in the grazing-food-chain is restricted by a seasonally lowest production, referring chiefly to attached algae, and large fluctuations in the abundance of primary producers provide a resource that is eventually utilized by benthic organisms of the detritus-food-chain. This hypotheses help to explain, for the lakes we cite, the facts that diverse grazing-food-chain organisms live on the littoral bottom of tropical lakes where there is relatively constant large algal production due to suitable conditions of water temperature and light penetration through the year ; while on the other hand, detritus-food-chain organisms are predominant on the littoral bottom of a boreal lake with seasonally fluctuating algal production and its pronounced lowest production in a year. The results based on the field surveys (measurement of DO based primary production and respiration, benthic animal community and their food, amount of detritus) during in the term of this project practically verify above hypothesis.