2010 年 16 巻 p. 241-246
We investigated the distribution of species becoming the problem as development of thick growth of trees in class A rivers and the effect of cutting and uprooting on the past vegetation management for those species in thirteen rivers. From the result that compared the data of the National Census on River Environments with the data of past vegetation management, Willow, Robinia pseudoacacia L and Bamboo were dominant species in Japanese rivers. Those species have been tending to increase in recent years, whereas periodical vegetation management has performed. From the result of field survey, the effect of cutting for those species was small in common. On the other hand, uprooting was effective by way of prevention for regeneration of trees as far as branches and roots were removed after uprooting. It is important that roots and branches were removed to raise preventive effect by uprooting.
