EVALUATING THE DYNAMICS OF ALIEN SPECIES (POACEAE) USED FOR EROSION CONTROL ON SAKURAJIMA VOLCANO

Abstract

Alien species in the family Poaceae play an important role as cover plants for erosion control
on slopes, particularly in Japan. However, concerns have arisen regarding the adverse effects of these species
on the local ecosystem and biodiversity. This study therefore examined the succession and seed propagation
of alien Poaceae that are used for erosion control on the cut slopes of Sakurajima volcano in southwestern
Japan. The results were as follows: Although the alien species used as cover plants were dominant for the
first couple of years following their introduction to the slopes, they were displaced entirely by native species
after the sixth year, which is considerably faster than ordinary succession. In addition, heading (flowering) of
alien species was also rarely observed in this period. It is considered that the observed results were caused by
the oligotrophic conditions of the slopes on Sakurajima volcano.