カジメ場造成への数値シミュレーション応用

抄録

The purpose for the establishment of kelp beds is to increase kelp biomass, thus, calculation of biomass change is a useful tool for the prediction. A photosynthetic production model is one of the major components used in the calculation of the biomass change. An estimation of grazing is another major component to be included in the calculation of biomass change. In this study, grazing effects on the biomass dynamics of Ecklonia cava are analyzed by using the biomass change model(Honda 2000) that combined the feeding equation of Ivlev(1961) with the photosynthetic production model that was developed by Honda(1999). Relationships between the rate of biomass change and standing biomass of E. cava are classified into three types : Type 1) the rate of biomass change is positive under a stable equilibrium, Type 2) the rate of biomass change is negative for all bioraasses, and Type 3) the rate of biomass change is positive between a stable equilibrium and an unstable equilibrium. The spore-bag and vegetative transplantation techniques are effective in the establishment of kelp beds for Type 1. For type 2, the spore-bag and vegetative transplantation techniques are not effective without the removal of herbivores or seafloor piling by the construction of artificial reefs. For Type 3, the vegetative transplantation can be used to increase the kelp biomass and overcome the instability, but the spore-bag technique is ineffective in overcoming an unstable equilibrium.