The purpose of this study was first, to investigate the process of site devastation, vegetative recovery, soil erosion, material. The survey was conducted in Fukuoka Prefecture, on Mt. Tateishi. This mountain is composed of a granite rock that is easily and rapidly weathered by wind, therefore soil formation is quite rapid. The results of the study are as follows. li Gullies were found to contain a series of benches, or stairs and directly beneath these stairs deepening is quite pronounced. Studies show that erosion was accelerated by the formation of stairs in gullies at Mt. Tateishi, Sakurajima and at Aso. Once the gully head has formed the formation of stairs soon follows, below the gully stairs a jar shaped depression forms and as the depression deepens it may expand, eventually eroding the support for the upper slope causing the upper extremely heavy deposit soil material in gullies, after which vegetation will colonize in areas where soil has accumulated . 2) As a result of the survey of collapsed areas it was found that the tree root system forms an intertwined arch that prevents gullies from expanding upslope. Additional simulations involving soil dynamics has also proven this process. This structure is only a temporary arch that is formed due to the collapse of the downward slope and it was found that the parabolic structure is resistant to slope failure depending on the degree of the root systems intertwining. The arch structure and net and pile action resist slope collapse in quite different manners. The size of the arch structure is decided by the size of the surrounding root system and in addition by the compression intensity and friction, and adhesive properties. These two latter factors are the principal characteristics that determine the shape and intensity of the structure. To effectively maintain the arch structure, supporting structures must be present, however, the arch structure may be damaged by the expansicm of a gully, the arch structure is then more vulnerable to collapse because the base cannot offer support. Frequent slope collapse and lands slides are caused by gully formation. 3) Investigations found that the dimension of the soil particles, type of soil particles, and the transportation force determines the degree of sedimentation in gullies. Areas of sedimentation are the result of soil loss obstructions such as, boulders. This study showed that the soil particle distribution and site stabilization by vegetation depends on the size of the herb and woody plant roots, and the distribution and density of herbs and woody plantsThe ability of vegetation to stabilize soil particles depends of the size of roots, the distribution and the density of herbs, and woody plants. Rills are effectively controlled by the root systems of small vegetation. Large vegetation such as trees. have a high ability to resist erosion but as the total stock volume is low, a dense ground cover of herbs has a greater ability to prevent erosion from starting. As the eroded soil particles pass through the colonizing vegetation the soil particles are stopped and will form distinct material will expand. Weathered rocky ares will show faster vegetative recovery than unweathered rocks, as weathered rocks, will have soil particles deposited in cracks and vegetation will quickly colonize in this sedimentated soil. This colonizing vegetation accelerates gradual soil movement control. The analysis of vegetative colonization in sedimentary soils examined, weathered soil, detritus, granite, volcanic ash soil, red soil, and the hardness of the soil layer. Soil hardness influences the invasion of vegetation, different soil parent material creates differences in soil hardness and effects the ability of vegetation to colonize a site. 4) Factors influencing soil formation are the distribution of the root system, organic litter, and decayed roots. Soil formation by annual herbs, provides large amounts of organic material but, erosion