This study aims to examine the evolution of the distribution of belt windbreaks as a case study of postwar pioneer farmland in Showa Village, Gunma Prefecture, and to evaluate the layout plan of these forests. The 30-year climatological standard typical wind direction at the nearest local meteorological station was predominantly from the north-northwest. In the basic layout plan of the windbreak in the area, the windbreak was positioned at the northern end of the fan, upwind of the prevailing winds, and several rows of the windbreak were extended inside the fan to the southwest-northeast, which is perpendicular to prevailing winds. The spacing of typical windbreak rows ranged from 410 to 730 m, with irregular intervals. A chronological analysis of aerial photographs demonstrated that the skeletal arrangement of the windbreaks has been in place since 1969. The majority of these were windbreak protection forests designated from 1957 to 1968, and the study determined that the designation of these forests was based on the windbreak forest layout plan. However, the study assumed that landowners in certain areas likely disagreed with the designation of windbreak protection forests at the time, and such windbreaks tended to disappear similar to insect bites up to the present. Based on an examination of previous colored aerial photographs and the identification of tree species in the field, the study inferred that deciduous broad-leaved trees originally growing in the area were left uncut during land clearing to form a banded windbreak. In recent years, however, the study observed that cypress is predominant in the forest due to sequential improvement and renewal through the replanting of windbreak protection forests.
