日本是开展沿海防护林研究工作最早的国家之一。他们针对海岸斜坡崩塌频繁,土壤盐碱度高,植被受到严重破坏的特点,着重于选择造林树种的研究,以保土性强、耐风害、耐盐碱的树种为发展方向。例如,经过试验,在北海岛唯一不受盐碱危害的树种为紫穗 Japan is one of the earliest countries to carry out research on coastal shelterbelts. In response to frequent landslides, high soil salinity and serious damage to vegetation, the researchers focused on the study of tree species selection and the direction of tree species with strong soil conservation, wind resistance and salt tolerance. For example, the only tree on the North Island that is free of salinity is purple