Planted circumstances and wind break techniques in the Isles of the East China sea.

In this paper the authors describe in detail the planted circumstances with wind-break effects developed in the isles of Tonaki and Aguni. tens of kilometers off the main island of Okinawa in the East China Sea; both these isles are abundunt in Fukugi, an evergreen, tall and sturdy tree of tropic origin; and the time-honored Fukugi groves have played an all-important role in protecting the people and their properties against the year-round strong winds and casual but frequent typhoons. The Fukugi trees have been planted around each of house premises on three or four sides, arranged in different ways; in Tonaki the village street crossings were so arranged as to be out of alignment in one direction, with a distinct intention of making such irregular arrangement resist any possible wind acceleration. In Tonaki, almost all houses would be built on sunken grounds, besides the Fukugi windbreaks, to avoid being hit direct by the fierce wind, while in Aguni no such artificial house-sites are found. These devices are fairly efficient, from the bioclimatic point of view because they are to mitigate the cooling-off effect on the entire house envelopes in the windy winter season of Okinawa area.