Abstract
We suggested a list of DI and DOD for tree that is a part of enhanced Fujita scale to estimate the intensity of tornadoes. The indicator of tree is one of main indicator in natural environment, in the relatively weak range of tornado intensity and common indicator that is expected to be used in worldwide.
We compared the critical wind speed for growing environment, forest, park, garden and along road. The roadside trees were estimated to have averagely higher critical wind speed. The reason was considered that the management by human to restrict the size of crown and the height. The values in the list were considered to be adequate to former reports that demonstrate critical wind speed for trees.
