Abstract
Microorganisms were isolated from wood adjacent to 459 wounds inflicted during winter, summer and autumn on 42 trees: 27 Acer rubrum, 5 Betula papyrifera, 5 Fagus grandifolia and 5 Quercus rubra. The fungi isolated most frequently from 1-4 wk old winter wounds were Cytospora spp.; from the same age summer wounds, Ceratocystis spp.; and from the same age autumn wounds, Phialophora spp. Bacteria were isolated frequently from 1-4 wk old summer and autumn wounds, but seldom from 1-4 wk old winter wounds. Bacteria and nonhymenomycetous fungi were the only microorganisms isolated from recently inflicted wounds. Hymenomycetes were isolated from a few 7, 8, 9 and 10 wk old summer wounds, but not from winter wounds until after 5 mo. The first microorganisms to invade wounds inflicted at different seasons in the NE USA are different. The time before Hymenomycetes are isolated also differs for wounds inflicted at different times of the year.