Dave Griswold points out fissures on the bark of a beech tree Sunday to Craig Phillips during a tree and bird identification walk on the Pettingill Park trails in Auburn. The wounds in the tree are caused by insects carrying fungal pathogens that weaken the trees, according to Griswold. The walk, hosted by the Lewiston Auburn Community Forest Board, was one of the activities planned for the 2021 Auburn Winterfest. Andree Kehn/Sun Journal Buy this Photo