ETIOLOGY OF A SUGAR MAPLE DECLINE

Studies in an 85-year-old sugar maple, Acer saccharum Marsh., stand indicated that since the early stages of stand development, sugar maples that are currently declining showed slower growth than healthy trees. A steady growth decline of all dominant trees during the last 30 years was significantly correlated with adverse climatic conditions. High levels of stand density (competition) appeared to predispose sugar maple trees to adverse affects of climatic (winters with periodic thaws and sparse snow cover, summer drought, low autumn soil water recharge) stresses. In some cases, sugar maple decline may be part of a natural stand density regulatory process, and it may be prevented by silvicultural intervention.