Nutrient stress predisposes and contributes to sugar maple dieback across its northern range: a review

Abstract

Over thelast60 years,multiple studies haveattributed sugarmaple (Acer saccharumMarsh.) diebackand decline tonutrientstatus,interactionandtreestress.Sitedifferencesindeficient,toxicorantagonisticlevelsofsoilcalcium, magnesium, phosphorus, potassium, manganese and aluminium are correlated with mortality and dieback in many studies. In general, a single nutrient is rarely determined to be responsible for poor sugar maple health. Other factors such as defoliation, management, climate fluctuations and soil biota can play key roles in dieback. Nutrient stresses can greatly increase the riskof injuryand mortality from other biotic orabiotic stresses. Anthropogenic inputs and climate change may also cause perturbation of nutrient or pH thresholds for sugar maple. Therefore, historical sugar maple sites may no longer be suitable to support a healthy sugar maple forest under current management regimes. The following is a review of locations, symptoms and studies of the relationshipofmineralstresstosugarmaplehealth,whichwillbeusefulinformationforforestresourcemanagers to consider when faced with maple health issues. Conclusions developed from this review are as follows: (1) land managersshouldconsidersoilnutritionindecision-making concerningsugarmaple,(2)standardizationofevaluation methods for tree nutrition is somewhat lacking and (3) additional multidisciplinary research is needed to clarify the interacting factors affecting sugar maple health and nutrition.