Response of ice-damaged northern hardwood stands in northern New York

Abstract

At three previously thinned, even-aged northern hardwood stands affected by the 1998 ice storm, we evaluated the responses of trees in plots given a rehabilitation treatment, and compared findings to adjacent untreated areas. In both the rehabilitated and untreated areas mortality seemed consistent with regional norms for northern hardwood stands. Trees that died after the storm had essentially complete crown loss due to ice loading, and 12% of living trees lost at least half of their crown. In both sets of plots, epicormic branching within the crown led to crown rebuilding, resulting in high levels of tree survival and good post-storm diameter growth on all plots. Release of selected upper-canopy trees by the rehabilitation cutting significantly increased diameter growth rates compared to those in untreated areas. While some epicormics developed below the base of the original crown in both treated and untreated plots, they largely emanated at > 5.2 m from the ground and did not degrade the butt log of most trees.Keywords: ice storm, even-aged northern hardwoods, rehabilitation treatment, stand growth, stand mortality, epicormic branching. RéSuméAu moyen de mesures effectuées dans des parcelles, nous avons évalué la réaction des arbres à la suite du verglas de 1998 dans trois peuplements équiennes de feuillus nordiques éclaircis qui avaient bénéficié d'un traitement de réhabilitation, et comparé les résultats à ceux des parcelles voisines n'ayant reçu aucun traitement. Tant dans les parcelles réhabilitées que dans celles non traitées, la mortalité semblait conforme aux standards régionaux pour les peuplements de feuillus nordiques. Les arbres qui sont morts après la tempête de verglas avaient essentiellement perdu l' ensemble de leur cime sous le poids de la glace et 12 % des arbres vivants avaient perdu au moins la moitié de leur cime. Dans les deux groupes de parcelles, la croissance des pousses adventives dans la cime a permis à celle-ci de se rétablir ce qui a donné un fort niveau de survie chez les arbres et une bonne croissance en diamètre post-tempête dans toutes les parcelles. Le dégage-ment des arbres choisis parmi les dominants au cours de la coupe de réhabilitation a considérablement augmenté les taux de croissance en diamètre, comparativement aux arbres des parcelles non traitées. Même si certaines pousses adventives se sont développées sous le niveau de la cime originale, tant dans les parcelles traitées que dans celles non traitées, elles se trouvaient en grande partie à plus de 5,2 m au-dessus du sol et n' ont pas déclassé la bille de souche de la plupart des arbres.

Response of the sugar maple borer to ice-damaged sugar maple in three northern hardwood stands

“…Estimates of crown damage to all trees in our ice storm plots varied from 33% to 47% (Nyland et al 2016). This generally compares with the post-storm condition of trees reported in New England by Shortle et al (2003).…”

“…Stand densities in 2010 were 22.0 m 2 /ha, 11.5 m 2 /ha, and 14.9 m 2 /ha for these three sites, respectively (Nyland et al 2016).…”

“…Similarly, in rehabilitated areas the average crown damage at Taylor Creek (43% ± 3%) was significantly higher (P = 0.003) compared to both Boeselager (35% ± 4%) and MacArthur (21% ± 3%). Average crown condition in 2010 was 34% ± 2% in untreated plots and 41% ± 2% in plots that received treatment (Nyland et al 2016). Differences in crown condition in 2010 between rehabilitated and untreated were similar among the three sites (P = 0.695).…”

“…Mean annual diameter growth of sugar maple during the ten-year period post-storm was significantly higher in rehabilitated plots (0.35 ± 0.02 cm ± SE) compared to untreated plots (0.18 ± 0.01) for all three sites combined. Within treatments, growth was similar at the three rehabilitated and the three untreated locations (Nyland et al 2016).…”

“…A 61 x 61 m grid of 0.08 ha (0.20 ac) plots was established in the middle of each 6-ha parcel (12 plots at Boeselager, 11 plots at MacArthur, 13 plots at Taylor Creek) in each of two parcels, treatment and control, in three stands (72 sample plots total). Plot centers were permanently marked in 2000 and all trees ≥14 cm diameter at breast height (1.4 m) within each plot received a metal tag and number to facilitate relocation and identification at a later date (Nyland et al 2016). Crown damage (% of crown missing following the storm) was estimated to the nearest ten percent using the method described by Woods (2002).…”