Lauri Kärenlampi, Andrew J. Friedland. (1988). Cytopathological and external observations on red spruce (Picea rubens Sarg.) needles damaged in winter in Vermont. Silva Fennica vol. 22 no. 3 article id 5358. https://doi.org/10.14214/sf.a15515

Keywords: Picea rubens; symptoms; United States; air pollution; cold tolerance; conifer needles; winter stress

Abstract | View details | Full text in PDF | Author Info

The red spruce (Picea rubens sarg.) population in the Green Mountains in Vermont has showed foliar deterioration that has not been fully explained. The most characteristic needle injuries of the sensitive trees appear in late winter when the first-year needles turn brown. The cytopathological and external observations on the symptoms support the interpretation that winter stress triggers the damage. It is possible that some anthropogenic stress factors (components of acid deposition or ozone) and/or natural factors predispose the trees to the damage.

The PDF includes an abstract in Finnish.

Kärenlampi, E-mail: lk@mm.unknown
Friedland, E-mail: af@mm.unknown

Category : Research article

article id 196, category Research article

Aaron R. Weiskittel, Laura S. Kenefic, Robert S. Seymour, Leah M. Phillips. (2009). Long-term effects of precommercial thinning on the stem dimensions, form and branch characteristics of red spruce and balsam fir crop trees in Maine, USA. Silva Fennica vol. 43 no. 3 article id 196. https://doi.org/10.14214/sf.196

Keywords: Acadian Forest; growth and yield; Abies balsamea; Picea rubens; precommercial thinning

Abstract | View details | Full text in PDF | Author Info

The effects of precommercial thinning (PCT) on stem dimensions, form, volume, and branch attributes of red spruce [Picea rubens Sarg.] and balsam fir [Abies balsamea (L.) Mill.] crop trees were assessed 25 years after treatment in an even-aged northern conifer stand. Treatments were a uniform 2.4 x 2.4-m spacing and a control (no PCT). The PCT treatment significantly increased individual tree diameter at breast height (DBH), height growth, crown ratio, and crown width, while it reduced the tree height to DBH ratio. PCT also significantly increased stem taper and consequently, regional volume equations overpredicted observed stem volume by 2 to 15%, particularly for the spaced trees. PCT also increased the number and maximum size of branches on the lower bole. The sizes of knots on half of the sampled spruce crop trees in the spaced plots precluded them from being used as select structural lumber; there were no other effects on log grade. Our findings indicate that PCT can have a long-term influence on the structural attributes of individual trees, and that improved stem-volume prediction equations are needed in the Acadian region of North America.

Weiskittel, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: aaron.weiskittel@umit.maine.edu
Kenefic, U.S. Forest Service, Northern Research Station, Bradley, ME 04411, USA E-mail: lsk@nn.us
Seymour, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: rss@nn.us
Phillips, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: lmp@nn.us

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