Occurrence, proportion, and vertical distribution of red heartwood in paper birch

Abstract

Normal paper birch ( Betula papyrifera Marsh.) wood has a clear and uniform color. However, some paper birch trees contain reddish-brown-, discolored wood known as red heartwood. Its occurrence, proportion, and vertical distribution were investigated. One hundred and fifty trees were randomly sampled from three stands located at the Montmorency Forest, 75 km north of Quebec City, Quebec, Canada. A subsample of 18 trees showing occurrence of red heartwood at stump height were felled, and 5 cm thick disks were cut at every 0.5 m of height. Red heartwood volume, proportion, and vertical distribution were determined from the disks. Trees with larger diameter at breast height and lower tree height had a higher probability of red heartwood occurrence. Red heartwood starts occurring in 40-year-old trees on average in the stands studied. The volume of red heartwood was positively correlated with tree age, and the proportion of red heartwood was positively related to tree age, and negatively related to the amount of sunlight on the live crown. Red heartwood proportion was 13.3% of the tree merchantable volume, mostly located under the live crown.

Predicting sugar maple (Acer saccharum) discoloured wood characteristics

“…Kadunc (2007) and Knoke (2003) found similar results for Acer pseudoplatanus L. and Fagus sylvatica. Likewise, red heartwood occurrence in Betula papyrifera was highly correlated with DBH and tree height (Giroud et al 2008). These results are contrary to those presented by Yanai et al (2009) for A. saccharum.…”

Internal Decay in Landscape Oaks (Quercus spp.): Incidence, Severity, Explanatory Variables, and Estimates of Strength Loss

“…Subsequently, the incidence and severity of decay were modeled separately using a two-part conditional model. Many existing studies [35][36][37] have used a similar approach because the underlying observations are constrained to the unit interval between zero and one, often with a large proportion of zeros. In the first stage, the probability of decay occurring in each tree was modeled using binomial logistic regression, and, in the second stage, the severity of decay in affected trees was subsequently modeled using beta regression.…”