Height growth and vertical development of an old-growthPseudotsuga-Tsugaforest in southwestern Washington State, U.S.A.

Abstract

A detailed analysis of diameter-height relationships was applied to an old-growth Pseudotsuga menziesii (Mirb.) Franco var. menziesii - Tsuga heterophylla (Raf.) Sarg. forest in southwestern Washington State, U.S.A., to predict future development of vertical stratification among tree species. Differences among species in relative abundance and size structure resulted in diameter-height regressions of varying certainty and stability. Damage and shading had negative impacts on predicted heights and estimates of maximum attainable height (Hmax) in all species. However, species varied as to the main causes and size dependency of damage in relation to tree height. Current height-growth rates of the upper canopy species declined with increasing tree height, reaching minimum values near the predicted Hmax. The future development of the forest canopy would involve a slow invasion of the upper canopy by Tsuga heterophylla and Thuja plicata Donn ex D. Don, as P. menziesii are near their maximum attainable height, and Abies amabilis Dougl. ex Forbes and Taxus brevifolia Nutt. are restricted to the middle to lower canopy. However, if current height-growth rates continue, P. menziesii should maintain its dominant status in the upper canopy for at least another century.

Canopy Layers Stratified Volume Equations for Pinus caribaea Stands in South West Nigeria using Linear Mixed Models

“…This finding confirms the assertions from previous studies [e.g. 27,28] of the existence and influence of canopy layers. The use of linear mixed models was designed to deal with the spatial heterogeneity in the data.…”

Simulation of tree-ring widths with a model for primary production, carbon allocation, and growth

“…Asymptotic height-diameter trajectories (Thomas, 1996;Ishii et al, 2000;Falster and Westoby, 2005) are modelled as…”

“…Such models are built on measurable relationships, such as that between stem diameter and height (Thomas, 1996;Ishii et al, 2000;Falster and Westoby, 2005), and crown area and diameter or height ) that arise because of functional constraints on growth. The pipe model represents the relationship between sapwood area and leaf area (Shinozaki et al, 1964;Yokozawa and Hara, 1995;Mäkelä et al, 2000).…”

The dynamics of rainfall interception by a seasonal temperate rainforest

“…Understory tree species include Pacific yew (Taxus brevifolia), Pacific silver fir (Abies amabilis), and vine maple (Acer circinatum). The canopy height is approximately 60 m, with the tallest trees reaching 65 m (Ishii et al, 2000). A high diversity of non-vascular plants exist in the canopy, dominated by lichens (∼1.3 t ha −1 ) in the mid and upper canopy and a similar amount of bryophytes in the lower canopy (McCune et al, 1997).…”