Download (PDF 2.43 MB): https://research.fs.usda.gov/download/treesearch/34944.pdf
Abstract
The branching pattern of
A. amabilis was regular (normal shoot-length distribution, less variable branching angle and bifurcation ratio), whereas that of
T. heterophylla was more plastic (positively skewed shoot-length distribution, more variable branching angle and bifurcation ratio). The two species had similar shoot morphologies: number of leaves per unit shoot length and leaf to axis dry mass ratio. Leaf morphology, in contrast, was significantly different. Leaves of
A. amabilis were larger and heavier than those of
T. heterophylla, which resulted in lower mass-based photosynthetic rate for
A. amabilis. Despite these differences, the two species had similar levels of leaf overlap and area-based photosynthetic characteristics. We inferred that the convergence of leaf display and photosynthetic characteristics between
A. amabilis and
T. heterophylla may contribute to the persistence of both species in the understory of this forest.
Citation
Ishii, Hiroaki; Yoshimura, Ken-Ichi; Mori, Akira. 2009. Convergence of leaf display and photosynthetic characteristics of understory Abies amabilis and Tsuga Heterophylla in an old-growth forest in southwestern Washington State, USA. Tree Physiology. 29: 989-998.
