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A stem analysis study was initiated at the Pothole Creek Study Area in 1998 in order to
model stem branch growth rates, foliage distribution in the crowns and wood quality characteristics of trees from uneven-aged IDF stands. The work involved
cutting apart a sample of trees of different heights and canopy positions outside the Permanent Sample Plot and
measuring the branch and stem growth increments in detail.
To assist light modelling, individual tree characteristics will be related to light penetration values. Foliage biomass and leaf area information will help improve the link between the light model tRAYci and
the growth and yield model TASS. Hemispherical photographs
were taken around each sample tree to characterize the canopy and local light conditions, and the locations, diameters and crown positions of neighbouring
trees were measured. The selected trees were then cut down and sectioned into ten lengths. Information gathered from each section included the diameter, length, radius, whorl count and location of branches, a subsample of which
were measured for terminal
growth and foliage characteristics. The foliage was weighed, and a subsample scanned and analyzed using the Winseedle® software package to estimate leaf area. After the tree
was removed, more hemispherical photographs were taken to
characterize the canopy and light conditions with the sample tree absent.
The study also investigates the relationship between crown morphology and wood quality characteristics of interior Douglas-fir. The properties of each annual ring (width, proportion of earlywood, relative density of earlywood and latewood) of
each of ten bole disks from each sample tree were analyzed at the Forintek wood products research laboratory in Vancouver. Foliar biomass and leaf area will be related to branch parameters. Additional relationships between crown morphology
(e.g.,
vertical distribution of foliage) and ring characteristics will follow.
See: Light Relationships and Brunner, A. 1998. A
light model for spatially explicit forest stand models. For. Ecol. Manage. 107:
19-46. Research Branch contact:
Catherine Bealle Statland
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