B. Song et al., MODELING CANOPY STRUCTURE AND HETEROGENEITY ACROSS SCALES - FROM CROWNS TO CANOPY, Forest ecology and management, 96(3), 1997, pp. 217-229
Canopy studies have been limited in ecological investigations due to p
roblems of canopy accessibility, and the lack of efficient sampling an
d modeling methods. The primary objective of this study was to develop
an efficient modeling approach to describe the 3-dimensional, hierarc
hical structure of individual crown shells within stands and correspon
ding canopy patches. Crown shells were modeled based on crown ratio, m
aximum cardinal radius, vertical position, and shape. Canopies were re
presented by adding unique crowns to simulated point patterns of trees
of known aggregation as measured by Pielou's index of nonrandomness.
Canopy patches were delineated at multiple horizontal and vertical sca
les using the ARC/INFO geographic information system (GIS). The patter
ns of canopy patches are clearly variable and scale dependent. Canopy
patterns become more diverse at broader horizontal scales, and change
greatly from the lower to the upper canopies. The modeling approach us
ed in this study has general utility in characterizing 3-dimensional c
anopies of many types of forests. (C) 1997 Elsevier Science B.V.