Geographic Patterns and Stand Variables Influencing Growth and Vigor of Populus tremuloides in the Sierra Nevada (USA)

Figure 1

Relationship between aspen basal area increment (BAI) and tree size (dbh), compared between locations around Lake Tahoe Basin (north/east and south/west sides of basin at low, medium, and high elevation) and according to aspen crown ratio for pure aspen stands at 50 m² ha⁻¹ BA ((a) and (b)), and as a function of competition in terms of BA and conifer encroachment in terms of percent BA ((c) and (d)). Unless otherwise stated, BAI estimates obtained from generalized linear mixed model were based on crown ratio 0.5, vicinity BA 50 m² ha⁻¹ composed of 50% conifer by BA, at 2,150 m elevation on the south/west side of Lake Tahoe Basin.

(a)

(b)

(c)

(d)