Cb. Halpern et al., EQUATIONS FOR PREDICTING ABOVEGROUND BIOMASS OF PLANT-SPECIES IN EARLY SUCCESSIONAL FORESTS OF THE WESTERN CASCADE RANGE, OREGON, Northwest science, 70(4), 1996, pp. 306-320
We present a set of 152 regression equations that predict the above-gr
ound biomass of 38 herb, shrub, and tree species common on early succe
ssional (clearcut) sites in the western Cascade Range of Oregon. For m
any of these species, biomass relationships have not been modeled prev
iously or have not been modeled for early successional sites. Biomass
of herbaceous taxa is best predicted by cover, while biomass of woody
species is best predicted by stem diameter and/or length. We discuss h
ow relationships between biomass and plant size vary with site age amo
ng species of diverse growth form and life history. We supplement best
-fit models with alternative equations that are easier that are easier
to implement in the field of that are less sensitive to sources of va
riation associated with time since disturbance. To minimize the misapp
lication of equations, we report the dimensional ranges of all plant v
ariables measured, whether or not they are explicitly modeled.