Analytical site index solution for the generalized log-logistic
height equation
Cieszewski CJ
JFOREST SCIENCE
46 (2): 291-296 MAY 2000
Abstract:
The generalized log-logistic height equation computes height as a function of
age and a fixed base-age site index. This equation and its modifications have
been used for many applications in various regions. It is seemingly apparent
that this equation is analytically insolvable for the site index; no general
analytical solution to this equation is readily available. This article
presents such a solution that has proven to be valid and useful with all tested
parameters. This solution is based on an adaptation of the Ramanujan's
(1887-1920) solution for a trinomial with real-number exponents. Ramanujan's
solution is a series that in many cases can be expressed as a closed-form
equation. In the present context, this series may be used for derivations of
various special cases of closed-form solutions, initial-condition difference
and differential equations, and for various analytical sensitivity and trend
analysis, as well as for efficient site index computations.
Author Keywords:
analytical solutions, numerical solutions, polynomial solutions, site index
models, base-age invariant, convergent series
KeyWords Plus:
LODGEPOLE PINE, GROWTH, CURVES, SWEDEN, MODEL
Addresses:
Cieszewski CJ, Univ Georgia, Sch Forest Resources, Athens, GA 30602 USA
Univ Georgia, Sch Forest Resources, Athens, GA 30602 USA
Publisher:
SOC AMER FORESTERS, BETHESDA
IDS Number:
437PX
ISSN:
0015-749X