Optimizing the Management of Uneven-aged Forest Stands

Abstract

Two perennial problems in the management of uneven-aged forests are considered: (i) determination of the optimal sustainable distribution of trees by diameter class, i.e. stand structure, for a given initial stocking level, and (ii) the optimal cutting schedule for the conversion of an irregular stand to a target structure. It is shown, using examples for northern hardwood stands in Wisconsin, that both problems can be solved via mathematical programming techniques. The programming approaches utilize a set of nonlinear equation models for stand table projections which consider the interdependence of size classes within the stand. To illustrate procedures, optimal stand structures are found for a case where initial stand basal area is constrained to specified levels and the objective is to maximize value growth over the cutting cycle. A conversion cutting schedule is then determined for a case in which the objective is maximization of present worth. It is emphasized that both the optimal distribution and conversion problems can be generalized to consider a broad range of objective functions, lengths of cutting cycle, and constraints on the growing stock.

A growth model for north Queensland rainforests

“…A weakness inherent in many other approaches, particularly stand-table projection approaches (e.g. Adams and Ek, 1974) and matrix approaches (e.g. Usher, 1966) is that predicted recruitment is not distinguished and the user is not explicitly warned of unrealistically long projections.…”

Growth model for uneven-aged loblolly pine stands : simulations and management implications

“…Several papers have reported on the ecological and economic implications of uneven-aged management of mixed northern hardwood forests (Adams and Ek 1974, Bare and Opalach 1987, Buongiorno and Michie 1980, and a few have dealt with some ecological implications (Buongiorno and Lu 1990, Buongiorno and others 1994, Lu and Buongiorno 1993. Other research to model the interrelationships among trees of different species in uneven-aged stands includes that of Michie and McCandless (1986), on oak-hickory forest types in Pennsylvania; Bowling and others (1989), on Appalachian hardwoods; Vanclay (1989), on rain forests of Queensland, Australia; and Mengel and Roise (1990), on models for southeastern bottomland hardwoods.…”

Stand-Level Forest Management Planning Approaches

“…In their model, state variables were described by the number of trees and total basal area per hectare as is the case in the classical framework. Uneven-aged stand management decisions have a long history in forestry, including early works by Duerr and Bond [69], Adams and Ek [70], Buongiorno and Mitchie [71], and Chang [72]. Recent interest in uneven-aged management has attracted a considerable amount of deterministic optimization studies especially in Europe, where even-aged stand management has been dominantly implemented [73].…”