The LANDIS model simulates ecological dynamics, including forest succession, disturbance, seed dispersal and establishment, fire and wind disturbance, and their interactions. We describe the addition to LANDIS of capabilities to simulate forest vegetation management, including harvest. Stands (groups of cells) are prioritized for harvest using one of four ranking algorithms that use criteria related to forest management objectives. Cells within a selected stand are harvested according to the species and age cohort removal rules specified in a prescription. These flexible removal rules allow simulation of a wide range of prescriptions such as prescribed burning, thinning, single-tree selection, and clear-cutting. We present a case study of the application of LANDIS to a managed watershed in the Missouri (U.S.A.) Ozark Mountains to illustrate the utility of this approach to simulate succession as a response to forest management and other disturbance. The different cutting practices produced differences in species and size-class composition, average patch sizes (for patches defined by forest type or by size class), and amount of forest edge across the landscape. The capabilities of LANDIS provide a modeling tool to investigate questions of how timber management changes forest composition and spatial pattern, providing insight into ecological response to forest management. Résumé : Le modèle LANDIS simule des dynamiques écologiques telles que les successions forestières, la dispersion et l'établissement des semences, les perturbations causées par le feu et le vent, ainsi que leurs interactions. Cet article décrit des ajouts faits au modèle LANDIS qui permettent la gestion de la végétation forestière, incluant la récolte. Les peuplements (groupes de cellules) sont priorisés pour la récolte en utilisant un des quatre algorithmes de classement qui utilisent des critères reliés aux objectifs d'aménagement forestier. Les cellules à l'intérieur d'un peuplement sélectionné sont récoltées par cohorte d'âge et d'espèce selon des règles de prélèvement spécifiées dans une prescription d'intervention. Ces règles souples de prélèvement permettent la simulation d'un large éventail de prescriptions telles que le brûlage dirigé, l'éclaircie, la coupe sélective et la coupe rase. L'utilisation de LANDIS est présentée à l'aide d'une étude de cas impliquant un bassin versant sous aménagement situé dans les montagnes Ozark du Missouri (États-Unis). L'étude de cas illustre l'utilité d'une telle approche pour simuler les successions écologiques en réponse à l'aménagement forestier et à d'autres types de perturbations. Les différents types de coupes ont généré des différences dans la composition des espèces et des classes de dimensions, la superficie moyenne des coupes (pour les coupes définies selon le type de forêt ou par classe de dimensions) et la quantité de bordures forestières sur l'ensemble du paysage. Ces capacités font de LANDIS un outil de modélisation pouvant servir à explorer de quelle façon l'aménagement forestier affecte la c...

The LANDIS model simulates ecological dynamics, including forest succession, disturbance, seed dispersal and establishment, fire and wind disturbance, and their interactions. We describe the addition to LANDIS of capabilities to simulate forest vegetation management, including harvest. Stands (groups of cells) are prioritized for harvest using one of four ranking algorithms that use criteria related to forest management objectives. Cells within a selected stand are harvested according to the species and age cohort removal rules specified in a prescription. These flexible removal rules allow simulation of a wide range of prescriptions such as prescribed burning, thinning, single-tree selection, and clear-cutting. We present a case study of the application of LANDIS to a managed watershed in the Missouri (U.S.A.) Ozark Mountains to illustrate the utility of this approach to simulate succession as a response to forest management and other disturbance. The different cutting practices produced differences in species and size-class composition, average patch sizes (for patches defined by forest type or by size class), and amount of forest edge across the landscape. The capabilities of LANDIS provide a modeling tool to investigate questions of how timber management changes forest composition and spatial pattern, providing insight into ecological response to forest management.

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A common method of modelling forest stand dynamics is to use permanent growth plot remeasurements to calibrate a whole-stand growth model expressed as an ordinary differential equation. To obtain an estimate of future conditions, either the differential equation is integrated numerically or, if analytic, the differential equation is solved in closed form. In the latter case, a future condition is obtained simply by evaluating the integral form for the age of interest, subject to appropriate initial conditions. An older method of modelling forest stand dynamics was to use a normal or near-normal yield table as a density standard and calibrate a relative density change equation from permanent plot remeasurements. An estimate of a future stand property could be obtained by iterating from a known initial relative density. In this paper we show that when the relative density change equation has a particular form, the historical method also has a closed form solution, given by a sequence of polynomials with coefficients from successive rows of Pascal's arithmetic triangle.

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