Stand growth model using volume increment/basal area ratios

MARTÍNEZ PASTUR G; CELLINI JM; LENCINAS MV; PERI P

Journal of Forest Science

Institute of Agricultural and Food Information

Lugar: Prague; Año: 2008 p. 102 - 108

1212-4834

Estimation of stand growth is crucial for forest planning. Usually was estimated using fixed values, and recently with individual tree-growth equations. An alternative is through stand growth models. The objective was to develop a simple model for Nothofagus pumilio stands with full density along site quality and age gradients. Sample was obtained from 125 stands (25-480 years and IS60= 9.7-23.2 m). In each plot, data of forest structure and samples for tree-ring measurement were taken in all trees (n= 2456) to estimate growths using biometric models previously developed. The growth values of each plot during the last twenty years were calculated to fit the model, using the ratio of total volume increment/basal area as independent variable. The developed model gives a ratio between stand volume increment and basal area (m.year-1) in function to the site quality and stand age. The statistics (r²=0.819, mean error=0.019, absolute mean error=0.033), residual analysis and biological performance were satisfactory. Values obtained through this model multiplied with the stand basal area offers the volumetric growth per hectare per year. The obtained stand growths varied between 1 to 20 m³.ha-1.year-1. This simple model allowed estimating growth values at stand level from easy field measurements from forest inventories.