Prognosis of the diameter structure of an Araucaria Forest with ratio movement and transition matrix

Abstract

The projection of the diameter structure of an Araucaria Forest was performed by the methods ratio movement and transition matrix. Data were collected in 25 permanent plots with an area of one hectare each. These plots were installed and measured in 2002 and re-measured in 2005 and 2008 in an Araucaria forest fragment with 1273 ha located in Irati National Forest, Parana State. All trees with diameter at breast height (dbh) greater than or equal to 10 cm were measured and identified. Based on data from 2002 and 2005 measurements, it was made to the projection of the diameter structure for 2008 using the methods ratio movement and transition matrix, comparing these projections with observed data from remeasurement of 2008 was projected. Regarding mortality and recruitment, the forest presented for the period between re-measurements (2002-2005 and 2005-2008) an average of 30.28 trees ha-1 (1.78% year-1) and 23.64 trees ha-1 (1.39% year-1), respectively. The methods of projection estimated quite close to observed values, and both methods presented a slight underestimation of the total number of trees per hectare, with a small advantage for the ratio movement method with values closest to real. The two methods tested produced satisfactory results on the projection of the diameter structure.

doi: 10.4336/2010.pfb.30.64.327