Avaliação da continuidade espacial de características dendrométricas em diferentes idades de povoamentos clonais de Eucalyptus sp.

Abstract

The knowledge on the structure of spatial continuity of dendrometric characteristics can provide an efficient control of variation in the variables to be estimated in successive inventories. This control can be achieved by using of stratifiers based on maps from statistical kriging. However, kriging lacks information on the spatial continuity of descriptor variables for Eucalyptus sp. stands, as well as the behavior of this characteristic over time. This study evaluated the structure of spatial continuity for three dendrometric characteristics of 23 clonal stands of Eucalyptus sp. in 3 successive measurements, located in different areas of SP state. For each stand, variable and measurement, experimental semivariograms were adjusted by the weighted least squares method. Through the degree of spatial dependence obtained by the experimental semivariograms, the behavior of the spatial continuity of variables was evaluated. More than 70% of the analyzed stands showed average to strong spatial dependence for volume and 80% for the variables basal area and dominant height. The range of the variables showed variations from 300 to 3.000 m, depending on the stand and age of measurement. The percentage of stands with strong spatial dependence decreases with age, tending to a sill of average spatial dependence, for all the analyzed variables. The degree of spatial dependence along successive measurements varies from stand to stand and from measurement to measurement, being likely to decrease or increase with time, suggesting a specific analysis of spatial dependence for the variable of interest for each stand and measurement.