Sample arrangements and spatial variability characterization of dendometrics parameters of Eucalyptus camaldulensis and physical soil attributes

Abstract

To evaluate the performance of different sampling arrangements, this work aimed to study, in a field of Eucalyptus camaldulensis, the variability and spatial dependence of some attributes of plant and soil (LATOSSOLO VERMELHO Distrófico [Typic hapludox]). To collect the soil (water content [WC] and soil mechanical penetration resistance [PR]) and plant data (tree height [TH] and circumference at breast height [CBH]), a sampling arrangement containing 122 points was used in an area of 1.98 ha and three other arrangements, with 84, 48 and 42 points. Except for the CBH, the reduction of points did not expressively affect the parameters of the classical statistics of all other parameters evaluated. Spatially, for TH and WC, the reduction of collection points did not significantly affect the geostatistical parameters, allowing estimating mapping similar to the initial mapping with high correlation coefficients. The WC at 0.10-0.20 m layer could be estimated from 48 samples of the WC at 0-0.10 m layer and 48 samples in the layer of 0.10-0.20 m with a correlation coefficient (r) equal to 0.94 when compared to initial kriging from an arrangement with 122 sample points.