Estimação do Volume de Eucaliptos por Krigagem e Cokrigagem no Semiárido Pernambucano

Abstract

RESUMOOs volumes de 1875 árvores de um plantio de eucalipto foram rigorosamente cubadas pelo processo de Smalian, conhecendo-se assim o volume total do plantio que é de 166,14 m 3 . As árvores foram localizadas em um plano cartesiano (X, Y) e duas técnicas geoestatísticas foram aplicadas: a krigagem e cokrigagem. Para a cokrigagem foi utilizada como variável secundária o diâmetro a altura do peito (DAP), variável com alta correlação com o volume de madeira (Vol) do eucalipto. Três tamanhos de amostras foram retirados -200, 100 e 50 -, e as estimativas dos volumes foram realizadas para cada uma das amostras usando as duas técnicas geoestatísticas. O tamanho da amostra não influiu nas estimativas do volume total do plantio. A cokrigagem forneceu melhores resultados do que a krigagem para as menores amostras. Os mapas da distribuição espacial do volume foram construídos.Palavras-chave: manejo florestal, Caatinga, Polo Gesseiro, combustível e Araripe. Estimating of the Volume of Eucalyptus with Kriging and Cokriging inSemi-arid of Pernambuco ABSTRACTThe volumes of 1875 eucalyptus plantation trees were strictly cubed by Smalian process, thus knowing the total volume of planting of 166.14 m3, the trees were located on a plane (X, Y) and two geostatistical techniques were applied, kriging and cokriging. For cokriging was used as the secondary variable (DBH) diameter at breast height of the entire population, variable with high correlation with the volume of Eucalyptus wood. Three sizes of samples were taken -200, 100 and 50 -and the estimates of the volumes were performed for each sample using both geostatistical techniques. The sample size did not affect the estimates of the total volume of planting. The cokriging provided better results than kriging for the smaller samples. The maps of spatial distribution volume were constructed.

Site Index in Eucalyptus Stands Applying Ordinary Kriging: An Approach With Different Models and Methods of Classification

“…Some studies have confirmed the strong spatial dependence of the dominant height in commercial stands of Eucalyptus sp. (MELLO et al, 2005;GUEDES et al, 2015;LUNDGREN et al, 2017;ATAÍDE et al, 2020). In addition, the regression models provide the average estimate of growth in dominant height and allow site index estimates only in places where there was a measured sample unit.…”

“…stands, as well as to other species, for example, Pinus sp. and Tectona grandis (MELLO et al, 2005;PELISSARI et al, 2014;GUEDES et al, 2015;PELISSARI et al, 2015;LUNDGREN et al, 2017;ZECH et al, 2018;ATAÍDE et al, 2020). Even with numerous studies evaluating the spatial structuring of dendrometric variables, few use the site index variable, mainly when obtained by mathematical models.…”