Site factors and growth of Palo Blanco (Tabebuia donnel-smithii Rose) plantations in Guatemala

Abstract

Tree growth is an expression of the confluence of factors such as eco-physiology and genetics of the species, site quality and forest management. The goal of this research is to determine the physicochemical properties of soils that influence the growth of Tabebuia donnell-smithii in pure plantations, to allow the identificationof relevant site factors that enhance or limitthe development of the species. Twenty sites were sampled systematically; sites were located in the Pacific and Atlantic lowlands of Guatemala; in each site a soil sample was collected in the surface (0-30 cm) layer. In the laboratory texture was determined and a routine nutrient analysis of soil was carried out. Using principal component analysis,the soil physicochemical properties that explain the soilvariability among sites were determined.By hierarchical agglomerative clustering, the sites were graded in classes;finally, by Pearson correlation test, the association between the physical and chemical parameters of soil and tree growth was established. As a conclusion, the content of Ca, Zn, organic matter and% of clay explained the site soil variability in 71.44%. Sites were classified into four classes. Class I, the one with best sites, showed soils with clay content of 11.60%, 5.99% organic matter, 6.72 mg/Kgof Ca and 3.56 mg/KG of Zn, respectively. Tree growth was linked directly to the content of soil organic matter by 0.97 (p-value = 0.032) and inversely to clay content -0.94% (p-value = 0.062).

Keywords

• Edafología forestal
• Plantaciones forestales
• Crecimiento arbóreo
• Especies forestales nativas