SILVICULTURAL FEATURES OF Eucalyptus hybrid PLANTATIONS IN THE LA NGA AREA, DONG NAI PROVINCE

Abstract

The paper presented the silvicultural characteristics of three types of Eucalyptus hybrid plantations (UP35, UP54, UP75) in La Nga area of Dong Nai province. The present study was carried out to evaluate the survival rate, growth and stability of three types of Eucalyptus hybrid plantations after 7 years of planting. Experimental ecological methods were used to analyze the growth performance and stability of three types of Eucalyptus hybrid plantations, in order to identify the Eucalyptus hybrid type most suitable for high productivity and environmental stability. The research results showed: (1) The three types of Eucalyptus hybrid plantations were significantly reduced through natural selection after seven years of planting. After this period, a strong differentiation in tree size was observed among individuals within the plantations. The UP35 Eucalyptus hybrid plantation was found to have a higher proportion of trees classified as good and average compared to the UP54 and UP74 hybrid plantations; (2) These three types of Eucalyptus hybrid plantations were characterized by poor stability in response to environmental changes. The average tree dimensions (diameter at breast height and height), basal area, and timber volume were found to be highest in the UP74 plantation, followed by UP54, and lowest in UP35; (3) Based on criteria including high survival rate, stable stand structure, good resistance, low incidence of hollow-heart disease and high wood quality, the UP54 Eucalyptus hybrid was selected for afforestation in the La Nga area of Dong Nai province.