Variação da espessura da casca de pinheiros tropicais em Penhalonga, província de Manica, aos 38 anos

Abstract

Mozambique is one of the few countries in Southern Africa that still has extensive arable areas, around 36 million hectares, with potential for agricultural development, including forestry plantations. The area with potential for forestry plantations is estimated at 7 million hectares. These areas are concentrated in the central and northern parts of the country. Despite all this potential, the planted area in the country is very small, around 60,000 hectares, of which the majority consists of young plantations established in the last 15 years. The increase in demand for timber products, combined with the exhaustion of native forest resources, has led many countries to initiate or expand reforestation programmes, with fast-growing species, particularly species of the genera Pinus and Eucalyptus. One of the problems that arise in these projects is knowing which species and origins to use in a given site. To this end, good practices recommend establishing a species and provenance test site before moving forward with large-scale plantations. This paper presents the results of bark thickness in a combined species and provenance test of pine trees in Penhalonga, at 38 years of age. The test includes genetic material from nine provenances from five countries (Anhembi, Brazil; Mount Pine Ridge, Belize; San Juan and Guanaja, Honduras; Alamicamba and Yacul, Nicuaragua; and Zimbabwe) of Pinus caribaea var hondurensis, P. caribaea var bahamensis, P. oocarpa, P. patula, P. kesiya and P. elliottii var elliottii. The test was established following a randomized complete block design, with nine treatments (species/provenances) and three replicates. Analysis of variance detected genetic variation: (i) significant in species and origins in bark thickness. The best materials for use in plantations in Penhalonga were: Pinus caribaea var. hondurensis from Guanaja, Honduras and Alamicamba, Nicuaragua; P. patula from Mount Pine Ridge, Belize and P. oocarpa from San Juan, Honduras. In this test, the worst materials were the origins of P. elliottii var. elliottii from Zimbabwe and P. Kesiya from Anhembi/Brazil. With Pinus caribaea var. hondurensis from the two origins that presented the thickest bark (1.93 cm and 1.95 cm), Pinus kesiya from Brazil and Pinus elliottii var. elliottii from Zimbabwe had the thinnest bark (0.74 cm and 1.13 cm)(TRADUÇÃO NOSSA)