VARIATIONS IN HEARTWOOD PROPORTION AND BASIC DENSITY BETWEEN PROVENANCES OF <em>EUCALYPTUS</em> <em>GRANDIS</em> IN KENYA

Abstract

Eucalyptus grandis is one of the exotic tree species that have received wide attention in Kenya because of its fast growth and multiple uses. In 1980, a provenance trial was established in Elburgon, Kenya to assess its growth performance. The wood quality variation between these provenances is not known. Trees from each of the 18 provenances were selected at 16 years of age to investigate variations in heartwood proportion and basic density. The study indicated large variations between provenances for the two properties assessed. The average heartwood proportion ranged from 29.5 to 61.5%. Heartwood proportion decreased with height with maximum at 1.3 m and minimum at 12.0 m. The average basic density ranged from 490.4 to 592.7 kg m^-3. Basic density decreased between 1.3 and 4.0 m height and thereafter increased slightly for most provenances except for south of Tyalgum, northern New South Wales and south of Murwillumbah whose density increased with sampling height.