MSc

An experiment was carried out during 1998-99 with the objective of
evaluating the anatomical and physiological variations among provenances and
species of Acacia and to correlate this with their growth characteristics. The
experimental materials consisted of 11 provenances which included five provenances
of Acacia mangium Willd., and two each of A. auriculiformis Cunn. ex., Benth., A.
crassicarpa Cunn ex., Benth and A. aulacocarpa Cunn. ex., Benth. They were planted
in a randomized block design in the farms of the College of Forestry, Vellanikkara in
1996. The ultimate objective of the study was to identify the most suitable
species/provenances from among these for the ecoclirnatic conditions ofKerala.
At four years of growth, provenances Balimo Aramia and Wipim to
Oriomo from Papua New Guinea and Research Seed Orchard from Queensland were
significantly superior to the rest. Among the four species, except A. aulacocarpa, the
other three species namely, A. mangium, A. auriculiformis and A. crassicarpa showed
superiority over height and collar girth. The most important component of total
biomass undoubtedly, was the bole volume. So in this regard, the superiority of the
species on height and collar girth indicates good volume production in future. A.
auriculiformis exhibited superiority over branch production throughout the study,
indicating its suitability for fire wood production.
As far as leaf area is concerned the species exhibited significant
.
variation while, provenances did not. A. mangium and A. aulacocarpa showed
maximum leaf area index, compared to A. auriculiformis and A. crassicarpa.









Irrespective or the species, all the provenances showed- higher stomatal
frequency on the lower leaf surface. Almost in all the provenances, transpiration late
was increased from predawn to afternoon hours. Significant differences in the
transpiration rate among the provenances and species was noticed between the
predawn and afternoon hours only during the month of April. Transpiration rate and
leaf water potential was negatively related in almost all the provenances. Provenances
and species exhibited no significant difference with respect to leaf temperature.
However, leaf temperature increased from predawn to afternoon in almost all the
provenances.
The provenance Balimo Aramia River of A. mangium as well as one each
of A. auriculiformis and A. crassicarpa, namely, Orchard Melville and Bensbach WP
registered the maximum heartwood percentage. The moisture content exhibited
significant differences between the provenances. The specific gravity was maximum
. for the provenance 7 KMSSE Mossman of A. auriculiformis while the minimum was
shown by the provenance Kapal Oriomo of A. crassicarpa. Generally, provenances of
A. mangium recorded higher specific gravity.
The length of fiber was maximum for provenances orchard Melville - 1,
NT and Kings Plain Lake, Queensland of A. auriculiformis while, minimum registered
by the provenances of A. mangium. The maximum length and width for vessel, ray and.
axial parenchyma was recorded by the provenances of A. mangium.