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Evaluation of tree performance, site conditions and silvicultural procedures in forest plantations at high altitude sites in Lesotho.Pama, Mokete M. January 2005 (has links)
The permanent sample plots (PSP) and silvicultural trial plots established by the Forestry
Research Section of the Forestry Department of the Ministry of Forestry and Land
Reclamation in Lesotho were used as a source of information for this study. The study
area is located in the forest plantations on high altitude sites in Lesotho which have the
aim to determine important aspects of timber production for commercial use and to
address the problem of fuel wood scarcity and energy crisis. The major objective of the
study was to describe performance (survival, growth and timber volume) of exotic tree
species introduced in Lesotho.
The height and diameter relationships for trees in the 33 plots of Eucalyptus rubida and
44 plots of Pinus radiata were determined by a simple linear regression. There are four
plots of Eucalyptus macarthurii, three plots of Pinus halepensis, one plot of Eucalyptus
nitens and one plot of Pinus pinaster. The permanent sample plots data were analysed
with the use of a statistical package Genstat (7th edition). Categorical analysis were used
to detect the number of live and dead trees. The correlation analysis was used to study
association between site and performance variables, while multiple regression analysis
was utilised to analyse relationships between site index and site variables. The growth
curves developed for E. rubida and P. radiata tended to indicate a sigmoidal shape.
Analysis of variance was utilised to analyse the performance of species in terms of
survival and growth (HT and DBH) for the four species and provenance trials.
The early mortality rate was 2% for E. macarthurii, 14% for E. rubida, 0% for E. nitens.
Later, it was found that the percentage of dead trees is as follows: 7% for E. macarthurii,
15% for E. rubida, 29% for E. nitens. It was detected that the mortality rate for eucalypts
was 14% at last assessments. Similarly, it was detected that the final mortality rate for P.
halepensis, P. pinaster and P. radiata was 2%, 19% and 20% respectively.
The mean diameter for P. radiata ranged between 1,87 cm at age 3,75 years and 24,49
cm at age 18 years. The mean height ranged from 1,51 m at age 0,75 yrs and 13,51 m at
16 years. It was discovered that the mean diameter is found between 8,0 cm at age
4,83 yrs and 14,41 cm at age 8,83 yrs for P. halepensis. The mean height was 2,1 m at
age 4,83 years and 16,48 m at age 13,50 years. The mean diameter ranged from 7,41 cm
at age 6,42 years and 15,92 cm at age 10,42 years for P. pinaster. Similarly, the mean
height was detected to be between 5 m at age 6,42 years and 7,75 m at age 12,42 years
for P. pinaster. It was noted that the mean diameter for E. rubida ranged from 2,04 cm at
age 2,25 years to15,87 cm at age 11,75 years. On the same line the mean height started at
4,55 m at age 2,42 years and ended at 16,15 m at age 11,75 years. The mean diameter for
E. macarthurii was noted to be 13,64 cm at age 10 years. It was noticed that mean height
is found between 3,8 m at age 2,17 years and 16,03 m at age 10 years. It was also
detected that the mean diameter started from 4,45 cm at age 2,50 years and 10,78 cm at
age 6,50 years for E. nitens. The mean diameter ranged from 5,98 cm at age 2,50 years
and from 12,05 m at age 6,50 years for E. nitens.
The mean annual increment (MAI) for P. radiata is found between 0,15 m3/ha/yr at age
2,25 years and 21,91 m3/ha/yr at age 6,50 years. The MAI ranged from 0,58 m3/ha/yr at
age 3,42 years and 10,81 m3/ha/yr at age 10,42 years for E. rubida. It was determined that
the MAI started from 0,25 m3/ha/yr at age 2,17 years to 9,99 m3/ha/yr at age 4,17 years
for E. macarthurii. The MAI started from 1,59 m3/ha/yr at age 2,50 years and to 7,54
m3/ha/yr at age 6,50 years for E. nitens. It was noted that the MAI for P. halepensis began
from 0,01 m3/ha/yr at age 4,83 years and 3,52 m3/ha/yr at age 13,50 years. Similarly, the
MAI began from 0,73 m3/ha/yr at age 6,42 years and 2,70 m3/ha/yr at age 10,42 years for
P. pinaster.
The Site indices for E. rubida and P. radiata were calculated. They ranged from 6,72 to
14,40 m and from 12,05 to 18,43 m for E. rubida and P. radiata at age 6 years and 15
years respectively.
The MAI and SI of different species justify that a viable commercial forestry can be
implemented in Lesotho, if advanced selection of genetic material, improved silviculture
and appropriate site species matching can be followed. It was noticed that various
silvicultural practices like proper land preparation methods, weed management and deep
planting have a large impact on tree performance. Based on these results, larger
afforestation projects for commercial timber production and bioenergy are recommended. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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Comparative evaluation of Celtis africana in Lesotho with that in KwaZulu-Natal, South Africa.Ts'ehlana, Moses Ts'eliso. January 2005 (has links)
Research was conducted in three study sites in Lesotho, and the fourth, which was used
on comparative basis, was in KwaZulu-Natal, South Africa.
The study was suitable for Lesotho as it is a small country with very limited natural
resources. Lesotho's weak economy, exacerbated by the increasing population, needs
concerted efforts to redress its socio-economic problems. This study is one of such efforts
to explore the potentials of the indigenous forests with the aim of addressing wood
demands. Celtis africana is one of the species with a proven record in Lesotho to have
been a well adapted, resourceful timber tree in the past. Over-exploitation has
degenerated it to its brink of extinction. It is against this background that this research
was conducted with the aim of restoring Celtis africana to its original status in Lesotho.
The results revealed that due to climatic conditions, seeds from Kwazulu-Natal are
heavier than those from localities in Lesotho. However, wood densities from study sites
in Lesotho are higher than those of KwaZulu-Natal. Pre-treatment method of manual
scarification showed the best outcomes in terms of germination percent and vigour while
the control was the last. The diverse nature of Celtis africana allows it to survive and
prosper in a wide and varying range of habitats. Its pliable and adaptive characters are
manifested by its ability to adapt in novel environments. Under ideal warm and moist
conditions Celtis africana keeps its foliage all the year round, but in dry or abnormally
cold years it becomes a deciduous tree. Though it is distributed in a variety of habitats,
Celtis africana prefers moist habitats. It also demonstrates greater "affinities" for the
carbonates in the soils, in particular, calcium carbonate (CaC03) and dolomite
(CaMgC03).
More research and determined reforestation programmes are required in order to improve
the status of Celtis africana in Lesotho. Its natural existence in Lesotho can curtail
expense of provenance identification. Both extension strategies and silvicultural
operations, which can assist in tree improvement, should be adopted. Social benefits
which, are rendered by Celtis africana in South Africa, can be emulated and adopted in
Lesotho. Other than being an admired and valuable recreational tree (planted in parks and
in the homesteads), it is a protected tree in South Africa. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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