African
Journals Online
Southern African Forestry Journal
Issue 194, July 2002
ABSTRACTS
Early
performance of Casuarina junghuhniana provenances / land races
at Lushoto, Tanzania: scientific paper
Mwihomeke, S.T.; Mugasha, A.G.; Chamshama,
S.A.O.; Mgangamundo, M.A.; Kumburu, O.C.; Lupala, Z.
Abstract:
A trial involving 21 provenances form Indonesia and 7
"local" seed sources of Casuarina junghuhniana was
established at Lushoto, Tanzania in March 1997. At 22 and 48 months of
age, the following characteristics were assessed: survival, root
collar diameter (RCD), breast height diameter (DBH) and height. The
following were only assessed at 48 months of age: stem volume, biomass
production and foliar nitrogen (N) and phosphorus (P) nutrient
concentration and content. At all assessment occasions except for
height (22 months of age), N and P concentration and P content (48
months of age), significant provenance/land race variation was
observed for the rest of the characteristics studied. At 48 months of
age, the four best performing seed sources were: Mt. Bromo, East Java;
Mt. Pohen, Bali; KARI, Muguga, Kenya and Mt. Brumo, East Java while
the four worst performing ones were: Kapan, Kumpang, Timor; 25 km
S.W.Soe, Timor; Noelmina River, Timor and Buat, Soe, Timor. Although
these results are based on early performance of the seed sources, the
promising seed sources are recommended for pilot planting at Lushoto
and similar sites. Further evaluation is however, necessary to confirm
the best provenances/land races.
Evaluation
of 19 provenances of Calliandra calothyrsus at Gairo and SUA
Farm, Morogoro, Tanzania: scientific paper
Herbert, M.; Mugasha, A.G.; Chamshama, S.A.O.
Abstract:
Performance evaluation was conducted among nineteen provenances of Calliandra
calothyrsus from meso-America, Indonesia and Tanzania. Two trials
were established in February and March, 1996 at Gairo (8 provenances)
and Sokoine University of Agriculture (SUA) Farm (17 provenances) in
Morogoro, Tanzania. Assessment was carried out at 3, 6, 14, 27, and 41
months for survival, root collar diameter and height. Biomass
production was assessed during the last assessment occasion at SUA
Farm (27 months after planting) and for Gairo at 27 and 41 months
after planting respectively. At 27 months, when final assessment was
done at SUA Farm, survival ranged from 33.3% (Lushoto Arboretum and
Babati provenances) to 91.7% (Gracie Rock provenance). Above ground
biomass production ranged from 4.81 to 17.26 t/ha for provenances
Lushoto Arboretum and San Ramon respectively. When final assessment
was done at Gairo site 41 months after planting, survival ranged from
50% for Apic Apac provenance to 75.0% for Fortuna and Cofradia
provenances. Above ground biomass production ranged from 12.60 to
22.35 t/ ha for Apic Apac and Fortuna provenances respectively.
Analysis of leaf samples showed low variation in N and P leaf contents
for the provenances studied (ranges 1.35-2.50 N% and 0.09-0.18 P%).
Based on the findings from this study, provenances Union Juarez, San
Ramon, Bandug, Bombana and Flores are recommended for the SUA farm
site and Fortuna, Cofradia, Bandung and San Miguel for the Gairo site.
Knowledge
on Sclerocarya birrea subsp. caffra with emphasis on its
importance as a non-timber forest product in South and southern
Africa: a summary: Part 1: Taxonomy, ecology and role in rural
livelihoods: review paper
Shackleton, Sheona E.; Shackleton, Charlie M.;
Cunningham, Tony; Lombard, Cyril; Sullivan, Caroline A.; Netshiluvhi,
Thiambi R.
Abstract:
Sclerocarya birrea (marula) is a widespread species throughout
the semi-arid, deciduous savannas of much of sub-Saharan Africa. It is
widely used by rural populations in most countries in which it is
found. It has multiple uses, including the fruits, kernels, oil, bark,
wood and leaves. Because of these multiple uses, and its significance
in the landscape, several African cultures have specific beliefs and
ceremonies associated with this species, and it is often maintained in
homestead and arable plots. Because of the widespread occurrence,
potentially high fruit production and use of S. birrea it has
frequently been identified as a key species to support the development
of rural enterprises based on the fruit, beer, oil or nuts and
therefore as a species for potential domestication. Localised breeding
and cultivation initiatives commenced in the 1970s and some continue.
Interest in this species was renewed after the development of a highly
successful liqueur using extracts from the fruit. This has developed
further in southern Africa over the last 3 to 5 years, especially
commercialisation initiatives orientated towards befitting the rural
poor. Recently, the UK Department for International Development (DFID)
initiated a project to examine the impacts of commercialisation of
non-timber forest products, such as marula, on the livelihood capital
of the rural poor. As a first phase, the research team compiled a
comprehensive literature review of S. birrea , with emphasis on
possible commercialisation. This is to be published in two parts. The
first part deals with the taxonomy, ecology and its subsistence use
and cultural value to rural households. The second part of the review
will focus on issues relating to specific properties of the marula,
management, intellectual property and its potential commercialisation.
Abnormal
compression wood in Pinus taeda: a review of current knowledge
and proposed future strategy: review paper
Malan, F.S.; Kassier, H.W.
Abstract:
Abnormal compression wood in P. taeda stands was first
discovered in the early 1980s. Since then several research projects
and surveys have been carried out in order to develop a better
understanding of the problem and to try to find a solution. Currently
a large proportion of the sawmill intake of logs in the Mpumalanga and
Northern Province forest regions consists of this species, of which a
reasonable proportion is affected by abnormal compression wood to
varying degrees. This paper summarises the existing knowledge on the
problem and current ways of dealing with it. Conclusions are that,
since on average about 95% of the trees are either free from abnormal
compression wood or manifest only a very slight presence of the
phenomenon, the impact of the problem may not be as severe as
generally thought, provided that a number of precautions are adhered
to. Procedures such as leaving the worst affected logs in the
plantations or labelling such logs as unsuitable for the production of
veneer or boards for value-adding applications, may help considerably
in reducing the impact of the problem. Graders at sawmills should be
trained to assess the severity of abnormal compression wood present in
sawn boards by inspecting the cross-cut ends of the boards where the
phenomenon is usually best observed. Such boards should be labelled as
not suitable for value-adding purposes or for further processing,
except for cross-cutting them into particular lengths, should that be
required. P. taeda has proved to be one of the best pine
species with respect to growth and wood quality and should not be
rejected outright. Further research on the phenomenon in order to
extend the existing knowledge on the effects of genetics and
silviculture is, therefore, strongly recommended. Tree breeding, in
particular, appears to be the most promising approach to return this
species to its former prominent position.
Establishment
of embryogenic suspension cultures of Pinus radiata Don.:
research note
Jacoby, A.; Van der Westhuizen, A.J.; Botha,
A-M.
Abstract:
The development of embryonal suspensor mass (ESM) from immature
embryos of Pinus radiata on a solidified growth medium
containing 0, 5 mgl -1 benzyladenine, 3, 0 mgl -1
2, 4-dichlorophenoxyacetic acid, 500 mgl -1 casein
hydrolysate and 250 mgl -1 L-glutamine was used as inoculum
to establish cell suspension cultures. Regular transplants of the ESM
established on the solidified medium onto a hormone-free medium
ensured sustainable growth and hence a source of ESM. Conditions for
optimal growth in liquid media were investigated. The cell suspension
turbidity was measured and used as a growth parameter. Optimal growth
and normal embryo development were obtained in a liquid medium
containing maltose as the carbohydrate source at a concentration of 3%
(m/v) and supplemented with 0, 5 mgl -1 2, 4-
dichlorophenoxyacetic acid. The results obtained from this study
present an opportunity for large-scale propagation of Pinus radiata
.
Post fire indicators of
fire intensity at indigenous forest margins in the southern Cape,
South Africa: research note
Schmidt, A.G.; Vlok, M.
Abstract:
The aim of this study was to identify post fire indicators of fire
intensity at indigenous forest margins in the southern Cape. Three
sites in the southern Cape were subjectively chosen in recently burnt
areas to represent areas of varying fire intensity. Tree mortality
outside the forest edge confirmed our subjective classification of the
three sample sites into high, medium and low fire intensity sites.
Fire intensity was correlated to Virgilia divaricata seedling
density, species richness, the width of the Virgilia divaricata
strip and the width of the burnt forest margin. These easy to measure
parameters could in future be used as practical field indicators of
post fire intensity. Fire intensity could then be correlated to
changes in forest species composition and structure to further
quantify the impacts of fires on the indigenous forest margin.
The estimation of the
growing stock of eucalypt plantation forests, based on spectral
signatures of satellite imagery, in South Africa: research note
Kätsch, Christoph; Van Laar, Anthonie
Abstract:
The present study deals with the application of spectral signatures,
obtained from multispectral satellite images, in order to obtain
regression estimates for the timber volume per unit area. The studies
were carried out in South African Eucalyptus plantations. The
greyscale values, recovered from sampling points based on 3 x 3
pixels, were satisfactorily closely correlated with the target
variable. Cost-efficiency calculations indicated that two-and
multiphase sampling with the aid of satellite images are an attractive
alternative for traditional terrestric measurements. Further research
is required.
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