The Ngorongoro Crater is a volcanic caldera located within the Ngorongoro
Conservation Area in Tanzania. The Crater comprises a flat grassland plain
surrounded by steep, bushy walls. It contains extremely high densities of
animals and is ecologically the central feature of Ngorongoro Conservation
Area. The management of the Ngorongoro Crater has changed significantly in
recent times, with cattle being removed and fire excluded about 30 years ago.
A detailed vegetation assessment was carried out in the Crater floor by
Herlocker & Dirschl in 1972. Since then noticeable changes in vegetation
structure and composition, with associated changes in wild herbivore numbers
have occurred. The original vegetation survey was repeated in this study as
accurately as possible using similar point-based techniques in order to
quartify changes and form a baseline for management decision-making and
future monitoring. In addition to repeating the vegetation survey, the standing
biomass was estimated using a Pasture Disc Meter with associated calibration
equations. Data were summarised using multivariate classification and
ordination techniques in order to delineate six Homogenous Vegetation Units
(HVUs) which can be used for management and management planning
purposes, define transects and HVUs in terms of dominant species, describe
the main species in relation to their occurrence in different associations and
determine the fuel load of the standing crop. A key grass species technique
was developed for rapid assessment of the Crater rangeland by the
Ngorongoro Conservation Area staff who only need to be familiar with the
dominant species. Bush surveys using a point centred quarter technique were
conducted along transects in two distinct vegetation types, namely the Lerai
Forest and Ngoitokitok Acacia xanthophloea forests and the lower caldera
scrub vegetation. The data collected from these transacts were analysed to
determine density and composition of the vegetation in the various height
classes and the overall structure of the vegetation communities, A range
monitoring system in conjunction with a controlled burning programme has
been developed to provide an objective means of managing the- rangeland of
the Ngorongoro Crater. Data revealed that changes have taken place in the vegetation, with a trend towards dominance by taller grasses and dominance
by fewer species. Lack of fire has probably contributed to these changes.
Reincorporating fire in the crater is recommended. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/5520 |
| Date | January 2006 |
| Creators | Amiyo, Amiyo T. |
| Contributors | Kirkman, Kevin Peter. |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
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