Cyrtanthus nutans (RA Dyer) is a KwaZulu-Natal Province near-endemic species,
classified as vulnerable in South Africa (IUCN Red Data categories). Literature
references suggest that no recent ecological research has been conducted on
Cyrtanthus nutans. Last assessed in 2007, the current study determined the
demographics and the abiotic and biotic factors that influenced the distribution and
range of Cyrtanthus nutans.
Key determinants influencing the autecology, distribution and population dynamics of
Cyrtanthus nutans were investigated. Anthropological factors influencing the decline
of populations were addressed. Two investigations were undertaken for the current
study on Cyrtanthus nutans in Dundee in North-western KwaZulu-Natal, South Africa
namely a survey to determine the population dynamics and autecology of the species
and the effect key determinants have on the recruitment and survival. Sites of
occurrence and the ecological and anthropological factors that influence the existence
of plants were documented. Experimental plots were conducted to determine the
influence of climatological factors, fire and defoliation on the emergence and survival
of Cyrtanthus nutans plants.
A preference was found for soils with high nitrogen and organic carbon, low
phosphorus and acidity levels situated on slopes of < 10% on mid to lower terrain
slopes within an altitude range of between 1 100 and 1 300 m (a.m.s.l.) in the Sour
Sandveld and Moist Tall Grassveld Bioresource Groups.
The influence that climatological factors, fire and defoliation had on the emergence
and seed recruitment of Cyrtanthus nutans were determined through a small plot
experiment in the Dundee area. Mean relative humidity (%) and mean rainfall two
weeks before emergence in conjunction with treatments were highly significant
(P<0.001). Burning treatments B (fire inclusion and defoliation inclusion) and BC (fire
inclusion and defoliation exclusion) were more highly significant on the emergence of
Cyrtanthus nutans plants than any other treatments.
ii | P a g e
Increasing fragmentation of thriving populations of Cyrtanthus nutans populations is
occurring through landuse change, mismanagement of veld and non-compliance of
legislation. Continued monitoring and awareness is essential in the survival of this
species. / Environmental Sciences / M. Sc. (Environmental Sciences)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:unisa/oai:uir.unisa.ac.za:10500/24856 |
| Date | 05 1900 |
| Creators | Ruddle, Lynne Michelle |
| Contributors | Van Zyl, Erika |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | 1 online resource (xiii, 143 leaves) : illustrations, color maps |
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