Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Themeda Triandra Renosterveld in the Heidelberg District

Thesis (MSc)--University of Stellenbosch, 2005.

Saved in:
Bibliographic Details
Main Author: Raitt, Gwendolyn R.
Other Authors: Boucher, C.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2012
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613799080525824
access_status_str Open Access
author Raitt, Gwendolyn R.
author2 Boucher, C.
author_browse Boucher, C.
Raitt, Gwendolyn R.
author_facet Boucher, C.
Raitt, Gwendolyn R.
author_sort Raitt, Gwendolyn R.
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MSc)--University of Stellenbosch, 2005.
format Thesis
id oai:scholar.sun.ac.za:10019.1/20939
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:41:52.972Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2012
publishDateRange 2012
publishDateSort 2012
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/20939 Themeda Triandra Renosterveld in the Heidelberg District Raitt, Gwendolyn R. Boucher, C. Milton, S. J. Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. Kangaroo grass -- South Africa -- Heidelberg Grasslands -- South Africa -- Management -- Environmental aspects Grassland ecology -- South Africa -- Heidelberg Renosterveld Theses -- Botany Dissertations -- Botany Thesis (MSc)--University of Stellenbosch, 2005. ENGLISH ABSTRACT: This study investigated the composition of Themeda triandra Renosterveld in part of the Grootvadersbosch Conservancy and the effects of selected environmental and management variables to provide guidelines for promoting the presence of Themeda triandra in the veld. The Zürich-Montpellier phytosociological method was used to determine the composition of the Renosterveld communities. The point quadrat method was used to determine the cover of Themeda triandra at three grass dominated sites and compare cover from one site with past cover measurements at the specific site. Ordination was used to examine the effects of the environmental and management variables on the plant communities. Two community groups, five communities and five subcommunities were identified and described. The Themeda triandra – Stoebe phyllostachys Grassland Community Group consists of two communities of which one has two subcommunities. The Themeda triandra – Elytropappus rhinocerotis Shrubland Community Group consists of three communities of which one has three subcommunities. The vegetation units described in this study have not been described previously in the literature. One community belongs to Silcrete Fynbos while another subcommunity is transitional between Renosterveld and thicket and gallery forest. The rest of the plant communities fit the definition for Renosterveld (the local Renosterveld type is Eastern Rûens Shale Renosterveld). Cover of Themeda triandra did not differ significantly either between sites or between years. The comparison of Themeda triandra cover between years was done at a site that had been burnt between the last two sampling times yet the cover was not significantly different. This indicates that fire and other management practices did not have a negative impact on Themeda triandra at the site. Unconstrained ordination of the dataset in which cover/abundance values were included, grouped the relevés by moisture and disturbance but the presence/absence dataset indicates that the two community groups have a slight transitional overlap. Constrained ordination of both datasets with a) soil variables and b) management variables, both showed a tendency to separate the relevés into community groups, that did not happen with topographic and vegetation variables. Ordination did not separate the community groups into their subdivisions. The soil variables (both nutrients and texture) influence the vegetation structure and the community distribution. Under the existing grazing management regime, fire at three to five year intervals promoted the dominance of Themeda triandra by affecting the structure of the plant communities, the abundance of species other than Themeda triandra, and influencing which plant community is present. The use of fire as a management tool was regulated by the importance of the natural veld pastures to the farmers. The natural veld pastures are not suitable for dairy cattle in milk. Thus dairy farmers are less likely to burn the natural veld (no planned burns only chance fires) than those who farm with mutton or beef (planned burns on a three to five year interval). AFRIKAANSE OPSOMMING: Die studie het die samestelling van Themeda triandra Renosterveld in ’n deel van die Grootvadersbosch-Bewaria en die uitwerking van geselekteerde omgewings- en bestuursveranderlikes ondersoek om riglyne vir die bevordering van Themeda triandra in die veld daar te stel. Die Zürich-Montpellier fitososiologiese metode is gebruik om die samestelling van die Renosterveldgemeenskappe te bepaal. Die puntkwadraat-metode is gebruik om ’n skatting van die dekking van Themeda triandra by drie gras-gedomineerde persele te bepaal en om ’n vergelyking te maak tussen die huidige en vorige dekking van ’n enkele perseel. Ordinasie is gebruik om die invloed van omgewings- en bestuursveranderlikes op die plantgemeenskappe te bepaal. Twee gemeenskapsgroepe, vyf gemeenskappe en vyf subgemeenskappe is geïdentifiseer en gedefinieer. Die Themeda triandra – Stoebe phyllostachys Grasland-gemeenskapsgroep bestaan uit twee gemeenskappe waarvan een in twee subgemeenskappe onderverdeel is. Die Themeda triandra – Elytropappus rhinocerotis Struik-gemeenskapsgroep bestaan uit drie gemeenskappe waarvan een in drie subgemeenskappe onderverdeel is. Die plantegroei-eenhede wat in die studie beskryf is, is nie voorheen in die literatuur beskryf nie. Een gemeenskap behoort aan Silkreet-fynbos en ’n ander subgemeenskap is ’n oorgangsfase tussen Renosterveld en struikbosveld of woud, terwyl die res van die plantgemeenskappe binne die definisie van Renosterveld val (die plaaslike Renosterveld tipe staan bekend as Oostelike Rûens Skalierenosterveld). Die bedekking van Themeda triandra het nie betekenisvol gevarieer tussen óf die verskillende lokaliteite óf die verskillende jare nie. Die vergelyking van Themeda triandra-bedekking oor tyd is onderneem in ’n gebied wat tussen opnames gebrand is. Die bedekking het nie betekenisvol verskil nie. Dit dui aan dat vuur en ander bestuurspraktyke nie ’n negatiewe invloed op Themeda triandra in hierdie gebied het nie. Onbeperkte ordinasie van die datastel met die vergelyking van bedekking/volopheidwaardes, groepeer die relevés volgens vogtigheid en versteuring, terwyl die datastel ten opsigte van teenwoordigheid/ afwesigheid aandui dat die twee gemeenskapsgroepe ’n effense oorgangs-oorvleueling het. Beperkte ordinasie van beide datastelle met a) grondveranderlikes en b) bestuursveranderlikes, toon albei ’n neiging om die gemeenskapsgroepe te skei, wat nie gebeur het met die topografiese- en plantegroeiveranderlikes nie. Ordinasie het nie die gemeenskapsgroepe onderverdeel in gemeenskappe of subgemeenskappe nie. Die grondveranderlikes (beide voedingstowwe en tekstuur) beïnvloed die struktuur en die verspreiding van die plantegroei. Met die bestaande weidingsbestuur bevorder brande met ’n interval van tussen drie tot vyf jaar die oorheersing van Themeda triandra deur die struktuur van die teenwoordige plantgemeenskap te beïnvloed, deur die getal van die verskillende plantsoorte te beïnvloed en selfs deur die plantgemeenskap se voorkoms te beïnvloed. Die waarde wat die boer aan die natuurlike veld as weiveld heg bepaal die mate waartoe hulle veldbrand gebruik as ’n deel van bestuur. Die natuurlike veld is nie geskik vir melkkoeie wat in die melkproduksiestadium is nie. Die melkboere is dus minder geneig om die natuurlike veld te brand (geen beplande brande nie net kans brande) as die boere wat met vleisbeeste of skape boer (beplande brande elke drie tot vyf jaar). 2012-05-09T10:04:46Z 2012-05-09T10:04:46Z 2005-12 Thesis http://hdl.handle.net/10019.1/20939 en_ZA Stellenbosch University xxi, 246 leaves : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Kangaroo grass -- South Africa -- Heidelberg
Grasslands -- South Africa -- Management -- Environmental aspects
Grassland ecology -- South Africa -- Heidelberg
Renosterveld
Theses -- Botany
Dissertations -- Botany
Raitt, Gwendolyn R.
Themeda Triandra Renosterveld in the Heidelberg District
title Themeda Triandra Renosterveld in the Heidelberg District
title_full Themeda Triandra Renosterveld in the Heidelberg District
title_fullStr Themeda Triandra Renosterveld in the Heidelberg District
title_full_unstemmed Themeda Triandra Renosterveld in the Heidelberg District
title_short Themeda Triandra Renosterveld in the Heidelberg District
title_sort themeda triandra renosterveld in the heidelberg district
topic Kangaroo grass -- South Africa -- Heidelberg
Grasslands -- South Africa -- Management -- Environmental aspects
Grassland ecology -- South Africa -- Heidelberg
Renosterveld
Theses -- Botany
Dissertations -- Botany
url http://hdl.handle.net/10019.1/20939
work_keys_str_mv AT raittgwendolynr themedatriandrarenosterveldintheheidelbergdistrict