Die plantekologie van die Waterberg Platopark

Loading...
Thumbnail Image
Date
1983-03
Authors
Jankowitz, Willem Jacobus
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
English: The object of this study is to provide a foundation for management based on sound scientific procedures. To classify the vegetation into different homogenous plant communities, the wellknown Braun-Blanquet-technique was used. A monitorsystem was applied to determine baseline data to evaluate future changes in the plant composition. The basal cover and relative frequency of the grasses were determined by using an altered wheelpoint method. The production of the standing crop was obtained by using the tuft-clipping method and quadrat clipping method. The production of the available browsing of the trees and shrubs was also calculated. The key fodder plants of the most numerous animal, the eland, was obtained through a feed preference study. The standing crop of these key plants was used to provide a system which could be utilized to classify the plant communities according to the feeding preferences of animals. The vegetation of the Waterberg~plateau Park can be described as a homogenous deciduous tree savanna where the shrub layer has become closed thicket Acacia atxacantha,. The vegetation of the Waterberg-plateau Park was classified into six major communities which were divided into a further 23 smaller units. The absence of well defined ecotones was apparent especially between the TerminaZia sericea-plant communities. These deep sand communities cover the greatest (29 000 ha) part of the game park, followed by the PeZtophorum africanum-rock communities which cover more or less 10 000 ha. According to the results obtained from the monitoring project, certain palatable grass species, for example Anthephora pubescens and Digitaria polevansii did benefit by the veld fires while SporoboZus fimbriatus was adversely affected. Similar observations which are important for management were made 1n the tree and shrub layers where the unpalatable Ochna pulchra proved to be sensitive to fire. This species is also partly responsible for the scrub encroachment. For the rest very few changes were observed in the plant composition. According to results determined by other workers and the quadrat-clipping method, the standing crop values obtained by the tuft-clipping method was too high. The highest standing crop (946 kg ha-1) is furnished by the Anthephora pubescens - Eragrostis superba-plant community. According to the carrying capacity determinations the Terminalia sericea - Melhania acuminata-plant community can sustain the highest number of animals, while the gamepark as a whole can carry more or less 2000 grazers. The results acquired from food preference study has indicated that although the eland is a selective feeder, it utilizes a wide range (42 species) of plant species. It was observed that during winter the eland ate herbs and a great amount of dry leaves off the ground. Terminalia sericea and Lonchocarpus nelsii proved to be very high on the preference list of these animals. With the help of the standing crop of the key fodder plant species of the eland, it was determined that the woody Terminalia sericea - Melhania acuminata-plant community is the best eland habitat in the game park. The available knowledge, obtained from this project, was used to provide the park with the necessary recommendations to place the future management on a sound scientific basis.
Afrikaans: Die plantekologie van die Waterberg-p1atopark is bestudeer met; die doel om die toekomstige bestuur van die wildtuin op n grondige wetenskaplike basis te plaas. Die plantegroei is floristies met behulp van die Braun-Blanquet-tegniek geklassifiseer. Met Walker se moniteringstelsel is grondlyndata daargestel om veranderinge in die plantegroeisamestelling in die toekoms vas te stel. 'n Gewysigde wielpuntmetode is gebuik om die basale bedekking en relatiewe frekwensie van die grassoorte te bepaal. Die weibare opbrengs van die grassoorte is bereken met behulp van die polkniptegniek en die kwadraatkniptegniek. Die weibare opbrengs van die boom- en struiksoorte is ook bereken. Slegs die weiplante van die talrykste diersoort, die eland, is bepaal deur n voedselvoorkeurstudie. Die voedselvoorkeure van die eland en die effektiewe weibare opbrengs van daardie spesies is gebruik vir die daarstelling van n sisteem waarvolgens plantgemeenskappe op grond van voedselvoorkeure van die diere geklassifiseer kan word. Die plantegroei van die Waterberg-p1atopark kan beskryf word as 'n homogene bladwisselende droëwoud waarvan die struikstratum opvallend verdig is deur veral Aoaoia ataxacantha. Die wildtuin is in ses hoofp1antgemeenskappe wat verder in 23 kleiner eenhede onderverdeel is, geklassifiseer. Die afwesigheid van duidelike ekotone is veral kenmerkend by die Terminalia sericea-p1antgemeenskappe. Hierdie diepsandgrondplantgemeenskappe het die grootste omvang (ongeveer 29 000 ha) en word gevolg deur die Peltophorum afrioanum-rotsgemeenskappe (ongeveer 10 000 ha). Die resultate van die moniteringsprojek dui daarop dat sekere smaaklike grassoorte soos Anthephora pubescens en Digitaria polevansii deur veldbrand bevoordeel is, terwyl die onsmaaklike Sporobolus fimbriatus benadeel is. Soortgelyke tendense, wat vir die bestuur van die wildtuin van belang is, is by die boom- en struiksoorte waargeneem. Dit is veral die onsmaaklike Ochna puZohra, wat ook medeverantwoordelik vir die verdigting van die struikstratum is, wat deur die vuur beskadig is. Andersins is baie min veranderinge in die plantegroeisamestelling oor die twee jaar moniteringsperiode bespeur. Die bepaling van die weibare opbrengs het getoon dat die polkniptegniek te hoë waardes gee. Die resultate wat met die kwadraatkniptegniek verkry is, het goed vergelyk met waardes wat elders in soortgelyke habitats bepaal is. Die Anthephora pubescens - Eragrostis superba-grassavanne lewer die hoogste weibare opbrengs (946 kg ha-1) in die wildtuin. Volgens die drakragbepalings: kan die Terminalia sericea - Melhania acuminata-boomstruiksavanne die meeste diere onderhou, terwyl die wildtuin in geheelongeveer 2000 grasvreters kan dra. Die voedselvoorkeurstudie van die eland het aangetoon dat hoewel hierdie diersoort 'n selektiewe vreter is, dit tog 'n wye reeks plantsoorte benut (42 soorte). Dit was opvallend dat die eland tydens die wintermaande op die voorkeurlys is, is Terminalia sericea en Lonchocarpus nelsii. Volgens die weibare opbrengs van hierdie sleutelweiplante van die eland is die bosryke Terminalia sericea - Melhania acuminata-boomstruiksavanne as die beste elandhabitat in die Waterberg-p1atopark geklassifiseer. Ten slotte is daar met die beskikbare inligting bestuursaanbeve1ings gedoen om die toekomstige bestuur van die wildtuin op 'n wetenskaplike basis te plaas.
Description
Keywords
Thesis (Ph.D. (Plant Sciences))--University of the Orange Free State, 1983, Ecology -- Namibia, Plant ecology -- Namibia
Citation