The influence of acacias on below canopy grass communities

 

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dc.contributor.advisor Midgley, Jeremy J en_ZA
dc.contributor.author Roberts, Anthony en_ZA
dc.date.accessioned 2017-12-08T07:35:51Z
dc.date.available 2017-12-08T07:35:51Z
dc.date.issued 2000 en_ZA
dc.identifier.citation Roberts, A. 2000. The influence of acacias on below canopy grass communities. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/26501
dc.description.abstract The influence of acacia species through their varying life stages (seedlings, juveniles, adults and dead trees) on sub-canopy grass communities was investigated at various sites in the Hluhluwe-Umfolozi Park (HUP). There were significant differences between classes (at p < 0.05} to each other and to the open sites, but to differing extents at the different rainfall regions within the HUP. Significant differences occurred between young acacias and the open sites more frequently at the drier sites than at the wetter sites. Young acacias do not influence below canopy grass communities in the high rainfall regions. ln the low rainfall sites, the young acacias act as refugia for 'bunch' grass species in the sea of 'lawn'. A switch back to lawns occur below the adult acacias dominated by the 'lawn' grass Dactyloctenium australe which occurs at differing proportions to the 'bunch' grass Panicum maximum below the canopy depending on the extent of animal disturbance, measured as density of droppings. Rainfall was responsible for separating communities out between the various sites in HUP. However, the impact of animals on the grass communities within each of the sites had more influence on the resulting grass communities in each of the classes. The response of a variety of grass species to light levels failed to explain the presence of particular species below adult acacias and others away from the influence of these acacias. Succession is occurring between grass communities as a result of establishment of acacias with the process being more evident in the dry areas of the HUP. The grass communities in the high rainfall areas revert back to early successional communities more rapidly once a tree dies than they do in the low rainfall areas. The influence of the adult acacias on the below canopy soils is greater and affects grass communities for a longer period of time in thc low rainfall areas than it is in the high rainfall areas even after the tree has died. en_ZA
dc.language.iso eng en_ZA
dc.subject.other Botany en_ZA
dc.title The influence of acacias on below canopy grass communities en_ZA
dc.type Bachelor Thesis
dc.date.updated 2017-02-06T13:52:48Z
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Biological Sciences en_ZA
dc.type.qualificationlevel Honours
dc.type.qualificationname BSc (Hons) en_ZA
uct.type.filetype
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Roberts, A. (2000). <i>The influence of acacias on below canopy grass communities</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/26501 en_ZA
dc.identifier.chicagocitation Roberts, Anthony. <i>"The influence of acacias on below canopy grass communities."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2000. http://hdl.handle.net/11427/26501 en_ZA
dc.identifier.vancouvercitation Roberts A. The influence of acacias on below canopy grass communities. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2000 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/26501 en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Roberts, Anthony AB - The influence of acacia species through their varying life stages (seedlings, juveniles, adults and dead trees) on sub-canopy grass communities was investigated at various sites in the Hluhluwe-Umfolozi Park (HUP). There were significant differences between classes (at p &lt; 0.05} to each other and to the open sites, but to differing extents at the different rainfall regions within the HUP. Significant differences occurred between young acacias and the open sites more frequently at the drier sites than at the wetter sites. Young acacias do not influence below canopy grass communities in the high rainfall regions. ln the low rainfall sites, the young acacias act as refugia for 'bunch' grass species in the sea of 'lawn'. A switch back to lawns occur below the adult acacias dominated by the 'lawn' grass Dactyloctenium australe which occurs at differing proportions to the 'bunch' grass Panicum maximum below the canopy depending on the extent of animal disturbance, measured as density of droppings. Rainfall was responsible for separating communities out between the various sites in HUP. However, the impact of animals on the grass communities within each of the sites had more influence on the resulting grass communities in each of the classes. The response of a variety of grass species to light levels failed to explain the presence of particular species below adult acacias and others away from the influence of these acacias. Succession is occurring between grass communities as a result of establishment of acacias with the process being more evident in the dry areas of the HUP. The grass communities in the high rainfall areas revert back to early successional communities more rapidly once a tree dies than they do in the low rainfall areas. The influence of the adult acacias on the below canopy soils is greater and affects grass communities for a longer period of time in thc low rainfall areas than it is in the high rainfall areas even after the tree has died. DA - 2000 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2000 T1 - The influence of acacias on below canopy grass communities TI - The influence of acacias on below canopy grass communities UR - http://hdl.handle.net/11427/26501 ER - en_ZA


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