Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Understanding the distribution, abundance and diversity of species and the mechanisms
causing these patterns has been the interest of ecologists and taxonomists for decades. The
exceptionally high plant diversity in the Fynbos biome has been well studied. Whilst early
arguments suggested that the high plant diversity is not reflected in the arthropod diversity
and that insect species richness is low compared to other comparable areas, these
observations might have been hampered by the taxonomic impediment. Despite global
recognition of the significance of this below-ground component of diversity for ecosystem
functioning, soil is one of the most poorly studied habitats of terrestrial ecosystems.
Although knowledge is increasing for epigaeic groups, other significant groups such as the
Collembola remain especially poorly understood. This thesis starts addressing this serious
gap in knowledge concerning the below-ground component of biodiversity in the Fynbos
biome and the effects of landscape transformation thereon. As part of the work,
considerable attention was given to resolving the taxonomic impediment for the springtail
fauna of the Fynbos biome using modern morphological and DNA barcoding methods, while
also examining the correlates of soil animal diversity in the biome, by using Collembola
(springtails) as exemplars. First, using a combination of published records of Collembola
from South Africa, various sampling methods and DNA barcoding, a species list is compiled
for the Western Cape. Currently 213 species are known to exist from the Western Cape. A
high level of cryptic diversity was also found in several genera, together with several
potential species radiations in the Ectonura, Seira, Parisotoma and Cryptopygus. A start is a
made at addressing the lack of taxonomic knowledge by describing five new species. Two
Ectonura Cassagnau 1980 species are described from Betty’s Bay and Grootvadersbosch
respectively and a key to the Neanurinae of South Africa is provided. The first record of the
genus Triacanthella Schäffer, 1897 is described from a cave in Table Mountain, while two
new species of Delamarephorura are described and the genera Spicatella Thibaud 2002 and
Delamarephorura Weiner & Najt 1999 are synonymized. Although fire is thought to be the
main form of decomposition in the Fynbos biome, recent work has shown that biological
decomposition may be more important than previously thought. I examine the resilience of
Collembola after a large-scale fire in Jonkershoek Nature Reserve using quantitative
sampling which is temporally replicated. The resilience of invertebrate fauna in the fynbos is
not well understood, thus I investigate the diversity of Collembola before and after a major
fire. Results show Collembola species richness and abundance recovered surprisingly quickly after the fire. On a larger scale, litterbags were deployed at six sites across the Western Cape
using different litter types. Here, a total of 113 morphospecies species was found. Local
richness was found to be highest in Kogelberg (32 species), while the turnover between sites
was also high. Thus, the degradation of local habitat patches will be as much of a threat to
Collembola as to the endemic plants in this region. / AFRIKAANSE OPSOMMING: Begrip van die verspreiding, spesierykheid en verskeidenheid van spesies en die meganismes
wat hierdie patrone veroorsaak is al die belangstelling van ekoloë en taksonome vir dekades.
Die buitengewoon hoë plant diversiteit in die Fynbos-bioom is goed bestudeer. Terwyl vroeë
argumente voorstel dat die hoë plantdiversiteit nie weerspieël word in die geleedpotige
diversiteit nie en dat insekspesierykheid laag is in vergelyking met ander gebiede, kon
hierdie waarnemings nie gemaak word nie as gevolg van taksonomiese hindernisse. Ten
spyte van die wêreldwye erkenning van die belangrikheid van hierdie ondergrondse
komponent van diversiteit vir die funksionering van die ekosisteem, is die grond een van die
swakste bestudeerde habitatte van terrestriële ekosisteme. Alhoewel kennis vermeerder vir
bogrondse groepe, word ander belangrike groepe soos die Collembola swak verstaan.
Hierdie tesis begin hierdie ernstige leemte in kennis aanspreek, met betrekking tot die
ondergrondse komponent van biodiversiteit in die Fynbos bioom en die gevolge van die
landskap transformasie daarop. As deel van die werk, is heelwat aandag gegee aan die
oplossing van die taksonomiese hindernis vir die springstert fauna van die fynbos bioom met
behulp van moderne morfologiese en DNA metodes, terwyl dit ook die ooreenkomste van
grond diere diversiteit ondersoek in die bioom, deur gebruik te maak van Collembola
(springsterte) as voorbeelde. Eerste, met behulp van 'n kombinasie van gepubliseerde
rekords van Collembola van Suid-Afrika, verskillende kolleksie metodes en DNA metodes is 'n
spesielys saamgestel vir die Wes-Kaap. Tans is 213 spesies bekend vir die Wes-Kaap. 'n Hoë
vlak van kriptiese diversiteit is ook gevind in verskeie genera, saam met verskeie potensiële
spesies radiasies in die Ectonura, Seira, Parisotoma en Cryptopygus. 'n Begin is gemaak op
die aanspreek van die gebrek van taksonomiese kennis deur vyf nuwe spesies te beskryf.
Twee Ectonura Cassagnau 1980 spesies van Bettiesbaai en Grootvadersbosch is beskryf en 'n
sleutel tot die Neanurinae van Suid-Afrika word verskaf. Die eerste rekord van die genus
Triacanthella Schaffer, 1897 word beskryf van 'n grot in Tafelberg, terwyl twee nuwe spesies
van Delamarephorura beskryf word en die genera Spicatella Thibaud 2002 en Delamarephorura Weiner & Najt 1999 gesinomiseer word. Hoewel vuur beskou word as die
belangrikste vorm van ontbinding in die Fynbos bioom, het onlangse werk getoon dat die
biologiese ontbinding belangriker mag wees as wat voorheen vermoed was. Ek ondersoek
die veerkragtigheid van Collembola na 'n groot skaal vuur in Jonkershoek Natuurreservaat
met behulp van kwantitatiewe steekproefneming wat tydelik herhaal. Die veerkragtigheid
van ongewerwelde fauna in die fynbos word nie goed verstaan nie, dus het ek ondersoek
ingestel na die diversiteit van Collembola voor en na 'n groot vuur. Resultate toon dat
Collembola se spesierykheid en hoveelheid verbasend vinnig herstel na die vuur. Op 'n
groter skaal, is kolleksies by ses plekke regoor die Wes-Kaap gebruik en verskillende
blaarafval word vergelyk. Hier word 'n totaal van 113 morfologiese spesies gevind. Daar is
gevind dat die hoogste aantal spesies in Kogelberg is (32 spesies), terwyl die omset tussen
plekke baie hoog was. So sal die agteruitgang van plaaslike habitatte net soveel van 'n
bedreiging inhou vir Collembola as vir die endemiese plante in hierdie streek.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/79796 |
| Date | 03 1900 |
| Creators | Janion, Charlene, Scheepers, Charlene |
| Contributors | Chown, Steven L., Bengtsson, Jan, Deharveng, Louis, Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 322 pages : illustrations, maps |
| Rights | Stellenbosch University |
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