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A historical perspective on recent landscape transformation: integrating palaeoecological, documentary and contemporary evidence for former vegetation patterns and dynamics in the Fleurieu Peninsula, South AustraliaBickford, Sophia Anastasia. January 2001 (has links) (PDF)
Includes bibliographical references (p. 301-319). Palaeoecological records, documented historical records and remnant vegetation were investigated in order to construct a multi-scaled history of vegetation pattern and change in the Fleurieu Peninsula, South Australia over the last c. 8000 years. Aims to better understand post-European landscape transformation and address the inherently historical components of the problems of regional biodiversity loss, land sustainability and the cumulative contribution to global climatic change.
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A historical perspective on recent landscape transformation: integrating palaeoecological, documentary and contemporary evidence for former vegetation patterns and dynamics in the Fleurieu Peninsula, South Australia / Sophia Anastasia Bickford.Bickford, Sophia Anastasia January 2001 (has links)
Includes bibliographical references (p. 301-319). / xx, 319, [30] leaves : ill. (some col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Palaeoecological records, documented historical records and remnant vegetation were investigated in order to construct a multi-scaled history of vegetation pattern and change in the Fleurieu Peninsula, South Australia over the last c. 8000 years. Aims to better understand post-European landscape transformation and address the inherently historical components of the problems of regional biodiversity loss, land sustainability and the cumulative contribution to global climatic change. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geographical and Environmental Studies, 2001
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Conservation in human-influenced areas : epigaeic arthropods in the Cape Floristic Region LowlandsBoonzaaier, Carmen 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The conservation of biodiversity is becoming increasingly challenging as habitats are
disturbed, fragmented or destroyed. Although nature reserves now cover more than 10 %
of the earths’ surface it has become clear that more will have to be done to ensure the
long-term survival of species. Therefore, focus is increasingly shifting towards
conserving biodiversity in natural and semi-natural remnants in human-influenced areas.
This study aimed to determine the contribution of remnants in human-influenced areas to
the conservation of biodiversity in the Cape Floristic Region (CFR) lowlands, using
ground-dwelling arthropods, specifically ants, as the focal taxon. Initially, base-line
information of arthropods and in particular ants was obtained. Sampling arthropods
generally involves a large sample effort. Therefore maximizing sampling effort for ants
in the CFR was investigated by trapping ground-dwelling ants at a single locality.
Doubling the number of grids of pitfall traps was found to be more effective in trapping a
greater number of species than doubling the duration of sampling. Therefore increasing
spatial sampling intensity rather than sampling duration maximizes sample effort for CFR
ants. Also, the seasonal changes of ground-dwelling arthropods, including ants, were
determined by sampling four times during the year at a single locality. Overall arthropod
abundance was found to peak in summer while dropping to a minimum in winter. This
pattern was mirrored by that of the ants, indicating that ant results have a broader
relevance than to ants only. The ground-dwelling fauna was dominated by ants
emphasizing their importance in the CFR lowlands, and demonstrating that ants are an
appropriate flagship taxon for epigaeic arthropod diversity in the CFR. Finally the
contribution of remnants in human-influenced areas to the conservation of the CFR was
investigated. A nested hierarchical approach was used, where five localities were selected
across the CFR, each containing one reserve site and one site with natural remnants. Ants
were sampled, along with environmental variables, namely weather, vegetation and soil.
Overall, remnants were found to support similar ant assemblages to those of reserves.
However for individual localities some remnants were significantly different to their
reserve counterparts. Differences in ant assemblages were found to be greater between
localities than between reserves and remnants. The relatively high heterogeneity of ants found in this study emphasizes the conservation significance of invertebrates along with
that of plants in the CFR. Remnants clearly show the potential to conserve ant
assemblages, however correct management is needed for these areas to maximize their
potential. Disturbances such as the presence of the invasive Argentine ant and increasing
soil nutrients by fertilization, pose a distinct threat to the ability of remnants to conserve
ant assemblages. This study has shown that remnants currently support ant assemblages
representative of those present in the CFR today. Therefore, some remnant patches of
habitat in agricultural areas currently do contribute highly to the conservation of a
functional important taxon in this global biodiversity hotspot, and if managed correctly,
may continue to do so in the future. / AFRIKAANSE OPSOMMING: Die vernietiging en fragmentering van habitatte maak die bewaring van biodiversiteit al
hoe meer van ‘n uitdaging. Alhoewel natuur reservate reeds meer as 10 % van die aarde
se oppervlak beslaan is dit duidelik dat meer gedoen sal moet word vir die lang-termyn
voortbestaan van spesies. Dus word die fokus van biodiversiteit-bewaring toenemend
gerig op bewaring van natuurlike en semi-natuurlike fragmente in menslik-beinvloede
gebiede. Die doel van hierdie studie was om te bepaal wat die bydrae van fragmente van
natuurlike veld in menslik-beinvloede gebiede is tot die bewaring van die streek. Dit is
gedoen deur van grond-lewende geleedpotiges en spesifiek, miere in die Kaapse floraryk
(CFR) gebruik te maak. Aanvanklik is kennis ingewin oor die geleedpotiges en spesifiek
miere in die omgewing. Omdat die versameling van geleedpotige diere gewoonlik baie
moeite vereis is ‘n maksimum steekproef gedoen by ‘n enkele lokaliteit. Daar is gevind
dat ‘n verdubbling van die aantal ruitsteekproefnemings met vanggate meer effektief is
om miere te vang as ‘n verdubbling in die tydperiode wat vanggate oop is. Dus, is ‘n hoër
ruimtelike steekproef intensiteit meer effektief in vergelyking met ‘n langer tydsduur vir
miere in die CFR. Die seisoenale veranderinge van grond-lewende geleedpotiges, sowel
as miere, was ook bepaal. Dit was gedoen deur vier seisoenale steekproewe te doen by ‘n
enkele lokaliteit. Die totale geleedpotige-talrykheid was die meeste gedurende die somer
en die minste in die winter. Die miertalrykheid het ook hierdie patroon weerspieël. Dit
dui daarop dat veranderinge in mier versamelings van breër belang is vir alle grondlewende
geleedpotiges. Miere was die dominante grond-lewende geleedpotiges en
beklemtoon die belangrikheid van miere in die CFR, sowel as hulle toepaslikheid as
vlagskip taksa vir grond-lewende geleedpotige diversiteit in die CFR. Laastens was die
bydrae van gefragmenteerde natuurlike veld in menslik–beinvloede gebiede tot die
bewaring van die CFR ondersoek. ’n Krimpende/ genestelde hiërargies benadering is
gebruik in vyf geselekteerde lokaliteite, elk het bestaan uit ‘n area in ‘n natuur reservaat
en ‘n area in ‘n naasliggende fragment. Miere was versamel saam met ‘n verskeidenheid
omgewings veranderlike, naamlik weer, plantegroei en grond. In die algemeen is gevind
dat fragmente en reservate gelyksoortige mier versamelings het. Daar was wel gevind dat
party fragmente aansienlik verskillend was van die reservaat teenstuk. Verskille in mier versamelings tussen lokaliteite was groter as verskille tussen reservate en fragmente. Die
relatief hoë heterogeniteit van miere beklemtoon die bewaringsbelang van invertebrate
saam met dié van plante in die CFR. Dit is duidelik dat fragmente wel ‘n potensiale
bydrae kan maak om die mier versamelinge te bewaar, maar gepaste bestuur is nodig om
hierdie potentiaal te maksimaliseer. Versteurings soos die teenwoordigheid van die
indringer Argentynse mier en toenemende grondvoedingstofkonsentrasie as gevolg van
bemesting is ‘n groot bedreiging tot die vermoë van fragmente om mier versamelings te
bewaar. Hierdie studie wys dat mier versamelings in gefragmenterde areas
verteenwordigend is van die algemene mier versamlings wat op die oomblik in die CFR
is. Dus lewer party fragmente in landbou gebiede op die oomblik ‘n wesenlike bydrae tot
die bewaring van ‘n funksioneel belangrike takson in hierdie globale
biodiversiteitsbrandpunt en die bydra sal volhoubaar wees met korekte bestuur.
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Vegetation patterns and dynamics of Renosterveld at Agter-Groeneberg Conservancy, Western Cape, South AfricaWalton, Benjamin Alan 03 1900 (has links)
Thesis (MSc (Conservation Ecology and Entomology)--University of Stellenbosch, 2006. / Swartland Shale Renosterveld is restricted to fertile fine-grained soils in the winter rainfall region of
the Western Cape. Between 91% and 97% of this vegetation type is transformed, mostly due to
agriculture. Remaining fragments have an irreplaceable conservation value due to a high richness of
endemic geophytes. Information on renosterveld vegetation composition and response to
disturbance is sparse. Research occurred at three sites near Wellington: Voëlvlei Provincial Nature
Reserve (CapeNature), Elandsberg Private Nature Reserve (Elandsberg Farms (Pty.) Ltd.), and
Krantzkop munitions factory (Armscor/Somchem) forming a contiguous fragment in the Agter-
Groeneberg Conservancy. The primary research aim was to identify or ascertain patterns of plant
succession in Swartland Shale Renosterveld and associated different-aged old fields (previously
ploughed), with the interaction of grazing. The key research questions are: (1) What are the plant
communities of unploughed renosterveld and different-aged old fields which originated in habitats
of ploughed renosterveld? (2) What are the most characteristic features of the floristic and
ecological relationship between the described plant communities in terms of ecological factors
operating within the studied system? (3) Does total species and life-form group richness differ
between natural vegetation and old fields? (4) Is life-form richness influenced by ploughing and
grazing or the interaction between these disturbances? (5) Is life-form cover-abundance influenced
by ploughing and grazing or the interaction between these disturbances? (6) Does alien plant
species richness differ amongst seres, and with different levels of grazing intensity? A comparison
of life-form richness and cover-abundance of old field vegetation was made with adjacent natural
unploughed “controls”. The effects of ploughing on community structure, with the inclusion of
grazing was established. These life-form richness comparisons also occur across a gradient of
increasing large mammalian herbivore grazing intensity. Sampling was conducted in winter and
spring using nested 1000m2 relevés.
A hierarchical classification, description and floristic interpretation of renosterveld and old field
vegetation were made using TWINSPAN, SYN-TAX 2000 and CANOCO. The samples were
classified with TWINSPAN and two communities were described at the association level, namely:
Ursinia anthemoides–Cynodon dactylon Grassland Community (with two variants) and the
Pterygodio catholici–Elytropappetum rhinocerotis Shrubland Community (with two subassociations),
respectively. The vegetation data were further hierachically classified using SYNTAX
2000 which revealed similar clustering of sample objects to that resulting from classification and ordination. Following ordination of sample objects with CANOCO, select groups of species
were used to depict their response curves in relation to seral development.
Briefly it was found that the effects of grazing vs. non-grazing was more pronounced on old fields
than in unploughed vegetation. Overall total species and life-form richness was reduced by
ploughing with old fields requiring a recovery period of 30 years to resemble unploughed
vegetation.
Keywords: Swartland Shale Renosterveld, phytosociology, vegetation patterns, life-forms,
succession, disturbance, ploughing, grazing, old fields.
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Dispersal of seeds as a constraint in revegetation of old fields in Renosterveld vegetation in the Western Cape, South AfricaShiponeni, Ndafuda Nangula 03 1900 (has links)
Thesis (MScFor )--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Species-rich Renosterveld vegetation does not return to old agricultural fields even
after many years (10-20) of abandonment. In most cases the fields are slowly taken
over by non-indigenous species, particularly alien pasture grasses and African lawn
grass. While poor survival of indigenous seedlings due to competition, grazing or any
other establishment constraints, might explain the failure of natural vegetation to
colonise old fields, here I am testing the hypothesis that recolonisation by indigenous
plant species is limited by seed dispersal. I have quantified changes in seed density
with distance from the natural vegetation into old fields using seed traps and soil seed
bank assessment. I have also looked at seed dispersal in the dung of large herbivores.
Shrubs (with the exception of Eytropappus rhinocerotis) were poorly represented in
the seed rain indicating that they might be seed limited. Dicerothamnus rinocerotis (a
dominant shrub in Renosterveld) and certain geophytes (that were recovered in the
soil bank) have proven that seed dispersal is not the primary constraint to their return
to ploughed fields. Dicerothamnus rinocerotis produces a large number of seeds that
are dispersed long distances into the old field and a number of geophytes were well
represented in the soil bank. Large herbivores are dispersing a lot of herbaceous forbs
in their dung but make very little contribution to the dispersal of indigenous tussock
grass and shrubs. Seeds of indigenous Renosterveld tussock grasses (e.g Tribolium
hispidum) were restricted to the edge of the natural vegetation. My research has
shown that some indigenous seeds, particularly those dispersed in wind and through
large mammals, do reach the old ploughed field. I therefore conclude that seed
dispersal is not the primary constraint to the natural recovery of populations of some
indigenous plant species on old fields, but may limit recovery of certain indigenous
geophytes, grasses and shrubs. / AFRIKAANSE OPSOMMING: Spesie-ryke Renosterveld plantegroei hervestig nie op ou landerye nie, selfs ná baie
jare (l0-20) van verlating. Oor die algemeen word hierdie grond stadig oorgeneem
deur uitheemse spesies, veral uitheemse weidingsgrasse en kweekgras. Terwyl swak
oorlewing van inheemse saailinge as gevolg van kompetisie, weiding of enige ander
vestigingsbeperkinge, die mislukte vestiging van natuurlike plantegroei op ou benutte
grond kan verduidelik, toets ek hier die hipotese dat hervestiging deur inheemse
plantspesies deur saadverspreiding beperk word. Ek het veranderinge in saaddigtheid
oor afstand vanaf die natuurlike plantegroei na ou landerye gekwantifiseer,
deur gebruik te maak van saadopvangsvalle en sand saadbank beraminge. Ek het
ook gekyk na saadverspreiding in die mis van groot herbivore. Struike (behalwe
Eytropappus rhinocerotis) was swak verteenwoordig in die "saadreën", wat mag toon
dat struike saadbeperk is. Eytropappus rhinocerotis ('n dominante struik in
Renosterveld) en sekere geofiete (wat in die saadbank gevind is) het bewys dat
saadverspreiding nie die hoofbeperking is vir hulle terugkeer na geploegde lande nie.
Eytropappus rhinocerotis produseer 'n groot hoeveelheid saad wat oor groot afstande
oor die ou landerye versprei word en 'n aantal geofiete was goed verteenwoordig in
die saadbank. Groot herbivore versprei 'n groot hoeveelheid kruidagtige forbe in
hulle mis, maar maak 'n baie klein bydrae tot die verspreiding van inheemse polgras
en struike. Saad van inheemse Renosterveld polgrasse (bv. Tribolium hispidum) was
beperk tot die some van die natuurlike plantegroei. My navorsing het getoon dat
sommige inheemse saad, veral dié wat deur die wind en deur groot herbivore versprei
word, wel die ou geploegde landerye bereik. Ek maak dus die gevolgtrekking dat
saadverspreiding nie die hoofbeperking is vir die natuurlike herstel van populasies
van sommige inheemse plantspesies op ou landerye nie, maar mag die herstel van
sekere inheemse geofiete, grasse en struike beperk.
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