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Stocking limits for South Australian pastoral leases : historical background and relationship with modern ecological and management theoryTynan, R. W. January 2000 (has links) (PDF)
Bibliography: leaves 308-333.
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Vegetation patterns of eastern South Australia : edaphic control and effects of herbivory / by Fleur Tiver.Tiver, Fleur January 1994 (has links)
Includes bibliographical references. / xvii, 144, [89] leaves, [18] leaves of plates : ill. (some col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1995?
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A comparison of the effects of grazing and mining on vegetation of selected parts of northern South Australia / Francis John Badman.Badman, Francis John January 2002 (has links)
Accompanying CD-ROM inside back cover, includes Appendices. / Bibliography: leaves 242-266. / System requirements for accompanying CD-ROM: IBM compatible computer with Pentium processor or higher and Windows 95, 98 or NT ; 4 MB or RAM. Other software: Acrobat Adobe Reader. / xv, 266 p. : maps, charts ; 30 cm. + 1 CD-ROM (4 3/4 in.) / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis examines the effects on vegetation at selected sites in northern South Australia of excluding various herbivores over a four and a half year period and of two intense but controlled grazing pulses over a six month period followed by an 18 month recovery period in a dune-swale land system. These changes are compared with changes recorded over an 11-year period at the Olympic Dam mine site. It found that short-term changes in vegetation revealed by ordination of periodical cover, density and species richness, are attributable to the periodicity of rainfall and that, under present grazing regimes, rainfall effects override grazing effects. Differences between the effects of sheep and cattle hoof damage are worthy of further investigation, as is the impact of kangaroo grazing. These two factors may have important implications for the management of Australian rangelands. / Thesis (Ph.D.)--University of Adelaide, Dept. of Environmental Biology, 2002
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The effects of timber harvest and herbivory on understory vegetation and composition of beef cattle diets on forested rangelandsWalburger, Kenric 28 October 2005 (has links)
Graduation date: 2006 / Best scan available. Ink on original is smeared.
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Using nutritional quality of forage and faeces for predicting sustainable livestock and game stocking rates at Pniel Estates in Northern Cape, South AfricaMbatha, Khanyisile R. 03 1900 (has links)
Thesis (PhD)--University of Stellenbosch, 2010. / The aim of the study was to assess the importance of spatial and temporal variation in diet quality and abundance for determining sustainable stocking rates on commercial, communal and game ranches in a semi-arid savanna, with the ultimate goal of avoiding land degradation in the long term, to provide sustainable livelihoods in rangelands and to make policy that will help in managing the available natural resources in the rangelands. Thus, firstly the effects of grazing, fire, nitrogen and water availability on nutritional quality of grass in semi-arid savanna was assessed. Secondly, spatial and temporal variation in plant quantity and quality among management (commercial, communal and game) types and habitat types (open savanna, rocky, shrubby and pans) and stocking rates in different management types were determined. Thirdly, the quality and quantity of variation inside and outside herbivore exclosures among commercial, communal and game management and habitat types in the semi arid savanna were estimated. Fourthly, faecal profiling was used to assess the effects of different management types on diet quality in semi-arid savanna. Lastly, policy based on the results of the present study was formulated.
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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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Riparian Wetland Response to Livestock Exclusion in the Lower Columbia River BasinHolmen, Sarah Ann 01 January 2011 (has links)
The purpose of this study was to examine the characteristics of riparian plant communities along a succession gradient of livestock exclusion in the Lower Columbia River Basin (LCRB). Livestock exclusion is an example of a passive restoration practice throughout the region. However, few studies have focused on the effects of livestock or livestock exclusion on riparian wetland ecosystems in this area. Two passive restoration sites, 3 and 13 years since livestock exclusion, and a control site with a continued livestock grazing presence were examined. It was hypothesized that native plant species richness would be lower in the excluded wetlands than in the grazed wetland due to the competitive exclusion from an increase in non-native plant dominance in the absence of grazing. Data were collected along six (45-60m) randomly distributed transects which were aligned perpendicular to the wetland shoreline of each site, providing a total of 18 transects with an accumulative length of approximately 990 meters. Vegetation cover data were collected for 10 cm intervals along these transects using the line intercept method during low water periods in August and September of 2009. The Kruskal-Wallis one-way nonparametric analysis of variance by ranks and the Mann-Whitney U test were used to detect significant (p
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The effects of soil type and management strategy on vegetation structure and function in a semi-arid savanna, South AfricaBritz, Mari-Louise January 2004 (has links)
Thesis (MSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Bush encroachment in savannas leads to reduced diversity, productivity and profitability of
rangelands. This holds important implications for the livestock and eco-tourism industries, as
well as for subsistence ranchers in the South African semi-arid savannas, who depend on this
vegetation type for economic and livelihood purposes. Soil moisture, nutrients, rue and
herbivory are generally regarded as the principal factors determining vegetation structure and
function within savannas. The factors and processes involved in the determination of the
tree:grass ratio within savannas are, however, not clearly understood. We investigated the
role of soil type and management strategy (cattle, game and communal grazing) in the
determination of the presence and distribution of plant species in general, and on the presence
and distribution of the encroaching tree species, Acacia mellifera, specifically. Both shortand
long-term trends were investigated. The study area, the Kimberley Triangle, (Northern
Cape Province, South Africa), was ideal for this kind of study because it has different
management strategies practised on several soil types, and bush encroachment is a widespread
phenomenon.
Contrary to the belief that heavy livestock grazing is the main cause of increases in the
tree:grass ratio, we found that soil type, through its effects on plant growth and on the
presence and availability of soil moisture and nutrients, is more important in determining
vegetation composition than management strategy. It was found that the various types of
grazing management mainly influenced vegetation structure and function by affecting the
competitive interactions between Ns-fixing woody species and non-Ns-fixing grasses. Of the
soil factors affecting vegetation composition, soil texture was a good indicator of the physical
conditions for plant growth in an area, and also of the presence and availability of soil
moisture and nutrients. We found that sand and clay soils are relatively resistant to bush
encroachment as compared to loamy-sand and -clay mixes. This is because woody growth is
impaired in the first-mentioned habitats by soil texture, soil moisture regimes and heavy
utilisation. In soils with combinations of loam, sand and clay, soil texture and moisture are
not limiting to woody growth and if the repressive competitive effect of grasses on woody
vegetation is removed, opportunities are created for recruitment of woody species and
encroachment. Additionally, rockiness increases soil moisture infiltration. In the study area,
woody species, and specifically A. mellifera, are associated with these areas. We suggest that in the study area, rocky areas are naturally encroached. This is in agreement with the patchdynamic
approach to savanna vegetation dynamics. Because soil moisture is such an
important factor in the determination of the tree:grass ratio in the study area, we further
suggest that in above-average rainfall years, when soil moisture conditions are optimal for
woody seed germination, establishment and growth, heavy grazing should be avoided, as it
would provide the opportunity for encroachment.
Keywords: Bush encroachment; N2-fixing species; game, cattle, communal grazing; soil
texture; soil moisture; soil nutrients; Acacia mellifera; tree-grass competition. / AFRIKAANSE OPSOMMING: Bosindringing in savanna gebiede het verlaagde diversiteit, produktiwiteit en winsgewendheid
van natuurlike weivelde tot gevolg. Behalwe dat dit die Suid-Afrikaanse vee- en ekotoerisme
bedrywe raak, is verskeie bestaansboerderye afhanklik van die plantegroei-tipe vir
oorlewing. Grondvog, grondvoedingstowwe, vuur en beweiding word algemeen aanvaar as
die belangrikste faktore wat die struktuur en funksie van savannas bepaal. Daar is egter nog
nie duidelikheid oor die prosesse wat betrokke is in die bepaling van die boom-gras
verhouding in savannas nie. In dié studie het ons ondersoek ingestel na die invloed van grond
tipe en beweidingstrategieë (beweiding deur beeste, wild, of kommunale beweiding) op die
algemene verspreiding van verskillende plant spesies, en ook op die van die indringer spesie,
Acacia mellifera. Beide kort- en lang-termyn patrone is ondersoek. Die studiegebied, die
Kimberley Driehoek in die Noord-Kaap, Suid-Afrika, was ideaal vir so 'n ondersoek omdat
verskillende beweiding strategieë op verskeie grond-tipes beoefen word maar bosindringing
steeds 'n algemene verskynsel in die gebied is.
Ons bevinding was dat, ten spyte van die feit dat daar oor die algemeen geglo word dat swaar
beweiding die hoof oorsaak van bosindringing is, grond-tipe belangriker is in die bepaling van
die spesie-samestelling van 'n gebied. Dit is as gevolg van die feit dat grond-tipe die groei
van plante beïnvloed deur die teenwoordigheid en beskikbaarheid van grondvog en -nutriënte
te bepaal. Die verskillende beweidingstrategieë beïnvloed meerendeels die kompetatiewe
interaksies tussen N2-bindende hout-agtige spesies teenoor nie-Nj-bindende gras-agtige
spesies. Grond-tekstuur was 'n goeie aanduiding van die algemene toestande vir plantegroei
en ook van die teenwoordigheid en beskikbaarheid van grondvog en -nutriënte. Ons het
bevind dat sand en klei grond, relatief tot leem, sand en klei kombinasies, weerstandbiedend
is teen bosindringing as gevolg van die tekstuur, water-regimes en swaar beweidings vlakke
wat op die grond-tipes voorkom. Omdat grond-tekstuur en grondvog nie beperkend is op die
leem-, sand- en klei-grond kombinasies nie, kan bosindringing maklik hier voorkom as die
onderdrukkende effek wat grasse op houtagtige plantegroei het, deur swaar beweiding
verwyder word. A. mellifera is ook oor die algemeen met klipperige gebiede geassosieer
omdat klipperigheid lei tot verhoogde infiltrasie van grondvog. In die studie-gebied is
klipperige areas dan ook van nature ingedring deur A. mellifera. Dit stem ooreen met die
siening dat savannas bestaan uit "laslappe" van verskillende plantegroei (patch-dynamic approach). Dit was duidelik dat grondvog 'n belangrike bepalende faktor is in die bepaling
van die boom-gras verhouding in die studiegebied. Ons stel dus voor dat in bo-gemiddelde
reënval jare, swaar beweiding vermy moet word, omdat houtagtige saailinge gedurende die
tydperke maklik kan ontkiem en vestig juis omdat grondvog dan nie beperkend is nie.
Sleutelwoorde: Bosindringing; N2-bindende spesies; bees, wild, kommunale beweiding;
grond tekstuur; grond-vog; grond-nutriënte; Acacia mellifera; boom-gras kompetisie.
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