• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 5
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 37
  • 14
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Alluvial stratigraphy and soil formation at Cox Ranch Pueblo, New Mexico

Vanbuskirk, Stephanie, January 2004 (has links) (PDF)
Thesis (M.A. in anthropology)--Washington State University. / Includes bibliographical references.
22

Tepe Ghabristan: A Chalcolithic tell buried in alluvium.

Schmidt, Armin R., Fazeli, H. January 2007 (has links)
No / The Chalcolithic tell of Ghabristan in northwest Iran is now buried by alluvium and a magnetometer survey of the tell and its surroundings was undertaken to reveal any features under this cover. After the abandonment of the tell in the late third millennium BC it was used as an Iron Age cemetery by inhabitants of the neighbouring tell of Sagzabad. The magnetometer data show a related irregularly shaped channel that is also considered to be of Iron Age date.Its shallow burial depth, compared with the thick sedimentary layers underneath, indicates a considerable slowdown of alluviation rates in the second millennium BC, possibly related to environmental changes. The survey also found evidence for undisturbed buried building remains, most likely associated with copper workshops.
23

Geology of the fluvial deposits of the Colorado River Valley, Central Texas

Weber, Gerald E. (Gerald Eric) 08 November 2012 (has links)
Terrace deposits along a 40 mile segment of the Colorado River between Austin and Bastrop, Texas, are mapped in detail. The following deposits have been delineated (lowest to highest): Floodplain, Sixth Street Terrace, Montopolis Terrace, Capitol Terrace, Hornsby Terrace, Asylum Terrace, and Delaney Terrace. The Hornsby Terrace deposits and the Montopolis Terrace deposits were previously unrecognized. A program of mechanical analysis was conducted on samples taken from the terrace deposits and the floodplain. Cumulative frequency curves of grain size from five samples collected up to 15 miles apart from the Asylum Terrace gravel, are distinctively grouped--different from all other samples. Cumulative frequency curves from five samples from the Hornsby Terrace gravel also plot in a close grouping distinct from other samples. Over short distances where abrasion is not a dominant factor it seems that grain size distribution may be useful as a means of correlation of terrace remnants. Analysis of the lithologies of these samples indicate that the Hornsby, Asylum and Delaney Terrace gravels are practically without limestone clasts, in a drainage basin that is, presently, composed dominantly of limestone. This suggests that the Commanche Series in the Edwards Plateau region was not extensively exposed but was covered by the Gulf Series at the time of the formation of these terraces. The Manor lag gravel, an upland gravel in the thesis area, is thought to be the remnant of a high terrace deposit of the Colorado River. All terrace gravels except the Capitol and Montopolis Terrace gravels are thought to be the result of lateral planation by a stream at or near grade. The Montopolis and Capitol Terrace gravels are thought to be the result of a lengthy episode of lateral planation by the Colorado River accompanied by slow degradation. / text
24

High-Resolution Holocene Alluvial Chronostratigraphy at Archaeological Sites in Eastern Grand Canyon, Arizona

Tainer, Erin Margaret 01 May 2010 (has links)
Understanding the nature of Colorado River deposits in Grand Canyon helps reveal how the river responds to changes in its Colorado Plateau tributaries and Rocky Mountain headwaters. This study focused on Holocene alluvial deposits associated with archaeological sites excavated near Ninemile Draw in Glen Canyon and at Tanner Bar in eastern Grand Canyon. Two previously-developed conceptual models of deposition were tested based on previous work. Previous researchers have suggested that Holocene alluvial deposits in Grand Canyon are a series of inset aggradational packages that correlate to valley fills and arroyo-cutting cycles in Colorado Plateau tributaries and are laterally consistent throughout the river corridor. An alternate hypothesis is that alluvial packages record paleoflood sequences along the Colorado River with no Holocene change in river grade. In this model, deposits are preserved more variably as a function of local hydrologic geometry, and they should be less correlatable. Detailed stratigraphic columns of terrace deposits and several stratigraphic panels of archaeological trenches, combined with facies interpretations, were used to reconstruct a high-resolution alluvial history at two locations. Optically stimulated luminescence (OSL) and radiocarbon dating methods were used at both locations with consistent results. At both sites, the sediment includes multiple depositional facies of mainstem and local-source material, and it consists of stratal packages bound by unconformities. These stratigraphic relations, combined with geochronology, lead to the interpretation that the alluvium is composed of six correlatable alluvial packages at overlapping heights above river level throughout the canyon. The four older packages include facies that imply aggradation throughout the river corridor, suggesting oscillations in river grade. The youngest two packages consist only of mainstem flood deposits. These packages suggest that preservation of deposits over the past ~1 ky has not been driven by aggradation, although incision since ~1 ky is possible. Comparison of the interpreted chronostratigraphy to climate records suggests that this large river's grade has not responded visibly to smaller century to millennial-scale climate oscillations. This work is the first to document that the alluvial record in Grand Canyon spans the entire Holocene, and conclusions support to both previous conceptual models of deposition.
25

Depositional environments comprising the Birch River section (Middle Pennsylvanian), Powell Mountain, Nicholas County, West Virginia

Rutland, Jeffrey R. January 2004 (has links)
Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains vii, 198 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 161-167).
26

Pre-vegetation alluvium : geological evidence for river behaviour in the absence of land plants

McMahon, William January 2018 (has links)
Pre-vegetation alluvium is unique; at the present day, plants affect multiple aspects of river functioning and deposition and so those rivers that operated before the evolution of land plants largely lack modern sedimentological analogue. However, such rivers were the norm for the first 90% of Earth history and so a better understanding of their sedimentary product enables insight into both the fundamental underlying mechanisms of river behaviour and the ways in which fluvial processes operated on ancient Earth and other rocky planets. This study presents five original fieldwork based case studies and an analysis of a holistic database of all of Earth’s pre-vegetation alluvium. Together these research strands offer perspectives on the sedimentological characteristics and stratigraphic trends of pre-vegetation alluvium and the behaviour and functioning of pre-vegetation rivers. Results show that, in pre-vegetation alluvial settings: 1) a variety of fluvial styles are represented, but diminished in comparison with syn-vegetation alluvium; 2) ‘sheet-braided’ architectures are common but may record a variety of fluvial planforms; 3) meandering planforms were less frequent, particularly in small- to moderate-sized river systems; 4) mudrock is on average 1.4 orders of magnitude less common than it is in syn-vegetation alluvium; and 5) microbial matgrounds were present, but had negligible effect on preserved architecture and facies. This thesis demonstrates that whilst the physical laws governing fluvial fluid-sediment interaction have not changed, the theatre in which they operated irrevocably evolved with the greening of the continents.
27

Senhora de bens: famílias, negócios e patrimônios administrados por mulheres no sertão dos Guayazes – 1760- 1840 / Lady uppers: families, businesses and assets managed by women in the backwoods of Guayazes - 1760 - 1840

Pereira, Gabriel da Silva 31 July 2013 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-10-20T16:46:58Z No. of bitstreams: 2 Dissertação - Gabriel da Silva Pereira - 2013.pdf: 1790194 bytes, checksum: b2459ecc0172e4a7a1cd4b6d158aca52 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-10-20T16:48:23Z (GMT) No. of bitstreams: 2 Dissertação - Gabriel da Silva Pereira - 2013.pdf: 1790194 bytes, checksum: b2459ecc0172e4a7a1cd4b6d158aca52 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-20T16:48:23Z (GMT). No. of bitstreams: 2 Dissertação - Gabriel da Silva Pereira - 2013.pdf: 1790194 bytes, checksum: b2459ecc0172e4a7a1cd4b6d158aca52 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-07-31 / The thesis that’s presented aims to revive women's groups seeking prestige, enrichment and power in Goiás, along the eighteenth century. We look at the sources the circumstances indicating the possibility of some form of consensual relationship to achieve the stories of their members, not only the relations in which concubinage actually happened. With this criterion, our eyes were directed to cases of widowhood, failure of marriage and singleness. This allowed us a more critical approach about what is reported by the women in the sources, because provided us relativize the importance of marriage in this society, and also highlight the scenarios of autonomy, construction and affirmation of their identities and powers and also their strategies sociability. Situations of "possible families" allowed to discover a group of power, with the presence of autonomous and capable women, who wished for social distinction, honor preservation, enrichment and increase their wealth, characterizing an peculiar nobility from Goiás, the alluvium nobility, which means a apparent wealth, surface such as gravel, sand, silt, and organic and inorganic materials left by the waters. In Goiás, during the eighteenth century, to enter into this category of nobility constituted in desire of men and women who, through their occupations and social relationships, accumulating richness, expanding their wealth and uppers, differing from most of his countrymen, because of the acquisition of honorifics or social power and influence that comes from the enrichment. This means that the in the mines from Goiás, we see the trajectory of several people who lived in this search, the desire to enrich themselves in a context of conquest, characterized by hostile realities, often marked by power struggles and violence. / A dissertação que ora é apresentada objetiva resgatar os grupos femininos que buscavam o prestígio, o enriquecimento e o poder em Goiás, ao longo do setecentos. Para alcançarmos as histórias de suas integrantes, procuramos nas fontes as circunstâncias que indicassem a possibilidade de algum tipo de relação consensual – como o concubinato – e não apenas os casos em que ela, de fato, ocorreu. Com base nesse critério, nosso olhar foi direcionado às situações de viuvez, de fracasso do matrimônio e de solteirice. Isso nos permitiu uma abordagem mais ampla e crítica ao que é relatado pelas próprias mulheres nas fontes, uma vez que nos proporcionou relativizar a importância do matrimônio nessa sociedade, bem como, destacar os cenários de autonomia, de construção e afirmação de suas identidades e poderes, além de suas estratégias de sociabilidades. As situações de famílias possíveis oportunizaram-nos descobrir um grupo de poder, composto por mulheres autônomas e capazes, que ansiavam por distinção social, preservação da honra, enriquecimento e aumento de seus patrimônios, caracterizando uma nobreza peculiar da região de Goiás, a nobreza de aluvião, ou seja, uma riqueza aparente, de superfície como o cascalho, areia, lodo e matérias orgânicas e inorgânicas deixado pelas águas. Em Goiás, durante o século XVIII, inserir-se nesta categoria de nobreza constituía-se em desejo de homens e mulheres que, por meio de seus ofícios e relações sociais, acumulavam riquezas, ampliando, assim, seus patrimônios e cabedais, diferenciando-se da maior parte de seus conterrâneos, devido à aquisição de títulos honoríficos ou, simplesmente, ao poder social e de influência que advém do enriquecimento. Neste sentido, as tramas da sociedade mineradora goiana denotam a trajetória de várias personagens que vivenciaram essa busca, essa vontade de se enriquecer – e seu alcance de fato – num contexto de conquista, caracterizado por realidades adversas e, muitas vezes, marcado pelos conflitos de poder e violência.
28

Neogene fluvial deposits along the south-west coast of South Africa understanding the palaeoclimate through proxies

Sciscio, Lara January 2011 (has links)
Branched glycerol dialkyl glycerol tetraether (GDGTs) membrane lipids have been used as a new proxy for the reconstruction of terrestrial palaeoclimates. These biomarkers (or molecular ‗fossils‘) in conjunction with palynology, have been effective in the novel analysis of Miocene organic-rich sediments from three South African west coast sites at Rondeberg, Noordhoek and Langebaanweg. Lastly, a Quaternary south coast site at Rietvlei, South Africa, was also studied to further elucidate the extent of use of this new proxy. The fluvial peat and organic-rich deposits of the Elandsfontyn Formation (Sandveld Group) were investigated at Noordhoek, Langebaanweg and Rondeberg to provide new evidence for the climate and vegetation patterns during Miocene in this region. Drill-core and quarry samples from all four sites were freeze-dried, powered, and prepared for biogeochemical and palynological analyses. The methylation index of branched tetraethers (MBT) and cyclisation ratio of branched tetraethers (CBT) proxies were used to calculate the mean annual air temperature (MAAT) and pH values of the organic-rich horizons at time of deposition. The Branched versus isoprenoid index of tetraethers (BIT) was used to assess the relative contributions of marine archaeal and terrestrial bacterial tetraethers, and thereby assess the validity of the MBT, CBT and calculated palaeoenvironmental factors. The results presented in this thesis suggest that the use of the MBT/CBT proxy has significant potential in southern Africa, and may complement previously attempted palaeoclimatic and palaeoecological studies of Neogene-aged South African sediments. This type of research has the capacity to provide palaeoenvironmental information where other proxies may be absent. Results indicate that all sites yielded branched tetraether membrane lipids with the exception of Rondeberg, where GDGTs were below detection as a result of poor preservation conditions. Palynological investigation confirmed proxy derived temperatures. Furthermore palynomorph analyses supplemented earlier studies of the Noordhoek site and were piloted for the Rondeberg site, reaffirming alternating sequences of tropical and subtropical palynofloras. The MAATs, likewise, show variability and pronounced trends through time at the Langebaanweg and Noordhoek sites, generally corresponding with the variation and diversity of the pollen population. The terrestrial MAAT results appear to compliment Southern Hemisphere sea level changes associated with Antarctic glaciations. Additionally, this data shows a pattern similar to the Southern and Northern Hemisphere marine isotope records of relative fluctuations in the global climate and sea level change from the early to middle Miocene. The application of these past climate change indicators have been proved to be useful in the reconstruction of South Africa Miocene palaeoclimates, and may aid in understanding the consequences of climate change in the Cape region.
29

Hydrogeology of heterogeneous alluvium in the Leona aquifer, Caldwell County, Texas

Hemphill, Lloyd Harrison, 1979- 24 June 2013 (has links)
The Leona aquifer is an important, but overlooked, water resource in Central Texas. The Quaternary Leona Formation occurs as several isolated alluvial deposits at the margins of the Edwards Plateau. Each of these deposits forms an aquifer. One of these aquifers is located near Lockhart, Texas. This aquifer is recharged by infiltration of precipitation and is discharged by numerous springs and seeps. Additional sources of discharge are evapotranspiration and cross-formational flow into the Wilcox aquifer. The saturated thickness at this location varies seasonally but is rarely greater than 3 m (10 ft). Groundwater flow in an aquifer of this scale is influenced by its heterogeneous nature. This research identified seven different facies in the Leona Formation and the underlying Wilcox Group. These divisions were based on sediment classification, lithology, and sedimentary structures. The Leona Formation is covered by sandy and silty clay soil and caliche. Each of these facies has different hydraulic properties. Many empirical relationships between grain size distribution and hydraulic conductivity (K) have been discussed in the literature. Equations developed by Hazen, Slichter, Terzaghi, Beyer, Saurbrei, and Kozeny were used to estimate hydraulic conductivity. Hydraulic conductivity was also measured in the laboratory with constant and falling head permeameters. Hydraulic conductivity of the Leona aquifer varies seven orders of magnitude. Hydraulic conductivity varies up to four orders of magnitude within a single facies due to small-scale differences in grain size distribution and degree of cementation. The arithmetic mean of hydraulic conductivity in vertical profiles through the Leona aquifer ranges from 0.013 cm/sec (37 ft/day) to 0.14 cm/sec (397 ft/day). Water quality is a concern for many unconfined shallow alluvial aquifers, including the Leona aquifer. Elevated nitrate levels indicate contamination resulting from agricultural land use. Nitrate concentration in the Leona aquifer ranges from 4 ppm nitrate as NO₃ to greater than 70 ppm nitrate as NO₃. These concentrations are significantly greater than those observed in the Wilcox aquifer. The U.S. Geologic Survey computer code MODFLOW was used to create a groundwater model of the Leona aquifer. In the best simulation, specific yield was 0.1 and horizontal hydraulic conductivity was 0.058 cm/sec (164 ft/day). The simulated hydraulic conductivity is an order of magnitude less than observed in gravel pit outcrops. Modeled recharge was 9 percent of annual precipitation in 2003 and 20 percent of precipitation in the first six months of 2004. Five hypothetical wells were placed in the model to examine the effects of pumping on the aquifer. Wells pumped for 61 days at 0.04 l/sec (0.6 gpm) cause insignificant drawdown while wells pumped at a rate of 3.5 l/sec (55 gpm) cause up to 0.55 m (1.8 ft) of drawdown. Natural drainage of the aquifer caused the water table to decline 0.8 m (2.6 ft) over this same period. MODPATH simulations using this groundwater model indicate an average residence time in the aquifer of 13 years and a maximum residence time of 70 years. / text
30

Large herbivore stocking rate effects on plant palatability, forage preference and soil properties in an Alluvium Fynbos-Renosterveld mosaic

Mubamu Makady, Elvis 03 1900 (has links)
Thesis (MSc (Conservation Ecology and Entomology))--Stellenbosch University, 2009. / ENGLISH ABSTRACT: An understanding of the interactions of herbivores, plant nutrients and soil properties is crucial for grazing management. Of particular interest are plant palatability and herbivore grazing preferences. These aspects, the focus of this thesis, were studied in a Swartland Shale Renosterveld and Swartland Alluvium Fynbos mosaic in the Western Cape of South Africa. This vegetation is classified as critically endangered due to the transformation of its landscape in favour of agricultural production and urban settlement. Pre-colonial herbivore vertebrates were hunted out by 1700, leading to a sparse knowledge of the early dynamics of the vegetation. However, currently game farmers and landowners are re-introducing selected species into the area. Thus, managers require knowledge on how to implement practical guidelines for best-practice grazing management. This study investigates, firstly, the relationship between plants and animals. This included seasonal assessment of seed germination from dung of bontebok and eland; the effect of stocking rates on plant palatability (crude protein, crude fibre, crude fat, moisture, tannin and mineral) of herbage was studied with the aim to understand how palatability influences herbivore forage decisions. Secondly, this study looked at how stocking rates influence soil nutrients (nitrogen, phosphorus), and others soil properties such as pH and soil moisture. The distribution of alien grasses was facilitated by grazers. About 58 % of grasses germinated from the dung of eland and Bontebok were alien species. Additionally, there was significant variation in palatability related to grazing pressure and plant maturity between sites and over seasons. Grasses on the high grazing site had higher carbohydrate (3%-5% higher) and protein content (1%-5% higher) than at the least grazed site. Mature grasses contained less water (10%-20%), but no obvious variation in tannin concentration than immature grasses. However, species such as Ficinia sp. showed variations with grazing pressure and maturity. Ficinia sp. on the high grazing site had higher tannin concentration (5mg/ml-22mg/ml) and crude protein (4%-9%) than at the least grazed site. When the plant ages, tannin concentration increase (ranging from 15% to19% higher). Two types of plant were recoreded according to their chemical response following grazing pressure. These types are 1) plants that are grazing tolerant and which produce more carbohydrate when grazed and 2) plants that are grazing intolerant under high grazing pressure and which produce chemical defence compounds such as tannin to deter herbivores attacks. The results indicate that in fynbos and renosterveld, the relationship between preference and plant chemical compounds is not consistent since no IV patterns emerged to explain what compounds drive preference. A combination of chemical compounds may be the reason for the selection by the grazers; alternatively, other compounds not included in the study may influence the forage selection by an herbivore. The second part of the study showed that stocking rates appeared to have a significant effect on soil properties investigated. Soil moisture was significantly affected by the stocking rate in autumn. The high grazing intensity site had the lowest soil moisture especially in autumn (10% lower than the control site), likely due to heavy trampling and soil compaction. pH was the lowest at the high grazing intensity site in all seasons compared to the control site. Likely reasons were the high deposition of nitrogen through dung and urine deposition, high removal of basic cations and animal exportation through hunting activities. Lastly, grazing maintains inorganic nitrogen at stable levels regardless of seasonal changes and increases the concentration of phosphorus especially under high grazing pressure compare to less grazed sites. The grazing dynamics of Swartland Shale Renosterveld - Swartland Alluvium Fynbos mosaic system are complex and multifaceted. Farmers need to pay attention to the nutritional status of plant species grazed to know whether they meet the nutritional requirements of the game in the area. Overstocking should be avoided in this system as it triggers the production of tanniferous compounds that could decrease the survivorship of herbivores. Moderate grazing 0.09 LAU/ha pressure provides the best stocking rates for effective grazing management. / AFRIKAANSE OPSOMMING: Vir suksesvolle weidingsbestuur is dit noodsaaklik om die interaksie tussen herbivore, plantvoedingstowwe en grondeienskappe te verstaan. Van besondere belang is plantsmaaklikheid en herbivore se weidingsvoorkeure. Hierdie aspekte, wat die fokus van hierdie tesis is, is bestudeer in ‘n Swartland Shale Renosterveld en Swartland Alluvium Fynbos-mosaïek in die Wes-Kaap Provinsie van Suid-Afrika. Hierdie plantegroei word as kritiek bedreigd geklassifiseer weens die transformering van sy landskap ten gunste van landbou-aktiwiteite en stedelike vestiging. Pre-koloniale herbivoor vertebrata is teen 1700 deur jagters uitgeroei, wat gelei het tot min kennis oor die vroeë dinamiek van die plantegroei. Wildsboere en grondeienaars is egter besig om geselekteerde spesies in die area te hervestig. Bestuurders moet dus weet hoe om praktiese riglyne vir beste-praktyk weidingsbestuur te implementeer. Hierdie studie ondersoek eerstens die verhouding tussen plante en diere. Dit sluit seisoenale evaluering van saadontkieming uit die mis van bontebokke en elande in; die effek van veegetalle op plantsmaaklikheid (ruproteïen, ruvesel, ru-vet, vogpeil, tannien en minerale) van die weiveld is bestudeer om vas te stel hoe plantsmaaklikheid herbivore se weidingsbesluite beïnvloed. Tweedens het die studie die invloed van veegetalle op grondvoedingstowwe (stikstof, fosfor) ondersoek, asook ander grondeienskappe soos pH en grondvogpeile. Die verspreiding van uitheemse grasse is deur weidende diere gefassiliteer. Ongeveer 58% van alle grasse wat uit die mis van elande en bontebokke ontkiem het, was uitheemse spesies. Verder was daar beduidende variasie in plantsmaaklikheid verwant aan beweidingsdruk en plantvolwassenheid tussen verskillende persele en oor seisoene. Grasse op die hoogs beweide persele het 3%-5% hoër koolhidraatinhoude en 1%-5% hoër proteïeninhoude gehad as die minder beweide persele. Volwasse grasse het 10%-20% minder water bevat as onvolwasse grasse, maar het nie in terme van tannienkonsentrasie van die onvolwasse grasse verskil nie. Spesies soos Ficinia sp. het variasies getoon met beweidingsdruk en volwassenheid. Ficinia sp. het op die hoog-beweide perseel ‘n hoër tannienkonsentrasie (5mg/ml-22mg/ml) en meer ruproteïen (4%-9%) gehad as op die minste beweide perseel. Wanneer die plant verouder, verhoog die toename in tannienkonsentrasie (met tussen 15% en 19%). Twee tipes plante is aangeteken volgens hul chemiese response ná beweidingsdruk. Hierdie tipes is 1) plante wat beweidingstolerant is en wat meer koolhidrate produseer wanneer hulle as weiding dien en 2) plante wat onder hoë beweidingsdruk beweidingsintolerant is en wat chemiese verbindings VI soos tannien produseer om herbivooraanvalle af te weer. Die resultate dui aan dat die verhouding tussen voorkeur en plante se chemiese verbindings nie konstant bly in fynbos en renosterveld nie, aangesien geen patrone na vore getree het wat kon verklaar watter verbindings bepalend is vir voorkeur nie. ‘n Kombinasie van chemiese verbindings mag die rede wees waarom die herbivore sekere plante verkies; alternatiewelik mag ‘n herbivoor se plantseleksie beïnvloed word deur chemiese verbindings anders as dié wat in hierdie studie ondersoek is. Die tweede deel van die studie het aangetoon dat veegetalle blyk ‘n beduidende invloed te hê op die grondeienskappe wat ondersoek is. Grondvogpeile is in die herfs beduidend beïnvloed deur die veegetalle. Die perseel met die hoë beweidingsintensiteit het die laagste grondvogpeil gehad, veral in die winter (10% laer as dié van die kontrole-perseel), waarskynlik weens erge getrappel en grondkompaktering. Vergeleke met die kontrole-perseel was pH die laagste op die perseel met die hoë beweidingsintensiteit, in alle seisoene. Waarskynlike redes hiervoor is die hoë neeerslag van stikstof deur mis- en uriene-neerslae, hoë verwydering van basiese katione en dierevervoer wat deur jagaktiwiteite teweeg gebring word. Laatstens behou weiding anorganiese stikstof teen stabiele vlakke ongeag van seisoenale veranderinge en toenames in die konsentrasie van fosfor, veral onder hoë beweidingsdruk vergeleke met minder beweide persele. Die weidingsdinamiek van die Swartland Shale Renosterveld - Swartland Alluvium Fynbosmosaïeksisteem is kompleks en veelvlakkig. Boere behoort aandag te skenk aan die voedingstofstatus van die plantspesies wat as weiding dien, sodat hulle kan weet of die voedingsbehoeftes van die wild in die omgewing bevredig word. Die aanhou van te veel vee in hierdie sisteem behoort vermy te word aangesien dit as sneller dien vir die produksie van tannienbevattende verbindings wat die oorlewingsvermoë van herbivore kan verlaag. Matige beweidingsdruk (0.09 LAU/ha) bied vir effektiewe weidingsbestuur die beste veegetalle.

Page generated in 0.0329 seconds