Academic literature on the topic 'Vegetation dynamics – KwaZulu-Natal'

Changes in phenology can be used as a proxy to elucidate the short and long term trends in climate change and variability. Such phenological changes are driven by weather and climate as well as environmental and ecological factors. Climate change affects plant phenology largely during the vegetative and reproductive stages. The focus of this study was to investigate the changes in phenological parameters of maize as well as to assess their causal factors across the selected maize-producing Provinces (viz: North West, Free State, Mpumalanga and KwaZulu-Natal) of South Africa. For this purpose, five phenological parameters i.e., the length of season (LOS), start of season (SOS), end of season (EOS), position of peak value (POP), and position of trough value (POT) derived from the MODIS NDVI data (MOD13Q1) were analysed. In addition, climatic variables (Potential Evapotranspiration (PET), Precipitation (PRE), Maximum (TMX) and Minimum (TMN) Temperatures spanning from 2000 to 2015 were also analysed. Based on the results, the maize-producing Provinces considered exhibit a decreasing trend in NDVI values. The results further show that Mpumalanga and Free State Provinces have SOS and EOS in December and April respectively. In terms of the LOS, KwaZulu-Natal Province had the highest days (194), followed by Mpumalanga with 177 days, while North West and Free State Provinces had 149 and 148 days, respectively. Our results further demonstrate that the influences of climate variables on phenological parameters exhibit a strong space-time and common covariate dependence. For instance, TMN dominated in North West and Free State, PET and TMX are the main dominant factors in KwaZulu-Natal Province whereas PRE highly dominated in Mpumalanga. Furthermore, the result of the Partial Least Square Path Modeling (PLS-PM) analysis indicates that climatic variables predict about 46% of the variability of phenology indicators and about 63% of the variability of yield indicators for the entire study area. The goodness of fit index indicates that the model has a prediction power of 75% over the entire study area. This study contributes towards enhancing the knowledge of the dynamics in the phenological parameters and the results can assist farmers to make the necessary adjustment in order to have an optimal production and thereby enhance food security for both human and livestock.

Eighty three of Acocks's sites, originally surveyed about 50 years ago, were resurveyed in 1996 to determine the extent of grassland change in the humid grasslands of KwaZulu-Natal. Sites were relocated using 1:10 000 scale ortho-photos and present land cover was determined for each site. Forty six of the sites that were still under original grassland were further examined to determine present species composition. A survey method was designed that would emulate Acocks's data and comparisons were drawn between original and present species composition. These differences were then analysed together with some environmental variables to try to determine the factors which had the most influence on the change and which environment and management factors are related to the present variation in composition among sites. Of the 83 sites, 26 had changed from natural vegetation to some other form of agriculture such as forestry or cultivation. Most of this change had occurred in the Natal Mistbelt Ngongoni Veld where large areas are forested. Cultivation is found predominantly in the communal areas where subsistence, cultivation practices are employed. The remainder of the sites had changed significantly in terms of their species composition. The most pronounced change had occurred in areas under communal tenure although significant changes had occurred in the commercially farmed areas. The direction of change was also more consistent towards species that commonly predominate in heavily grazed areas in the communal areas compared to the commercial areas. The exact reasons for this were unclear but this could possibly be attributed to heavier stocking rates in the communal areas. Change in floristic composition was also more pronounced at lower altitudes where the mean annual rainfall is lower and the mean annual temperature higher. This could possibly be a result of the vegetation at lower altitudes being less stable and thus less resistant to change. Basal cover differed significantly between commercial and communally grazed sites. Lower basal cover was found in the communal sites where intensive grazing limits the growth of individual tufts. Number of species found at each site did not differ significantly between communal and commercially grazed sites. This study was also a practical implementation of the resurveying of Acocks's sites and the original data set was found to be a useful baseline data set to determine coarse long-term changes in the vegetation.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.

A dissertation Submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, for the Degree of Master of Science. .
The cyclone Domoina floods of 1984 were responsible for the large scale destruction and devastation of riverine vegetation in the Umfolozi Game Reserve. This event highlighted the need to gain an understanding af the structure and dynamics of riverine vegetation and to use this knowledge to develop a management strategy directed at the future recovery and maintenance of riverine vegetation in the Umfolozi Game Reserve. (Abbreviation abstract)
Andrew Chakane 2018

Considerable understanding of the functioning of semi-arid systems is still needed to enable range managers to formulate management policies, with a degree of confidence. Long term data sets that encompass a wide range of interactions between the various major components of a semi-arid system (vegetation, herbivory, animal performance, landscape and rainfall), are unfortunately rare but essential to provide sufficient depth of data to adequately test various hypotheses about rangeland dynamics. This study comprises an analysis of a ten year data set derived from two cattle stocking rate trials in the semi-arid savanna of KwaZulu/Natal. Statistical analysis revealed that the most pronounced and rapid compositional change was due to rainfall, but that stocking rates between 0.156 and 0.313 AU ha ¯¹ had an important effect as well. Sites on steeper slopes with heavy stocking rates, exhibited the greatest amount of compositional change between 1986 and 1996 (40 Euclidean points in heavy stocking rate treatments on slopes vs 21-24 Euclidean points in heavy stocking rate treatments on flatter land, or 11-24 Euclidean points in low stocking rate treatments). Heavy stocking rates in conjunction with low rainfall tended to cause decreases in densely tufted perennial grasses and increases in annuals and weakly tufted perennials. Multiple regression analysis revealed that seasonal peak grass production (measured as disc height) declined between 1986 and 1996 only at those sites on steeper slopes with heavy stocking rates. The camps that declined in productivity also underwent the greatest degree of compositional change. The decline in grass productivity in certain high stocking rate camps did not translate into a decline in cattle performance. Depending on rainfall, cattle gained on a seasonal basis between 112 and 241 kg at low stocking rates, 82 and 225 kg at medium stocking rates and 84 and 217 kg at high stocking rates Rainfall, compared with stocking rate, accounted for the greatest amount of variance in seasonal peak grass production and cattle performance. Cattle performance had a strong curvilinear response to rainfall, which also proved to be a better predictor of cattle performance than grass biomass. There were no clear trends in soil physical and chemical characteristics between low and high stocking rates that could provide convincing evidence that loss of soil nutrients was an important mechanism of range degradation. The total standing crop of plant nitrogen but not of phosphorus tended to decline at high stocking rates. Plant nutrient and van Soest analyses suggested that forage quality was higher at heavy stocking rates. The results of this study generally supported traditional concepts of rangeland dynamics with regard to rainfall and grazing effects on compositional change and seasonal grass production. The results were important in being able to show quantitatively that heavy stocking rates result in a decline in grass production and that this effect is dependent on an interaction between stocking rate and landscape position or slope, and that there is a link between a decline in seasonal grass production and compositional change. The results also highlighted areas for future research that would be useful for furthering our understanding of various aspects of rangeland dynamics and mechanisms of degradation.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

Data collected between 1992/93 and 1996/97 from two long-term grazing trials were used to investigate the interaction between grazing animals and veld grass. In the first trial, the impacts of stocking rate and time of stocking in spring on both livestock performance and veld vigour (defined as the ability of a grass plant to regrow after defoliation) and condition were investigated. In the second trial comparisons were made, firstly between the impacts of sheep and cattle grazing, and secondly between various types and frequencies of rest, on veld vigour and condition. Treatments applied in the first trial comprised four stocking rates, namely 7, 10, 13 and 16 sheep ha¯¹ for the duration of the grazing season, and two times of stocking, namely as early as possible after spring burning and three weeks later. Sheep grazed each treatment continuously throughout the growing season. Treatments were applied to alternate blocks in a two-year cycle with each block resting for a year within a grazing cycle. Animal performance (mass gains over the season) was measured to quantify livestock performance. Herbage availability was measured on a species basis at intervals throughout each season using a dry-weight-rank procedure to determine grazing patterns. Residual effects of the grazing treatments on vigour were determined by measuring herbage regrowth on a species basis during the rest season which followed a season of grazing and comparing these measures to a previously ungrazed control treatment. Effects of the grazing treatment on proportional species composition were determined using a nearest plant point technique. Stocking rate had a non-linear effect on livestock performance, with livestock performance on the lightest stocking rate being less than on the two intermediate stocking rates. The mass gains on the heaviest stocking rate were generally the smallest. Delaying the time of stocking in spring resulted in smaller mass gains during the resultant shorter season. The sheep from both the early and late time of stocking groups had similar mean masses at the end of the season. The advantage of stocking early can thus be attributed more to saving the cost of alternative feed for the interim period than to additional mass gains due to stocking early. Quantification of livestock performance in terms of selected and available feed quality, quantity and species availability throughout each season was extremely complex due to multiple thresholds in the measured variables and no simple cause and effect relations could be established that would hold for spatial or temporal extrapolation. The negative impact of grazing on veld vigour was severe. Stocking rate and time of stocking had a secondary impact with the vigour loss positively related to increasing grazing pressure. The main factor influencing vigour loss was grazing, irrespective of time of stocking or stocking rate, as opposed to no grazing. The impact of grazing on vigour was severely negative in the palatable species, variable in the species of intermediate palatability and positive in the unpalatable species that were rarely, if ever, grazed. The stocking rate and time of stocking rate had an impact on the proportional species composition, with the more palatable species declining in proportion. There was an observable relation between impact of grazing on vigour and on species composition. Treatments applied in the second trial involved applying a full growing season rest in alternate years, half a growing season rest (late season) in alternate years and no rest to veld grazed by sheep or cattle at similar stocking rates. Residual effects of the treatments on veld vigour were determined by measuring species regrowth using a dry-weight-rank technique during the season following treatment application, and comparing it to controls ungrazed for one and two seasons respectively. Changes in proportional species composition were determined using a nearest plant point technique. The vigour of veld grazed by sheep declined rapidly relative to veld grazed by cattle. The vigour of palatable species was severely impacted, vigour of intermediate species was variably impacted and vigour of unpalatable species increased dramatically on veld grazed by sheep compared to the control treatments. Similar trends occurred in veld grazed by cattle, but to a lesser degree. Resting was beneficial for vigour recovery in both sheep and cattle treatments but it seems that the grazing treatment between rests has a greater influence on the veld vigour and condition than the rest itself. The veld grazed by sheep remained at a substantially lower productivity level than veld grazed by cattle. This was particularly evident in the change in productivity balance between palatable and unpalatable species in the sheep treatments, where palatable species vigour declined and unpalatable species vigour increased relative to veld grazing by cattle. Species composition of veld grazed by sheep deteriorated over the trial period in contrast to the veld grazed by cattle, which improved in species composition. Grazing management recommendations for sourveld should include a bias towards cattle, optimising stocking rate for improved performance and resting for enhancing vigour of the palatable grasses.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1999.

The overall aim of the study was to investigate re-vegetation of disturbed sites, using nursery grown plugs (from seedling trays) of Themeda triandra, Heteropogon contortus and Hyparrhenia dregeana in order to reach practical management guidelines for re-vegetation using indigenous grass plugs. A number of field trials were set up at Kamberg Nature Reserve (29°24'S, 29°40'E) on a site that was clear felled of A. mearnsii in October 1997. The trials were established in January 1998 and January 1999. A total of approximately 52 ,000 nursery raised plugs of T. triandra, H. contortus and H. dregeana were planted into an area of approximately 7,000 m2 . In the planting density trial , plugs of H. dregeana only and a combination of T. triandra/H. contortus were planted at 15 cm and 30 cm spacings. The T. triandra/H. contortus combination at 30 spacing showed the greatest survival and lateral plant growth (tiller number and basal area) and this combination is thus recommended. In the over-sowing trials, the H. dregeana and T. triandra/H. contortus combination at both 15 cm and 30 cm spacing were over-sown with E. curvula. The survival and lateral growth of the T. triandra/ H. contortus combination at 30 cm was again greater than the other treatments. Over-sowing with E. curvula suppressed the survival and lateral growth of the planted plugs across all treatments compared to not over-sowing. The over-sown conditions showed a significant decrease in the diversity of the plots, both in the number of species present and the Shannon diversity index. An area that had been cleared of A. mearnsii and sown to E. curvula 25 years previously was shown to have a lower number of species than the neighbouring veld. Nursery raised plugs of T. triandra were planted into the mature E. curvula in an attempt to improve the biodiversity of these areas. To re-introduce T. triandra into these E. curvula swards the plugs must be planted into the centre of a gap rather than around the base of an E. curvula plant. For improved survival of the plugs the E. curvula tufts must be clipped, while for best lateral growth the E. curvula tufts must be sprayed with a glyphosate herbicide three months prior to planting and clipping. However, the added expense of spraying and clipping is not warranted as the clipped treatments also showed good growth. Transplant shock is common when planting nursery raised plugs out into the field, as there is a relatively small root volume in the plug compared to the above ground leaf biomass. Alleviation of moisture stress at planting using a starch based polymer with high water holding capacity (Terrasorb®) and a white, needle punched geo-fabric (Agrilen®) to provide a seven day period of artificial shade after planting did not show significant improvements over the control with regards to survival or plant growth. Thus these methods of moisture amelioration are not recommended in revegetation through planting of plugs at this study site. A trial was established to investigate the biomass production of six different treatments to determine their potential to support a fire. The total biomass for the plots which were over-sown by E. tef and planted to only H. dregeana were on average sufficient for a fire, but there was a discontinuous fuel load across these plots, especially in the replications that had very low survival rates and thus these plots could not be burnt. The control and herbicide sprayed plots also showed sufficient fuel load for a fire, but this fuel load was made up of A. mearnsii saplings and bramble with very little grass cover and thus a fire would not have burnt through these plots either. The T. triandra/H. contortus combination did not produce sufficient fuel load, due to poor survival. Thus only the plots over-sown with E. curvula were able to burn in this trial and as a burning trial per se the trial was abandoned. Seed bearing hay (thatch) was collected in early summer (December 1997) and late summer (April 1998). Both times of year of harvesting proved to be successful in terms of grass cover, although the early harvested thatch had a greater number of species per plot. The Shannon diversity indexes of the two treatments were not significantly different. The multi-response permutation procedure technique confirmed that there was a compositional difference between the treatments. By the end of the trial Harpochloa falx and T. triandra and H. dregeana were indicators for the early and the late harvested thatch respectively. Comparing the thatching trial and the planting density trial indicated that the T. triandra/H. contortus combination at 30 cm spacing would be recommended to maximize biodiversity. The summer months have been shown to be the best time to plant the plugs, although the actual success will be dependant on the conditions within a particular year. The plugs should not be kept in the nursery for longer than three months and larger plugs (96 seedlings per tray) should be used. Nursery raised plugs of T. triandra and H. contortus were planted in an equal mix in an area that was cleared of A. mearnsii in 1996. By June 1998 661 H. contortus seedlings and 14 T. triandra seedlings had germinated naturally. The November 1998 population consisted of 418 H. contortus seedlings and 18 T. triandra seedlings. By May 2000 the June 1998 population showed a survival of 78.4% and the November 1998 population showed a survival of 91 .1 %. In the various trials, the ability of the nursery raised plugs used for re-vegetation to suppress the regrowth of A. mearnsii was investigated by determining the number of A. mearnsii seedlings per metre squared. The plant spacing and species of plugs used did not have a significant effect on the number of A. mearnsii seedlings per metre squared. Over-sowing with E. curvula did, however, significantly suppress the wattle re-growth. In the thatching trial the early harvested plots showed lower numbers of A. mearnsii per metre squared than the late harvest plots, as they were covered with a thick layer of thatch soon after the A. mearnsii was cleared which suppressed the A. mearnsii re-growth. Although E. curvula is able to produce a high biomass and suppress the A. meansii seedlings, it has a detrimental effect on the biodiversity of the area. Therefore, in conservation areas, where biodiversity is of great importance the planted plugs (at 30 cm spacing) or seed bearing hay must be used in preference to sowing E. curvula , although it must be remembered that greater follow up control is likely to be needed with planted plugs or seed bearing hay. The area must be planted or thatched as soon as possible after clear felling to provide competition for the A. mearnsii seedlings.
Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

The objective of this study was to describe the impacts of the density of Chromolaena odorata (chromolaena) on species composition in coastal grasslands and to investigate serial changes in the vegetation following the implementation of a burning programme. The thesis deals with key ecological concepts and issues, so a comprehensive literature review is included. Chromolaena invades coastal grasslands that are not burnt regularly (i.e. biennially). Grasslands that were not burnt for 30 years were seral to secondary forest. The successional pathway from open grassland to closed canopy forest varied according to soil type. Coastal grasslands on Glenrosa soils were characterised by savanna at an intermediate stage between the grassland and forest states. Shading ended the persistence of savanna species (e.g. Combretum molle, Dichrostachys cinerea and Heteropyxis natalensis) in forest, whereas forest precursors (e.g. Canthium inerme, Maytenus undata and Protorhus longifolia) only established where fire was absent. Chromolaena infestations were characterised by multi-stemmed adult plants of variable height (i.e. 1-3 m), depending on soil type. Regic sands did not support stratified woody vegetation and chromolaena infestations were self-supporting, reaching a maximum height of 1.5 m. Glenrosa soils supported tree communities and chromolaena reached more than 3 m in places. The density of chromolaena affected species composition in grasslands with moderate to dense stands (> 5 adult plants m ¯² or >50000 shrubs ha ¯¹). Chromolaena stands became monospecific when the number of adult plants exceeded 7 m ¯². Succession to forest also ceased once chromolaena became thicket-forming. Fire-induced mortality of the chromolaena depended on grass fuel loads. Grass cover of 30% (c. 1 000 kg ha ¯¹) was required to achieve 80% mortality of the parent infestation after the initial burn. Dense infestations could only be killed by running head-fires from adjacent grasslands into thickets. Under conditions where head-fires could not be used, infestations were slashed and burnt at the height of the dry season (July to August) to achieve an 80% kill rate. Seedlings were killed (99%) by annual burning in sparse (≤ 10000 shrubs ha ¯¹) to moderate < 50 000 shrubs ha ¯¹) infestations. The suppression of chromolaena and other alien species, establishing on bare ground after clearing dense infestations, required chemical control until grass cover was sufficient (i.e. 1 000 kg ha ¯¹) to effect uniform burning. Certain secondary alien invaders (e.g. Lantana camara, Psidium guajava and Solanum mauritianum) persisted by coppicing profusely after fire and herbicides need to be integrated into burning programmes when these species occur. Grasslands on regic sands (e.g. Ischaemum fasciculatum, Panicum dregeanum and Themeda triandra) were more resilient to the modifying effects of woody vegetation, than grasslands on Glenrosa soils. Grasslands on Glenrosa soils did not revert to an open state but persisted as ruderal savanna grassland (e.g. Eragrostis curvula, Hyparrhenia tamba and Cymbopogon validus) once fire-resistant tree species (e.g. Combretum molle and Heteropyxis natalensis) had established. Depending the objectives for land management and the vegetation's condition, coastal grasslands can be rehabilitated and managed in multiple states, i.e. grassland, savanna or forest communities. A state-and-transition model based on the empirical data recorded in the study is presented and shows chromolaena altering vegetation states from open grassland to chromolaena dominated thicket. The model illustrates chromolaena thickets as the dominant phase of a moist coastal forest/savanna succession, irrespective of soil type, in absence of appropriate land management practices (e.g. control burning and integrated control of alien vegetation). This model should aid in planning strategies for the control of chromolaena in subtropical grasslands in South Africa.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.

The vegetation along the north coast of KwaZulu-Natal has long been considered to have originally consisted of forest, scrub forest and savanna. The classical view is that in the last 600 years the early Africans and European farmers were responsible for the removal of forest and scrub forest along the coast. This view was not based on direct evidence but on the theory that the eastern part of the country has a climate "suitable" for forest and scrub forest. The present 'false' grasslands were thus thought to have developed through anthropogenic influences. All of this has its basis in the paradigm of ecological succession and the presence of a "climatic climax". This traditional view has been contested recently, based on archaeological, historical, biogeographical and ecological evidence that has become available since the 1950's. It is suggested that South Africa's grass lands have been in existence for the last two thousand years but probably for more than ten thousand years. This study aims to investigate this controversy in greater detail, using evidence from archaeological records, travellers records, transcripts, historical reviews, and diarised records. The locations of archaeological sites within the study area were determined and mapped out, followed by an analysis and interpretation of the data with reference to vegetation change. Archaeological evidence included shell middens, evidence of iron working and pottery remains. The activities of the early humans included iron smelting, agriculture and stock farming. Their activities required the selective use of vegetation for specific purposes, and vegetation was cleared for homesteads and villages. However, the density of people within the study area was low, and there was limited technological development, such that extensive clearing by relatively few people is unlikely. Furthermore, sites are concentrated along the coastline, with fewer sites away from the coast, suggesting that impacts would have been greatest along the coastline. However, this is where forests presently occur. Overall, the evidence suggests that the natural vegetation on the north coast was not modified drastically by precolonial settlers. Historical accounts of early travellers and settlers indicate a strip of forest along the coastline and a grassland/woodland mosaic away from the coast. Records of mammals suggest a fauna typical of savannas and not forest. With settlement over time, the major activity that impacted on the north coast vegetation, was agriculture. Sugar cane plantations contributed considerably to the clearing of vegetation that seems to have consisted primarily of open grasslands with patches of trees. Colonial settlement of this area resulted in various activities that required the large-scale removal of natural vegetation. It is important to know the human disturbance history of an area as this helps to assess the extent of change and to design appropriate management strategies for conservation of plant resources. The belief that the early vegetation of the north coast was forest has placed great emphasis on the conservation of forests along this coastal area. Based on this study, it seems that this vegetation type should not be the focus of conservation efforts, but that coastal grasslands with scattered bush clumps should be given much greater emphasis. Grasslands were more widespread in the region prior to European settlement, and based on this, conservationists should place greater emphasis on preserving this habitat.
Thesis (M.Sc.)-University of Natal, Durban, 2000.

Aristida junciformis subsp. junciformis Trin. et Rupr. is an indigenous, densely tufted, evergreen perennial grass associated with the degeneration of grasslands over large areas of South Africa. More than two hundred thousand square kilometres of veld, c. 17% of the total land area of South Africa, contains A. junciformis. The aim of this study was to improve our understanding of the mechanisms by which this species invades and dominates grassland, specifically in this study, Southern Tall Grassveld. Aristida junciformis also has a low nutritional value resulting in a very low grazing value. The unpalatability of the plant is due to the high tensile strength of the leaves, whose hard, fibrous laminas are very difficult for a grazing animal to crop once their length attains 30 cm or more. This species lack of response to conventional grazing practices has often resulted in a grassland in which the carrying capacity has diminished to such an extent as to be virtually useless for grazing in a relatively short time. The extent of encroachment of veld by A. junciformis appears dependant on the frequency of disturbance and rest afforded to the veld. Annual burning and mowing maintained the species composition of A. junciformis at levels <10% whilst protection from fire, burning or grazing allows this species to dominate the herbaceous layer at levels approaching 90%. Aristida junciformis does not become moribund and is unlikely to die if left undefoliated. As the abundance of A. junciformis increases, veld deterioration gradually accelerates through increased selective grazing on remaining palatable species. Competition from adult A. junciformis plants increases the mortality of seedlings and constrains growth of surviving seedlings. Tiller production of Aristida junciformis seedlings declined from an average of 5.2 tillers per seedling in a no competition situation to 2.2 tillers per seedling when subjected to full competition. Tiller production of T. triandra seedlings decreased from 9.6 tillers per seedling free from competition to 3.3 tillers per seedling subject to full competition for resources. Once these seedlings have become adult plants they are avoided by grazing animals and grazing pressure on the remaining palatable species consequently increases. This allows the A. junciformis plants to increase their size and density in the sward. Once this density is sufficiently high, grass seedlings of either A. junciformis or more desirable grass species such as T. triandra are unable to establish, eventually resulting in a monospecific stand of A. junciformis if left undisturbed. Large amounts of caryopses are produced by A. junciformis - up to a 19 000 caryopses from a large mature plant (c. 38 000 caryopses/m²). Of these c. 40% is likely to be infertile but the remaining c. 60% viable caryopses are dispersed in a typically leptokurtic distribution, the number of caryopses dispersed rapidly declining within a 10 metre radius. A large proportion of the caryopses was trapped in surrounding foliage but in open swards caryopses had greater opportunity to be blown further distances than in a closed sward. The density of A. junciformis caryopses on the soil surface was positively correlated with the density of flowering adult plants in the area and varied from 400 caryopses/m² (density of parent plants c. 0.6 plants/m²) in less effected areas to 11000 caryopses/m² (density of adult plants c. 6 plants/m²) in severely encroached areas. The primary function of the three awns appears to be orientating the caryopsis correctly for in its descent from the parent plant to expedite germination. Caryopses orientated vertically with the awns uppermost exhibited the highest and most rapid germination (67%) compared to caryopses lying horizontally (35%) whilst only 1% of inverted caryopses germinated. Caryopses trapped in litter and effectively held off the soil surface failed to germinate. Removal of the glumes from A junciformis seed greatly enhanced the rate and overall germination of the seed except for inverted seed of which <1% germinated. The highest numbers of A. junciformis seedlings (32 seedlings/m²) were found in those areas with the highest density of caryopses on the soil surface. Despite the large amounts of caryopses produced, dispersed and landing in apparently suitable micro-sites for germination, comparatively few A. junciformis seedlings (n=992) were found and overall germination ranged between 1 % and 4% of the initial caryopses density on the soil surface. Seedling survival through winter was low with only 13% surviving to the following spring. The basal areas of A. junciformis increased overall by 66% whilst that of other grass species increased overall by only 3% in the time monitored. These results suggest that the primary method of encroachment of A. junciformis in the grass sward appears to be through vegetative expansion and not seedling recruitment. Frequent defoliation of the sward and avoidance of overgrazing to enhance the competitive abilities of palatable species and provide as high a fuel load as possible appear to be the most economically and logistically feasible ways to remove or at least inhibit A. junciformis veld encroachment at present.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

The Albert Falls Area had witnessed severe competition over land use between agriculture, recreation, conservation and other land uses. The area also has been the scene for inefficient land management that led to degradation of land resources. For proper land use planning and environmental management, information on land use/cover change is vital. This study has developed a spatial and descriptive historical land use/cover databases for the years 1944, 1967, 1989, and 2000 to provide an understanding of land use/cover patterns in Albert Falls Area. The databases were created by interpreting historical aerial photographs and using Geographic Information Systems. The data was subsequently analyzed to detect relevant trends in land use/cover patterns in the study area. Generally land use/cover pattern of Albert Falls Area during the period 1944 to 2000 may be described as being mainly agricultural. The results showed a marginal increase of indigenous forests attributed to the continuous efforts by different governmental departments and policies that focused on the protection of the remaining patches of indigenous forests. Grassland not only decreased by more than half but it also deteriorated in quality during 1944 to 2000. Commercial Forestry predominates the study area and showed an increasing trend from 1944 to 1967. Cultivated Land was observed to decrease at the expense of Commercial Forestry plantations and Waterbodies. Although sugarcane plantations increased after 1967, total Cultivated Land showed a decreasing trend. The construction of Albert Falls Dam and other small Farm Ponds within the agricultural farms increased the land areas covered by Waterbodies. Residential Area coverage generally decreased irrespective of the encroachment of informal settlements, while that outside Non-Residential Area and Transportation Routes generally increased with the development of commercial agriculture in the area. Barren Land decreased continuously due to higher land demand in the study area. The study showed that land use/cover changes in Albert Falls Area. have resulted in habitat fragmentation, development of monoculture land use, flourishing of Farm Ponds in agricultural farms, and expansion of agricultural activities on marginal lands. Creation of corridors/linkages between the fragmented forest patches; commencement and implementation of the already well drafted land and land resource policies and regulations; commencement of the holistic management plans in the area were recommended for a sustainable land use.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.