Euryops floribundus encroachment in Eastern Cape communal rangelands: indigenous and scientific understanding of effects on range
- Authors: Gxasheka, Masibonge
- Date: 2013
- Subjects: Euryops -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape , Food security -- South Africa - Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11585 , http://hdl.handle.net/10353/d1016203 , Euryops -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape , Food security -- South Africa - Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Description: The study was conducted in Eastern Cape Province to 1) investigate local people’s knowledge and perceptions on Euryops floribundus and 2) landscape distribution and effect of Euryops floribundus on herbaceous vegetation and soil. A total of 90 households who own livestock were randomly selected from the three communal areas, namely; Tsengiwe, Upper Mnxe and Manzimdaka for household surveys and group discussions. For landscape study, a total of about 5 ha of land were selected at Upper Mnxe communal area. Selection criteria included the presence of E. floribundus and different landscape gradients. A total of four 50mx50 plots were marked along the landscape gradients: Bottom, Middle, and Upper Slope and upland positions. To study the effect of E. floribundus invasion on the herbaceous vegetation and soil, a total of 4 ha communal land was selected in an accessible area which had a largely flat terrain. The area was selected to have adjacent sites with no invasion (< 5% shrub cover), light (5-15% shrub cover), moderate (>15-35) and heavy invasions (>35% shrub cover) of E. floribundus. The average household size in the study area was 6.8± 0.7. All people in the three communal areas unanimously ranked sheep as the most important species for their livelihood, but the ranking of cattle and goat varied among the communal areas. All elder groups agreed that Europs floribundus decreases both the quantity and quality of herbaceous forage as well as livestock production. Moreover, invaded patches create more bare areas which are responsible for the loss of top fertile soils and the formation of rills and gullies. The result showed that the total density of E. floribundus significantly increased from the topland (2301 plants ha-1) moving to the bottomland (4888 plants ha-1). Canopy cover was significantly lowest in the topland (17.9%), but the remaining gradients had similar cover. Grass dry matter yield was higher in the bottomlands and sloppy gradients than the toplands. Soil organic carbon was significantly higher (P<0.05) in the flat than the sloppy terrain. Soils from higher elevations (toplands and upper sloppy) had significantly higher N than the lower elevations (bottomlands and Middle sloppy). The lowest dry matter was observed at low invasion and non-invaded sites. Soil chemical properties were generally different from all density levels. In conclusion, E. floribundus encroachment was found to be major cause of decline in the peoples’ livelihood because as this reduces the vegetation diversity and livestock production, both of which are the major of their livelihoods.
- Full Text:
- Date Issued: 2013
- Authors: Gxasheka, Masibonge
- Date: 2013
- Subjects: Euryops -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape , Food security -- South Africa - Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11585 , http://hdl.handle.net/10353/d1016203 , Euryops -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape , Food security -- South Africa - Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Description: The study was conducted in Eastern Cape Province to 1) investigate local people’s knowledge and perceptions on Euryops floribundus and 2) landscape distribution and effect of Euryops floribundus on herbaceous vegetation and soil. A total of 90 households who own livestock were randomly selected from the three communal areas, namely; Tsengiwe, Upper Mnxe and Manzimdaka for household surveys and group discussions. For landscape study, a total of about 5 ha of land were selected at Upper Mnxe communal area. Selection criteria included the presence of E. floribundus and different landscape gradients. A total of four 50mx50 plots were marked along the landscape gradients: Bottom, Middle, and Upper Slope and upland positions. To study the effect of E. floribundus invasion on the herbaceous vegetation and soil, a total of 4 ha communal land was selected in an accessible area which had a largely flat terrain. The area was selected to have adjacent sites with no invasion (< 5% shrub cover), light (5-15% shrub cover), moderate (>15-35) and heavy invasions (>35% shrub cover) of E. floribundus. The average household size in the study area was 6.8± 0.7. All people in the three communal areas unanimously ranked sheep as the most important species for their livelihood, but the ranking of cattle and goat varied among the communal areas. All elder groups agreed that Europs floribundus decreases both the quantity and quality of herbaceous forage as well as livestock production. Moreover, invaded patches create more bare areas which are responsible for the loss of top fertile soils and the formation of rills and gullies. The result showed that the total density of E. floribundus significantly increased from the topland (2301 plants ha-1) moving to the bottomland (4888 plants ha-1). Canopy cover was significantly lowest in the topland (17.9%), but the remaining gradients had similar cover. Grass dry matter yield was higher in the bottomlands and sloppy gradients than the toplands. Soil organic carbon was significantly higher (P<0.05) in the flat than the sloppy terrain. Soils from higher elevations (toplands and upper sloppy) had significantly higher N than the lower elevations (bottomlands and Middle sloppy). The lowest dry matter was observed at low invasion and non-invaded sites. Soil chemical properties were generally different from all density levels. In conclusion, E. floribundus encroachment was found to be major cause of decline in the peoples’ livelihood because as this reduces the vegetation diversity and livestock production, both of which are the major of their livelihoods.
- Full Text:
- Date Issued: 2013
Evaluation of range condition, soil properties, seed banks and farmer's perceptions in Peddie communal rangeland of the Eastern Cape, South Africa
- Authors: Mndela, Mthunzi
- Date: 2013
- Subjects: Rangelands -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Forage , Range management -- South Africa -- Eastern Cape , Nguni cattle -- South Africa -- Eastern Cape , Soil seed banks -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11583 , http://hdl.handle.net/10353/d1013153 , Rangelands -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Forage , Range management -- South Africa -- Eastern Cape , Nguni cattle -- South Africa -- Eastern Cape , Soil seed banks -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape
- Description: South African rangelands in combination with their surrounding homesteads occupy 13% of the entire land surface in South Africa. These rangelands are a source of forage for communal livestock. The rangelands in communal tenure system are degraded due to high human population and livestock numbers. The rangeland of Peddie was never evaluated since the introduction of Nguni Cattle Empowerment Project. Therefore, socio-ecological evaluation was conducted in order to interlink farmer‟s perceptions and scientific data to recommend appropriate rangeland management and restoration programme. Two structured questionnaires consisting of close and open ended questions were used to investigate farmer‟s perceptions on rangeland condition, dynamics, and their causes. Sixty households were randomly selected on the bases of livestock ownership and the membership in Nguni Cattle Project. In each household, any respondent of 20 years or greater, and a key informant of age greater than 40 years were selected. For scientific assessment of range condition, three homogenous vegetation units namely grassland, scattered and dense bushland were demarcated into four 100m x 50m replicates. In each replicate, two 100m transects were laid parallel to each other with 30m equidistant apart. The step point and harvesting method along each transect were employed for herbaceous species composition and biomass production. The point-to-tuft distance was also determined as a proxy for basal cover. Woody density, species composition and tree equivalents were determined in 200m2 belt transects in each HVU replicates. The germination method for soil seed bank evaluation was also employed to find plant species composition and density. The soil nutrients (OC, N, P, K, Na, Ca, Mg, Zn, Cu and Mn) and pH were analysed through solution preparation and observation under photospectrometer to determine functional capacity of the soil of Peddie rangeland. The farmer‟s perceptions comprised of 63% females and 37% males (n = 120) with a mean household of 8 people, 5 adults and 3 children. It was perceived by 93.3% respondents that the rangeland of Peddie have undergone changes over two decades. These changes were perceived by 83% respondents to be accompanied by decline in livestock numbers. Woody encroachment and overgrazing were perceived to be the major attributes of these vegetation changes. The scientific rangeland condition assessment confirmed that these changes were more pronounced as bush density increases. Dense bushland had a significantly high (p<0.05) encroached condition with 6650 trees ha-1 and 4909.5 TE ha-1 beyond the recommended thresholds of 2400 trees ha-1 and 2500 TE ha-1 respectively. Scattered bushland had a fair condition of 1950 trees ha-1 and 1198.1TE ha-1. Themeda triandra as a key species was significantly higher (p<0.05) in grassland (31.1%) than scattered (15.6%) and dense bushland (6.1%). There was a declining trend in biomass production from grassland to dense bushland. The summer biomass production was significantly higher (p<0.05) in grassland than scattered and dense bushland but winter biomass was not significantly different (p>0.05) from all homogenous vegetation units of Peddie rangeland. However, the soil fertility increased with an increase in bush density except organic carbon (OC) which was 1.61% in grassland, 1.46% in scattered and 1.53% in dense bushland respectively. Soil N, K, P, Mg2+ Na+, Ca2+, Cu, Zn, Mn and pH were significantly higher (p<0.05) in dense bushland than grassland and scattered bushland. High soil fertility in dense bushland may be attributed to by abscission of woody plants and litter decomposition. In the soil seed bank, the abundances of forbs were significantly higher than sedges (χ2 = 12, df = 1, p = 0.001) and grasses (χ2 = 8.333, df = 1, p = 0.004) in all homogenous vegetation units while sedges were not significantly different (χ2 = 3, df = 1, p = 0.083) from grasses. The Sorensen‟s index indicated that soil seed bank and extant vegetation were significantly different (p<0.05). Annual and biennial forbs and sedges had high abundances while perennial grasses formed a bulk in above ground vegetation. This provided an insight that a reliance on soil seed bank for restoration of Peddie rangeland would not be advisable because it can result in retrogression. The communal rangeland assessment provided clear qualitative and quantitative data when the combination of indigenous knowledge and scientific assessments was done. The rationale is that conclusions and recommendations of range assessment are relient on the farmer‟s perceptions pertinent to their livestock production systems and their rangeland management objectives. This study has shown that inclusion of communal farmers in policy making can provide better insight because those are the people experiencing the consequences of range degradation.
- Full Text:
- Date Issued: 2013
- Authors: Mndela, Mthunzi
- Date: 2013
- Subjects: Rangelands -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Forage , Range management -- South Africa -- Eastern Cape , Nguni cattle -- South Africa -- Eastern Cape , Soil seed banks -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11583 , http://hdl.handle.net/10353/d1013153 , Rangelands -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Forage , Range management -- South Africa -- Eastern Cape , Nguni cattle -- South Africa -- Eastern Cape , Soil seed banks -- South Africa -- Eastern Cape , Ethnoscience -- South Africa -- Eastern Cape
- Description: South African rangelands in combination with their surrounding homesteads occupy 13% of the entire land surface in South Africa. These rangelands are a source of forage for communal livestock. The rangelands in communal tenure system are degraded due to high human population and livestock numbers. The rangeland of Peddie was never evaluated since the introduction of Nguni Cattle Empowerment Project. Therefore, socio-ecological evaluation was conducted in order to interlink farmer‟s perceptions and scientific data to recommend appropriate rangeland management and restoration programme. Two structured questionnaires consisting of close and open ended questions were used to investigate farmer‟s perceptions on rangeland condition, dynamics, and their causes. Sixty households were randomly selected on the bases of livestock ownership and the membership in Nguni Cattle Project. In each household, any respondent of 20 years or greater, and a key informant of age greater than 40 years were selected. For scientific assessment of range condition, three homogenous vegetation units namely grassland, scattered and dense bushland were demarcated into four 100m x 50m replicates. In each replicate, two 100m transects were laid parallel to each other with 30m equidistant apart. The step point and harvesting method along each transect were employed for herbaceous species composition and biomass production. The point-to-tuft distance was also determined as a proxy for basal cover. Woody density, species composition and tree equivalents were determined in 200m2 belt transects in each HVU replicates. The germination method for soil seed bank evaluation was also employed to find plant species composition and density. The soil nutrients (OC, N, P, K, Na, Ca, Mg, Zn, Cu and Mn) and pH were analysed through solution preparation and observation under photospectrometer to determine functional capacity of the soil of Peddie rangeland. The farmer‟s perceptions comprised of 63% females and 37% males (n = 120) with a mean household of 8 people, 5 adults and 3 children. It was perceived by 93.3% respondents that the rangeland of Peddie have undergone changes over two decades. These changes were perceived by 83% respondents to be accompanied by decline in livestock numbers. Woody encroachment and overgrazing were perceived to be the major attributes of these vegetation changes. The scientific rangeland condition assessment confirmed that these changes were more pronounced as bush density increases. Dense bushland had a significantly high (p<0.05) encroached condition with 6650 trees ha-1 and 4909.5 TE ha-1 beyond the recommended thresholds of 2400 trees ha-1 and 2500 TE ha-1 respectively. Scattered bushland had a fair condition of 1950 trees ha-1 and 1198.1TE ha-1. Themeda triandra as a key species was significantly higher (p<0.05) in grassland (31.1%) than scattered (15.6%) and dense bushland (6.1%). There was a declining trend in biomass production from grassland to dense bushland. The summer biomass production was significantly higher (p<0.05) in grassland than scattered and dense bushland but winter biomass was not significantly different (p>0.05) from all homogenous vegetation units of Peddie rangeland. However, the soil fertility increased with an increase in bush density except organic carbon (OC) which was 1.61% in grassland, 1.46% in scattered and 1.53% in dense bushland respectively. Soil N, K, P, Mg2+ Na+, Ca2+, Cu, Zn, Mn and pH were significantly higher (p<0.05) in dense bushland than grassland and scattered bushland. High soil fertility in dense bushland may be attributed to by abscission of woody plants and litter decomposition. In the soil seed bank, the abundances of forbs were significantly higher than sedges (χ2 = 12, df = 1, p = 0.001) and grasses (χ2 = 8.333, df = 1, p = 0.004) in all homogenous vegetation units while sedges were not significantly different (χ2 = 3, df = 1, p = 0.083) from grasses. The Sorensen‟s index indicated that soil seed bank and extant vegetation were significantly different (p<0.05). Annual and biennial forbs and sedges had high abundances while perennial grasses formed a bulk in above ground vegetation. This provided an insight that a reliance on soil seed bank for restoration of Peddie rangeland would not be advisable because it can result in retrogression. The communal rangeland assessment provided clear qualitative and quantitative data when the combination of indigenous knowledge and scientific assessments was done. The rationale is that conclusions and recommendations of range assessment are relient on the farmer‟s perceptions pertinent to their livestock production systems and their rangeland management objectives. This study has shown that inclusion of communal farmers in policy making can provide better insight because those are the people experiencing the consequences of range degradation.
- Full Text:
- Date Issued: 2013
Species and spatio-temporal variation in the yield, nutritive value and in vitro ruminal fermentation characteristics of selected grass species from two communal grazing lands of the Eastern Cape
- Authors: Kwaza, Ayanda
- Date: 2013
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: http://hdl.handle.net/10353/987 , vital:26515
- Description: Communal rangelands sustain a large proportion of the livestock in South Africa. A few dominant grass species contribute to the bulk of the livestock forage in these rangelands. Little is known on the chemical composition and in vitro ruminal fermentation characteristics of grass species grazed by ruminants in the communal grazing lands of Eastern Cape Province in South Africa. The objectives of this study were therefore to investigate seasonal and altitudinal variations in biomass yield, chemical composition, and in vitro ruminal degradability and cumulative gas production of selected (dominant) grass species. The grass species were collected over four seasons (summer, autumn, winter and spring) from three altitudes/landscape gradients (upland, gentle sloppy and bottomlands) across two communal areas (Hala in highland (Highveld) and Gqumashe in lowland (Lowveld)) of the Eastern Cape province, South Africa. In each altitude, three 50 m x 20 m plots, which served as replicates were marked to collect vegetation samples. A 5 x 4 x 3 factorial experiment in a randomised complete block design was used with season, altitude and grass species being the main factors, and with the plots within altitudes serving as blocks (replicates). Data analysis was done separately for the two communal study areas using the General Linear Models (GLM) procedure of SAS to test differences between species, seasons and altitudes. The common grass species in both grazing lands were Cynodon dactylon, Eragrostis chloromelus, Eragrostis plana, Sporobolus africanus and Themeda triandra. When the DM yield of all the grasses was combined, the results showed a generally low forage dry matter yield during the dry season. There was no significant (P>0.05) interaction between any of the main factors. Macro and micro mineral content of plant samples collected from the two communal grazing lands showed great variations (P<0.05) between species, seasons and altitude. In the Highveld, CP ranged from 3.9 to 6.5% DM being significantly highest (P<0.05) in Cynodon dactylon and lowest in E. plana. When all species were combined, higher CP was recorded for samples harvested in summer (5.5%) followed by spring and autumn, and lowest in winter (3.8%). In the Lowveld, Eragrostis chloromelus had higher (P<0.05) CP level followed by C. dactylon and T. Triandra. When all species were pooled, forage samples harvested in summer had a significantly higher (P<0.05) CP followed by spring, autumn and winter. In summary, CP content of all grasses was below the critical maintenance level for livestock especially during late dry seasons. In both areas, the highest NDF level was measured for Eragrostis plana and lowest for Themeda triandra. As for altitudinal differences, samples collected from the upland areas had generally the lowest (P<0.05) CP and highest ADF contents. For grasses harvested from the Highveld, C. dactylon produced the most (P<0.05) gas after 48 h of fermentation (794.6 ml/g DM) and also had the highest 48h DMD (415.1 g kg-1). Themeda triandra produced least (P<0.05) gas (742 ml/g DM) 48h post-incubation. The least (P<0.05) degradable species after 48 h was E. chloromelus (372.9 g kg-1). For grasses harvested from Lowveld, the 48h cumulative gas production was highest (822.7 ml/g DM) in E. plana and lowest (742.8 ml/g DM) in E. chloromelus, while S. africanus had least 48h DMD (327.9 kg-1). In both the Highveld and Lowveld, gas production and DMD were highest in the autumn season. It was concluded most grasses were deficient in calcium, magnesium, phosphorus and potassium. Therefore, it is recommended that mineral supplements should be offered to animals to improve animal productivity throughout the year. Findings of this study suggested that addition of protein and energy sources may be desirable in both grazing areas to meet the maintenance/production requirements of the grazing ruminants throughout the year. Key words: Forage yield, chemical composition, landscape gradient; seasonal variations; in vitro ruminal gas production; dry matter degradability.
- Full Text:
- Date Issued: 2013
- Authors: Kwaza, Ayanda
- Date: 2013
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: http://hdl.handle.net/10353/987 , vital:26515
- Description: Communal rangelands sustain a large proportion of the livestock in South Africa. A few dominant grass species contribute to the bulk of the livestock forage in these rangelands. Little is known on the chemical composition and in vitro ruminal fermentation characteristics of grass species grazed by ruminants in the communal grazing lands of Eastern Cape Province in South Africa. The objectives of this study were therefore to investigate seasonal and altitudinal variations in biomass yield, chemical composition, and in vitro ruminal degradability and cumulative gas production of selected (dominant) grass species. The grass species were collected over four seasons (summer, autumn, winter and spring) from three altitudes/landscape gradients (upland, gentle sloppy and bottomlands) across two communal areas (Hala in highland (Highveld) and Gqumashe in lowland (Lowveld)) of the Eastern Cape province, South Africa. In each altitude, three 50 m x 20 m plots, which served as replicates were marked to collect vegetation samples. A 5 x 4 x 3 factorial experiment in a randomised complete block design was used with season, altitude and grass species being the main factors, and with the plots within altitudes serving as blocks (replicates). Data analysis was done separately for the two communal study areas using the General Linear Models (GLM) procedure of SAS to test differences between species, seasons and altitudes. The common grass species in both grazing lands were Cynodon dactylon, Eragrostis chloromelus, Eragrostis plana, Sporobolus africanus and Themeda triandra. When the DM yield of all the grasses was combined, the results showed a generally low forage dry matter yield during the dry season. There was no significant (P>0.05) interaction between any of the main factors. Macro and micro mineral content of plant samples collected from the two communal grazing lands showed great variations (P<0.05) between species, seasons and altitude. In the Highveld, CP ranged from 3.9 to 6.5% DM being significantly highest (P<0.05) in Cynodon dactylon and lowest in E. plana. When all species were combined, higher CP was recorded for samples harvested in summer (5.5%) followed by spring and autumn, and lowest in winter (3.8%). In the Lowveld, Eragrostis chloromelus had higher (P<0.05) CP level followed by C. dactylon and T. Triandra. When all species were pooled, forage samples harvested in summer had a significantly higher (P<0.05) CP followed by spring, autumn and winter. In summary, CP content of all grasses was below the critical maintenance level for livestock especially during late dry seasons. In both areas, the highest NDF level was measured for Eragrostis plana and lowest for Themeda triandra. As for altitudinal differences, samples collected from the upland areas had generally the lowest (P<0.05) CP and highest ADF contents. For grasses harvested from the Highveld, C. dactylon produced the most (P<0.05) gas after 48 h of fermentation (794.6 ml/g DM) and also had the highest 48h DMD (415.1 g kg-1). Themeda triandra produced least (P<0.05) gas (742 ml/g DM) 48h post-incubation. The least (P<0.05) degradable species after 48 h was E. chloromelus (372.9 g kg-1). For grasses harvested from Lowveld, the 48h cumulative gas production was highest (822.7 ml/g DM) in E. plana and lowest (742.8 ml/g DM) in E. chloromelus, while S. africanus had least 48h DMD (327.9 kg-1). In both the Highveld and Lowveld, gas production and DMD were highest in the autumn season. It was concluded most grasses were deficient in calcium, magnesium, phosphorus and potassium. Therefore, it is recommended that mineral supplements should be offered to animals to improve animal productivity throughout the year. Findings of this study suggested that addition of protein and energy sources may be desirable in both grazing areas to meet the maintenance/production requirements of the grazing ruminants throughout the year. Key words: Forage yield, chemical composition, landscape gradient; seasonal variations; in vitro ruminal gas production; dry matter degradability.
- Full Text:
- Date Issued: 2013
Vegetation and soil characteristics around water points under three land management systems in semi-arid rangelands of the Eastern Cape, South Africa
- Authors: Simanga, Siyabulela
- Date: 2013
- Subjects: Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11584 , http://hdl.handle.net/10353/d1015795 , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Description: This study investigated the vegetation and soil characteristics in relation to distance from water points under different land management systems in semi-arid rangelands of South Africa. Six study sites, two each from communal grazing, commercial farming and game reserves were selected. Two watering points were selected in each study site. Two 500 m transects were laid from the selected watering points. Each transect was divided into sub-transects at 25 m, 50m, 100m, 200m, 300m and 500m from water points. A 100 m2 plot was marked in each sub-transect to record grass biomas, species composition, structure and distribution of woody vegetation and physical and chemical soil properties. Data were collected for two seasons 2012/13 (winter and summer). Thirty and 41 grass and woody species respectively were identified in all study areas. The most common and dominating grass species include Cynodon dactylon, Digitaria eriantha, Eragrostis obtusa, Setaria sphacelata and Sporobolus fimbriatus. Cynodon dactylon and S. sphacelata occurred more abundantly (p < 0.05) in the game reserves than in the other land management catergories. All the grass species had similar (p > 0.05) abundance along distance gradient from water points. Grass dry matter (GDM) showed significant differences (p < 0.05) between and within land management systems. However, GDM was not significantly affected by season, location of water point within each farm or reserve and distance along water points. Acacia karoo, Coddia rudis and Ehretia rigida were the most dominant woody species. Tree equivalent (TE) density of all encroaching woody plants combined was significantly (p < 0.05) higher on the communal area (1732 TE ha-1) than the commercial ranches (1136 TE ha-1) and game reserves (857 TE ha-1), but with no marked variations along distance from water points under all the land management systems. The electric conductivity (EC) was significantly (P < 0.01) higher in game reserves than in communal grazing areas and ranches. Soil organic matter percentage showed greatest and lowest values in the game reserves and commercial respectively. Soil pH and bulk density did not vary but soil organic matter (SOM), EC, bulk density and soil compaction were significant different with no increasing or decreasing trends. Soil properties were affected by herbivore pressure and trampling around water points with inconsistence magnitude and direction. In conclusion, grass species composition and GDM did not respond to distance from water points because either grazing gradient was absent or the length of transects was not enough to explain the absence or presence of gradients. High proportion of A. karoo and high densities of seedlings and saplings would seem as very good indicators of the woody vegetation changes in the different land management systems and distance from water points. The soil quality indicators around the water-points showed that livestock and game affected soil parameters.
- Full Text:
- Date Issued: 2013
- Authors: Simanga, Siyabulela
- Date: 2013
- Subjects: Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11584 , http://hdl.handle.net/10353/d1015795 , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Biodiversity conservation -- South Africa -- Eastern Cape , Range ecology -- South Africa -- Eastern Cape
- Description: This study investigated the vegetation and soil characteristics in relation to distance from water points under different land management systems in semi-arid rangelands of South Africa. Six study sites, two each from communal grazing, commercial farming and game reserves were selected. Two watering points were selected in each study site. Two 500 m transects were laid from the selected watering points. Each transect was divided into sub-transects at 25 m, 50m, 100m, 200m, 300m and 500m from water points. A 100 m2 plot was marked in each sub-transect to record grass biomas, species composition, structure and distribution of woody vegetation and physical and chemical soil properties. Data were collected for two seasons 2012/13 (winter and summer). Thirty and 41 grass and woody species respectively were identified in all study areas. The most common and dominating grass species include Cynodon dactylon, Digitaria eriantha, Eragrostis obtusa, Setaria sphacelata and Sporobolus fimbriatus. Cynodon dactylon and S. sphacelata occurred more abundantly (p < 0.05) in the game reserves than in the other land management catergories. All the grass species had similar (p > 0.05) abundance along distance gradient from water points. Grass dry matter (GDM) showed significant differences (p < 0.05) between and within land management systems. However, GDM was not significantly affected by season, location of water point within each farm or reserve and distance along water points. Acacia karoo, Coddia rudis and Ehretia rigida were the most dominant woody species. Tree equivalent (TE) density of all encroaching woody plants combined was significantly (p < 0.05) higher on the communal area (1732 TE ha-1) than the commercial ranches (1136 TE ha-1) and game reserves (857 TE ha-1), but with no marked variations along distance from water points under all the land management systems. The electric conductivity (EC) was significantly (P < 0.01) higher in game reserves than in communal grazing areas and ranches. Soil organic matter percentage showed greatest and lowest values in the game reserves and commercial respectively. Soil pH and bulk density did not vary but soil organic matter (SOM), EC, bulk density and soil compaction were significant different with no increasing or decreasing trends. Soil properties were affected by herbivore pressure and trampling around water points with inconsistence magnitude and direction. In conclusion, grass species composition and GDM did not respond to distance from water points because either grazing gradient was absent or the length of transects was not enough to explain the absence or presence of gradients. High proportion of A. karoo and high densities of seedlings and saplings would seem as very good indicators of the woody vegetation changes in the different land management systems and distance from water points. The soil quality indicators around the water-points showed that livestock and game affected soil parameters.
- Full Text:
- Date Issued: 2013
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