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1
Popp, Alexander. "An integrated modelling approach for sustainable management of semi-arid and arid rangelands." Phd thesis, kostenfrei, 2007. http://opus.kobv.de/ubp/volltexte/2007/1510/.
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Dube, Sikhalazo. "A model for adaptive livestock management on semi-arid rangelands in Texas." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/3975.
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A stochastic, compartmental Model for Adaptive Livestock Management (MALM) was developed for cow-calf enterprise for Rolling Plains of Texas from an existing model, Simple Ecological Sustainability Simulator (SESS). The model simulates forage and animal production. It runs on a monthly time step. Two stocking strategies, flexible and fixed, were evaluated at seven stocking levels for effects on forage and animal production, range condition, and net ranch income. Evaluation data were obtained from published and unpublished data from Texas A&M Agricultural Experimental Station at Vernon for Throckmorton. The model adequately simulated forage and animal production. Light fixed stocking rates and flexible stocking strategies resulted in cows of median body condition score (BCS) 5, compared to low BCS of 4 under moderate fixed stocking rate, and BCS of 3 under heavy fixed stocking. BCS declined from autumn to early spring and peaked in summer. Cows under light fixed stocking rates and under flexible stocking were heavier (460 kg) compared to those under heavy fixed stocking (439 kg). Replacement rates were lower under light stocking (22 %), compared to flexible (37 %) and heavy stocking (56 %). Calf crops were all above the reported 90 % expected for bred heifers because of the replacement policy. Flexible stocking strategy resulted in higher net income ($19.62 ha-1), compared to fixed light ($5.93 ha-1) or fixed heavy ($-17.35 ha-1) stocking strategies. Coefficient of variation (CV) in net income was highest under heavy stocking (90%) compared to light stocking (60%) and flexible stocking (50%). Maximum net income was obtained between 0.05 AUM·ha-1 and 0.13 AUM·ha-1 when fixed stocking strategy was used but when flexible stocking strategy was used maximum net income was obtained between 0.1 AUM·ha-1 and 0.17 AUM·ha-1. Range condition rapidly declined under fixed heavy stocking, increased under fixed and light flexible stocking, and remained constant under moderate flexible stocking. Heavy fixed stocking decreased range condition rapidly over a 20-year period. MALM was an effective tool to demonstrate effects of different management strategies. The model can function as a strategic or a tactical decision aid. It is concluded that there is potential for this model to assist managers in improving the sustainability of agriculture.
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Hobbs, Trevor J., and n/a. "Herbage production modelling and assessment in the arid rangelands of Central Australia." University of Canberra. Applied Science, 1994. http://erl.canberra.edu.au./public/adt-AUC20060725.143830.
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The management and sustainable use of Central Australian rangelands for
livestock production and conservation requires improved knowledge of the
temporal and spatial distribution of primary production in this region. To provide
such information, this thesis investigated methods that could rapidly and efficiently
estimate regional herbage biomass production in these arid landscapes. Two
different approaches were examined, using (1) ground-based or (2) satellite-based
data sources.
Soil moisture and herbage growth data were collected over several growth
seasons and five landscape types in Central Australia, and the data used to develop
a model of soil moisture balance and herbage production for the region. The
model has few parameters and only requires inputs of rainfall and potential
evaporation to predict daily soil moisture and plant growth. Moisture loss in the
0-500 mm soil profile was modelled using a negative exponential function that
depends on available soil moisture and is driven by potential evaporation. The
growth of herbage, whilst soil moisture is above wilting point, is a linear function
of actual evapotranspiration, with the decay of plant material represented by a
logistic curve through time.
Soil moisture, herbage biomass and species composition assessments made
at hectare and square kilometre scales at four locations within Central Australia
were examined to determine if a small sample area could be used to accurately
describe the soil and plant conditions at a landscape scale. Moisture levels of the
0-200 and 0-500 mm soil profiles from nine samples were analysed for the
beginning and conclusion of a growth season, whilst herbage biomass and species
composition from 50 samples were compared at the end of the growth season.
Results suggest that mean soil moisture levels determined in a 1 ha area are
comparable with mean values in the surrounding 1 km2 area. Herbage biomass
and species richness for a square kilometre can be assessed at a hectare site for
some landscape types, but a larger sampling area (> 1 ha) is recommended for
most rangeland assessments.
Satellite data (NOAA-11) were examined for their potential application in
assessing primary productivity in Central Australia. Several image correction
techniques were tested to minimise the adverse effects of atmospheric
contamination and illumination. Two measures of atmospheric moisture: (1)
radiosonde data and (2) temperature differences between bands 4 and 5 of the
NOAA satellite (split-window) were used to explain variations in NOAA-11
normalised difference vegetation index (NDVI) on inert desert sites. The splitwindow
approach provided the best single factor relationship (r2=0.63) and, when
combined with scattering angle (illumination) effects, up to 81% of the variation
in NDVI data could be explained.
Field measurements of herbage biomass were correlated with four growth
indices derived from NOAA-11 NDVI data. The influence of preflight and sensor
degradation calibrations of Bands 1 and 2, and atmospheric correction techniques
were also tested. Correlations between temporal sums of NDVI and herbage
biomass data were relatively poor (r2<0.42) and unsuitable for herbage
assessment in Central Australia. However, correlations between atmospherically corrected
and background-adjusted maximum NDVI data and observed herbage
biomass were strong (r2=0.91), that will allow primary production in the arid
rangelands of Central Australia to be assessed rapidly and efficiently using
remotely-sensed information.
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Venter, Daniel Barend. "An ecological approach to the reclamation and improvement of arid rangelands using adapted fodder plants." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-03262007-124226.
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Knight, Colt Watson. "Intake, Reproductive, and Grazing Activity Characteristics of Range Cattle on Semi-arid Rangelands." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/612879.
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ABSTRACT: Study One - Our objective was to characterize mature range cows based on intake and grazing activity. Starting in the early spring of 2013, 4 experiments were conducted. First, mature range cows (n = 137) were fitted with radio frequency identification tags (RFID) and placed in a dry-lot pen equipped with GrowSafe® technology to monitor DMI of alfalfa hay. These data were then used to assign cows a residual feed intake (RFI) value utilizing the National Research Council (NRC) (1996) model to predict intake of beef cattle. Cattle with negative and positive RFI were characterized as low-intake and high-intake, respectively. In addition, the following data were also recorded: weight (kg), age (mo), days pregnant (d), and body condition score (BCS). Second, 30 mature range cattle were selected from the first trial and fitted with pedometers for 7 d to monitor activity with step counts and estimate distance traveled. Third, mature range cows (n = 25) selected from the first trial were fitted with global position system (GPS) collars, and placed on pinyon-juniper rangeland from 20 June 2014 to 17 September 2014. Forth, mature range cows (n = 28) were fitted with GPS collars, and placed on ponderosa pine rangeland from 17 September 2014 to 15 October 2014. Distance traveled, slope, distance from water, elevation data were collected from both GPS trials. Low-intake and high-intake cows consumed 9.3 and 12.2 kg/d, respectively (P < 0.0001). Low-intake cattle became pregnant sooner (P = 0.002) than high-intake cattle (average of 16 d sooner). Cattle age (mo) equaled 90 and 98 for low- and high-intake cows, respectively (P = 0.04). Weight, predicted DMI, and BCS did not differ between groups (P > 0.06). Step counts for low- and high-intake animals were 5839 and 5383 ± 2089, respectively (P = 0.61), and estimated distance traveled was 4.31 and 5.35 ± 1.66 km d⁻¹ for low- and high-intake animals, respectively (P = 0.77). Low-intake cows (6.23 km d⁻¹) traveled farther (P = 0.005) each day than high-intake cows (5.84 km d⁻¹) on pinyon-juniper rangelands, and high-intake cows utilized (P = 0.013) steeper slopes. No differences were detected (P ≥ 0.06) for distance traveled, distance from water, and elevation for cows grazing ponderosa pine rangeland). However, low-intake cattle preferred (P = 0.046) steeper slopes on ponderosa pine rangeland than high-intake cattle. These results indicate that low-intake animals may travel farther on some rangelands and rebreed earlier. Study Two - Commercial grade heifers (n = 173) born and raised on the University of Arizona's V bar V Ranch from 2012 to 2014 were fitted with radio frequency identification tags (RFID) and placed in a drylot equipped with Growsafe® technology (8 bunks) for 60 d in 3 groups based on birth year in order to calculate DMI, residual feed intake (RFI), ADG, G:F, and residual gain (RG). Birth date, birth weight, weaning weight, age at start of trial, initial trial weight, and final trial weights were also recorded. Residual feed intake scores were utilized to place heifers in one of three treatment groups, low-, medium-, and high-intake. Reproductive and calf data were collected on heifers born in 2012. Means for birth date, birth weight, weaning weight, initial weight, final weight, and ADG did not differ among the three treatments. Residual gain for low-, medium-, and high-intake heifers were different (P < 0.05) at 0.07, 0.00, and -0.07 kg d⁻¹, respectively. Low-intake cattle had an improved (P < 0.05) GF ratio of 0.19 when compared to the medium- and high-intake heifers with ratios of 0.15 and 0.13 (P > 0.05), respectively. Differences (P <0. 05) in DMI were detected with low-, medium, and high-intake heifers consuming 5.2, 6.2, and 7.5 kg d⁻¹, respectively. No differences were detected for pregnancy rate, calving rate, percent bred artificial insemination (AI), percent bull calves, calf birth weight, and calf birth date among treatments (P > 0.05).Study Three - Commercially available GPS tracking collars for cattle are cost prohibitive to most researchers. This paper will present a low-cost alternative to those collars (Knight GPS tracking collars), and provide detailed instructions on where to source materials and how to fabricate inexpensive GPS tracking collars. In addition, the two types of collars will be compared in a study where Brangus cattle (n = 8) were each fitted with LOTEK® 3300 and Knight GPS tracking collars for 31 d beginning 14 March 2015 at the Chihuahuan Desert Rangeland Research Center (CDRRC) 37 km north of Las Cruces, New Mexico. Location, slope, distance from water, distance traveled and elevation were recorded every 10 min. A record of GPS fix rate was logged. No differences were detected (P≥0.369) between collar types for location, slope, or distance from water. However, there was a tendency (P = 0.08) for Knight collars to report a lower estimate for distance traveled at 6171 m d⁻¹ compared to Lotek collars at 7104 m d⁻¹. Fix rate was greater (P≤0.001) for Lotek collars compared to Knight collars at 99.9 and 66.2%, respectively. Study Four - Previously characterized commercial cows (n = 26) were placed into either high (positive RFI) or low intake (negative RFI) groups. On 14 May 2015, 13 high- and 13 low-intake cows were fitted with modified igotU GT-120® GPS logging collars. Cattle were then placed on rangeland for 120 d. The first 30 d period animals transitioned from desert shrubland to pinyon-juniper. From 31 to 60 d, animals grazed pinyon-juniper rangeland. Next, during days 61 to 90, animals transitioned from pinyon-juniper to ponderosa pine, and the last 30 d were spent in ponderosa pine. Time periods will be referred to as month 1, 2, 3, and 4 for days 0 to 30, 31 to 60, 61 to 90, and 91 to 120, respectively. Location, slope, distance from water, elevation, and time spent close to water were recorded every 10 min. No differences were observed in the utilization of elevation or distance traveled, or distance from water (P>0.05). Low intake animals used a higher maximum slope (P < 0.05) during month 3, but slope utilization differences were not detected for other portions of the trial (P > 0.05). Study Five - Hereford sires (n = 35) with 7 or more cow offspring on the University of Arizona V bar V ranch in Rimrock, Arizona were tested at Neogen laboratories in Lincoln, NE for an Igenity Gold genetic profile. Their residual feed intake (RFI), ADG, tenderness, marbling score, milk production percent choice, yield grade, fat thickness, ribeye area, heifer pregnancy rate, stayability, maternal calving ease, birthweight and docility were estimated. Sires were given a genetic RFI score based on their RFI profile and placed into one of three intake groups, low (< 0.5 SD), medium (± 0.5 SD) and high (> 0.5 SD). Performance traits of cow offspring (n = 839) from those sires were also compared based on their sire's intake group. No differences (P > 0.05) were detected among sire intake groups for ADG, tenderness, marbling score, percent choice, yield grade, fat thickness, ribeye area, heifer pregnancy rate, stayability, maternal calving ease, birthweight and docility. Residual feed intake differed among groups (P < 0.05), and high intake cattle had more estimated milk production compared to low intake animals (P < 0.05). Cows from low intake sires were born later in the year (P < 0.05). High intake cattle had a higher (P < 0.05) birthweight and survived longer (P < 0.05) in the herd when compared to low and medium intake cows. Genetic RFI and expected milk production were moderately to highly correlated.
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Van, den Berg Loraine. "The evaluation and promotion of best practices for the restoration of arid- and semi-arid rangelands in southern Africa / Loraine van den Berg." Thesis, North-West University, 2007. http://hdl.handle.net/10394/2036.
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Child, Brian. "The role of wildlife utilization in the sustainable economic development of semi-arid rangelands in Zimbabwe." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481088.
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Fonnesbeck, Brook B. "Digital Soil Mapping Using Landscape Stratification for Arid Rangelands in the Eastern Great Basin, Central Utah." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4525.
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Digital soil mapping typically involves inputs of digital elevation models, remotely sensed imagery, and other spatially explicit digital data as environmental covariates to predict soil classes and attributes over a landscape using statistical models. Digital imagery from Landsat 5, a digital elevation model, and a digital geology map were used as environmental covariates in a 67,000-ha study area of the Great Basin west of Fillmore, UT. A “pre-map” was created for selecting sampling locations. Several indices were derived from the Landsat imagery, including a normalized difference vegetation index, normalized difference ratios from bands 5/2, bands 5/7, bands 4/7, and bands 5/4. Slope, topographic curvature, inverse wetness index, and area solar radiation were calculated from the digital elevation model. The greatest variation across the study area was found by calculating the Optimum Index Factor of covariates, choosing band 7, normalized difference ratio bands 5/2, normalized difference vegetation index, slope, profile curvature, and area solar radiation. A 20-class ISODATA unsupervised classification of these six data layers was reduced to 12. Comparing the 12-class map to a geologic map, 166 sites were chosen weighted by areal extent; 158 sites were visited. Twelve points were added using case-based reasoning to total 170 points for model training. A validation set of 50 sites was selected using conditioned Latin Hypercube Sampling. Density plots of sample sets compared to raw data produced comparable results. Geology was used to stratify the study area into areas above and below the Lake Bonneville highstand shoreline. Raster data were subset to these areas, and predictions were made on each area. Spatial modeling was performed with three different models: random forests, support vector machines, and bagged classification trees. A set of covariates selected by random forests variable importance and the set of Optimum Index Factor covariates were used in the models. The Optimum Index Factor covariates produced the best classification using random forests. Classification accuracy was 45.7%. The predictive rasters may not be useful for soil map unit delineation, but using a hybrid method to guide further sampling using the pre-map and standard sampling techniques can produce a reasonable soil map.
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Pando, Marisela. "A new approach in the use of Landsat imagery for inventory of rangeland /." University of Adelaide, 1987. http://web4.library.adelaide.edu.au/theses/09SM/09smp189.pdf.
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Saley, Moussa Abdoulaye. "Evaluation of selected soil properties in semi-arid communal rangelands in the Western Bophirima district, South Africa / Abdoulaye Saley Moussa." Thesis, North-West University, 2007. http://hdl.handle.net/10394/1306.
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Kent, Vivien Tempest. "The status and conservation potential of carnivores in semi-arid rangelands, Botswana : the Ghanzi farmlands : a case study." Thesis, Durham University, 2011. http://etheses.dur.ac.uk/728/.
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The persistence of many species of carnivore may depend on their survival outside protected areas where they come into conflict with humans and their livestock. Knowledge of these wildlife populations and of the perceptions and attitudes of the stakeholders in the areas in which they live is of critical importance in the quest for coexistence. The Ghanzi farmlands in western Botswana are a prime example of semi-arid rangeland where humans, domestic livestock and wildlife live side by side with varying degrees of success. But little research has been conducted in the area into either the wildlife or the white Afrikaner minority who own the majority of the land. This study aimed to fill some of these gaps in knowledge by adopting an interdisciplinary approach, and employing methodologies from both the biological and social sciences, to determine the potential for conservation of carnivores in the area. The farm block was found to contain good carnivore species diversity and a reduced, but healthy, naturally occurring prey base. Densities of cheetah and leopard were low, but comparable to, or better than, those reported for other similar environments. A good population of brown hyaena was found to exist in the area which could be of importance to the conservation of the species as a whole. The farming community were supportive of conservation in principle, but generally intolerant of predators that killed their livestock. A wide variety of land management and livestock husbandry practices were apparent, with some farmers prepared to do more than others to actively protect their livestock. Farmers with small stock suffered from greater levels of depredation than those who farmed only cattle, while some species of predator elicited greater feelings of antipathy than others. Some farmers professed a distrust of government interference in their affairs which served to hamper efforts to obtain reliable data on livestock depredation and monitor the lethal control of predators.
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Tomlinson, Hannah Angie Kelsey. "Brine Impacted Soils in Semi-Arid Rangelands: Greenhouse Electrical Conductivity Thresholds and Ex Situ/In Situ Remediation Comparisons." Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/27965.
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Brine is a by-product of oil and gas extraction that can have profound impacts on soil chemistry and vegetation assemblages when discharged onto the soil surface. Brine spill remediation aims to remove or minimize the saturated paste electrical conductivity (ECe) to levels suitable for plant growth. My research focused on evaluating ECe and plant parameters on topsoil excavation and chemical amendment sites, and examining brine thresholds of several native grasses. Halophytic grasses had a higher brine threshold between 18.6 and 34.6 dS m-1 whereas glycophytic grasses exhibited a lower threshold (9.70 and 18.6 dS m-1). Halophytes examined in this study may aid in revegetating salt-affected sites. Soil ECe was not different (p ? 0.05) between remediation techniques to the 60 cm depth. Functional plant groups were also not different (p ? 0.05) between remediation techniques. Both techniques were successful at reducing soil ECe to facilitate natural and assisted vegetation recovery.
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Weiss, Jeremy, and Michael Crimmins. "DroughtView: Satellite-based Drought Monitoring and Assessment." College of Agriculture, University of Arizona (Tucson, AZ), 2017. http://hdl.handle.net/10150/625291.
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6 pp.Remotely sensed data are valuable for monitoring, assessing, and managing impacts to arid and semi-arid lands caused by drought or other changes in the natural environment. With this in mind, we collaborated with scientists and technologists to redevelop DroughtView, a web-based decision-support tool that combines satellite-derived measures of surface greenness with additional geospatial data so that users can visualize and evaluate vegetation dynamics across space and over time. To date, users of DroughtView have been local drought impact groups, ranchers, federal and state land management staff, environmental scientists, and plant geographers. Potential new applications may include helping to track wildland fire danger. Here, we present the functionality of DroughtView, including new capabilities to report drought impacts and share map information, as well as the data behind it.
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Olbrich, Roland [Verfasser], and Stefan [Akademischer Betreuer] Baumgärtner. "Environmental Risk and Sustainability: The Case of Commercial Livestock Farming in Semi-Arid Rangelands / Roland Olbrich. Betreuer: Stefan Baumgärtner." Lüneburg : Universitätsbibliothek der Leuphana Universität Lüneburg, 2012. http://d-nb.info/1034147544/34.
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Knapp, Paul Aaron. "THE USE OF LARGE-SCALE AERIAL PHOTOGRAPHY FOR DETECTING CHANGES OF AN ARID RANGELAND IN SOUTHWESTERN ARIZONA." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/292059.
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Interpretation of large-scale color infrared and color aerial photography can be a labor and cost-effective means for inventorying and monitoring rangelands while maintaining accuracy. Ground measurements of vegetation cover at Organ Pipe Cactus National Monument were taken in 1975 and 1984. Large-scale (1:1200) color and color infrared aerial photo estimates were compared to these ground measurements through regression and correlation to check photo accuracy. Relationships between photo estimates and ground measurements of total vegetation and shrub cover were strong when using either film type. Color infrared photo estimates corresponded better with ground measurements for both tree cover and cactus cover than color photo estimates. Large-scale aerial photography is also useful for determining some of the causes of vegetation change. Evidence gathered from both sets of photos suggested that vegetation change at OPCNM was largely the result of domestic livestock removal and short-term climatic fluctuations.
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Al-Tabini, Raed Jazi. "An evaluation of the potential of Atriplex nummularia for sheep production in arid Jordanian rangelands : the effects of defoliation management." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366537.
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Simanga, Siyabulela. "Vegetation and soil characteristics around water points under three land management systems in semi-arid rangelands of the Eastern Cape, South Africa." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1015795.
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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.
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Martin, Romina [Verfasser], Michael [Akademischer Betreuer] Bonkowski, Helmut [Akademischer Betreuer] Arndt, and Karin [Akademischer Betreuer] Frank. "Livelihood security of pastoralists in semi-arid rangelands under global change - A social-ecological modelling study / Romina Martin. Gutachter: Michael Bonkowski ; Helmut Arndt ; Karin Frank." Köln : Universitäts- und Stadtbibliothek Köln, 2013. http://d-nb.info/1038486408/34.
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Jessop, Peter. "Response of arid vegetation to cattle grazing and the development of indicators for range assessment with particular reference to the rangelands of northern South Australia /." Title page, contents and summary only, 1995. http://web4.library.adelaide.edu.au/theses/09AS/09asj58.pdf.
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Khalili, Davar 1955. "A decision methodology for the resource utilization of rangeland watersheds." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/191118.
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Degradation of rangeland resources leading to the desertification process is viewed in terms of human and climatic influences. While climatic impacts are important, resource utilization as practiced by man is the major cause of desertification. A multi-objective .decision methodology is developed here which is intended for the analysis of alternative management plans of rangeland watersheds under climatic variability. First, a system model is employed to portray the dynamics of a rangeland as it would respond to climatic changes and different grazing intensities. This approach allows for an interaction of inputs such as rainfall, solar radiation, and temperature with the state of the system which is a range condition index, and with outputs such as production and sediment yield. A simulation package is developed to implement the system model by actually using available data and providing some output values for production and sediment yield. At this stage a number of alternative management plans are identified. The information obtained from the simulation as well as other information of interest are represented by performance criteria, leading to an array of alternative versus criteria. Then, management plans need to be evaluated as they would impact the criteria. A multiobjective decision making technique is selected to perform the analysis for an identification of prefered management alternatives.
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Coetzee, Marisa. "Best land-use strategies towards sustainable biodiversity and land degradation management in semi-arid western rangelands in southern Africa, with special reference to ants as bio-indicators / Marisa Coetzee." Thesis, North-West University, 2006. http://hdl.handle.net/10394/3686.
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In South Africa, the unsustainable use of natural resources by domestic livestock has led to resource depletion and serious land degradation. Rangeland degradation, especially bush encroachment and soil
erosion, is particularly acute in the North-West Province, where all districts show signs of desertification and a loss of biodiversity resulting in a deterioration of human and animal health. This has a major
impact on livestock productivity and the economic viability of livestock farming with serious consequences for the livelihoods of pastoral communities. It is important to recognise ecological change before irreversible changes occur. The aim of this study, which falls within the Global Environmental Facility Desert Margins Programme (GEF-DMP), was to investigate to what extent vegetation in combination with ant communities can be used as indicators of ecosystem change due to anthropogenic human induced land-use patterns and how can this information be used in land degradation management and biodiversity conservation in the semi-arid western rangelands of Southern Africa. Sites, representing a degradation
gradient (relative poor and relative good rangeland condition extremes) within each of three Tribal-, three Commercial- and three Reserve areas, were surveyed. The impacts of these land uses on the
herbaceous species composition, woody-, soil- and ant components were evaluated. Both the woody and herbaceous species components reflected the existence of a rangeland condition/degradation gradient
across the larger study area. The herbaceous species composition reflected similar degradation tendencies within the Commercial and Reserve land uses, with sites being associated with low rangeland
as well as high rangeland condition scores. The tendencies differed between these two land uses based on the woody degradation gradient. The entire Tribal herbaceous- and woody species components showed a transitional shift towards another state, which differed significantly from the Commercial and Reserve land uses. Both the Tribal herbaceous and woody components were associated with low to intermediate rangeland condition ranges, with no significant rangeland condition gradient existing within the Tribal land use.
Understanding and quantification of the soil-vegetation dynamics hold important implications for rangeland degradation management. This study provided criteria for selecting the most appropriate
measures when incorporating the soil parameters as additive data in the multivariate analyses with the
vegetation, ant and nominal environmental data. Different land use practices resulted in different soil patterns, with significant gradients pertaining to the soil stratum and openness/woodiness groups. There was a significant though neglectable difference pertaining to the rangeland condition/degradation gradient based on the soil component. Ants have been extensively used as bio-indicators, also with regard to the monitoring of the environmental effects of rangeland pastoralism. Ant species compositional patterns and functional
groups displayed congruent clustering and diversity patterns as those of the vegetation and soil components. In contrast to the vegetation components, ant assemblages did not reflect a degradation
gradient, but rather reflected environmental changes (modifications) to the habitat structure and - heterogeneity as a result of different land use disturbances.
Both vegetation and ant diversity measures were mainly associated with the Tribal land use. These diversity indices were indicators of habitat complexity, heterogeneity and moderate disturbance, rather than indicators of a rangeland condition/degradation gradient. The diversity patterns are best described
by a dichotomy between the humped-shaped productivity/diversity and the habitat
complexity/heterogeneity models. Vegetation and ant diversity measures for this study should be considered as environmental indicators of habitat disturbance rather than as biodiversity indicators.
It is suggested that vegetation, soil and ant patterns are best described by the state-and-transition model, which encompasses both equilibrium and non-equilibrium systems. The resilient nature of these rangelands, typical of non-equilibrium systems, was reflected by the low to intermediate differences
between land uses with regard to the herbaceous, woody, soil and ant components. However, densitydependent coupling of herbivores to key resources resulted in transitional shifts and modification of the
vegetation composition and structure within and between land uses, displaying the equilibrium dynamics pertaining to these rangelands. Small disturbances in these rangelands may result in detrimental
“snowball” interactive biotic-biotic /abiotic cascades. Spatial heterogeneous patterns within and between
land uses as displayed by the vegetation, soil and ant parameters, necessitate that monitoring and management at patch, paddock and landscape scale should be conducted, cautioning against the extrapolation and over simplification of management strategies across all land uses. Because these arid rangelands are linked socio-ecological systems, it is not possible to address biophysical issues associated with land degradation without including the human dimensions. A “Key assessment matrix” is provided for monitoring and management purposes pertaining to land degradation and diversity aspects within and between the different land uses, and can be used by the land user, extension officer and scientist.Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2007.
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Haveron, Sara Elizabeth. "Comparing small mammal assemblages between communal and commercial rangelands within a region of the Succulent Karoo, South Africa." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2367.
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Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008.The widespread ecological impacts of overgrazing by livestock within the Succulent Karoo have received considerable attention. Literature shows communal and commercial rangelands have been thoroughly studied, and vegetation responses have been investigated in an attempt to understand the effects of overgrazing. Regarding animal species, literature is in short supply. In a one-year study of small mammal assemblages, the effect of the rangelands, and subsequently vegetation, on small mammal assemblages was examined, as well as the effects on number of occupied, unoccupied and collapsed burrows. This study shows that vegetation composition differs between rangelands, with a greater perennial shrub cover on the communal rangelands and a greater perennial succulent cover on commercial rangelands, consequently creating different habitats for animal assemblages. This study supports the notion of small mammal composition relating to vegetation structure, with certain species being impacted by heavy grazing. Four small mammal species were found in greater abundances on commercial rangelands, with one being exclusive, while communal rangelands were exclusively occupied by three nocturnal species. Diet and habitat requirements are the most important factors regarding species occurrence. With small mammal species composition differing between rangelands, and species richness not being affected by rangeland type, this study illustrates that the disappearance of certain species may arise without these different rangelands. This could result in reduced species richness, and thus diversity being lost. Regarding species present on both rangelands, no differences were observed in body mass, body size or body condition. Despite no differences found in body condition, calculating a body condition index is a good method for investigating how a species is coping within an environment. The proportion and number of occupied and collapsed burrows can be seen as a measure of trampling effect. It was expected for grazing intensity, as well as vegetation changes, to affect the occurrence of such burrows. This study showed differences between the communal and commercial rangelands as negligible. As expected, numbers of burrowing small mammal species were negatively correlated with numbers of collapsed burrows. However, a lack of consistency deemed this result unimportant. Results show that the effects of overgrazing on small mammal populations are complex and require more attention if to be fully explained. This study provides insights into the effects of land use on small mammals and burrow numbers, which have implications for the conservation of these species within arid regions.
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Badman, Francis John. "A comparison of the effects of grazing and mining on vegetation of selected parts of northern South Australia." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phb136.pdf.
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Accompanying CD-ROM inside back cover, includes Appendices. Bibliography: leaves 242-266. This thesis examines the effects on vegetation at selected sites in northern South Australia of excluding various herbivores over a four and a half year period and of two intense but controlled grazing pulses over a six month period followed by an 18 month recovery period in a dune-swale land system. These changes are compared with changes recorded over an 11-year period at the Olympic Dam mine site. It found that short-term changes in vegetation revealed by ordination of periodical cover, density and species richness, are attributable to the periodicity of rainfall and that, under present grazing regimes, rainfall effects override grazing effects. Differences between the effects of sheep and cattle hoof damage are worthy of further investigation, as is the impact of kangaroo grazing. These two factors may have important implications for the management of Australian rangelands. System requirements for accompanying CD-ROM: IBM compatible computer with Pentium processor or higher and Windows 95, 98 or NT ; 4 MB or RAM. Other software: Acrobat Adobe Reader.
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Faramarzi, Marzban. "Rangeland vegetation in relation to management and environmental variables in semi-arid rangeland in western Iran." Göttingen Cuvillier, 2009. http://d-nb.info/993315119/04.
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Wellens, Jane. "Monitoring and modelling rangeland vegetation in Tunisia using satellite and meteorological data." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359492.
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Derry, Julian F. "Piospheres in semi-arid rangeland : consequences of spatially constrained plant-herbivore interactions." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/600.
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This thesis explains two aspects of animal spatial foraging behaviour arising as a direct consequence of animals' need to drink water: the concentration of animal impacts, and the response of animals to those impacts. In semi-arid rangelands, the foraging range of free-ranging large mammalian herbivores is constrained by the distribution of drinking water during the dry season. Animal impacts become concentrated around these watering sites according to the geometrical relationship between the available foraging area and the distance from water, and the spatial distribution of animal impacts becomes organised along a utilisation gradient termed a "piosphere". During the dry season the temporal distribution of the impacts is determined by the day-to-day foraging behaviour of the animals. The specific conditions under which these spatial foraging processes determine the piosphere pattern have been identified in this thesis. At the core of this investigation are questions about the response of animals to the heterogeneity of their resources. Aspects of spatial foraging are widely commented on whilst explaining the consequences of piosphere phenomena for individual animal intake, population dynamics, feeding strategies and management. Implicated are our notions of optimal foraging, scale in animal response, and resource matching. This thesis addressed each of these. In the specific context of piospheres, the role of energy balance in optimal foraging was also tested. Field experiments for this thesis showed a relationship between goat browsing activity and measures of spatial impact. As a preliminary step to investigating animal response to resource heterogeneity, the spatial pattern of foraging behaviour/impacts was described using spatial statistics. Browsing activity varied daily revealing animal assessment of the spatial heterogeneity of their resources and an energetic basis for foraging decisions. This foraging behaviour was shown to be determined by individual plants rather than at larger scales of plant aggregation. A further experiment investigated the claim that defoliation has limited impact on browser intake rate, suggesting that piospheres may have few consequences for browser intake. This experiment identified a constraining influence of browse characteristics at the small scale on goat foraging by relating animal intake rate to plant bite size and distribution. Computer simulation experiments for this thesis supported these empirical findings by showing that the distribution of spatial impacts was sensitive to the marginal value of forage resources, and identified plant bite size and distribution as the causal factors in limiting animal intake rate in the presence of a piosphere. As a further description of spatial pattern, piospheres were characterised by applying a contemporary ecological theory that ranks resource patches into a spatial hierarchy. Ecosystem dynamics emerge from the interactions between these patches, with piospheres being an emergent property of a natural plant-herbivore system under specific conditions of constrained foraging. The generation of a piosphere was shown to be a function of intake constraints and available foraging area, whilst piosphere extent was shown to be independent of daily energy balance including expenditure on travel costs. A threshold distance for animal foraging range arising from a hypothesised conflict between daily energy intake and expenditure was shown not to exist, whereas evidence for an intermediate distance from water as a focus for accumulated foraging activity was identified. Individual animal foraging efficiency in the computer model was shown to be sensitive to the piosphere, while animal population dynamics were found to be determined in the longer term by dry season key resources near watering points. Time lags were found to operate in the maintenance of the gradient, and the density dependent moderation of the animal population. The latter was a direct result of the inability of animal populations to match the distribution of their resources with the distribution of their foraging behaviour, because of their daily drinking requirements. The result is that animal forage intake was compromised by the low density of dry season forage in the vicinity of a water point. This thesis also proposes that piospheres exert selection pressures on traits to maximise energy gain from the spatial heterogeneity of dry season resources, and that these have played a role in the evolution of large mammalian herbivores.
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Aralova, Dildora, Kristina Toderich, Ben Jarihani, Dilshod Gafurov, Liliya Gismatulina, Babatunde A. Osunmadewa, and Abualgasim Majdaldin Rahamtallah. "Environmental resilience of rangeland ecosystems: Assessment drought indices and vegetation trends on arid and semi-arid zones of Central Asia." SPIE, 2016. https://tud.qucosa.de/id/qucosa%3A35118.
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The Central Asian (CA) rangelands is a part of the arid and semi-arid ecological zones and spatial extent of drylands in CA (Tajikistan, Kazakhstan, Uzbekistan, Kyrgyzstan, and Turkmenistan) is vast. Projections averaged across a suite of climate models, as measured between 1950-2012 by Standardised Precipitation-Evapotranspiration Index (SPEI) estimated a progressively increasing drought risks across rangelands (Turkmenistan, Tajikistan and Uzbekistan) especially during late summer and autumn periods, another index: Potential Evapotranspiration (PET) indicated drought anomalies for Turkmenistan and partly in Uzbekistan (between 1950-2000). On this study, we have combined a several datasets of drought indices ( SPIE, PET, temperature_ToC and precipitation_P) for better estimation of resilience/non-resilience of the ecosystems after warming the temperature in the following five countries, meanwhile, warming of climate causing of increasing rating of degradations and extension of desertification in the lowland and foothill zones of the landscape and consequently surrounding experienced of a raising balance of evapotranspiration (ET0). The study concluded, increasing drought anomalies which is closely related with raising (ET0) in the lowland and foothill zones of CA indicated on decreasing of NDVI indices with occurred sandy and loamy soils it will resulting a loss of vegetation diversity (endangered species) and raising of wind speeds in lowlands of CA, but on regional level especially towards agricultural intensification (without rotation) it indicated no changes of greenness index. It was investigated to better interpret how vegetation feedback modifies the sensitivity of drought indices associated with raising tendency of air temperature and changes of cold and hot year seasons length in the territory of CA.
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Rath, Thomas. "Nutrition and productivity of milking cattle on a semi-arid rangeland in West Africa /." Stuttgart : Grauer, 1999. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009038584&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Goff, Bruce Franklin. "Dynamics of canopy structure and soil surface cover in a semiarid grassland." Thesis, The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_503_sip1_w.pdf&type=application/pdf.
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Wolfaard, Graeme. "An evaluation of techniques for monitoring rangeland health in semi-arid savannas in southern Africa." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/65521.
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Rangeland health plays an important role in increasing the connectivity/contact between wildlife, livestock and people. Communal rangelands throughout the savanna areas of South Africa are experiencing increasing magnitudes of pressure as they are reduced in size mainly due to a rapidly expanding human population. These pressures emanate in greater levels of degradation, which results in greater competition between livestock and wildlife across the interface for ecosystem services (such as grazing). Ultimately, this brings wildlife and livestock closer together and enhances the probability of disease transmission. Long-term monitoring of rangeland health using survey methods that are comprehensive, rigorous (and accurate) and efficient in terms of time and cost are essential for the development of sustainable management approaches that aim to optimise the ecological, social and economic well-being of an area. The primary aim of this study was to objectively assess a number of rangeland monitoring techniques [Multiple Indicator Monitoring (MIM) method, Adapted Point-centred Quarter (APCQ) method, Basal Cover (BC) method, Line-point Intercept (LPI) method and the Disc Pasture Meter (DPM) method that uses 100 recordings)]; taking into account efficiency (time and cost) and usefulness in recording indicators of rangeland health. The findings further provide a basis for the implementation of sound management practises across multiple land-use types. The Mnisi Study Area (MSA) is situated in the Lowveld region of Mpumalanga, South Africa, and is comprised of communal rangelands and land zoned for conservation purposes. The rangelands under communal tenure belong to community members from various villages; and are the sole source of available grazing to the local livestock population, made up mainly of cattle and goats. Some of the communal rangelands exist at the wildlife-livestock interface of the Manyeleti Game Reserve. The Manyeleti is managed as an open system and contains a full suite of wild herbivores endemic to the area. The MIM method was considered to be an efficient and rigorous survey method that can be used to detect comprehensive information of the health and status of rangelands across semi-arid savannas of southern Africa.Dissertation (MSc)--University of Pretoria, 2017.
Veterinary Tropical Diseases
MSc
Unrestricted
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Van, der Zweep Richard Adrian 1962. "Evaluation of the Water Erosion Prediction Project's watershed version hydrologic component on a semi-arid rangeland watershed." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/192067.
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Detailed evaluation of the Water Erosion Prediction Project (WEPP) Watershed Model hydrologic component was performed using hydrologic data from three small semi-arid watersheds located within the USDA Walnut Gulch Experimental Watershed in southeastern Arizona. Evaluation includes both calibration and validation procedures. Favorable results were obtained when the model was calibrated. The parameter estimation procedures within the WEPP model did not produce accurate estimates. Peak rainfall intensity simulated by the rainfall disaggregation model was less than the observed data, causing simulated runoff to be lower. The peak runoff rate simulated by the approximate method was higher than values simulated by the kinematic wave model. Cumulative distribution curves of simulated runoff were significantly different the observed curves, due to model's inability to accurately simulate the runoff of smaller events. On the small watershed used in this study, transmission losses were relatively insensitive to changes in channel hydraulic conductivity.
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Kgosikoma, Olaotswe Ernest. "Understanding the savanna dynamics in relation to rangeland management systems and environmental conditions in semi-arid Botswana." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/5874.
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This thesis investigates the effects of rangeland management systems on savanna ecosystems under different environmental conditions in Botswana, Southern Africa. The soil sampling and vegetation assessment were conducted in twenty–three transects located in communal and ranching grazing lands across three sites. Pastoralists were also interviewed on vegetation change on their respective grazing lands. Soil texture, pH, bulk density and soil organic carbon differed between sites, but not between communal and ranching lands. Soil organic carbon was positively affected by soil clay content. The herbaceous vegetation composition showed heterogeneity between sites, but Matlolakgang and Xanagas rangelands were in poor condition, particularly the communal grazing land that had high cover of increasers II species. Higher herbaceous biomass was observed in ranches than communal lands and biomass also increased with increasing soil organic carbon. Bush encroachment was observed in communal and ranching grazing lands at Matlolakgang and Xanagas, but not Goodhope. Woody plant cover, density and diversity increased with decline in soil clay content, but not linearly. Pastoralists indicated that herbaceous vegetation compositions had changed in some areas, with increase of unpalatable grass species and bush encroachment especially in communal land. Pastoralists considered bush encroachment a problem as it suppress herbaceous vegetation productivity, but they also considered woody vegetation as a valuable grazing resource. The long-term indicators of ecosystem degradation (soil and woody cover) showed that communal and ranching grazing did not affect the savanna ecosystem differently. This is contrary to assumptions of Tribal Grazing Land Policy of Botswana, which promote ranching as a more sustainable management system. The results revealed that rainfall and soil clay strongly influence rangeland condition. These results have implications for the management policies of communal grazing lands throughout sub-Saharan Africa and in similar arid habitats across the world.
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Whitaker, Martha Patricia Lee 1965. "Small-scale spatial variability of soil moisture and hydraulic conductivity in a semi-arid rangeland soil in Arizona." Thesis, The University of Arizona, 1993. http://hdl.handle.net/10150/192081.
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The correlation scales of soil moisture and hydraulic conductivity were investigated within a 4.4 hectare semi-arid rangeland watershed using measurements obtained from time domain reflectometry and disc permeameters, respectively. Soil moisture measurements were collected at four different times in 1991 to yield a varied set of natural soil moisture conditions. Soil moisture was sampled over a 30 meter grid, two perpendicular transects at 5 meter intervals, once at 1 meter intervals, and once at intervals of — 0.10 m within a 1 xl meter plot. Variogram functions showed evidence of spatial correlation only when the grid and perpendicular transect data were combined. A total of 30 measurements each of saturated and unsaturated hydraulic conductivity were collected along a 300 meter curvilinear transect at approximately 10 meter intervals. Although spatial correlation was evident, variogram resolution may possibly be improved by obtaining more measurements.
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Govender, Saloshnie Simone. "A survey on external (Ixodidae) and gastrointestinal parasites of small ruminants on an arid communal rangeland in South Africa." University of Western Cape, 2020. http://hdl.handle.net/11394/7338.
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Magister Scientiae (Biodiversity and Conservation Biology)Parasites pose a major constraint on livestock farming. Its impacts are represented as transmission of disease to humans and economic costs for prevention and treatment as well as loss in terms of; livestock mortality and, lowered productivity. Although the impacts of parasitic loads can be decreased through proper management, extensive management systems are depended on external factors such as rainfall and forage availability, which, in its absence, promote malnutrition and therefore parasite susceptibility.
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Biot, Y. "Forecasting productivity losses caused by sheet and rill erosion in semi arid rangeland : A case study from communal areas of Botswana." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383247.
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Price, Gary Norman. "Assessing the growth performance of European olive (Olea europea L.) on Mount Weld pastoral station." Curtin University of Technology, Department of Environmental Biology, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17424.
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This thesis describes the growth of European olive (Olea europaea L.) at three different trial sites located near Laverton, in the north-eastern Goldfields region of Western Australia. The local region comprises part ofthe rangelands area of Australia and has a semi-arid climate. The initial reason for planting olives was indirectly related to the rapid decrease in the local population and the economic downturn that resulted within that community during the late 1990's. This prompted an investigation into other possibilities for economic diversity for remote communities such as Laverton, which are located in the rangelands area of Australia. In Australia, much of the southern and eastern areas of the country have similar climate to traditional olive growing areas in Europe. [n the rangelands however, the environment is different to most other areas in the world where olive trees are grown and there is a notable absence of a commercial olive industry. Whilst locally, individual trees were also observed to be growing well and fruiting abundantly, it is not known whether it is possible to grow olive trees successfully on a commercial scale. Two preliminary trials were established in an ad-hoc manner, to examine whether olive trees could be grown successfully in the rangelands environment. Eighty-eight trees of 5 different cultivars were planted on a shallow, clay soil profile at the first trial site. Ninety-eight trees of 11 different cultivar were planted on a deep sand soil profile at the second site. Higher mortality rate occurred at the first site, with most tree deaths being recorded in the first two years. Peak growth of branch tips occurred during the spring-summer seasons at both sites. Differences in trial design and timing of planting prevented statistical comparison of growth performance between sites however.A third olive trial, consisting of 3 olive groves was established according to randomised design. In the north and middle groves, 54 trees of 3 different cultivar were planted on a deep alluvial soil profile. In the south grove, 53 trees of 3 different cultivar were planted on a shallow clay soil profile. High mortality rates were recorded at all 3 groves during the first year, as a result of high salinity levels in irrigation water during the establishment period. Overall, most tree mortality was recorded at the south grove. Significantly higher growth performance occurred within the deeper alluvial soil profile at the north and middle groves, compared to the shallow clay soil profile in the south grove. Negligible olive fruit production occurred at the first site. At the second site, small quantities of olive fruit were produced during some seasons only. No olive fruit production occurred at any grove at the randomized site. Successful fruit formation appears directly related to tree health, as a function of water supply. Ripening of olive fruit occurred earlier than at other more temperate olive growing areas of Australia. Similar major and trace element deficiencies occurred at all sites, interpreted to be a function of universal alkaline ground-water conditions.
This study failed to confirm conclusively, whether European olive could be grown successfully in the semi-arid climate, typical of much of the rangelands area of Australia. As a result of the study however, successful growth in this environment is confirmed to be highly dependent on three factors. Firstly, availability of reliable irrigation waters of sufficient quality. Secondly, choice of suitable soil types. Thirdly, selection of suitable cultivars. Quality of olive oil produced from fruit appears to be influenced by local climatic factors The study also highlighted the issues of land tenure, current management attitudes and level of support within the local community as having a direct and significant impact on the trial.
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Ndhlovu, Thabisisani. "Impact of Prosopis (mesquite) invasion and clearing on ecosystem structure, function and agricultural productivity in semi-arid Nama Karoo rangeland, South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6751.
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Thesis (MScConEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: I evaluated the impact of Prosopis invasion and clearing on ecological structure, function and agricultural productivity in heavily grazed Nama Karoo rangeland on two sheep farms near the town of Beaufort West in the Western Cape Province of South Africa. My aims were to (1) determine the effects of invasion and clearing on rangeland vegetation composition, diversity (alien and indigenous species richness) and structure (alien and indigenous species cover), soil vegetation cover (plant canopy and basal cover) and agricultural productivity (grazing capacity), (2) describe the vegetation processes that underlay the invasion and clearing impacts and (3) evaluate the success of clearing in facilitating unaided restoration of ecological structure, function and agricultural productivity in formerly invaded rangeland. I hypothesised that invasion would significantly change rangeland vegetation composition and structure, leading to greater alien species richness and cover and lower indigenous species richness and cover while clearing would lead to lower alien species diversity and cover and greater indigenous species richness and cover. In addition I hypothesized that invasion would reduce rangeland plant canopy and basal cover and grazing capacity while clearing would substantially increase them. Finally I predicted that vegetation composition, alien and indigenous species cover and richness, plant canopy and basal cover and grazing capacity would revert to pre-invasion status and levels within four to six years of clearing. My results suggest that in heavily grazed Nama Karoo rangeland Prosopis invasion (~15 percent canopy cover) and clearing can significantly change rangeland vegetation composition, with invasion leading to greater alien species cover and lower indigenous species richness, while clearing leads to lower alien species richness and cover and greater indigenous species richness and cover. However invasion seems to have no effect on alien species richness and overall indigenous species cover. Clearing appears to facilitate the spontaneous restoration of alien species cover and indigenous species richness within four to six years but not species composition, alien species richness and indigenous species cover. In addition my results also indicate that Prosopis invasion can lower rangeland plant canopy and basal cover and grazing capacity while clearing, even under heavy grazing, can substantially raise them. Clearing however does not seem to facilitate the restoration of rangeland plant canopy and basal cover and grazing capacity to pre-invasion levels within four to six years after clearing.
AFRIKAANSE OPSOMMING: Ek het die impak van Prosopis indringing en verwydering van indringers op ekologiese struktuur, funksie en landbou produktiwiteit in ‘n swaar beweide Nama Karoo gebied op twee skaapplase naby Beaufort-Wes in die Wes-Kaap provinsie van Suid-Afrika geëvalueer. My doelwitte was om (1) te bepaal wat die gevolge van die indringing en verwydering van indringers op die natuurlike plantegroei samestelling, diversiteit (uitheemse en inheemse spesiesrykheid) en struktuur (uitheemse en inheemse spesies bedekking) sal wees, sowel as die effek op plantegroei bedekking (kroon en basalebedekking) en landbou produktiwiteit (weidingkapasiteit), (2) die plantegroei prosesse te beskryf wat onderliggend deur die impakte van indringing en verwydering van indringers veroorsaak word, en (3) die sukses van die verwydering van indringers te evalueer deur die fasilitering van blote restorasie van ekologiese struktuur en funksie en landbou produktiwiteit in voorheen ingedringde gebiede. My hipotese is dat indringing ‘n aansienlike verandering in natuurlike plantegroeisamestelling en struktuur sal veroorsaak, wat sal lei tot groter uitheemse spesiesrykheid en bedekking met minder inheemse spesiesrykheid en bedekking, terwyl die verwydering van indringers sou lei tot minder uitheemse spesie diversiteit en bedekking met 'n groter inheemse spesiesrykheid en bedekking. Verder vermoed ek dat indringing die natuurlike kroon- en basalebedekking en weidingkapasiteit sal verminder, terwyl die verwydering van indringers dit aansienlik sal verhoog. Ten slotte voorspel ek dat plantegroei samestelling, uitheemse en inheemse spesiesbedekking en -rykheid, kroon- en basalebedekking en weidingkapasiteit sou terugkeer na voor-indringing status en vlakke binne vier tot ses jaar na die verwydering van indringers. My resultate daarop dat die indringing van Prosopis (~ 15 persent kroonbedekking) en die verwydering van indringers in swaar beweide Nama Karoo gebiede ‘n aansienlike verandering in die gebied se natuurlike plantegroei samestelling toon, waar indringing gelei het tot groter uitheemse spesiesbedekking en minder inheemse spesiesrykheid, terwyl die verwydering van indringers lei tot minder uitheemse spesiesrykheid en groter inheemse spesiesrykheid en - bedekking. Dit lyk egter of indringing geen effek op uitheemse spesiesrykheid en algehele inheemse spesiesbedekking het nie. Die verwydering van indringers blyk om die spontane herstel van indringerbedekking en inheemse spesiesrykheid binne vier tot ses jaar te fasiliteer, maar nie spesiesamestelling, uitheemse spesiesrykheid of inheemse spesiesbedekking nie. Benewens dui my resultate ook aan dat Prosopis indringing die natuurlike kroon- en basalebedekking sowel as weidingskapasiteit verlaag, terwyl die verwydering van indringers, selfs onder swaar beweiding, die bedekking aansienlik kan verhoog. Verwydering van indringers lyk egter nie asof dit die herstel van die gebied se natuurlike kroon- en basalebedekking en weidingkapasiteit na voor-indringing vlakke toe kan fasiliteer binne vier tot ses jaar na die verwydering van indringers nie.
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Montague-Drake, Rebecca School of Biological Earth & Environmental Sciences UNSW. "Strategic management of artificial watering points for biodiversity conservation." Awarded by:University of New South Wales. School of Biological, Earth and Environmental Sciences, 2004. http://handle.unsw.edu.au/1959.4/30122.
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Since pastoralism began in Australia???s rangelands, the number of artificial watering points (AWPs) has increased dramatically, such that today, few areas of rangeland are further than 10 km from water. This increased availability of water has caused many ecological impacts. Unfortunately, such impacts are poorly understood in the context of an Australian conservation reserve, thus hindering strategic management. This study examined the spatial distribution of vertebrate (kangaroos, small mammals, lizards and avifauna) and vegetative variables around open AWPs as well as AWPs that have been closed since pastoralism (sheep-grazing) ceased nearly thirty years ago in Sturt National Park, arid New South Wales. The study also examined vertebrate use of AWPs, with a particular emphasis on kangaroos and avifauna. The study revealed that most variables showed few differences in spatial distribution with distance from open and closed AWPs, thus suggesting that the observed piospheric impacts were primarily attributable to historical sheep-grazing. Indeed, piospheric patterns were weak suggesting some recovery over the last thirty years. That kangaroos did not exhibit water-focused grazing is no surprise, since despite their regular use of AWPs, particularly during hot, dry times, the current spatial arrangement of AWPs facilitates regular travel to, and from, such resources allowing kangaroos, like much other fauna, to distribute themselves in relation to food and shelter preferences rather than in relation to water supply. In contrast, the majority of avifaunal groups (excluding ground-dwelling species) were clustered around open AWPs, often irrespective of season, because of food and water requirements. Such spatial concentrations of avifauna are thought to cause a range of interspecific effects. Experimental AWP closure and GIS modelling showed that whilst closure of AWPs will increase the average distance to water, which will have key benefits, the majority of areas in Sturt National Park would still be accessible to most water-dependent species even if all unused AWPs were closed. Strategic retention of AWPs to replace water sources lost since European settlement, aid threatened and migratory species??? conservation and enhance nature-based tourism opportunities is thus recommended and an example of a strategic management and monitoring plan outlined.
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Walsh, Fiona Jane. "To hunt and to hold : Martu Aboriginal people's uses and knowledge of their country, with implications for co-management in Karlamilyi (Rudall River) National Park and the Great Sandy Desert, Western Australia." University of Western Australia. School of Plant Biology, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0127.
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[Truncated abstract] This ethnoecological study examines land uses by modern Martu Aboriginal people on their country. They occupy very remote settlementsParnngurr, Punmu and Kunawarritjiin the Great and Little Sandy Deserts. In 1990, their country included Crown Lands and Rudall River National Park. The study investigated the proposition that the knowledge and practices of Martu were of direct relevance to ecosystem processes and national park management. This research commenced in the wider Australian research context of the late 1980s early 90s when prevailing questions were about the role of customary harvest within contemporary Aboriginal society (Altman 1987; Devitt 1988) and the sustainability of species-specific harvests by Australian indigenous people (Bomford & Caughley 1996). Separately, there was a national line of enquiry into Aboriginal roles in natural resource and protected area management (Williams & Hunn 1986; Birckhead et al. 1992). The field work underpinning this study was done in 19861988 and quantitative data collected in 1990 whilst the researcher lived on Martu settlements. Ethnographic information was gathered from informal discussions, semi-structured interviews and participant observation on trips undertaken by Martu. A variety of parameters was recorded for each trip in 1990. On trips accompanied by the researcher, details on the plant and animal species collected were quantified. Martu knowledge and observations of Martu behaviour are interpreted in terms of the variety of land uses conducted and transport strategies including vehicle use; the significance of different species collected; socio-economic features of bush food collection; spatio-temporal patterns of foraging; and, the 'management' of species and lands by Martu. The research found that in 1990, hunting and gathering were major activities within the suite of land uses practiced by Martu. At least 40% of trips from the settlements were principally to hunt. More than 43 animal species and 37 plant food species were reported to be collected during the study; additionally, species were gathered for firewood, medicines and timber artefacts. Customary harvesting persisted because of the need for sustenance, particularly when there were low store supplies, as well as other reasons. The weight of bush meats hunted at least equalled and, occasionally, was three times greater than the weights of store meats available to Parnngurr residents. ... Paradoxically, hunting was a subject of significant difference despite it being the principal activity driving Martu expertise and practice. There is potential for comanagement in the National Park but it remains contingent on many factors between both Martu and DEC as well as external to them. The dissertation suggests practical strategies to enhance co-management.
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Vetter, Susan M. "Drought, change and resilience in South Africa's arid and semi-arid rangelands." 2009. http://hdl.handle.net/10962/d1006017.
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Droughts can have serious ecological and economic consequences and will pose an increasing challenge to rangeiand users as the global climate is changing. Finding ways to reduce ecological and economic impacts of drought should thus be a major research thrust. Resilience, defined as the amount of perturbation a social or ecological system can absorb without shifting to a qualitatively different state, has emerged as a prominent concept in ecosystem ecology and more recently as a conceptual framework for understanding and managing complex social-ecological systems. This paper discusses the application and relevance of resilience to understanding and managing ecosystem change, and enhancing the capacity of land users to adapt to droughts. Drought can trigger vegetation change and factors such as grazing management can influence the likelihood of such transitions. Drought can cause differential mortality of perennial plants and this could provide an opportunity for rangeland restoration by opening up establishment sites for desirable species. The capacity of land users to cope with drought is influenced by the resilience of their agro-ecosystems, the diversity of livelihood options, access to resources and institutional support. By these criteria, current agricultural development approaches in South Africa, particularly in communal rangelands and areas of land reform, are unlikely to enhance land users' resilience to drought and other perturbations.
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Popp, Alexander [Verfasser]. "An integrated modelling approach for sustainable management of semi-arid and arid rangelands / Alexander Popp." 2007. http://d-nb.info/985911573/34.
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Jakoby, Oliver. "Risk management in semi-arid rangelands: Modelling adaptation to spatio-temporal heterogeneities." Doctoral thesis, 2011. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-201112078601.
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Livestock grazing is the most important type of land-use in arid and semi-arid regions. In these regions, uncertain and highly variable climate conditions cause scarce and spatio-temporally variable resource availability. The major challenge to livestock grazing is the efficient utilisation of these resources without running the risk of degradation. Therefore, well adapted grazing strategies that consider both local environmental characteristics and the farmers' individual needs and perceptions are crucial for sustaining human livelihoods. Particularly, rotational grazing is presumed to render adaptation to spatio-temporal heterogeneities possible. A systematic investigation, however, that analyses the interrelations between the major components of rotational grazing systems on appropriate spatial and temporal scales was missing so far.
This doctoral thesis investigates different management strategies for sustainable livestock grazing in semi-arid rangelands. Using an integrated modelling approach, it enters into the question: how to adapt grazing systems to spatio-temporal heterogeneous rangeland conditions, variable and changing climate conditions, and different individual needs and goals of livestock farmers?
In order to address these issues, the taken approach tackles both methodical challenges and applied concerns. In the first part of this study, a generic modelling framework is developed that incorporates important components of grazing systems on appropriate spatial and temporal scales. To parameterise the model, a pattern-oriented approach is developed that uses qualitative patterns to derive a broad range of plausible parameter sets supporting a general model analysis.
In the second part, a variety of management strategies is explored under different climatic, ecological, and economic conditions. The research focuses in particular on combined effects between and relative importance of different management components. The question how the results of different management strategies depend on the type of vegetation is investigated. Furthermore, the performance of rotational grazing strategies is analysed under different economic requirements and rainfall conditions. The study also identifies management strategies that are suitable to adapt a grazing system to spatio-temporally variable rangeland conditions.
Overall, this thesis contributes to a general understanding of basic principles for adaptation to spatio-temporal heterogeneities as well as the interplay of different management components. The results allow an evaluation of management strategies for specific situations and the identification of strategies that are robust to a broad range of situations including different aspects of global change.
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Müller, Birgit. "Sustainable grazing management in semi-arid rangelands. An ecological-economic modelling approach." Doctoral thesis, 2006. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2006032813.
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The loss of utilisable rangeland in semi-arid areas results in huge economic and social costs worldwide. Only adaptive management strategies are able to cope with these systems, which are largely driven by unpredictable and stochastic rainfall. Additionally they are characterized by strong feedback mechanisms between economic and ecological factors. This study aims to contribute to the identification of basic principles for sustainable grazing management. The approach emphasizes learning from existing management systems through the use of ecological-economic modelling. Two apparently successful management systems in Namibia are used as a starting point for a broader analysis: the Gamis Karakul sheep farm and the land use system of the semi-nomadic Ova-Himba. Although the economic systems differ strongly, their management seems to have similarities: the importance of pasture resting and of adapting livestock numbers to available forage. This PhD thesis contributes substantial insights about the relevance and functioning of pasture resting for sustainable grazing management in semi-arid regions. Assessment of the two case studies leads to the hypothesis that resting in the rainy season, particularly during wet years, is fundamental for ensuring pasture productivity under low regeneration potential of the vegetation. The thesis highlights that resting during wet years acts as a risk reducing strategy. Additionally, the study reveals that access to economic risk management strategies, such as rain-index-insurance, may change farmer´s behaviour towards less conservative strategies. The used approach - learning from existing apparently successful grazing strategies by ecological-economic modelling - offers a powerful tool for tackling new questions related to global change. The scope and the limits for generalizing the key factors discovered for sustainable grazing management can be easily detected under changing ecological, climatic and economic conditions.
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Wilcock, Trove Elizabeth. "Use of selected fodder shrubs in the reclamation of degraded arid rangelands." Diss., 2010. http://hdl.handle.net/2263/27304.
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Aspects, which influence the choice of species for the rehabilitation of degraded arid areas, were studied. Although only one trial was established in the target area (transition area between the Succulent and Nama Karoo) seed of the indigenous species used was collected from this area. In the initial trials the effect of rumen digestion on the germination of fodder shrubs was observed. Species included the exotic Atriplex nummularia and Cassia sturtii, and the indigenous Sutherlandia microphylla, Tetragonia calycina, Tripteris sinuatum and Salsola glabrescens. No seed of T. calycina germinated. In T. sinuatum and S. glabrescens rumen digestion prevented germination while in the other species percentage germination was reduced. In the establishment trial with A. nummularia and C. sturtti, on a bare area onfarm, in the arid Northern Cape Province, no seed germinated. Observations showed that, for both species, protection is essential, where the risk of herbivory is high. Of the two species, C. sturtti shrubs appeared to be more drought tolerant. A further trial addressed the intra-species variation in the palatability of A. nummularia. Established shrubs of the F1 “elite” generation were browsed by sheep. The most palatable shrubs were identified and seed from these shrubs will be used to produce seedlings that will go into further selection trials. The final section of this study was a comparison, in terms of quantity, quality and re-growth, of C. sturtii, T. sinuatum and S. microphylla, at, and subsequent to, five different harvest dates. In the first three harvests no significant differences were observed in the total plant material produced, between the three species. In Harvest 5 both indigenous species had produced more edible material (leaf and <3mm stem material) than C. sturtii. The edible material of Harvests 1, 3 and 5, was analysed for crude protein content, in vitro digestibility and mineral concentrations. All three species had sufficient crude protein as well as calcium, phosphorus and magnesium, to meet maintenance requirements of sheep. Trace minerals, manganese and copper, were present in adequate amounts and toxicity could be more of a concern. The concentrations of zinc in all three species, however, were only sufficient in material obtained in Harvests 1 and 3. Re-growth of all shrubs 21 weeks after Harvest 5 was assessed in terms of survival, healthiness, leafiness, volume and dry matter production. C. sturtii shrubs harvested at a later stage in the initial trial had the best survival. For most re-growth periods, C. sturtii shrubs also appeared healthier and leafier than the indigenous species. S. microphylla seedlings had, however, established in the S. microphylla plots, which was a plus for that species. CopyrightDissertation (MScAgric)--University of Pretoria, 2010.
Plant Production and Soil Science
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Venter, Daniel Barend. "An ecological approach to the reclamation and improvement of arid rangelands using adapted fodder plants." Diss., 2006. http://hdl.handle.net/2263/23495.
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The world we live in is changing rapidly. Ecological, economic and social aspects and understandings are all undergoing paradigm shifts. Communities, farmers and individuals in arid zones are experiencing climate changes, more so than city dwellers. A better understanding of the current thinking in range ecology and management, especially of arid environments, is critical to the management of these delicate, complex systems. Ecosystems in equilibrium or in disequilibrium react differently to management and reclamation efforts. An understanding of the basic principles and how they evolved is important in order to apply these principles correctly in the management of arid zones. The use of keystone species and simple technologies, such as water harvesting and mulching, can all be used to reclaim and manage the arid zones. Understanding the differences between systems in equilibrium and disequilibrium can be used as a guide for planning appropriate future research in the arid zones. Searching for new indigenous species to help in the reclamation of arid zones is of the utmost importance. An ecological criterion was used to identify potential plant species for reclamation of degraded arid rangelands of southern Africa. Tripteris sinuatum and Sutherlandia microphylla were identified as possible candidates. Germination studies, with seeds harvested from naturally occurring plants, were conducted for both species. Treatments were based on the natural seed dispersal mechanisms for both species. S. microphylla has the potential to become an important plant species for reclamation purposes in arid zones of southern Africa. Not only potential new species should be sought, but also the management of species, already in use, are of critical importance. The relative palatability and survival of 16 different Atriplex species and accessions were determined at two different localities in the arid Northern Cape Province of South Africa. Significant differences were found between species at both localities. It is believed that because of the variety of species in the Atriplex genus, relative palatability and survival should be used to determine which of the different species could be useful under specific climatic and soil conditions. The establishment and reaction of Atriplex nummularia and Cassia sturti were tested for season of planting and the use of a stone mulch at two locations in the Northern Cape Province of South Africa. A. nummularia reacted the best to a moderate pruning treatments, while Cassia sturtii reacted best to severe pruning. These results should aid in the management of planted fodder plantations. Numerous attempts at improving natural veld have failed in the past. An examination of landscape function and the potential to harvest water in localized areas should drive veld improvement in arid zones. Seeds from two different plants species (Tetragonia calycina and Tripteris sinuatum) were used to inter-seed a bare patch in the Northern Cape Province of South Africa. The two species, with two treatments, (brush packing or not) in two different locally occurring eco-topes, were used to determine plant establishment. The water run-on eco-tope showed a significantly higher plant establishment percentage than the water run-off eco-tope. The establishment of perennial grass species was also found on the water run on eco-tope, three years after establishing the reclamation site. Such sites could form an important link in biodiversity conservation.Dissertation (MSc Agric (Pasture Science))--University of Pretoria, 2007.
Plant Production and Soil Science
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Khalili, Davar. "A decision methodology for the resource utilization of rangeland watersheds." 1986. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1986_585_sip1_w.pdf&type=application/pdf.
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Harrison, Kristen S. "Litter decay processes and soil nitrogen availability in native and cheatgrass-dominated arid rangelands." Thesis, 2003. http://hdl.handle.net/1957/32054.
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Mogashoa, Regina Etla. "Bush encroachment effects on above-ground biomass, species, composition, plant diversity and selected soil properties in a semi-arid savanna grassland." Thesis, 2020. http://hdl.handle.net/10386/3394.
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Thesis (M.Sc. Agriculture (Pasture Science)) -- University of Limpopo, 2020Bush encroachment is a major problem in arid and semi-arid savannas characterized by a grass layer interspersed with a shrub stratum. Land cover change as a result of rapid proliferation of woody species in previously open rangelands alters herbaceous species and impacts soil properties. So far, little is known about the threshold at which woody plant density and cover affects herbaceous cover and the underlying mechanisms driving bush encroachment in arid and semi-arid rangelands are still debated. The objectives of this dissertation were to (1) to assess woody species composition and structure along an encroachment gradient and to explore the relationship between woody vegetation and herbaceous vegetation. (2) To determine the effect of increasing tree density and cover on grass species richness, diversity, evenness and selected soil nutrients in a bush encroached rangeland. In order to address these objectives, a semi-arid rangeland was demarcated into three encroachment gradients spanning from open to intermediate and intensive. Within each encroachment gradient six plots of 10 m x 10 m were randomly selected, whereby woody and herbaceous vegetation were assessed and soil properties determined. A discernible increase in woody species diversity and evenness was found along the transition from open to intensive bush encroached rangeland. Leguminous woody species Vachellia spp. and Dichrostachys cinerea were dominant along the bush encroachment gradient. Tree height was found to be positively correlated with long crown diameter (LCD) and short crown diameter (SCD). Furthermore, increasing tree density resulted in a 53% decline in grass species richness (GR). A decline in GR mirrored an increase in the composition of the decreaser species Panicum maximum (90%). Increasing woody plant density and cover also increased macro-nutrients; total carbon, nitrogen, phosphorus, exchangeable calcium and magnesium by 21%-159% in the shallow rangeland soils. Such quantitative information will assist rangeland managers to better understand the effects of varying bush encroachment intensities on herbaceous species composition, richness and soil properties in semi-arid savanna rangelands.
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Müller, Birgit [Verfasser]. "Sustainable grazing management in semi-arid rangelands : an ecological-economic modelling approach / vorgelegt von Birgit Müller." 2005. http://d-nb.info/980111730/34.
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Fisher, Jolene Tichauer. "People, parks and rangelands: an analysis of three-dimensional woody vegetation structure in a semi-arid savanna." Thesis, 2014.
Find full textAbstract:
A thesis submitted to the Faculty of Science, University of the Witwatersrand,
Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy
29 July 2013 in Johannesburg, South AfricaEffective management of protected areas and communal rangelands, which are often juxtaposed in developing countries, is essential to prevent biodiversity decline and ensure a sustainable resource base for rural communities. However, in human-modified landscapes, there are complex interactions between factors that determine woody vegetation structural patterns. While the underlying biophysical template continues to influence vegetation patterns in a predictable manner; the intensity and type of disturbances that are the result of resource extraction, fire and herbivory can have an overriding impact. In order to effectively conserve biodiversity and plan for sustainable resource use, an understanding of land-use and land management is required. A case study of adjacent protected areas (Kruger National Park (KNP), a national protected area and Sabi Sand Wildtuin (SSW), a private game reserve) and communal rangelands (in Bushbuckridge Municipality (BBR) with varying intensities of use) in north-eastern South African savannas was used to study the spatio-temporal patterns of three-dimensional (3D) woody vegetation structure as a result of natural resource management and abiotic drivers. The aim of this PhD thesis is to advance our understanding of the effects of management of natural resources on spatio-temporal patterns of 3D woody vegetation structure across land uses in a heterogeneous semi-arid savanna system. Vegetation structure was measured using small-footprint, discrete-return LiDAR (Light Detection and Ranging) collected by the CAO (Carnegie Airborne Observatory) Alpha System over 35 000 ha across the study area. 3D woody vegetation structure was compared both within land uses (KNP versus northern SSW, and within BBR) and between land-uses (southern SSW versus BBR) to address two objectives, namely 1. Can LiDAR be used as a monitoring tool for management of woody vegetation structure and biodiversity in semi-arid savannas and 2. What is the impact of land use and the corresponding management of resources on woody vegetation structure in semi-arid savannas? Different land-use legacy timelines and current management objectives at sites in KNP and northern SSW has resulted in an average of 2.5 times higher vegetation density <3 m and >6 m in SSW. These differences in vegetation structure are exacerbated by current management practices, with implications for faunal biodiversity conservation across all scales. Not all reserves are equal in their ability to conserve biodiversity and such knowledge should be considered in conservation planning and management. In the communal rangelands, intense fuelwood harvesting has resulted in coppiced trees <3 m in height, and the only trees >5 m are preserved for cultural reasons, producing similar vegetation patterns to Sabi Sand Wildtuin. Disturbance (extraction and grazing) gradients occur with distance from settlements, with utilization intensity affecting vegetation cover within the size class distributions, but not the shape. Gradients diminish under heavier utilization resulting in a more structurally homogenous landscape, which may be used as an early warning sign of woodland degradation. The increase in >3 m tall trees was twice as high in low intensity use CRs adjacent to SSW compared to those in southern SSW from 2008 to 2010, indicating the impacts of treefall from megaherbivores and fire management reducing plant recruitment/regeneration in the protected area. Knowledge from investigation of socio-ecological drivers in the two land-uses were used to construct an ecologically relevant 3D woody vegetation structural classification which can be used by land managers to plan for sustainable resource use and effective conservation of biodiversity. The management of natural resources, including direct use of fuelwood and the management of herbivory and fire affects woody structural dynamics; however, a lack of knowledge exists around the social and ecological context of natural resource management. The use of remote sensing, the knowledge of savanna ecology and an understanding of community-based natural resource management is integrated in this thesis to contribute to the context specific understanding of drivers of woody vegetation structure in two socio-ecological systems (protected areas and communal rangelands) which can be used in sustainable natural resource management plans.