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The use of fire in rangeland has become standard practice for decades; however, there is no shared understanding of how fire affects soil properties. The exact relationship between fire and soil properties is still yet to be understood. The differences in fire frequency, fire intensity, fire severity, the period between fire and sampling resulted in contradictory results amongst studies. A long-term trial at the University of Fort Hare provides a valuable experimental layout for fire research. The trial was established in 1980 with the aim of investigating the effect of burning frequency on vegetation species composition and biomass production. The objective of this study was however to determine the effect of fire management on soil chemical and physical properties under the long-term burning experiment. The treatments of the study site were: no burn (K), annual (B1), biennial (B2), triennial (B3), quadrennial (B4) and sexennial (B6) burns. A line intercept sampling technique was used to collect the soil samples from the surface (0 to 75 mm) for both chemical and physical analysis. All Burning treatments significantly (p < 0.05) increased the bulk density (Db), soil pH, total cations, Magnesium (Mg) and Calcium (Ca), but reduced the soil porosity and exchangeable acidity when compared to the control. Hydraulic conductivity (Ks), water conducting macroporosity (WCM) and total nitrogen were reduced under more frequent burning treatments (B1, B2), as compared to less frequent burning treatments (B3, B4, B6). The aggregate stability showed an opposite trend. Total organic carbon (TOC) was reduced only under annual burning treatment. Burning frequencies did not impact the extractable Phosphorus (p), Potassium (K), Sodium, soil water repellency and water content significantly (P > 0.05). The risk associated with annual burning showed in this study might facilitate processes such as overflow that lead to soil degradation. Triennial burning in rangeland ecosystem supports soil conservation practices. Further studies that measure the quality of rangeland in triennial burning is necessary.

Thesis (Ph. D.)--University of Montana, 2006. / Title from title screen. Description based on contents viewed Mar. 30, 2007. Includes bibliographical references (p. 142-151).

Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S. in natural resource sciences)--Washington State University, August 2009. / Title from PDF title page (viewed on Sept. 21, 2009). "Department of Natural Resource Sciences." Includes bibliographical references (p. 42-44).

Thesis (M.A.)--Memorial University of Newfoundland, 1999. / Bibliography: leaves 107-121.

Thesis (M.S.)--Missouri State University, 2009. / "May 2009." Includes bibliographical references (leaves 41-47). Also available online.

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves - ). Also available on the World Wide Web.

To proffer a sustainable solution to ecological degradation in rangeland ecosystems as a consequence of fire, grazing and browsing, an understanding of rangeland ecological processes is vital. Due to the complexity of ecological processes and their interrelationships, it is usually difficult or expensive to directly measure status of ecological processes. Therefore, biological and physical characteristics are often used to indicate the functionality of ecological processes and site integrity. Long-term effects of fire, grazing and browsing on characteristics of the vegetation and organic matter and their subsequent effects on selected rangelands ecosystem ecological processes was conducted at Honeydale section of the University of Fort Hare farm in the Eastern Cape Province of South Africa and Matopos Research Station in Zimbabwe. In this study, attributes of biotic community integrity (species richness, composition and diversity), soil stability (basal cover, standing dead grass biomass, tuft to tuft distance, tufts diameter, canopy distance and stem to stem distance), productivity and plant vigour (grass yield, total canopy volume, plant height, canopy height, canopy diameter, main stem diameter, sprouts diameter and number of sprouts) and hydrologic function and nutrient cycling (grass litter biomass, soil organic carbon and microbial biomass carbon) were used to estimate long-term effects of burning, grazing and browsing by goats on the functionality of ecological processes in the rangeland ecosystem. Burning did not have differential effect on grass species richness (P>0.05), woody species diversity as well as compositional percentage for D.eriatha, C.plurinodis, S.fimbriatus, A.karro and E.rigida. Burning increased decreasers and increaser II species proportions and reduced (P ≤ 0.05) grass yield, total canopy volume, tree height, canopy height main stem diameter and sprouts diameter. Long-term burning, grazing, and goats browsing had differential effects on site stability. The effects on basal cover, tuft to tuft distance, tufts diameter, canopy distance and basal distance as a consequence of long-term burning, grazing, and goats browsing were not significantly different, whereas the effects on standing dead grass biomass as a result of long-term burning frequencies were significantly different. Long-term effects of burning followed by ten-year period of fire exclusion had significantly different effects on tuft-tuft distance but did not have statistically different effects on tufts diameter, canopy distance and basal distance. Long-term burning grazing and browsing had significantly different effects on attributes of hydrologic functions and nutrient cycling in the rangeland ecosystem (grass litter biomass, SOC and BMC). Long-term effects of burning followed by ten-year period of fire exclusion had significantly different effects on grass litter biomass, and SOC. Through their effect on vegetation and organic matter characteristics, burning, grazing and browsing could influence functionality of selected rangeland ecological processes such as biological community integrity, productivity and plant vigour, site stability, hydrologic function and nutrient cycling.

Bush encroachment or the thickening of woody vegetation is a phenomenon occurring throughout savannas, which tends to be more pronounced in small protected areas. The consequences of bush encroachment are often negative for the conservation of biodiversity, for the promotion of tourism and the prevention of wildfires. Hence, effective monitoring of woody vegetation and the factors which influence its spread are essential. This is particularly the case for protected areas such as that of Bwabwata National Park (BNP) in north-east Namibia. With a complex land use history and different fire management approaches being adopted throughout the area, the effect of fire on woody vegetation in BNP is currently poorly understood. This study used a 20-year-old repeat photography monitoring project and satellite-based remote sensing products to explore woody cover dynamics in BNP. Results revealed that woody cover has increased by 13% since 1999 in BNP. Furthermore, the results show differences in the structure of woody vegetation. Repeated late dry season fires in the west of the park have driven an increasing dominance of 3m in eastern sections of the park. This influence of different fire regimes spatially across BNP, suggests that local fire management is a significant determinant of woody vegetation change. Woody vegetation change differs spatially across BNP due to frequent late dry season fires prevailing in the west and less frequent earlier season fires occurring in the east. Therefore, in order to reduce the mortality of woody species and conserve heterogenous height structure in the west, a reduction of frequent late dry season fires is required. Early dry season fires are shown to reduce the rate of increasing total woody cover change and, therefore, this fire management strategy arguably contributes towards the reduction of wildfire risk, conservation of biodiversity and promotion of tourism.