This thesis examines the Schultz Fire as a case study to explain the complex history of fire suppression management in America’s forests, and to gain further understanding of how management practices have affected the increase in fire severity levels and how forests respond to such a disturbance. The thesis objectives were: (1) to analyze the causes of the fire severity of the Schultz Fire, especially: topography, fuels, or weather; (2); to examine the possible correlation between fire severity and tree density; (3) to investigate whether post-fire species richness was related to fire severity two years after the Schultz Fire; (4) to investigate whether post-fire plant species richness, plant cover, and tree regeneration was related to fire severity two years after the Schultz Fire; and (5) to interlink and convey how these factors relate to the history of fire management and policy and public perception. The history of fire related policy and management has significantly changed the dynamics of America's national parks and forests. Understanding the larger context of this history, both of national fire management and of the effects of language and perception on policy and public reaction, is part of understanding the Schultz Fire as a whole. Based on modeling, high winds combined with the presence of high surface fuel load were the main causes of the Schultz Fire's high fire severity levels. As fire severity increased there was a statistically significant increase in species richness. Severity level had little variation on percentage of cover by plants. No statistically significant relationship between tree density and fire severity levels was found. These findings underline the need for fuel treatments in southwest Ponderosa Pine forests, and effective cooperation between communities, managers, and ecologists. The Schultz Fire serves as an example in understanding the intricacies of how history affects the present and future of fire management. How fire has been managed and portrayed in the past has left an indelible mark on how fire is presently viewed. Without a clear understanding of the history of fire management and the role of fire in the ecology, future policies towards fire will be unable to account for and manage for the diversity of ecosystems and fires effects on those ecosystems across the United States. / Graduation date: 2013

Fire plays an important role in structuring and maintaining savanna grassland ecosystems. Although regular fires are a characteristic feature of savannas, the effects of fire frequency on these systems are less well known, particularly with respect to how frequency of fire influences large herbivore distribution and behaviour. The expectation is that large herbivores should be attracted to frequently burned sites as a consequence of changes in forage quality and quantity, and/or vegetation structure and composition. The former could be driven by alterations in soil nutrients, such as N and P. Alterations in vegetation also could be important in determining risk of predation. For example, an increase in woody vegetation could decrease predator visibility making large herbivores more vulnerable to predation. The objectives of this study were to investigate the effects of long-term alterations in fire frequency on herbivore distribution and behaviour, as well as the mechanisms (soil nutrients, vegetation structure and composition, and forage quality and quantity) potentially driving the distribution of large herbivores. To address these objectives, I conducted large herbivore surveys on a bi-weekly basis from 2009-2010 in a series of plots in the Experimental Burn Plots (EBPs) burnt at different frequencies (annual, triennial and unburnt) over the last five decades at three study sites in the Kruger National Park, South Africa. Surveys also were conducted on new plots that were established adjacent to the long-term plots. These new plots have a fire return interval of 4 years which is similar to the triennially burned plots of the EBPs. They were established in the landscape adjacent to the EBPs to assess whether the responses of herbivores to fire observed in the EBPs reflected was at landscape level. The distribution of all large herbivore species combined and of grazers (e.g. zebra) or browsers (e.g. kudu) only were not affected by fire frequency. In contrast, the abundance of mixed-feeders, such as impala, was significantly higher in the unburnt (control) and annually burned plots than the triennially burned plots. Although season did not have a significant impact on the distribution of browsers and mixed-feeders, overall more grazers were recorded across all burn treatments in the dry season compared to the wet season. Similar patterns of herbivore distribution were observed between the new plots and the triennially burned EBP plots, suggesting that responses observed to the long-term fire frequency treatments reflects herbivore responses at the landscape level. The long-term fire frequency treatments significantly affected soil nutrients (N, organic C, P, and K were significantly lower with annual burning), vegetation structure (abundance of woody plants were greater in unburned plots), and forage quantity (unburned plots had higher biomass) but not quality. More frequent fires improved visibility by reducing tree height and density and herbaceous biomass, thereby potentially reducing predation risk, when compared to less frequent burning. As a result, herbivores selected sites with more frequent fires. The behaviour of the herbivore species investigated was predominantly influenced by seasonal-induced changes to their environment rather than fire frequency. In the wet season irrespective of the burning treatment visibility was low due to high rainfall that increases plant biomass, whereas in the dry season visibility was improved because there is little to no rainfall. This potential alteration in predation risk likely resulted in herbivores being more vigilant in the wet season than the dry season. Overall, results from this study suggest that the combination of fire frequency and season drive herbivore distribution and behaviour by altering mainly the vegetation structure which can influence predation risk. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

A series of trials and investigations were implemented to address concerns surrounding the dynamics of the fire-climax wooded/edaphic grasslands within the iSimangaliso Wetland Park, northern KwaZulu-Natal, South Africa. The research problem surrounded inadequate historical evaluations of changes in vegetation structure, grasslands progressing to a woody dominated composition, and increases in Helichrysum kraussii (Curry bush). These were addressed as follows: Firstly, the recovery of vegetation in response to different periods of fire exclusion in different communities along a topographical gradient of a coastal dune area, was assessed over a two year period. Secondly, the regeneration after wildfire of the persistent, stress tolerant shrub H. kraussii, was studied on different catenal positions with differing fire exclusion periods and with and without defoliation of surrounding plant biomass in the coastal edaphic grasslands north of Manzengwenya, South Africa. Thirdly, aerial photography from 1937, 1975, and 2000 was georectified, digitised and analysed using a Geographic Information System to examine broad vegetation changes in response to different management regimes for a site on the Eastern Shores of Lake St Lucia and a site within the Tewate Wilderness Area. In the absence of fire, the coastal edaphic grasslands progressed to a closed canopied scrub forest within six years. An increase in fire exclusion period resulted in a decrease in species abundance, an increase in woody height, and a decrease in plant density. Richness increased initially but declined marginally with increased fire exclusion period. Higher lying east and west facing sites had a better veld condition index compared with bottom sites and had an increased response (vigour) to defoliation but were far more likely to succeed through to woody scrub forest. Woody plant biomass vigour was greater for west facing sites. Ordination of species composition across sites in response to fire exclusion and catenal position revealed greater similarities within exclusion periods than between. Bottom sites were more similar with similarity decreasing for east and west facing sites. Fire exclusion resulted in an initial increase in woody species and a subsequent increase in herbaceous species. iii Growth response of H. kraussii was unaffected by catenal position and fire exclusion period, whereas defoliation of surrounding grass tended to increase in size (P<0.05). Density and height for this species however increased with increasing fire exclusion. An increase in soil moisture negatively affected H. kraussii growth indicating susceptibility to high water tables. The number of other woody species establishing beneath H. kraussii may be due to changes in the transmission of light through the canopy where an increase in canopy diameter resulted in an increase of photosynthetically active radiation at the soil surface. The effects of fire on landscape change were investigated for the Eastern Shores and Tewate Wilderness Area, iSimangaliso Wetland Park, South Africa using aerial photography. Changes to historical disturbance regimes largely through active exclusion of fire resulted in the majority of the higher lying coastal grasslands changing to savanna scrub or closed canopied forest within 63 years on the Eastern Shores. The degree of fragmentation of these grasslands was greatly reduced within the Tewate Wilderness Area where disturbance regimes included greater frequencies of fire. Hygrophilous grasslands remained largely unaffected by woody encroachment but did not preclude woody species establishment indicating possible susceptibility during long drier periods. Frequent fires result in the maintained distribution of the higher grasslands. This vegetation type is a system which becomes resilient in response to fire, whereas in the absence of fire readily progresses to Dune Forest. The coastal grasslands above the high water table are therefore highly unstable and transformed easily in the absence of regular disturbance. It would appear that a threshold of approximately six years exists, after which substantial management intervention may be required to reverse the succession back to grassland. The growth of H. kraussii was unaffected by fire and remained persistent irrespective of fire exclusion period. An ability to attain size (height and canopy diameter) was limited with increased soil moisture but density was reduced through regular burning. Frequent fires are necessary to reduce density of H. kraussii and reduce the competitive advantage gained with age. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

Wildfires destroy large tracts of veld and forest land every year in South Africa. These fires can be devastating, resulting in loss of human lives, the destruction of property and the loss of income, for example the forest fire in the Sabie district in Mpumalanga in 2007 which destroyed about 7% of South Africa’s forested areas. There are frequently legal disputes with respect to the origin of wildfires, the extent of the fire and the land cover destroyed by the fires. The forensic capabilities of remote sensing in detecting and analysing post-wildfire characteristics have become an important contribution towards solving such legal disputes and in understanding wildfire characteristics. These post fire products can be used as evidence in court cases. Most of the time those court cases came up a few years after the fire event. By then, little or no evidence can be found on the terrain where the fire was. Remote sensing archives provide a reliable source of data that can be used to analyse these events after these long intervals. The objective of this project is to highlight the methods used to generate these post-wildfire analysis products. / Environmental Sciences / M. Sc. (Environmental Science)

Wildfires destroy large tracts of veld and forest land every year in South Africa. These fires can be devastating, resulting in loss of human lives, the destruction of property and the loss of income, for example the forest fire in the Sabie district in Mpumalanga in 2007 which destroyed about 7% of South Africa’s forested areas. There are frequently legal disputes with respect to the origin of wildfires, the extent of the fire and the land cover destroyed by the fires. The forensic capabilities of remote sensing in detecting and analysing post-wildfire characteristics have become an important contribution towards solving such legal disputes and in understanding wildfire characteristics. These post fire products can be used as evidence in court cases. Most of the time those court cases came up a few years after the fire event. By then, little or no evidence can be found on the terrain where the fire was. Remote sensing archives provide a reliable source of data that can be used to analyse these events after these long intervals. The objective of this project is to highlight the methods used to generate these post-wildfire analysis products. / Environmental Sciences / M. Sc. (Environmental Science)

The increase of woody vegetation (also known as bush or shrub encroachment) in savannas has become of global concern to conservationists and rangeland managers alike. Bush encroachment has been associated with a decrease in rageland palatability. In addition, the increase in woody biomass has consequences for climate change, carbon sequestration, rangeland hydrology and nutrient cycling. As a result of these large changes in ecosystem functioning with bush encroachment, biodiversity may be threatened. Fire is considered to be one of the most important management tools used to control woody biomass in savannas. However, despite the use of fire in Ithala Game Reserve, areas have become encroached. This thesis assesses the role of fire in bush encroachment in Ithala Game Reserve. I start this thesis with a discussion of the bottom-up (water, nutrients, and light) and topdown (fire and herbivory) ecosystem components in the literature review. This sets the foundation for an understanding of the factors that affect savanna tree:grass ratios for the rest of this thesis. In addition the review discusses the potential effects of climate change on savanna tree:grass ratios. Recently, it has been proposed that increasing atmospheric carbon dioxide concentrations result in an increased competitive ability for C3 woody plants against C4 grasses. Many models have been produced to explain savanna dynamics. By assessing the role of fire in Ithala Game Reserve, its functioning is assessed in light of the current issues of bush encroachment. Textural analysis is a remote sensing technique that has been used to detect changes in woody vegetation using aerial photographs. Textural analysis was used to assess changes in woody vegetation cover and density from 1943 (earliest period for which aerial photographs were available for the study area) to 1969, 1990 and 2007 in Ithala Game Reserve (IGR). Field surveys were performed to assess the effects of the fire regime in IGR on woody vegetation structure and composition. Transects were performed in areas with different fire frequencies. The effects of fire frequency were compared between similar vegetation communities. Textural analysis showed that woody vegetation cover (+32.5%) and density (657.9 indiv. ha-1) increased from 1943 to 2007. Importantly, in some areas of IGR, the suppression of fire led to the rapid invasion of woody plants from 1990 to 2007. Field studies demonstrated the importance of fire in controlling woody vegetation in IGR. The densities of the encroachers, Dichrostachys cinerea and Acacia karroo were resistant to annual burns. However, the height of these deciduous microphyllous woody encroachers was reduced by more frequent fires. Following the suppression of fire, these trees grew taller and their negative impact on the herbaceous layer increased. Consequently, fuel loads (grassy biomass) declined and prevented the use of frequent and intense fires by management. The reduction in fire frequency allowed the invasion of woody evergreen macrophyllous species. Continued development of fire-resistant patches of evergreen macrophyllous vegetation will further reduce the effectiveness of fire in controlling bush encroachment. To control bush encroachment in IGR and the consequential loss of biodiversity, an intermediate fire frequency (one burn every 2 to 4 years) is required. Burns also need to be hot enough to increase the current rate of topkill. Management should act to optimize the accumulation of grassy biomass to fuel fires. / Thesis (M.Sc.)-Unversity of KwaZulu-Natal, Pietermaritzburg, 2010.

Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Veld fires in the mountain regions of the South Western Cape are an annual occurrence. These veld fires occur as a result of human, natural and unknown causes. The Mediteranean weather conditions of the South Western Cape and its typical vegetation are conducive to these fires. Within the mountain regions of the South Western Cape, the use of fire can be advantageous for conservation and forest managers as a tool for fire management e.g. preparation of fire belts, reduction of veld fire occurrence by burning fuel load, rejuvenation of indigenous vegetation and enhancing the water yield of surrounding areas within their management area. Abnormally high incidences and run away veld fires within the management area of conservation and forest managers leads to. the loss of biodiversity, destruction of properties and loss of human lives, and extensive soil erosion. This study aimed at identifying factors contributing towards the occurrence of veld fires in the mountain regions of the South Western Cape, and using GIS to analyse spatially the contributing variables, and to generate seasonal veld fire hazard maps. Potential veld fire occurrence on a seasonal basis was mapped using spatial analyses of variables that are significant to the distribution of veld fires within the study area. Variables used to assess potential veld fire occurrences were: vegetation, slope, population density (human influence), proximity to roads, mean monthly maximum temperatures and mean monthly rainfall. The veld fire hazard maps generated indicated that potential for veld fire occurrence is high in the summer and autumn months, decreasing to a low in the winter and spring seasons. The exception is the Southern Cape sub-region where the possibility of veld fires can be quite high in winter as a result of Fohn-like berg winds. These winds are characterized by sudden increases in temperature and decreases in humidity that may pose severe fire hazards. Reducing and containing veld fires in the mountain regions of the South Western Cape depends on the effective use of the seasonal veld fire hazard maps. The maps can be used to delineate critical zones of veld fire occurrence which can be used for evaluating costeffective control measures and can be implemented to reduce the level of veld fire danger within the management areas of conservation and forest managers. There is a need for a Catchment Management System (CMS) (Richardson, Van Wilgen, Le Maitre, Higgins & Forsyth, 1994) that can be used to generate daily probabilities of veld fire occurrence and to link these to fire-spread models for predicting or simulating expected fire directions and severities or intensities, and educating people about fires and the damage it can do. / AFRIKAANSE OPSOMMING: Elke jaar kom daar veldbrande in die berggebiede van die Suidwes-Kaap voor. Die oorsake van hierdie veldbrande is van menslike, natuurlike of onbekende oorsprong. Die Mediterreense weersomstandighede en die tipiese plantegroei van die Suidwes-Kaap is ook bevorderlik vir die ontstaan van veldbrande. In die berggebiede van hierdie streek kan die gebruik van vuur egter ook tot voordeel van natuurbewaring en bosbou aangewend word deurdat dit gebruik kan word as 'n metode om die brande te bestuur, soos in die voorbereiding van brandpaaie, in die vermindering van die voorkoms van veldbrande deur vooraf van die brandbare materiale af te brand, in die vernuwing van die inheemse plantegroei en in die verhoging van wateropbrengs in die omliggende gebiede binne die area wat bestuur moet word. 'n Abnormale hoë voorkoms van veldbrande binne die bestuursgebied van bewarings- en bosboubestuurders lei egter tot 'n verlies aan biodiversiteit, die vernietiging van eiendom, 'n verlies aan menselewens en uitgebreide gronderosie. Die doel van hierdie studie was om die faktore wat bydra tot die voorkoms van veldbrande in die berggebiede van die Suidwes-Kaap te identifiseer, om GIS te gebruik om 'n ruimtelike analise van die bydraende veranderlikes te doen en om dan 'n seisoenale veldbrandgevaarkaart saam te stel. Die potensiële voorkoms van veldbrande op 'n seisoenale basis is gekarteer deur gebruik te maak van ruimtelike analises van die veranderlikes van belang in die verspreiding van veldbrande in die studiegebied. Die volgende veranderlikes is gebruik om die potensiële voorkoms van veldbrande te bepaal: plantegroei, helling, bevolkingsdigtheid (invloed van mense), afstand vanaf paaie, gemiddelde maandelikse maksimum temperature en gemiddelde maandelikse reënval. Die veldbrandgevaarkaarte wat ontwikkel is, het aangetoon dat die potensiële voorkoms van veldbrande hoog is in die somer- en herfsmaande en dan afneem tot 'n laagtepunt in die winter en lente. 'n Uitsondering is die Suid-Kaap-substreek waar die moontlikheid van veldbrande selfs in die winter taamlik hoog is as gevolg van Fëhn-tipe bergwinde. Hierdie winde word gekenmerk deur In skielike toename in temperatuur en In afname in humiditeit wat die brandgevaar skerp kan verhoog. Die vermoë om veldbrande in die berggebiede van die Suidwes-Kaap te verminder en te beperk, sal grootliks afhang van die effektiewe gebruik van die seisoenale veldbrandgevaar-kaarte. Die kaarte kan gebruik word vir die afbakening van kritieke sones vir die voorkoms van veldbrande wat dan gebruik kan word vir die evaluering van koste-effektiewe beheermaatreëls. Hierdie kaarte kan dan geïmplementeer word om die vlakke van veldbrandgevaar binne die gebiede waarvoor bewarings- en bosboubestuurders verantwoordelik is, te verminder. Daar is In behoefte aan In opvanggebiedbestuurstelsel (OGB) (Richardson, Van Wilgen, Le Maitre, Higgins & Forsyth 1994) wat gebruik kan word om daaglikse waarskynlikhede vir die voorkoms van veldbrande te genereer. Dit kan gekoppel word aan brandverspreidingsmodelle wat die verwagte rigting van brandverspreiding, asook die ems of intensiteit daarvan, kan voorspelof simuleer. Die publiek moet ook ingelig word oor veldbrande en die skade wat daardeur aangerig kan word.

<p dir="ltr">To examine how forest management affects terrestrial salamanders, this dissertation: (1) examines the effects of timber harvesting strategies on salamanders; (2) examines the effects of prescribed fire for oak regeneration on salamander populations; and (3) explores the influence of artificial cover object (ACO) wood type, size and shape, and placement on salamander monitoring results. These projects were conducted at the Hardwood Ecosystem Experiment (HEE) and Martell Experimental Forest in Indiana. Long-term salamander monitoring data from the HEE were used to examine the effects of clearcuts, shelterwoods, and patch cuts on salamander captures collected up to eleven years post-harvest and were analyzed with a before-after-control-impact (BACI) design. Clearcuts and patch cuts had negative effects on salamanders 4-6 years post-harvest, which coincided with a drought; however, preparatory and establishment shelterwood harvests showed no effects on salamander captures, suggesting that retaining canopy cover may protect salamanders from compound disturbances such as drought. Also at the HEE, capture-recapture techniques were used to examine salamander population estimates before and after fire. Only two of three fires affected salamander populations. In the short term, prescribed fire effects on salamanders may be weak and intermittent and microclimate may have a greater effect on populations, although the longer-term effects of fire remain unknown. At Martell Experimental Forest, salamander numbers were compared beneath ACOs of different wood types, sizes and shapes, and grid arrays of different spacings. Pine ACOs were preferred over ash, while several small ACOs yielded equal salamander numbers to one large ACO of equal total area. High ACO density may increase capture probability but reduce the area sampled by each ACO, while lower density ACO grids may cover a larger area with the same sampling effort and produce more comparable results, but with less precision; choice of ACO experimental design will therefore require careful consideration of management goals. This dissertation also suggests strategies to support salamander populations as guidelines for managers to consider in management planning.</p>