Shrubland fire regime scenarios in the Swartberg Mountain Range, South Africa: implications for fire management

2007 ◽  
Vol 16 (1) ◽  
pp. 81 ◽  
Author(s):  
A. H. W. Seydack ◽  
S. J. Bekker ◽  
A. H. Marshall

Over the last seven decades, the Mediterranean-type shrublands of the Swartberg Mountain Range (170 856 ha), South Africa, have been subject to divergent fire management policies. Management objectives sequentially focused on grazing, fire control, water and biodiversity conservation during successive fire management periods. The aim of the present study was to explore the factors that determined the prevailing fire regime patterns during these fire management periods. This was considered particularly relevant in view of the ongoing debate on the relative role of fuel characteristics versus weather and ignition rates in shaping fire regime patterns. The extent of burning followed climatic cycles of alternating periods of relatively high temperatures and summer rainfall with cooler periods and increased winter rainfall. Accordingly, fires occurred more extensively during the former and were largely unaffected by the absence or presence of fire control measures. Fire return intervals were strongly inversely related to productivity of the vegetation. Long-term means between 30 and 55 years were found to apply in low-altitude xeric shrubland types. Corresponding fire return intervals were generally shorter in mesic shrublands at mid to high altitudes (15–30 years). Proteoid shrublands younger than 6 years were practically non-flammable. Two basic fire regime scenarios were identified. Fire regime patterns in xeric shrublands at lower altitudes were largely controlled by the rate of fuel accumulation, whereas climatically controlled ignition frequencies and fire climate constituted the dominant controls in proteoid shrublands at mid to high altitudes. The spatiotemporal distribution of fire regime parameters (fire frequencies, season, size and intensity) as recorded in the present study for the Swartberg Mountain Range under natural fire zone management (predominance of lightning fires since 1980), appeared to be conducive to the maintenance of biodiversity according to our current understanding of the fire–vegetation system.

1994 ◽  
Vol 4 (1) ◽  
pp. 17 ◽  
Author(s):  
DM Richardson ◽  
BW van Wilgen ◽  
DC Le Maitre ◽  
KB Higgins ◽  
GG Forsyth

This paper describes a Catchment Management System (CMS) that provides objective procedures for managing fire. Prescribed burning is carried out in the mountain catchments of the Cape Province, South Africa, to enhance water yield, to rejuvenate the indigenous shrubland vegetation, to reduce fire hazard and to control invasive alien plants. Fire is the only practical tool for achieving these aims in the mountainous terrain. Recent research has improved understanding of the response of these systems to fire, but managing fire to achieve goals is very difficult. The CMS comprises a central geographical information system for managing and processing spatial data, linked to personal computers with DBase IV data-bases and simple rule-based models for decision-making. Current applications are: prioritization of areas for burning, monitoring the success of fire management, mapping fire hazard for fire control planning, and the production of management summaries and statistics. This paper presents examples of these applications from three areas in the Cape Province with different management problems and priorities: the Kammanassie in the southern Cape, and the Kogelberg and Table Mountain areas in the western Cape.


2018 ◽  
Vol 18 (3) ◽  
pp. 935-948 ◽  
Author(s):  
Giorgio Vacchiano ◽  
Cristiano Foderi ◽  
Roberta Berretti ◽  
Enrico Marchi ◽  
Renzo Motta

Abstract. Modeling and assessing the factors that drive forest fire ignitions is critical for fire prevention and sustainable ecosystem management. In southern Europe, the anthropogenic component of wildland fire ignitions is especially relevant. In the Alps, however, the role of fire as a component of disturbance regimes in forest and grassland ecosystems is poorly known. The aim of this work is to model the probability of fire ignition for an Alpine region in Italy using a regional wildfire archive (1995–2009) and MaxEnt modeling. We analyzed separately (i) winter forest fires, (ii) winter fires on grasslands and fallow land, and (iii) summer fires. Predictors were related to morphology, climate, and land use; distance from infrastructures, number of farms, and number of grazing animals were used as proxies for the anthropogenic component. Collinearity among predictors was reduced by a principal component analysis. Regarding ignitions, 30 % occurred in agricultural areas and 24 % in forests. Ignitions peaked in the late winter–early spring. Negligence from agrosilvicultural activities was the main cause of ignition (64 %); lightning accounted for 9 % of causes across the study time frame, but increased from 6 to 10 % between the first and second period of analysis. Models for all groups of fire had a high goodness of fit (AUC 0.90–0.95). Temperature was proportional to the probability of ignition, and precipitation was inversely proportional. Proximity from infrastructures had an effect only on winter fires, while the density of grazing animals had a remarkably different effect on summer (positive correlation) and winter (negative) fires. Implications are discussed regarding climate change, fire regime changes, and silvicultural prevention. Such a spatially explicit approach allows us to carry out spatially targeted fire management strategies and may assist in developing better fire management plans.


Author(s):  
Giorgio Vacchiano ◽  
Cristiano Foderi ◽  
Roberta Berretti ◽  
Enrico Marchi ◽  
Renzo Motta

Abstract. Modelling and assessing the factors that drive forest fire ignitions is critical for fire prevention and sustainable ecosystem management. In southern Europe, the anthropogenic component of wildland fire ignitions is especially relevant. In the Alps, however, the role of fire as a component of disturbance regimes in forest and grassland ecosystems is poorly known. The aim of this work is to model the probability of fire ignition for an alpine region in Italy using a regional wildfire archive (1995–2009) and MaxEnt modeling. We analyzed separately: i) winter forest fires; ii) winter fires on grasslands and fallow land; iii) summer fires. Predictors were related to morphology, climate, and land use; distance from infrastructures, number of farms, and number of grazing animals were used as proxies for the anthropogenic component; collinearity among predictors was reduced by a Principal Component Analysis. 30 % of ignitions occurred in agricultural areas, 24 % in forests. Ignitions peaked in the late winter–early spring. Negligence from agro-silvicultural activities was the main cause of ignition (64 %); lightning accounted for 9 % of causes across the study timeframe, but increased from 6 % to 10 % between the first and second period of analysis. Models for all groups of fire had a high goodness of-fit (AUC 0.90–0.95). Temperature was proportional to the probability of ignition, and precipitation inverse proportional. Proximity from infrastructures had an effect only on winter fires, while the density of grazing animals had a remarkably different on summer (positive correlation) and winter (negative) fires. Implications are discussed regarding climate change, fire regime changes, and silvicultural prevention. Such spatially explicit approach allows to carry out spatially targeted fire management strategies, and may assist in developing better fire management plans.


Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Willem A. Nieman ◽  
Brian W. van Wilgen ◽  
Alison J. Leslie

Abstract Background Fire is an important process that shapes the structure and functioning of African savanna ecosystems, and managers of savanna protected areas use fire to achieve ecosystem goals. Developing appropriate fire management policies should be based on an understanding of the determinants, features, and effects of prevailing fire regimes, but this information is rarely available. In this study, we report on the use of remote sensing to develop a spatially explicit dataset on past fire regimes in Majete Wildlife Reserve, Malawi, between 2001 and 2019. Moderate Resolution Imaging Spectroradiometer (MODIS) images were used to evaluate the recent fire regime for two distinct vegetation types in Majete Wildlife Reserve, namely savanna and miombo. Additionally, a comparison was made between MODIS and Visible Infrared Imager Radiometer Suite (VIIRS) images by separately evaluating selected aspects of the fire regime between 2012 and 2019. Results Mean fire return intervals were four and six years for miombo and savanna vegetation, respectively, but the distribution of fire return intervals was skewed, with a large proportion of the area burning annually or biennially, and a smaller proportion experiencing much longer fire return intervals. Variation in inter-annual rainfall also resulted in longer fire return intervals during cycles of below-average rainfall. Fires were concentrated in the hot-dry season despite a management intent to restrict burning to the cool-dry season. Mean fire intensities were generally low, but many individual fires had intensities of 14 to 18 times higher than the mean, especially in the hot-dry season. The VIIRS sensors detected many fires that were overlooked by the MODIS sensors, as images were collected at a finer scale. Conclusions Remote sensing has provided a useful basis for reconstructing the recent fire regime of Majete Wildlife Reserve, and has highlighted a current mismatch between intended fire management goals and actual trends. Managers should re-evaluate fire policies based on our findings, setting clearly defined targets for the different vegetation types and introducing flexibility to accommodate natural variation in rainfall cycles. Local evidence of the links between fires and ecological outcomes will require further research to improve fire planning.


2013 ◽  
Vol 26 (5) ◽  
pp. 1654-1668 ◽  
Author(s):  
R. C. Blamey ◽  
C. J. C. Reason

Abstract A combination of numerous factors, including geographic position, regional orography, and local sea surface temperatures, means that subtropical southern Africa experiences considerable spatial and temporal variability in rainfall and is prone to both frequent flooding and drought events. One system that may contribute to rainfall variability in the region is the mesoscale convective complex (MCC). In this study, Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) data is used to document the precipitation produced by MCCs over southern Africa for the 1998–2006 period. Most of the rainfall associated with MCCs is found to occur over central Mozambique, extending southward to eastern South Africa. High precipitation totals associated with these systems also occur over the neighboring southwest Indian Ocean, particularly off the northeast coast of South Africa. MCCs are found to contribute up to 20% of the total summer rainfall (November–March) in parts of the eastern region of southern Africa. If the month of March is excluded from the analysis, then the contribution increases up to 24%. In general, the MCC summer rainfall contribution for most of the eastern region is approximately between 8% and 16%. Over the western interior and Botswana and Namibia, the MCC contribution is much less (<6%). It is also evident that there is considerable interannual variability associated with the contribution that these systems make to the total warm season rainfall.


1990 ◽  
Vol 20 (10) ◽  
pp. 1559-1569 ◽  
Author(s):  
Christopher H. Baisan ◽  
Thomas W. Swetnam

Modern fire records and fire-scarred remnant material collected from logs, snags, and stumps were used to reconstruct and analyze fire history in the mixed-conifer and pine forest above 2300 m within the Rincon Mountain Wilderness of Saguaro National Monument, Arizona, United States. Cross-dating of the remnant material allowed dating of fire events to the calendar year. Estimates of seasonal occurrence were compiled for larger fires. It was determined that the fire regime was dominated by large scale (> 200 ha), early-season (May–July) surface fires. The mean fire interval over the Mica Mountain study area for the period 1657–1893 was 6.1 years with a range of 1–13 years for larger fires. The mean fire interval for the mixed-conifer forest type (1748–1886) was 9.9 years with a range of 3–19 years. Thirty-five major fire years between 1700 and 1900 were compared with a tree-ring reconstruction of the Palmer drought severity index (PDSI). Mean July PDSI for 2 years prior to fires was higher (wetter) than average, while mean fire year PDSI was near average. This 490-year record of fire occurrence demonstrates the value of high-resolution (annual and seasonal) tree-ring analyses for documenting and interpreting temporal and spatial patterns of past fire regimes.


1999 ◽  
Vol 21 (1) ◽  
pp. 39 ◽  
Author(s):  
AB Craig

This paper examines a range of environmental, research and practical issues affecting fire management of pastoral lands in the southern part of the Kimberley region in Western Australia. Although spinifex grasslands dominate most leases, smaller areas of more productive pastures are crucially important to many enterprises. There is a lack of local documentation of burning practices during traditional Aboriginal occupation; general features of the fire regime at that time can be suggested on the basis of information from other inland areas. Definition of current tire regimes is improving through interpretation of NOAA-AVHRR satellite imagery. Irregular extensive wildfires appear to dominate, although this should be confirmed by further accumulation, validation and analysis of fire history data. While these fires cause ma,jor difficulties. controlled burn~ng is a necessary part of station management. Although general management guidelines have been published. local research into tire-grazing effects has been very limited. For spinifex pastures, reconimendations are generally consistent with those applying elsewhere in northern Australia. They favour periodic burning of mature spinifex late in the year, before or shortly after the arrival of the first rains, with deferment of grazing. At that time. days of high fire danger may still be expected and prediction of fire behaviour is critical to burning decisions. Early dry-season burning is also required for creating protective tire breaks and to prepare for burning later in the year. Further development of tools for predicting fire behaviour, suited to the discontinuous fuels characteristic of the area, would be warranted. A range of questions concerning the timing and spatial pattern of burning, control of post-fire grazing, and the economics of fire management, should be addressed as resources permit. This can be done through a combination of opportunistic studies, modelling and documentation of local experience. The development of an expert system should be considered to assist in planning and conducting burning activities. Key words: Kimberley, fire regimes, fire management, pastoralism, spinifex


2021 ◽  
Author(s):  
Sarah E. Thomas ◽  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez

Abstract L. camara is a highly variable ornamental shrub, native of the neotropics. It has been introduced to most of the tropics and subtropics as a hedge plant and has since been reported as extremely weedy and invasive in many countries. It is generally deleterious to biodiversity and has been reported as an agricultural weed resulting in large economic losses in a number of countries. In addition to this, it increases the risk of fire, is poisonous to livestock and is a host for numerous pests and diseases. L. camara is difficult to control. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures. This species has been the target of biological control programmes for over a century, with successful control only being reported in a few instances.


2009 ◽  
Vol 18 (2) ◽  
pp. 127 ◽  
Author(s):  
Andrew C. Edwards ◽  
Jeremy Russell-Smith

The paper examines the application of the ecological thresholds concept to fire management issues concerning fire-sensitive vegetation types associated with the remote, biodiversity-rich, sandstone Arnhem Plateau, in western Arnhem Land, monsoonal northern Australia. In the absence of detailed assessments of fire regime impacts on component biota such as exist for adjoining Nitmiluk and World Heritage Kakadu National Parks, the paper builds on validated 16-year fire history and vegetation structural mapping products derived principally from Landsat-scale imagery, to apply critical ecological thresholds criteria as defined by fire regime parameters for assessing the status of fire-sensitive habitat and species elements. Assembled data indicate that the 24 000 km2 study region today experiences fire regimes characterised generally by high annual frequencies (mean = 36.6%) of large (>10 km2) fires that occur mostly in the late dry season under severe fire-weather conditions. Collectively, such conditions substantially exceed defined ecological thresholds for significant proportions of fire-sensitive indicator rain forest and heath vegetation types, and the long-lived obligate seeder conifer tree species, Callitris intratropica. Thresholds criteria are recognised as an effective tool for informing ecological fire management in a variety of geographic settings.


Bothalia ◽  
2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Norbert Hahn

Background: The first checklist for the Soutpansberg was published in 1946, and the second list was compiled by the author in 2006 as part of his doctoral thesis. Currently, there is a need for an updated account of the biodiversity of the Soutpansberg Centre of Endemism and Diversity for conservation planning in the Vhembe Biosphere Reserve, within which the Soutpansberg is the principle geomorphological feature.Objectives: To present an updated list of vascular plants recorded for the Soutpansberg.Method: The list was compiled from various sources including literature reviews, herbarium specimens, herbarium databases and personal observations.Results: This article presents the most geographically accurate and taxonomically updated list of the indigenous vascular flora of the Soutpansberg, the northernmost mountain range of South Africa. Altogether 2443 taxa are recorded belonging to 922 genera in 187 families and 64 orders.Conclusion: The list presented in this article confirms the status of the Soutpansberg as a centre of floristic diversity in southern Africa. Notable is the higher-order diversity of the flora. It is likely that both future surveys and reviews of herbarium collections will add new taxa to the current total.


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