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Effects of perennial fires on the woody vegetation of Mole National Park, GhanaSackey, I., Hale, William H.G. January 2008 (has links)
No / Recurrent fires have a considerable potential to influence the structure and composition of savanna vegetation. In Mole National Park in Ghana, the policy is to burn the vegetation annually early in the dry season. This study aimed to assess the effects of these perennial fires on the trees and shrubs of the Park. To achieve this, scars on tree bole bases as well as mortality and top-kill to trees ¿ 2 m tall resulting from perennial fires were assessed in twenty 50 m x 50 m plots in the savanna vegetation near Grupe camp at the south-western section of the Park. Fire scars on tree bole bases were widespread, but were significantly more frequent on large trees (> 5 m tall) than small ones (< 2 m tall). Also, certain tree species, notably Burkea africana and Detarium microcarpum were more
prone to scarring. The greater proportion of the scars had reached an advanced stage and the affected individuals were either moribund or were likely to be killed by subsequent fires or toppled by the wind. Contrary to the popular opinion that fire generally affects tree recruitment and not adult survival, fire-induced mortality and top-kill to large trees (> 5 m tall) was widespread among all the tree species, particularly Acacia dudgeoni, Burkea africana, Detarium microcarpum and Vitellaria paradoxa. These fire impacts will likely lead to changes in the relative abundance of the constituent tree species as well as a decline in the density of woody elements in the plant community as a whole unless burning frequency is reduced. The areas for which these predicted vegetation changes are valid can be generalized to include the vegetation in the northern half of the Park where similar
conditions of high fuel load and intense fires are likely to prevail.
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Structure and diversity of the dry woodland savanna of northern Namibia / Struktur und Diversität der trockenen Savannenwälder im norden NamibiasGraz, Friedrich Patrick 04 February 2005 (has links)
No description available.
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FACTORS INFLUENCING THE ESTABLISHMENT AND SURVIVAL OF NATIVE HARDWOOD TREE SEEDLINGS OF THE KENTUCKY INNER BLUEGRASS BLUE ASH-OAK SAVANNA-WOODLANDShaffer, James D 01 January 2013 (has links)
Historically, the Kentucky Inner Bluegrass blue ash-oak savanna-woodland was the primary ecosystem of the Inner Bluegrass Region (IBR) of Kentucky. After European settlement, the majority (>99%) of Bluegrass savanna was converted to agricultural and urban land uses. Currently remnant savanna tree species are failing to recruit. Therefore, a long-term restoration ecology project researching competition and disturbance on seedling establishment, survival, and growth has been established at Griffith Woods (the largest remaining savanna in Kentucky) in Harrison Co., KY. Fourteen native hardwood tree species (a total of 6,168 seedlings) have been experimentally planted. Light, soil, surrounding vegetation, and herbivory, factors thought to influence seedling survival, have been initially assessed. Results show that soils differed spatially in P, Ca, Mg, Zn, pH, N percent and soil organic matter percent. Light was significantly reduced by diffusive filtering through vegetation. Vegetation biomass was influenced by pH and Mg. Initial seedling survival was high, but significantly differed by species type, location, and soil pH, Mg, and Zn. This research demonstrates that under a similar range of conditions, native hardwood tree seedling establishment is possible. Therefore, the potential exists to restore Bluegrass savanna-woodland in order to return proper ecological functioning into a degraded landscape.
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