Как выбрать гостиницу для кошек
14 декабря, 2021
Much of the current knowledge of fire and its effects on Zambezian Phytoregion structure and functioning has come from anecdotal evidence supplemented by information derived from limited number of experiments. The interest of focus among the early researchers has been more on later stages in changing of vegetation communities with emphasis on ecological groups (see Lawton 1978). However, several studies attempted to determine the effects of fire frequency and burning period on the structure and function of the miombo woodlands (see Trapnell 1959; Kikula 1986; Chidumayo 1988a, b; Zolho 2005). In Zambia, Trapnell (1959) and Chidumayo (1988a, b) studied the response of miombo species to varying burning regimes. Similar studies were conducted in Tanzania (Kikula 1986) and Mozambique (Zolho 2005). All recent studies (Kikula 1986; Chidumayo 1988a, b; Zolho 2005) confirmed the findings of Trapnell (1959) about sprouting behavior of miombo species under fire influence. The effects of fire on forest composition have also been observed in other vegetation types such as the forest in Okavango in Namibia (Geldenhuys 1977) and Kruger National Park in South Africa (Higgins et al. 2007). These studies demonstrated that species dominance and coppice effectiveness can be influenced by fire frequency and intensity. This is because fire may affect the perennating organs and root food reserves. Fire attack on perennating organs and food reserves usually results in die-back of shoots as a result of depletion of root food reserve of parent plants due to systematic and continuous effect of fire (Kennard et al. 2002). From a management perspective, fire management in extensively managed woodland should take into account the age of the woodland, the phenology of the dominant and/or desirable species, the type of land use and the management objectives of the area. Burning may not be necessary where livestock grazing or litter harvesting removes most of the fuel biomass. If burning is carried out in woodland areas where wood is a desired product, it should be done at the end of the rainy season, when the moisture levels in both grass and tree layer are relatively high (Trapnell 1959; Chidumayo et al. 1996).