Vegetative growth, reproduction, browse production and response to tree clearing of woody plants in African savanna
AbstractThis review deals with issues including the determinants of vegetative growth of woody plants (soil water availability, water stress, soil nutrient availability, carbohydrate reserves, plant hormones, atmospheric CO2 concentration, tree age, competition, defoliation and shoot pruning, fire pathogens, soil and climatic conditions), reproduction (the ability of mature trees to flower and produce viable seeds, the ability of seeds to disperse and germinate, seedling survivorship), and browse production. Emphasis is placed on how these may be influenced by tree clearing, either through exploitation or through deliberate actions aimed at reducing the suppressive effect of an increase in woody plant density on the production of the herbaceous layer. A diverse range of aspects, related to the dynamics of the woody component of savannas, had received attention in the literature. It has contributed to some understanding of the nature and dynamics of the vegetative growth, reproduction and browse production (including animal-plant interactions) of woody plants in various savanna ecosystems. It has also demonstrated the complexity and heterogeneity of the different savanna ecosystems. Gaps in our knowledge, linked to specific options of land use, were identified. Within the context of the importance of woody plants, some recommendations on future research in savanna are made.
Keywords: africa; age; botany; browse production; bush encroachment; clearing; co2;concentration; defoliation; ecosystem; exploition;herbaceous layer; heterogeneity; hormones; interaction; interactions; land use; pathogens; physical determinants; plant density; plants; pruning; reproduction; reserves; review; savanna; seed; seedling; seeds; soil water; stress; survivorship; tree thinning; tres; vegetative growth; water availability; water stress; woody plants
African Journal of Range & Forage Science, Vol. 13(2), pp. 77-78