Silvicultural characteristics and management of miombo woodlands
1993
Chidumayo, E. N.
The climate in the 2.7 million square kilometres covered with Brachystegia-Julbernardia (miombo) woodland in Central and Southern Africa is characterised by a long dry season (7-8 months) during which the surface litter is burnt by man-made fires. Miombo woodland provides grazing and browse, but its major human use is conversion to agriculture and the extraction of a variety of produce, such as timber, poles, edible fruits, caterpillars, mushrooms and honey. The majority of miombo woodland species are deciduous during the dry season but because they possess deep taproots, which ensure access to deep soil moisture and nutrients, they flush before it ends. Flowering occurs throughout the year with a peak during August-November. In many species, fruit production is irregular and seed dormancy is rare. Generally seed germination occurs during the rainy season immediately after dispersal. Germination rates are good although seedling mortality may be very high during germination and the first year. Seedlings grow very slowly as they initially allocate more biomass to root growth. Shoot growth is also hampered by recurrent dieback caused by both drought and fire. Post-felling regeneration of miombo is from coppice of stump and root origin and from stunted seedlings in the herb layer. Recruitment from seedlings in the first regrowth makes up over 50% of tree density. A n1ajority of species require high light intensities for sapling development. Competition and fire reduce tree density during regrowth maturation. Many of these silvicultural characteristics of miombo woodland are adaptations to fire, drought and felling. Past management of miombo woodland in Zambia has involved strip clear-felling and selective felling with intensive early burning to protect regrowth from destructive late dry season fires. Future management practices should take into account silvicultural characteristics of the constituent species, cost and the multiple functions of miombo woodland.
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