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This study developed growth models forEucalyptus salignaSm.,E. camaldulensisDehnh.,E. macarthuriiH.Deane & Maiden,E. resiniferaSm.,E. siderophloiaBenth. andE. grandisHill ex. Maiden, for the central highlands of Angola, and used these models to simulate the development of stand characteristics. The obtained model set included dominant height, diameter increment, tree height and self-thinning models. The study was based on 10 499 radial increment observations measured on cores taken from about 700 trees growing in 22 plots located in seven sites in the Angolan highlands. The model set makes it possible to simulate stand development on an individual tree basis. Comparison of simulated stand development and measurements indicated good performance of the models. A non-linear fixed-effects diameter increment model performed best for most species, but a non-calibrated linear mixed-effects model used with the Snowdon correction was better forE. salignaandE. macarthurii. This study showed a similar dominant height development of young stands as found in most previous studies done for southern Africa. Some differences emerged at older ages. [ABSTRACT FROM PUBLISHER]

This study used linear programming (LP) to analyse land-use alternatives in the traditional Umbundu farming system in the Angolan central highlands. Farmers of the region have traditionally produced maize and pulses for subsistence and vegetables and timber as cash crops. Different pasture and forest fallow rotations are used along catena production sites. The system is labour-intensive and uses animal traction. LP problems were formulated and solved for a baseline land-use alternative, improved diet alternative and maximal timber production alternative. All three problem formulations included constraints that guaranteed sufficient food and firewood production and sufficient pasture area for animals while being feasible in terms of human labour and animal traction consumption. Of the alternative production systems, cash crops with forest fallow had the highest land expectation value (LEV), while cereals under short grazing fallow showed even negative LEVs. Changing the diet by diversifying carbohydrate and protein sources increased LEV and reduced the need for women labour during the peak season. When timber production was maximised the optimal share of land devoted to pure forestry was 57%, and less labour was required. [ABSTRACT FROM AUTHOR]

Eucalyptus species have been planted in Angola since the early twentieth century. The species introduction experiment of Tchianga, in the Angolan Highlands, was established in 1966/1967. The experiment included several tropical pines and eucalypts. The plots were 43 years old when measured in 2009. Species included Eucalyptus saligna Sm., E. camaldulensis Dehnh., E. macarthurii H. Deane & Maiden, E. resinifera Sm., E. siderophloia Benth., and E. grandis Hill ex. Maiden. E. saligna had the highest stand volume at 43 years (1427m3 ha-1), followed by E. grandis (1006m3 ha-1). E. macarthurii and E. camaldulensis had the lowest stand volume (423 and 511m3 ha-1, resp.). Using X-ray analyses of increment cores, it was possible to study the temporal development of the stand characteristics. An analysis of the mean annual increment showed that the optimal rotation length for most of the studied eucalypts is around 22 years with the exception of E. resinifera, for which 12-15 years is the best. E. saligna had the highest maximum mean annual increment (MMAI) of 37m3 ha-1 attained at 22 years of age. E. grandis reached its MMAI of 25m3 ha-1 at 28 years. The results suggest that E. saligna is the most recommended Eucalyptus species for new plantations in Angola. [ABSTRACT FROM AUTHOR]