Shoot characteristics of Acacia tortilis (Forsk.) in wildlife and rangeland habitats of Botswana
Length, branch production, orientation, spinescence and biomass were measured for current shoots of Acacia tortilis shrubs in a range of habitats in Botswana. All shoot characteristics varied between individuals and between habitats with longer, less spinescent shoots produced in the habitat recently protected from wildlife. Biomass allocated to woody material increased with shoot length at the expense of leaf mass, whilst investment in straight prickles was as much as 6% of shoot dry mass. Shoot length had significant effects on