Elephant damage to trees of wooded savanna in Zakouma National Park, Chad

Damage caused by elephants was monitored in two woodland stands of Zakouma National Park (Chad) between February and March 1998. The Acacia seyal savanna was more severely damaged (29.8% of trees damaged of which 13.2% severely) than the Combretaceae savanna (26.5% of trees damaged of which only 4.2% severely). Nearly all severely damaged trees showed resprouts (respectively 86.8% and 88.5% in Combretaceae and A. seyal savannas). Both low damage rate and low mortality rate indicate that no serious 'elephant problem' occurred in Zakouma National Park. Elephants selected trees to damage according to species and height. Such selection also occurred for severe damage in A. seyal savanna, but only height affected severity of damage in Combretaceae savanna. In both savannas, the plots close to a water point were the most frequently damaged. In Combretaceae savanna, the distribution of damaged trees was clumped. On the other hand, spatial auto-correlation was not significant for the severity or the frequency of damage in A. seyal savanna. Neither tree density nor diversity of woody species affected the spatial patterns of damage or severe damage.