Vegetation Monitoring
Taking stock of the impact of elephant grazing In 2000, STE recruited two volunteers to establish four permanent vegetation plots along the riverine vegetation in the Samburu reserve to monitor elephant damage on selected tree species. Recently undergraduate volunteer Chris Gordon and STE research assistant Bernard Lesowapir began an extensive study to measure impact of elephants on species of Acacia. More plots are being established along the Ewaso Ngiro River and its tributaries in Samburu, Buffalo Springs and Shaba Reserves, and within the lodges and campsites. Results from sampling almost 8,000 trees demonstrate the selective impact of elephants on different Acacia species.
Acacia elatior is the dominant riverine tree species, representing 64% of all trees, and is the species most damaged by elephants. Results from nine plots (not including lodges which are fenced to exclude elephants) show that 51% of this A. elatior were ring barked and thus killed by elephants compared with only 20% of Acacia tortilis, the second most common tree species. Long-term monitoring of these permanent vegetation plots will provide information on elephant impact to the fragile riverine vegetation in the Samburu Reserve. In an effort to reduce elephant damage to large Acacia trees in selected sites along the river, STE with support from Elephant Watch Safaris began a project to protect the trees by wrapping their trunks in chicken wire.
This was done at eight selected sites along the river. Placing bee hives in trees is now being used to protect trees (see section 2.6) and results so far show that 62% of the trees that were either wired or hived were left undamaged by elephants which suggests that these methods afford substantial protection to the trees.
References:
Gordon, C. (2003) The impact of elephants on the riverine woody vegetation of the Samburu National Reserve. Report to Save the Elephants. Unpublished.
Acacia elatior is the dominant riverine tree species, representing 64% of all trees, and is the species most damaged by elephants. Results from nine plots (not including lodges which are fenced to exclude elephants) show that 51% of this A. elatior were ring barked and thus killed by elephants compared with only 20% of Acacia tortilis, the second most common tree species. Long-term monitoring of these permanent vegetation plots will provide information on elephant impact to the fragile riverine vegetation in the Samburu Reserve. In an effort to reduce elephant damage to large Acacia trees in selected sites along the river, STE with support from Elephant Watch Safaris began a project to protect the trees by wrapping their trunks in chicken wire.
This was done at eight selected sites along the river. Placing bee hives in trees is now being used to protect trees (see section 2.6) and results so far show that 62% of the trees that were either wired or hived were left undamaged by elephants which suggests that these methods afford substantial protection to the trees.
References:
Gordon, C. (2003) The impact of elephants on the riverine woody vegetation of the Samburu National Reserve. Report to Save the Elephants. Unpublished.