Nitrogen fixation in southern African savanna ecosystems: a stable isotope approach to gain baseline data

A pilot study on the ability of Philanoptera violacea to fix atmospheric nitrogen was carried out within the Nkuhlu large animal exclosure on the Sabie River in Kruger National Park. Individuals from different ages (seedlings, saplings, mature trees) were taken from two areas in the riparian zone of the Sabie River within Kruger National Park. Samples were also taken from a reference tree, Diospiros mespiliformis (seedlings and juveniles). Foliar samples was taken in March 2005, dried, ground and sent for analysis by the Archaeometry Unit within the Department of Archaeology at the University of Cape Town. The data output from the mass spectrometer included δ15N, δ13C, total N and total C.