Nitrogen (N) cycling was analyzed in the Kalahari region of southern Africa, where a strong precipitation gradient (from 978 to 230 mm mean annual precipitation) is the main variable affecting vegetation. The region is underlain by a homogeneous soil substrate, the Kalahari sands, and provides the opportunity to analyze climate effects on nutrient cycling. Soil and plant N pools, N-15 natural abundance (delta(15)N), and soil NO (Nitric oxide) emissions were measured to indicate patterns of N cycling along a precipitation gradient. Keywords: Nitrogen fixation, Nitric oxide emissions, Soil nitrogen pools, Plant nitrogen pools, Kalahari region - Southern Africa, Biodiversity conservation, Environmental sciences.