|Middens are amazingly rich patches!|
|Termite mounds produce fine-scale variation in nitrogen, Serengeti, Aug 2011|
|Grazing lawns are locally high in nutrient, Kruger, June 2011|
|This Vachellia tortilis will be creating a nitrogen hotspot. Serengeti NP Dec 11|
Put together and you have a picture of variation in nutrient quality at a large scale, with fine scale variatoin superimposed to make an incredibly complex picture. I also like the way they show how the savanna big four influence one another - fire changes nutrients, which changes grazing, which further changes nutrients, etc. It's a wonderfully complicated set of processes, and I thoroughly encourage you to read this paper if you want a more detailed overview of nitrogen in the savanna biome!
Coetsee, C., Jacobs, S., & Govender, N. (2011). An Overview of Nitrogen Cycling in a Semiarid Savanna: Some Implications for Management and Conservation in a Large African Park Environmental Management, 49 (2), 387-402 DOI: 10.1007/s00267-011-9779-0