Environmental Management

, Volume 49, Issue 2, pp 387–402 | Cite as

An Overview of Nitrogen Cycling in a Semiarid Savanna: Some Implications for Management and Conservation in a Large African Park

Article

Abstract

Nitrogen (N) is a major control on primary productivity and hence on the productivity and diversity of secondary producers and consumers. As such, ecosystem structure and function cannot be understood without a comprehensive understanding of N cycling and dynamics. This overview describes the factors that govern N distribution and dynamics and the consequences that variable N dynamics have for structure, function and thresholds of potential concern (TPCs) for management of a semiarid southern African savanna. We focus on the Kruger National Park (KNP), a relatively intact savanna, noted for its wide array of animal and plant species and a prized tourist destination. KNP’s large size ensures integrity of most ecosystem processes and much can be learned about drivers of ecosystem structure and function using this park as a baseline. Our overview shows that large scale variability in substrates exists, but do not necessarily have predictable consequences for N cycling. The impact of major drivers such as fire is complex; at a landscape scale little differences in stocks and cycling were found, though at a smaller scale changes in woody cover can lead to concomitant changes in total N. Contrasting impacts of browsers and grazers on N turnover has been recorded. Due to the complexity of this ecosystem, we conclude that it will be complicated to draw up TPCs for most transformations and pools involved with the N cycle. However, we highlight in which cases the development of TPCs will be possible.

Keywords

Ecosystem management Elephants Fire Herbivores Mineralisation Savanna Total soil N 

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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Corli Coetsee
    • 1
  • Shayne Jacobs
    • 2
  • Navashni Govender
    • 3
  1. 1.School of Natural Resource ManagementNelson Mandela Metropolitan UniversityGeorgeSouth Africa
  2. 2.Department of Conservation Ecology and EntomologyStellenbosch UniversityStellenboschSouth Africa
  3. 3.Sanparks Scientific ServicesKruger National ParkSkukuzaSouth Africa

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