Document


Title

Forage nutritive quality in the Serengeti Ecosystem: the roles of fire and herbivory
Document Type: Journal Article
Author(s): T. Michael Anderson; Mark E. Ritchie; Emilian P. Mayemba; Stephanie L. Eby; James B. Grace; S. J. McNaughton
Publication Year: 2007

Cataloging Information

Keyword(s):
  • Africa
  • biomass
  • ecosystem dynamics
  • fertility
  • fire frequency
  • fire management
  • forage
  • forage nutrients
  • grasses
  • grasslands
  • grazing
  • herbivory
  • leaves
  • mammals
  • N - nitrogen
  • national parks
  • nutrients
  • P - phosphorus
  • plant communities
  • population density
  • precipitation
  • pyric herbivory
  • range management
  • savannas
  • Serengeti
  • sodium
  • soil nutrients
  • soil organic matter
  • soils
  • structural equation modelling
  • Tanzania
  • Themeda spp.
  • Themeda triandra
  • wildfires
Region(s):
  • International
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 18107
Tall Timbers Record Number: 21900
TTRS Location Status: In-file
TTRS Call Number: Fire File
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Fire and herbivory are important determinants of nutrient availability in savanna ecosystems. Fire and herbivory effects on the nutritive quality of savanna vegetation can occur directly, independent of changes in the plant community, or indirectly, via effects on the plant community. Indirect effects can be further subdivided into those occurring because of changes in plant species composition or plant abundance (i.e., quality versus quantity). We studied relationships between fire, herbivory, rainfall, soil fertility, and leaf nitrogen (N), phosphorus (P), and sodium (Na) at 30 sites inside and outside of Serengeti National Park. Using structural equation modeling, we asked whether fire and herbivory influences were largely direct or indirect and how their signs and strengths differed within the context of natural savanna processes. Herbivory was associated with enhanced leaf N and P through changes in plant biomass and community composition. Fire was associated with reduced leaf nutrient concentrations through changes in plant community composition. Additionally, fire had direct positive effects on Na and nonlinear direct effects on P that partially mitigated the indirect negative effects. Key mechanisms by which fire reduced plant nutritive quality were through reductions of Na-rich grasses and increased abundance of Themeda triandra, which had below-average leaf nutrients.

Online Link(s):
Citation:
Anderson, T. Michael; Ritchie, Mark E.; Mayemba, Emilian; Eby, Stephanie; Grace, James B.; McNaughton, Samuel J. 2007. Forage nutritive quality in the Serengeti Ecosystem: the roles of fire and herbivory. American Naturalist 170(3):343-357.