Document


Title

The origin of the savanna biome
Document Type: Journal Article
Author(s): David J. Beerling; Colin P. Osborne
Publication Year: 2006

Cataloging Information

Keyword(s):
  • aerosols
  • C - carbon
  • C4 photosynthesis
  • cloud physics
  • CO2 - carbon dioxide
  • cover
  • droughts
  • ecosystem dynamics
  • feedbacks
  • fire frequency
  • fire management
  • flammability
  • grasses
  • grasslands
  • land use
  • mortality
  • photosynthesis
  • plant growth
  • regeneration
  • savannas
  • systems analysis
  • trees
  • wildfires
Record Maintained By:
Record Last Modified: June 20, 2018
FRAMES Record Number: 47996
Tall Timbers Record Number: 24041
TTRS Location Status: In-file
TTRS Call Number: Fire File
TTRS Abstract Status: Fair use, Okay, 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

Savannas are a major terrestrial biome, comprising of grasses with the C4 photosynthetic pathway and trees with the C3 type. This mixed grass-tree biome rapidly appeared on the ecological stage 8 million years ago with the near-synchronous expansion of C4 grasses around the world. We propose a new hypothesis for this global event based on a systems analysis that integrates recent advances in how fire influences cloud microphysics, climate and savanna ecology in a low carbon dioxide (CO2) world. We show that fire accelerates forest loss and C4 grassland expansion through multiple positive feedback loops that each promote drought and more fire. A low CO2 atmosphere amplifies this cycle by limiting tree recruitment, allowing the ingress of C4 grasses to greatly increase ecosystem flammability. Continued intensification of land use could enhance or moderate the network of feedbacks that have initiated, promoted and sustained savannas for millions of years. We suggest these alterations will overprint the effects of anthropogenic atmospheric change in coming decades.

Online Link(s):
Citation:
Beerling, David J.; Osborne, Colin P. 2006. The origin of the savanna biome. Global Change Biology 12(11):2023-2031.