On incorporating fire into our thinking about natural ecosystems: A response to Saha and Howe

Ecologists long have had a fascination with fire impacts, although they have been slow to incorporate this ecological factor into serious thinking about the structure of communities and evolution of species (Bond and van Wilgen 1996).  The remarks by Saha and Howe (2001, in this issue) illustrate some of the problems ecologists have in trying to apply fire to their thinking about natural ecosystems.  Fire is commonly perceived qualitatively in terms of presence or absence, and the variation in frequency and intensity, as well as other components of the fire regime (e.g., fig. 1), is ignored.  Often not considered is the fact that plant life histories are fine-tuned to particular fire regims, and in this regard, landscapes present a range of selective peaks and valleys, both figuratively and literally.  Because landscape patterns affect the propagation of natural fires, it is imperative that the degree of human disturbance be considered (e.g. Marsh [1864] 1965; Gadgil and Guhu 1993) and the limitations of basing evolutionary arguments on anthropogenically derived landscapes be recognized (e.g., Janzen and Martin 1982).