Natural fires occurred long before humans emerged and flammable ecosystems predate anthropogenic burning by millions of years. In fact, we cannot understand ecosystem distribution without including fire as a process in the natural history of our planet. During most of Earth’s history fire has been integral to the evolution of fauna and flora and is still a major influence on biodiversity.
Many biodiverse ecosystems are fire-prone and include boreal forests, eucalyptus woodlands, shrublands, grasslands and savannahs. The diversity of form found in these ecosystems is due largely to the diversity of natural fire regimes.
Different fire regimes produce different landscape patterns and select for different plant attributes, so it follows that changes in the fire regime within a given landscape will have significant consequences for species composition, biodiversity and hence ecosystem function.
Humans have had profound impacts on fire regimes by increasing fire frequency in some cases and suppressing fire in others. The impact of this on ecosystems is still unclear but because of the long evolutionary history of fire in many ecosystems, species are adapted to a particular fire regime rather than to fire itself and any departures from that regime can have devastating impacts on the sustainability of many ecosystem components.
This OpenLearn course is an adapted extract from the Open University course.