This review assesses the role of fire in ecosystem within theoretical framework of disturbance. Fire has essentially been considered disturbance which represents one of the oldest forms of interaction between human and environment. This review traces the history of fire and various types of interaction between human and environment in which fire has played a central role. There are total seven sections in this review. Followed by introduction to disturbance and disturbance regime, it discusses the fire as one of the disturbance along with major events in the history of fire. Fourth and fifth section deals with analysis of role of fire in shaping vegetation structure and its role as one of the forces of evolution respectively. The various uses of fire as a resource extraction tool have been highlighted in section six. The review concludes with highlighting the possible future direction of research in fire ecology.
This review largely focuses on the forest ecosystem, although relevant examples from other ecosystems have been taken to explain certain phenomenon. Analysis of use of fire as management tool is based on the case studies from India only.
2. Concept of disturbance and disturbance regime
Disturbance is a central concept in ecology, origin of which is as old as the discipline of ecology itself. There is no single of definition of disturbance. It has been conceptualized in number of ways, which has lead to its multiple definitions. The variations in the definition should not be seen as confusion in theoretical understanding of this concept. Rather, it represents various treatment of this concept by taking phenomenon or process of interest under consideration. Following four examples of definition of disturbance brings out different treatment to this concept:
“Discrete event in time that disrupts ecosystem, community or population structure and changes resources, substrate availability or the physical environment” - (Pickett & White, 1985)
“Discrete, punctuated killing, displacement, or damaging of one or more individuals (or colonies) that directly or indirectly creates an opportunity for new individuals (or colonies) to become established” - (Sousa, 1984)
“Discrete event that damages or disrupts community structure and functioning, resulting in the mortality of organism and loss of biomass.” - (Huston & Huston, 1994)
“A multi-species, spatiotemporal pattern of mortality of non-competitive origin” (Bartha, 1997)
Although, these definitions vary in their description of “disturbance”, there are few common themes that are central to all these definition. For an event to be categorized as disturbance, it needs to be discrete in nature, over and above the magnitude of natural environmental fluctuation for the organism concerned. It must also create an opportunity to new set of organism to establish at that location by changing resource allocation pattern or through direct mortality of individuals.
Disturbance can be...