Review of advances in dendropyrochronology.

Abstract

As a significant cross-discipline of dendrochronology and forest fire ecology, dendropyrochronology is the science that uses tree rings to date and study past and present changes in wildfires, dating the fire scars left in tree rings to determine how often fires occurred in the past. Dendropyrochronology has great advantages in forest fire history research due to its exact dating, high yearly resolution and long temporal span. This paper briefly reviews advances in Chinese and foreign dendropyrochronology. Chinese dendropyrochronology research is still at the beginning stage, while the study abroad mainly focuses on three items. 1) Spatio-temporal regimes of fire history, which mainly includes fire return interval, spatial extent and severity, spatio-temporal interaction, relationship between forest fire occurrence and standing environment, effect of forest fire on species succession, integration of fire scar and other methods to precisely date fire occurrence. 2) Influence of global climate change on fire history. Temperature and precipitation are the main climatic factors influencing fire occurrence. For example, when it is dry in a year after relatively wet years, forest fire is inclined to occur. Fire history is also related to large-scale climatic events. For instance, fire always occurs in the years of transition from El Ni?o to La Nia, and phase combination of large-scale climatic events is more likely than a single event to lead to fire. 3) Relationship between fire history and human activity and land-use. Wars and increased population easily lead to fire occurrence, while grazing activity can decrease fire occurrence. Forest fire exclusion since the beginning of 20th century has decreased fire occurrence while increasing the possibility of large fire. The prospects of dendropyrochronology research mainly include: scale effect of fire spatio-temporal pattern, driving mechanisms of fire variation on climate change and human activity and development of fire history research methods.