Fire-rainfall relationships in Argentine Chaco savannas

We used dendroecological techniques to date fire scars in woody species growing in a subtropical savanna of the Argentine Chaco dry forests, and to explore the temporal trends of fire with rainfall variability at different temporal scales during the 20th century. Eight sampling sites were located along an ecotone between savanna and a dry forest, and a composite chronology was developed for a savanna, based on a total of 21 fire dates. The mean fire frequency was 0.18 fires year-1 and the mean fire interval was 3.3 years. The period post 1971 (which had 22% more rainfall) experienced a fire frequency more than two times higher than the period 1925-1970 (p