ABSTRACT
Fire records from freshwater wetlands in Everglades National Park (1948-92) and Water Conservation Areas 2 and 3 (1980-90) were analyzed for temporal and spatial patterns. During the 45 years of record in Everglades National Park, 752 fires were registered, with sizes ranging up to -75,000 ha; over the 11 years of record in the Water Conservation Areas, 127 fires burned, the largest of which was -34,000 ha. Rank order pattern of fire sizes follows a log-normal distribution, with an anomalous clustering of fires ranging from 8000 to 15,000 ha. Fourier analyses of the two data sets revealed dominant cycles with frequencies of 7 months, 1 year, and 10-14 years. The annual and monthly frequencies occur at the same scale as seasonal variation in both drying patterns (rainfall and surface moisture) and in nonhuman ignition sources. The factor influencing the longer cycles appears to be climatic variation, although the causal mechanisms are unclear. Human-caused fires account for most fires and area burned, although more lightning fires have been recorded in recent years.
