SOIL TEMPERATURES AFTER THE PASSAGE OF A FIRE - DO THEY INFLUENCE THEGERMINATION OF BURIED SEEDS

Soil temperatures down to a depth of 5 cm were measured in the days fo llowing one fire in summer, one fire in winter and in unburnt vegetati on during summer. Soil temperatures did not rise above 40 degrees C af ter the winter fire or in unburnt vegetation during summer. Consequent ly, no impact on seed dormancy in the soil seedbank was expected. Afte r a summer fire, soil temperatures above 40 degrees C were found up to 4.5 cm in depth, while temperatures above 60 degrees C were found onl y in the top 0.5 cm of soil. These temperatures are sufficient to brea k seed dormancy in some legume species in the seedbank. Hence, the sea son of burn may influence the number of seeds in the soil that have th eir dormancy broken and subsequent germination levels.