The response of sub-adult savanna trees to successive fires of various seasons

Abstract In mesic savannas worldwide, trees experience frequent fires, almost all set by humans. Management fires are set to reduce or enhance tree cover. Success depends greatly on responses of sub-adult trees to such fires. To date, the number of successive years that sub-adult trees can resprout nor the number of years that they must resist being top-killed by successive fires, nor the requisite height, have been reported. In a six-year experimental field study in Guinean savannas of West Africa, we monitored annually the heights and responses of 1,765 permanently tagged sub-adult trees under annual fires set in three different periods of the long dry season: early-dry season (EDS), mid-dry season (MDS) and late-dry season (LDS). Annual MDS fires are the common local management fires of these savannas. Results showed that overall, the proportion of sub-adults that resisted being top-killed differed across fire seasons. Further, resisting one fire gave a better chance of resisting the...