Effects of fire season and intensity on <i>Prosopis glandulosa</i> Torr. var. <i>glandulosa</i>

TitleEffects of fire season and intensity on Prosopis glandulosa Torr. var. glandulosa
Publication TypeJournal Article
Year of Publication2003
AuthorsDrewa P.B.
JournalInternational Journal of Wildland Fire
Date PublishedJune 1, 2003
ARIS Log Number141594
AbstractIn pyrogenic ecosystems, responses of resprouting woody vegetation may depend more on fire season than intensity. I explored this hypothesis by examining fire season and intensity effects on response of Prosopis glandulosa, a resprouting shrub in Chihuahuan Desert grasslands of the southwestern United States. Clipping, as well as low and high intensity fires (natural and added fuels, respectively), was applied during the 1999 growing season and the 2000 dormant season. Both fire season and intensity affected shrub responses. Numbers of resprouts were 16% greater and heights were 8% taller after dormant season than growing season treatments of fire and clipping combined. Height and resprout number decreased with increased fire intensity. Fire season and intensity effects on canopy area and stem growth were generally not detected. My results do not support the hypothesis. Instead, fire season and intensity use two different mechanisms that influence shrub responses. Prosopis glandulosa has the potential to respond more after dormant season than growing season fires as determined by carbohydrate availability in underground organs at the time of fire. However, realization of this potential is contingent on fire intensity as influenced primarily by fuel amount. In turn, fire intensity will determine the amount and duration of heat penetration into soils and thus the amount of damage to growing points of underground organs.