Bud traits and post-fire responses of Cerrado woody species, Southeastern Brazil

1) Species growing in fire-prone savannas usually persist by resprouting
from their buds. In this study, we evaluated how various persistence
traits allow bud protection for improved survival in fire-prone
ecosystems. 2) Using an integrative morphological and macroanatomical
approach, we analyzed how woody plants protect their buds. We tested bud
protection at the community level and evaluated: a) how bud protection
changes along a fire frequency gradient, b) if it differs between shrubs
and trees and c) whether the level of bud protection is related to
post-fire responses of 28 woody savanna species. 3) A mix of traits
involving bud protection may enable woody species persistence in
fire-prone ecosystems. Savanna species better protected their buds than
forest species by developing bark and trichomes that allowed resprouting
after fire. Regarding growth forms, shrub species capable of resprouting
aboveground had their buds better protected than trees. 4) Bud protection
is not only linked with their position to the bark, but also with the
presence of trichomes. Profuse trichomes covering buds were related to
savanna species. Some species with no bud protection by bark but with
trichomes covering their buds were able to resprout after fire. The
presence of accessory buds is also a trait more related to savannas,
possibly influencing the resprouting after fire as they are better
protected and increase the bud bank. Finally, different persistence traits
interact with one another to better protect the buds, requiring a detailed
screening of the traits to assess species responses to fire. 5) Synthesis.
During fire, species have their aerial biomass consumed by the flames. To
be able to resprout new branches and persist in the environment, they must
have well-protected buds. In this study, we evaluated different ways that
woody species protect their buds and related them with their resprouting
strategy after fire. We investigated the protection by the bark, presence
of trichomes and accessory buds. By studying the woody community in a
gradient of savannas and forests we found that buds can be protected by
bark, trichomes, or soil. Species can present a mix of these traits and
strategies, which enhances their resprouting after fire.