Acta Botanica Brasilica
Print version ISSN 0102-3306
On-line version ISSN 1677-941X
BICALHO, Elisa Monteze et al. Do the structures of macaw palm fruit protect seeds in a fire-prone environment?. Acta Bot. Bras. [online]. 2016, vol.30, n.4, pp.540-548. Epub Oct 27, 2016. ISSN 0102-3306. http://dx.doi.org/10.1590/0102-33062016abb0077.
Fire is an abiotic disturbance that regulates vegetation structure and biodiversity. Some plant species have adapted to fire prone environments by evolving protective structures. Acrocomia aculeata (macaw palm) is widely distributed throughout tropical America, and is found in environments continuously influenced by anthropogenic fire. We aimed to determine whether the fruit characteristics of A. aculeata enable seeds to resist the effects of fire and also the consequent effects of fire on fruit biometric traits and embryo viability. After a fire event in a region of pasture-forest transition, we marked 30 individuals of A. aculeata. The trees were separated by UPGMA analysis into 5 groups according to fire exposure, ranging from trees with no exposure to trees with fruit completely exposed to fire. Fruit exposure to high temperatures led to lower values in fruit fresh weight, length, density, and processable mass.Fire had no significant effect on seed biometric variables, because of the structures of the fruit, including its lignified endocarp and its insulating and mucilaginous mesocarp. These structures helped to maintain the embryos viability by preventing oxidative damage. In conclusion, the fruit structure of the macaw palm may facilitate seed persistence, even when subject to increasingly frequent fire events.
Keywords : Acrocomia aculeata; biometry; burning; climate change; seed viability.