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| Author(s): |
Marco Antonio Chiminazzo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Rio Claro. 2021-01-27. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro |
| Defense date: | 2020-10-29 |
| Advisor: | Alessandra Fidelis; Aline Bertolosi Bombo |
| Abstract | |
Fire is a disturbance in many parts of the world, controlling biomes’ distribution and shaping different vegetation types. In the Cerrado, fire occurs in the savanna vegetations through different frequencies and intensities, being responsible for selecting species able to survive the disturbance and limiting savanna and forest boundaries. After the fire event, the species have their aerial biomass consumed by the flames or damaged by the heat, being necessary the resprout of new branches to assure their persistence in the environment. However, for the resprout occur, the structures responsible for developing in new branches (buds) must be protected enough so they can survive the flames’ damage. Therefore, this research had as main goal the analysis of the different characteristics and strategies of woody plants to overcome fire and persist in fire-prone environments. Thus, it was raised the following questions: how do functional traits related to aerial buds are distributed across savanna and forest species? Which functional traits and life-forms can be related to the post-fire responses in these vegetations? To explore these questions, it was sampled species in a vegetational gradient between savannas and forests by considering the different fire frequencies between them. For each sampled species, individuals were collected to analyze the presence of four functional traits related to the persistence of woody species: the bud protection by bark; the presence of trichomes protecting the buds’ meristems; the presence of accessory buds and the bark growth rate. It was also analyzed the post-fire responses of woody species by considering their degree of bud protection, the position from the shooting branches and the individuals’ height. This study showed that species that better protected their buds and produced more bark were related to savanna vegetations were fire is present. The presence of trichomes over the buds was also related to species of savanna vegetations, suggesting a possible role like the bark in protecting the buds. In the same fashion, accessory buds were more present in savanna species, indicating a greater capacity of aerial resprouting when compared to forest species. Lastly, species that better protected their buds also produced more bark per time. Concerning the species’ post-fire responses, the ones that showed greater degrees of bud protection were more capable to resprout from aerial buds, but they were also capable of resprouting from basal buds. Few species were capable of resprouting from aerial buds even with their buds unprotected by bark. However, these species showed trichomes covering their buds. Due to the distribution of such traits protecting the buds, the study showed the great adaptation and resilience that cerrado woody species have to resist and persist the fire events, indicating that fire presence is an intrinsic phenomena of savanna ecosystems. (AU) | |
| FAPESP's process: | 18/21300-6 - Does the protection of aerial buds in woody plants occur in response to fire in Cerrado? |
| Grantee: | Marco Antonio Chiminazzo |
| Support Opportunities: | Scholarships in Brazil - Master |