Banca de QUALIFICAÇÃO: THOMAZ GABRIEL BARROS DA ROCHA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : THOMAZ GABRIEL BARROS DA ROCHA
DATE: 02/10/2023
TIME: 15:00
LOCAL: Google Meet
TITLE:

Seeds functional traits and germination strategies in a seasonally dry tropical forest

KEY WORDS:

Functional Traits; Dormancy; Dry Forests; Germination; Seed Coat; Storage Reserves

PAGES: 60
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

In seasonally dry forests, water is a limiting resource for the processes of germination and plant growth, therefore, the strategies of dormancy, orthodoxy and the storage of reserves that confer resistance to desiccation in seeds are crucial to ensure the survival of species, especially during periods of water restriction. These strategies are driven by functional traits of the seeds, which affect germination and plant recruitment. This dissertation aimed to answer the question of the mechanisms of dormancy and investment in functional traits that ensure seed germination in a seasonally dry tropical forest. For this purpose, we used germination experiments, measured the biomass of reserves stored in the tissues and the biochemical composition of primary compounds, and measured the biomass of tegument investment for 22 tree species native to the Caatinga. In the first chapter, we sought to determine the predominant dormancy strategy, the intensity of dormancy and the most effective treatments for germination. Our results show that non-dormancy and rapid germination are the predominant strategies among the species used and we recommend the most effective germination treatments for each species. In the second chapter, we investigated the trade-offs between the functional traits of the seeds and the formation of distinct functional groups, and the effects of these traits on the germination speed of the species. We found a conservative functional group of large seeds, which germinate slowly and store reserves to the detriment of tegument protection. The acquisitive functional group of small seeds germinates fast and investments in tegument protection, while storing less reserves. Thus, this work provides an understanding of the different adaptation strategies used by plants to produce seeds in a seasonally dry tropical forest, as well as the mechanisms that ensure survival and the colonization process of these seasonal environments. In addition, we have contributed to methodological advances aimed at ensuring the success of ecological restoration in seasonally dry forests.

COMMITTEE MEMBERS:
Interno - 1837921 - ALEXANDRE FADIGAS DE SOUZA
Presidente - 1677189 - GISLENE MARIA DA SILVA GANADE
Externa ao Programa - 1516627 - JULIANA ESPADA LICHSTON - null