Banca de DEFESA: BRUNO GABRIEL MELATI

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : BRUNO GABRIEL MELATI
DATE: 31/08/2023
TIME: 14:00
LOCAL: Ambiente Virtual
TITLE:

The role of water availability on the dynamic of interaction between ants and plants with extrafloral nectaries

PAGES: 145
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUBÁREA: Ecologia Teórica
SUMMARY:

Mutualisms are conditional interspecific interactions in which individuals of different species exchange resources and services between each other. This exchange entails costs for individuals, with the outcome of the interaction being variable and determined by the offsetting of these costs by the benefits obtained through interaction partners. Much of this variation can be shaped by the environmental context in which the interaction occurs. Specific environmental conditions can affect the balance of mutualisms through two main mechanisms: changes in individuals' investment in the exchanged resources of the interaction and shifts in the composition of mutualistic partners across communities. These two mechanisms, for instance, are likely means through which abiotic factors influence the balance of mutualisms between plants with extrafloral nectaries and ants. The balance of this mutualism for plants tends to increase in drier environments, yet the mechanisms underlying this variation are not yet understood. To address this gap, I investigated in this thesis two mechanisms by which spatial variations in water availability may influence the balance of mutualism between plants with extrafloral nectaries and ants. More specifically, (i) I examined how water availability affects the quality of extrafloral nectar provided by plants to ants and how ants respond to variations in the production of this nectar, and (ii) how variation in the plant and ant community along environmental gradients influences interaction patterns and emergent properties of these interactions at the community level. In the first investigation, I observed that water availability has a nonlinear effect on extrafloral nectar production. At the onset of water restriction, plants with extrafloral nectaries increased their investment in nectar, but this investment decreased as water restriction persisted. This nectar production pattern had a similar effect on ant visitation patterns, with ants becoming more abundant and active on plants at the start of water restriction and decreasing in occurrence as water restriction prolongs.Regarding the second study, I noted that water availability has an indirect effect on the interaction pattern between plant and ant species by directly impacting the species richness of plants and ants along water gradients. Thus, water availability has the potential to affect how much plant and ant species invest in the interaction and, consequently, interact at the local scale. However, the distribution of interactions along large-scale water gradients is primarily explained by variations in the assembly of partner species along the gradient.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 058.701.134-31 - LAURA CAROLINA LEAL DE SOUSA - NENHUMA
Membro Titular - Examinador(a) Externo à Instituição - CAIAN SOUZA GEROLAMO
Membro Titular - Examinador(a) Externo à Instituição - PEDRO JOAQUIM BERGAMO - UNESP
Membro Titular - Examinador(a) Externo à Instituição - XAVIER ARNAN VIADIU - UFPE
Membro Titular - Examinador(a) Externo à Instituição - TALITA CÂMARA DOS SANTOS BEZERRA - UFPE
Membro Suplente - Examinador(a) Interno ao Programa - 1768895 - GUSTAVO MUNIZ DIAS
Membro Suplente - Examinador(a) Externo à Instituição - PAULO ENRIQUE CARDOSO PEIXOTO - UFMG
Membro Suplente - Examinador(a) Externo à Instituição - RODRIGO HIRATA WILLEMART - USP