Banca de DEFESA: Natalia Diesel Mello

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Natalia Diesel Mello
DATE: 03/04/2024
TIME: 14:30
LOCAL: Auditório 03 do IB
TITLE:

"Spatio-temporal factors and environmental filters shaping Orthoptera communities in the Cerrado biome".

KEY WORDS:

diversity partitioning, environmental heterogeneity, grasshoppers, plant biomass, seasonality.

PAGES: 95
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Unraveling the patterns of natural diversity and the processes and mechanisms determining them are central issues in Ecology research and conservation planning, particularly in the tropics, where diversity is high. This study aims to evaluate how Orthoptera communities are structured both locally and regionally, and partitioned across two vegetation types in the Cerrado biome (campo sujo and savanna) over three seasons (rainy, transition from rainy to dry, and dry), in addition to identifying the environmental filters shaping these communities. To address our objective's questions, this dissertation was divided into two chapters. For this purpose, we sampled Orthoptera communities across the three seasons (rainy, transition, and dry), in two conservation units (UCs) in the Federal District, Brazil. In each UC, we selected three sample plots in savanna (cerrado sensu stricto) and grassland (cerrado campo sujo) areas, totaling six areas per UC. Orthopterans were sampled both actively (manually and using sweep nets) and passively (with pitfall traps). To understand the environmental filters shaping grasshopper assemblies, we also evaluated some environmental factors of the sample areas, such as vegetation structure (height, diversity, and coverage proportion of plant life forms), biomass availability over time, and local microclimatic conditions (temperature and relative humidity). We found Orthoptera communities with high diversity in the Cerrado, with many rare species and few abundant ones. Grassland areas showed higher Orthoptera abundances and species richness compared to savanna. This pattern was maintained across seasons, and the highest adult abundances were observed during the dry season. The species composition of communities differed between vegetation types and also across seasons, suggesting high species turnover, as confirmed in the diversity partitioning analysis. The local scale was most important in determining Orthoptera diversity, and species turnover contributed most to the partitioning of beta diversity. Considering only grasshoppers (suborder Caelifera), we observed that above-ground biomass availability and biomass components (green and dry grasses and forbs) were the environmental factors with the largest effects on the abundance and species richness of assemblies. Microclimatic conditions also showed some effect, but only for maximum temperatures and average relative humidity, with small effect magnitudes. In other words, Orthoptera communities in savanna and grassland areas of the Cerrado are species-rich and have their diversity components strongly associated with the vegetation structure of their habitats, mainly influenced by the availability of plant resources.

COMMITTEE MEMBERS:
Externo à Instituição - LUCAS NAVARRO PAOLUCCI - UFV
Externa ao Programa - 3325655 - FERNANDA VIEIRA DA COSTA - nullInterna - 2476936 - MARINA REGINA FRIZZAS
Presidente - 1147029 - PEDRO HENRIQUE BRUM TOGNI