Banca de DEFESA: VITOR MATEUS RIGOTTI

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VITOR MATEUS RIGOTTI
DATE: 26/04/2023
TIME: 14:00
LOCAL: Videoconferência: meet.google.com/jax-tmov-hpt
TITLE:

Impacts of the conversion of native grassland to soybean monoculture on the epiedaphic springtail fauna of the Brazilian Pampa

KEY WORDS:

Bioindicators, Collembola, ecology, inventory, mesofauna

PAGES: 35
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUBÁREA: Ecologia de Ecossistemas
SUMMARY:

The edaphic fauna holds a great importance for the dynamics of soil ecosystems. Among the components of the edaphic fauna the Collembola stand out. They are small arthropods which present great sensitivity to the changes on the physicochemical nature in the environment where they are inserted. The Pampa Biome is a highly diverse grassland domain, poorly protected and sensitive to environmental changes. Thus, in this study ecological indices of Collembola populations were used to identify the impacts of the changes in the conversion of native fields in the Pampa biome into soybean monoculture. The Collembola fauna was compared in nine paired native grasslands areas and soybean sites in four municipalities in the Brazilian state of Rio Grande do Sul, taking into account both the effects of the conversion and the main environmental factors. A matrix data of the specimens was generated for comparison between the areas. A total of 975 individuals were sampled: 359 in the native grassland areas and 616 in the soybean sites. The analyses indicated significant changes in the composition of the communities. While the abundance indices were higher in the soybean areas, the Shannon Diversity Index was higher in the native field areas. No significant differences were observed in richness and Pielou Eveness Index between the studied areas. Regarding environmental variables, the Shannon Diversity Index was positively affected by the variables: elevation, plant richness, plant diversity and richness of non-grass plants. The increase in the population of Collembola may reflect a phenomenon of classical resurgence and would indicate a simplification in trophic chains. The reduction in the number of predators, the changes in the physicochemical characteristics of the soil and a possible resistance of some Collembola to some groups of insecticides could explain this phenomenon.

COMMITTEE MEMBERS:
Externa à Instituição - KAUANE MAIARA BORDIN - UFRGS
Presidente - 1879211 - BRUNO CAVALCANTE BELLINI
Externo à Instituição - RUDY CAMILO NUNES - IFPI