Banca de DEFESA: Pedro Henrique Santos Ferreira

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : Pedro Henrique Santos Ferreira
DATA : 21/07/2023
HORA: 15:00
LOCAL: Online transmitido via Google Meet - Nova Xavantina - MT
TÍTULO:

 

"Connectivity governs the Pantanal aquatic insect metacommunity"

PALAVRAS-CHAVES:

Primary productivity, habitat heterogeneity, alpha diversity, ecological uniqueness, lake ecosystems.

PÁGINAS: 30
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia de Ecossistemas
RESUMO:

The Pantanal has high spatio-temporal heterogeneity due to the seasonal flooding regime of its rivers. Aquatic communities in shallow lakes in the biome are influenced by local processes linked to environmental heterogeneity and spatial factors such as connectivity and the distance from other water bodies. Taking advantage of these natural ecosystems of interconnected shallow lakes, we analyzed if aquatic insects inhabiting Pantanal shallow lakes in association with macrophytes are explained by connectivity, productivity, habitat heterogeneity, area, and distance from the Cuiabá River. In order to understand the structure of the aquatic insect metacommunity, we conducted analysis of the abundance, diversity and species richness along the natural design of the net interconnected shallow lakes, considering the importance of dispersal distinctiveness and functional complementarity among species. We investigated the impact of connectivity in association with a set of lake descriptors to test the following hypotheses: i) in connected lakes, we expect higher abundance and richness of aquatic insects associated with higher algal primary productivity. On one hand, ii) the dominance of insects in more productive lakes may contradict these expectations of the richness-energy theory (hypothesis i), resulting in the absence of an effect of primary productivity on species richness, but still reflecting high abundance of some taxa independently of connectivity. On the other hand,  iii) we expect disconnected lakes to exhibit higher insect species richness, diversity, and evenness abundance distribution due to a greater number of species adapted to macrophyte-provided habitat heterogeneity. In addition, we test whether iv) the presence of limnological gradients such as eutrophication (e.g., chemical enrichment) affects alpha diversity of aquatic insects. Finally, in accordance with predictions from Island Biogeographic Theory, we expect that: v) species richness decreases with distance from the lake to the main channel of the Cuiabá River as a continuous source of individuals; and we tested whether vi) species richness increases with area size due to its positive effect on habitat heterogeneity. We observed that heterogeneity was higher in disconnected lakes, considering both limnological predictors and habitat diversity. Despite higher algal productivity in connected lakes, abundance, richness, diversity, and equity were similar between river-connected and disconnected lakes. Algal productivity had a negative effect on insect abundance. The interaction between connectivity with algal productivity negatively affected aquatic insect abundance, and its interaction with PC-I limnological gradients positively affected Shannon's equity. Our results indicate that connectivity plays a key role for habitat and limnological heterogeneity as well as primary productivity, but does not always affect the insects studied. Our results further suggest low support for our hypotheses of the influence of primary productivity, habitat heterogeneity, area and distance to the river. On the other hand, there is high support for the effect of productivity and limnological gradients on insect abundance. Additionally, limnological effects were also observed for Shannon richness, diversity and equity, while distance to the river positively affected Shannon diversity. We discuss these findings in relation to the impacts of eutrophication, habitat homogenization, and isolation on insect biology and the implications for biodiversity conservation of shallow Pantanal lakes.

MEMBROS DA BANCA:
Presidente - 020.530.721-30 - DENIS SILVA NOGUEIRA - UFG
Interno - 114819007 - RICARDO KEICHI UMETSU
Externo ao Programa - 561163100 - ULLY MATTILDE POZZOBOM COSTA