Understanding the aquatic macroinvertebrat disproportionality in the biomass-abundance relationships in Atlantic Forest streams

• Grant number: 23/15982-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• End date: July 31, 2025
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Victor Satoru Saito
• Grantee: Julia Maria Braga
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The Metabolic Theory is one of the main theories used to understand food webs and energy flows in ecosystems. Generally, a decrease in population density is expected as individual body size of the species increases, thus sustaining the flow of energy that must flow from the smaller organisms to the larger ones. In this project, we will attempt to understand the disproportionality in size-abundance relationships of macroinvertebrates observed in Atlantic Forest streams, potentially influenced by the functional uniqueness of taxa and the environmental variations between streams. We expect to show that foraging strategies of some species generate a highly positive ratio between resource acquisition and energy expenditure, resulting in a disproportion in their abundance, as they take advantage of less explored niches. To analyze our hypotheses, we will describe the Global Size-Density Relationship (GSDR) and relate their residuals (species more abundant than expected) to the species' functional uniqueness values. Subsequently, we will relate the disproportion to environmental variations in space and time in order to elucidate how functional uniqueness makes better use of resources and can explain the disproportionate abundance of some macroinvertebrate taxa in neotropical streams that cannot be explained by simple allometric relationships.