Testing the island rule in Angiosperms from sky islands and true islands within megadiverse Neotropical environments

• Grant number: 24/20342-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Fábio Pinheiro
• Grantee: Gabriel Pavan Sabino
• Supervisor: Juliano Sarmento Cabral
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Universität Bonn, Germany
• Associated to the scholarship: 23/02443-9 - Exiled flora: diversity patterns of insular vascular plant communities, BP.DR

Abstract

The island rule is an evolutionary pattern observed in species on islands, where small mainland species tend to become larger on islands, while large mainland species evolves to be smaller. Although many studies have focused on insular size changes in animals, much less attention has been given to plants, especially in isolated island-like habitats such as inselbergs and sky islands. This study aims to test for size changes in stature, leaf area, and flower length in angiosperm plant communities inhabiting maritime and land inselbergs in the Atlantic Forest biome, southeast Brazil. By constructing an extensive dataset from herbarium specimens, flora descriptions, and field measurements, we will analyze whether insularity promotes size changes in the sampled traits by comparing species (or congeneric in case of endemism) present in insular environments with those in non-insular systems such as forests. We will conduct ordinary linear regressions, paired t-tests and linear mixed-effects models (LMM) with phylogenetic controls (e.g. PLSR - Phylogenetic least-square regressions) to examine how isolation influences plant trait variation. The study leverages the unique conditions of maritime inselbergs based on the continental shelf, which became true islands after being isolated by the sea during the last glacial maximum, as well as comparisons with naturally isolated mainland inselbergs, both providing natural experiments to test the magnitude of island rule under contrasting degrees of isolation. The results will enhance our understanding of plant evolution on maritime islands and mainland island-like systems, contributing to broader ecological and evolutionary studies in insular environments.