Ecological survey reveals exotic tree dominance and biotic homogenization in Amazonian urban squares, highlighting the displacement of native flora in tropical cities.
Key Points
To assess the composition, diversity, and native representativeness of tree communities across urban squares in the Central Amazon, testing how square size and age influence diversity and biotic homogenization.
Surveyed all trees with a diameter at breast height (DBH) ≥ 5 cm across 35 public squares in Manaus, Central Amazonia, categorizing species by biogeographic origin.
Identified exotic species with known invasive potential across the urban landscape.
Modeled the influence of square area and age on community structure, species dominance, alpha diversity, and beta diversity.
Recorded 1218 individual trees representing 88 species and 31 families, with exotic species constituting 61.4% of individuals and including 15 species with invasive potential.
Square area was the sole positive predictor of species richness, whereas older squares had significantly lower alpha diversity and higher dominance by species such as Mangifera indica and Moquilea tomentosa.
Beta diversity showed no significant relationship with square age or size, demonstrating widespread biotic homogenization across the urban landscape.