Effects of a broadly distributed invasive species (Leucaena leucocephala) on local and regional dynamics of regenerating communities

Author(s)

Juliano Zardetto

• Document type: Master's Dissertation
• Press: Rio Claro. 2023-07-10.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Rio Claro
• Defense date: 2023-05-29
• Advisor: Tadeu de Siqueira Barros

Abstract

Biological invasions are complex scale-dependent processes. Metacommunity ecology frameworks are useful to understand the effects of invasive non-native species (INNS) because they explicitly consider local and regional scales and the three main components of biodiversity: alpha, beta, and gamma. White-popinac (Leucaena leucocephala (Lam) de Wit) is an important INNS in regenerating forests in the Atlantic Forest (Brazil). White-popinac invasions form an interesting, unique spatial structure because the species forms dense and homogeneous patches, instead of spreading individuals throughout invaded areas. Here we took advantage of this unique spatial configuration formed by patches of native forest, regenerating areas, and patches of white-popinac to investigate how local and regional dynamics of plant (meta-)communities under natural regeneration are affected by white-popinac. We conducted floristic surveys in 131 communities distributed among 29 metacommunities of regenerating forests that had different ages of white-popinac invasion. We found (i) mirrored responses among local and regional scales: at both scales, native species richness decreased with the increase of invasion age, whereas INNS richness increased; and (ii) β-diversity decreased with the increase of invasion age, showing that time-advance of invasion led to a homogenizing effect. We also found evidence that the advance of white-popinac patches towards regenerating forests increases with time and proximity to the forest fragment. Our results may be consequences of biotic indirect effects, and they suggest that the effects of white-popinac invasions on regenerating forests can be so vigorous that they propagate from local to regional scale, via decrease in β-diversity. We reinforce the importance of considering multiscale approaches on assessing effects of plant invasions. (AU)

• FAPESP's process: 20/14104-6 - The role of a broadly distributed alien invasive plant (Leucaena leucocephala) in the local and regional dynamics of regenerating communities
• Grantee: Juliano Zardetto
• Support Opportunities: Scholarships in Brazil - Master