Slow recovery and loss of species richness in a semi-deciduous seasonal Atlantic Forest after selective logging and drought events

Research article: https://doi.org/10.1111/jvs.70153

Abstract

Questions
The structure and dynamics of tropical forests face increasing pressures from historical land use and climate change. We asked: 1) Is there a significant difference in forest structure and species composition over 23 years? 2) Which tree species increases or decreases in density and/or basal area during this period? 3) Does drought exert a more pronounced effect on the tree community in more recently disturbed site?

Location
Guaxindiba State Ecological Station in São Francisco do Itabapoana (21°24’ S, 41°04’ W), Rio de Janeiro, Brazil.

Methods
Over 23 years, we monitored all trees with ≥10 cm DBH in four permanent 0.25 ha plots established in 1995 at each of two sites: one with signs of selective logging until 1960 (US60) and another selectively logged until 1990 (LS90). We assessed changes in basal area, density, species richness, evenness, and turnover, and calculated recruitment, mortality, and relative growth.  Climate variability was assessed using precipitation and temperature anomalies and maximum cumulative water deficit.

Results
Both sites showed slow recovery, with small increases in tree density and basal area and declines in species richness and evenness. Dominant species, such as Metrodorea nigra and Marlimorimia contorta, gained prominence, indicating a possible inhibitory role in the successional process. Recruitment decreased and mortality increased over time at both sites, possibly related to drought events. LS90 experienced greater species loss and structural changes compared to US60. Highlighting persistent selective logging legacies, exacerbated by recurrent droughts.

Conclusions
Selective logging and recurrent droughts created long-lasting impacts on SSAF, reducing resilience and slowing ecological recovery. Community trajectories converged toward floristic simplification, with drought-tolerant dominants displacing less resilient species. These findings underscore the vulnerability of seasonal tropical forests to compound disturbance and climate stress, emphasizing the need for targeted conservation to enhance resilience, sustain biodiversity, and preserve ecosystem services.

Keywords: Atlantic Forest, semi-deciduous forest, climate change, drought impacts, forest resilience, selective logging legacies, tropical forest dynamics, species richness and composition, biodiversity conservation, long-term monitoring