Forest Responses to Fire Regime in the Humid Chaco of Paraguay

Aim Vegetation responses to fire regimes are increasingly relevant as fire frequency and intensity rise globally. This is particularly relevant in poorly studied, fire‐prone regions such as the Gran Chaco (GC), where limited information on fire behavior is currently available. This study aimed to assess how different fire regimes affect plant functional traits, diversity and community assembly in the Humid Chaco forests. Location The study was conducted in the Humid Chaco of Paraguay, a subregion of the GC ecoregion characterized by seasonal subtropical forests and increasing fire occurrence. Methods Thirty‐one experimental plots of 0.1 ha (20 m × 50 m) were established in fragmented forest areas subjected to No Fire regimes ( n = 12), Low ( n = 12) and Medium ( n = 8). Within these plots, data on species composition, vegetation structure and fire‐adaptive traits were collected. Functional diversity indices—including functional richness, evenness, divergence and dispersion—and multivariate analysis were conducted to evaluate vegetation responses to fire. Results Species' taxonomic composition and vegetation structure were similar across fire regimes, with dominance of Fabaceae and typical mesoxerophytic forest species. Evidence of increased resprouting was observed in individuals from fire‐affected plots, indicating a functional response associated with fire occurrence. Although structural attributes of vegetation remained relatively consistent, functional dispersion was lower in the No Fire regime, indicating more homogeneous trait assemblages in fire‐excluded areas. Conclusions Fire regimes in the Humid Chaco are associated with subtle but consistent shifts in plant community functional composition, primarily affecting species dominance and trait syndromes rather than causing marked changes in taxonomic composition or structure. The findings underscore the importance of considering functional responses in fire ecology and highlight the potential role of forest patch preservation in maintaining landscape heterogeneity and moderating fire spread in this increasingly fire‐prone landscape.