Pollen rain deposition along a hydromorphic savannah gradient in midwestern Brazil

This is the authors' abstract. We don't add key points for this paper.

Veredas are wetland ecosystems of the Brazilian Cerrado that play a central role in hydrological regulation and biodiversity conservation, yet their spatial variability in palynological assemblages remains poorly understood. This study analysed modern palynological assemblages from 23 samples distributed across nine localities in the Chapada dos Guimarães National Park, Mato Grosso State, Brazil, encompassing different successional stages of vereda vegetation. Palynological richness was estimated using Hill number q = 0 and standardised to a common sample size, while assemblage composition was evaluated through non-metric multidimensional scaling (nMDS) and PERMANOVA. The results indicated high sample coverage (SC > 0.94) and no significant differences in palynological richness among vegetation types. In contrast, palynological composition differed sigmificantly among localities, which accounted for 64% of the observed variation (R2 = 0.64; p = 0.001), indicating pronounced spatial structuring among sampling areas. Taxa such as Mauritia flexuosa L. f., Poaceae Barnhart, and Lycopodium L./Lycopodiella Holub. showed a broad distribution across successional stages, consistent with the integration of local and regional palynological signals. These results demonstrate that vereda palynological assemblages are spatially structured and that interpretations based solely on vegetation successional stages should be made with caution.The palynological data obtained also reinforce their potential as modern analogues for paleoecological interpretations of tropical wetlands, with conservation implications emphasising the importance of spatial heterogeneity and connectivity among vereda areas.