Phenological cycles in the Pantanal woody communities: Responses to climate and soil moisture seasonality

highest Fournier intensity throughout the annual cycle, with the intensity of phenological events reaching 12% in July. The wet-dry transition season (June to July) marked the repro- ductive phase in this community, when 36% and 32% of the species (e.g., L. parvifolius, M. guianensis, and V. divergens) and c. 15% of the individuals were active. The flowering of IS and CS peaked during the dry season, with significant concentrations of species occurring around the mean date in July (rc = 0.68, p = 0.001) and September (rc = 0.28, p = 0.02), respectively. The major flowering event in the IS occurred from June to Sep- tember, during which 20–36% of the species and 6–9% of the individuals exhibited activity at an intensity of 3–5%. For example, T. aurea, V. cymosa, and V. divergens flowered during this period. In CS, despite a weak seasonal pattern of synchrony of flowering events revealed by the low length of the mean vector of the circular analysis (<0.50), the mean date of flower production was significant. There were two peaks of maximum activity in the wet (January, 17% species, 2% individuals) and dry (August, 17% species, 4% individuals) seasons. The Fournier intensity during flowering was low throughout the year, reaching a relatively high value in August (<2%) when the soil moisture was the lowest (8%). Typical Cerrado species, e.g., E. anguifu- gum, E. florida, C. fasciculata, C. americana, and T. aurea, were responsible for the highest indices of activity and intensity of this phenophase.

In the LSDF, the circular analysis revealed strong seasonality and interspecific synchrony (rc = 0.58, p = 0.002), with a mean flowering concentration in the rainy season of December. The flowering activity peaked in the rainy month of January, when 10% of the species, Table 1. Comparison of mean periods of vegetative and reproductive phenological event intensity across the seven communities via the Watson-Williams test. The null hypothesis is that means are equal across groups. Significant differences (p < 0.05) between community phenological patterns are highlighted with asterisks. Leaf fall Flowering Fruiting Community F p F p F p Invaded Savanna x Shrubland 3.46 0.08 2.63 0.12 1.35 0.26 Invaded Savanna x Cerrado Savanna 0.39 0.54 7.19 0.01* 0.48 0.50 Invaded Savanna x Parkland Savanna 0.10 0.75 4.26 0.05* 0.02 0.89 Invaded Savanna x Lowland SD Forest 3.12 0.09 5.49 0.03* 0.70 0.41 Invaded Savanna x Alluvial SD Forest 0.65 0.43 5.83 0.02* 0.10 0.75 Invaded Savanna x Monodominant Forest 0.65 0.43 1.00 0.33 0.36 0.56 Shrubland x Invaded Savanna 3.95 0.06 1.23 0.28 1.04 0.32 Shrubland x Parkland Savanna 2.71 0.11 0.06 0.81 0.17 0.26 Shrubland x Lowland SD Forest 0.60 0.45 0.44 0.52 1.56 0.22 Shrubland x Alluvial SD Forest 3.19 0.09 0.56 0.46 1.44 0.24 Shrubland x Monodominant Forest 2.39 0.14 3.21 0.09 1.06 0.31 Cerrado Savanna x Parkland Savanna 0.06 0.81 5.85 0.02* 0.37 0.55 Cerrado Savanna x Lowland SD Forest 4.35 0.05* 1.05 0.32 1.48 0.24

Cerrado Savanna x Alluvial SD Forest 0.09 0.76 0.90 0.35 0.82 0.38 Cerrado Savanna x Monodominant Forest 0.12 0.73 4.61 0.04* 0.002 0.96 Parkland Savanna x Lowland SD Forest 2.23 0.15 0.79 0.38 1.00 0.33 Parkland Savanna x Alluvial SD Forest 0.20 0.66 1.28 0.27 0.21 0.65 Parkland Savanna x Monodominant Forest 0.22 0.65 3.66 0.07 0.26 0.61 Lowland SD Forest x Alluvial SD Forest 3.17 0.09 0.03 0.88 0.26 0.62 Lowland SD Forest x Monodominant Forest 1.88 0.18 4.12 0.05* 1.17 0.29 Alluvial SD Forest x Monodominant Forest 0.01 0.94 4.22 0.05* 0.64 0.44 https://doi.org/10.1371/journal.pone.0316011.t001 PLOS ONE Phenological cycles in the Pantanal woody communities PLOS ONE | https://doi.org/10.1371/journal.pone.0316011 February 7, 2025 12 / 30