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

Plant community phenology Leaf phenology. All seven communities had more than 50% of individuals semideciduous or deciduous, i.e., shedding more than 50% of their leaves at least once a year (Fig 3). The com- munities with a greater number of deciduous individuals were found at both extremes of the soil hydrological gradient. Specifically, IS and MF, located at the wetter end, represented 54% and 23% of deciduous individuals, respectively, whereas PS, which occupied the drier end, rep- resented 51% of deciduous plants. Cerrado savanna accounted for 13% of the deciduous area and 58% of the semideciduous area. The two semideciduous forests contained approximately 50% semideciduous individuals and 10% deciduous individuals, and presented the greatest number of evergreen individuals (LSDF = 39%, ASDF = 35%). Circular analysis of the phenological data revealed interspecific synchronism and seasonal responses to leaf fall in four of the seven communities, namely, the PS (rc = 0.21, p< 0.001), ASDF (rc = 0.19, p< 0.001), SHB (rc = 0.18, p< 0.001), and MF (rc = 0.12, p< 0.001) commu- nities (Fig 4A). Most of these communities are characterized by the dominance of a few spe- cies. On the other hand, sub-annual seasonal patterns of leaf fall were observed in the activity of the populations in other communities and, to a greater extent, in the intensity of the event, reflected in the low values of the concentration coefficient (rc) for these and other communities. The average length of the vector represented the average number of consecutive months

with the highest population activity. The average month with a high concentration of active species in the PS and ASDF was June, which represented the period of reduced rainfall and a decrease in the moisture content of the local soil. During this period, 94% of the PS species, including H. heptaphyllus, C. fasciculata, and M. hirtum, and 75% of the individuals exhibited leaf loss. In the ASDF, Cordia glabrata and Pseudobombax marginatum were among the 54% Fig 1. Hydroclimatic annual variability between July 2017 to July 2018 representing the Cuiaba´ fluvial fan system. A. Precipitation (mm); B. Water level of the Cuiaba´ River (mm); C. Maximum, mean, and minimum temperatures (˚C); D. Actual Evapotranspiration (mm month-1), and relative humidity (%) (sources: National Water Agency (ANA) and the National Institute of Meteorology (INMET)). https://doi.org/10.1371/journal.pone.0316011.g001 PLOS ONE Phenological cycles in the Pantanal woody communities PLOS ONE | https://doi.org/10.1371/journal.pone.0316011 February 7, 2025 8 / 30