Fenologia reprodutiva de Portea petropolitana (Wawra) Mez (Bromeliaceae) sob o contexto das sob o contexto das mudanças climáticas: integração de registros de herbário e observações de campo

Abstract

Environmental changes can modify the timing of life-cycle events in plants, making the analysis of phenological patterns an important tool for understanding potential vegetation responses to global change. This study aimed to analyze the reproductive phenology of Portea petropolitana (Wawra) Mez, an Atlantic Forest endemic bromeliad, by integrating field monitoring and historical herbarium records. Field observations were carried out between August 2025 and January 2026 at the Botanical Garden of the Federal University of Juiz de Fora, located within Mata do Krambeck, in Juiz de Fora, Minas Gerais, Brazil. Fifty adult individuals were monitored and classified according to the phenophases of floral scape, flower buds, open flowers, and fruits. In parallel, reproductive records available from the Reflora, speciesLink, and JABOT platforms were compiled and subsequently analyzed using circular statistics, the Rayleigh test, mean vector, and comparisons among historical periods through the Mardia-Watson-Wheeler test. The relationship between flowering and environmental variables was evaluated using Generalized Linear Models with a quasibinomial distribution. In the field, 25 individuals showed reproductive activity, with flowering beginning in August, gradually increasing until November, and fruiting occurring between September and January. In the herbarium dataset, 118 reproductive records were analyzed, of which 89 corresponded to flowering. Circular analysis indicated significant seasonality, but with low temporal concentration of records, showing that flowering was broadly distributed throughout the year. Comparisons among historical periods did not reveal a significant phenological shift, indicating no robust evidence of temporal change in flowering over the decades. At the local scale, flowering was positively associated with photoperiod and precipitation, whereas temperature did not show a significant effect. Thus, the results suggest that the species exhibits prolonged and poorly synchronized reproduction, modulated by local seasonal factors, without confirmation of the hypothesis of temporal displacement in flowering based on the historical dataset analyzed.