Climate-driven Modeling of the Initial Development of Brazilian Forest Species Under Current and Future Climates

Abstract Modeling the initial development stage helps assess climate change impacts and species vulnerability under future scenarios. This study calibrated and validated two development models - the Phyllochron (Phyl) and Wang and Engel (WE) - under field conditions and identified potential alterations in the development of Brazilian forest species ( Bauhinia forficata , Ceiba speciosa , Handroanthus chrysotrichus , Handroanthus impetiginosus , and Tabebuia roseoalba ) throughout the 21st century. The Phyl and WE models estimate daily leaf appearance, which, when integrated over time, provides the duration of initial development. Field experiments conducted between 2022 and 2024 supported model calibration and validation. The best-performing model was applied to simulate development under current (1995–2014) and three future periods (2041–2060, 2061–2080, and 2081–2100) and three socioeconomic scenarios (SSP2-4.5, SSP3-7.0, and SSP5-8.5). Sixteen General Circulation Models from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) were used. Both models accurately estimated leaf number for all species, with lower precision for development duration. The Phyl model performed better for C. speciosa (RMSE = 1.30 leaves, 29.8 days) and H. chrysotrichus (1.41 leaves, 23.0 days), while the WE model performed better for B. forficata (1.14 leaves, 11.9 days), H. impetiginosus (1.50 leaves, 32.3 days), and T. roseoalba (1.32 leaves, 25.2 days). Projected temperature increases (+ 1.3 to + 4.5 °C) will alter leaf emergence and development duration, with reductions (− 1 to − 55 days) for sowing from February to July and increases (+ 1 to + 24 days) from August to January. Adjusting sowing schedules and controlling seedling environments are key adaptation strategies under global warming. Graphical Abstract