Climate change impact on the initial development of tropical forest species: a multi-model assessment

Air temperature is a key variable in the development of tropical forest species, and the increasing temperature projected to occur over the twenty-first century can bring additional threats to the development of these species, particularly during the initial development. The aim of this study was to evaluate the impact of air temperature increase in the initial development of three tropical forest species in the seedling stage: Psidium guajava L., Citharexylum myrianthum Cham., and Bixa orellana L. We used the Phyllochron and Wang and Engel development models, both set for current (1980–2005) and projected for future (2021–2050 and 2071–2100) climate conditions, in two scenarios of radiative forcing (RCP 4.5 and 8.5) and considering twelve development simulation planting dates. We used 10 Earth Systems Models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). The projections indicated that the increases in air temperature (~ 1.4 to ~ 3.9 °C) can be sufficient to change the development rates of the three species. The simulations carried out from March to June may have the early development accelerated and the seedling stage reduced. Differently, the simulations from September to December may slow down the development and increase the seedling stage duration, mainly for Citharexylum myrianthum, the most sensitive to air temperature increase. We conclude that while changing the planting date is a feasible adaptation measure against the threats of climate change, shading and irrigation may reduce the quality of seedlings. Outlining appropriate, timely, and cost-effective adaptation measures is critical for the sustainability of the Brazilian nursery sector.