Forest seedling development of two Brazilian native species under global warming: assessments, adaptation measures, and financial implications

Abstract Global warming impacts could be particularly severe during the seedling stage of Brazilian native tree species, as they are located in persistent climate change hotspots. Moreover, adopting adaptation measures to cope with the impacts may generate additional costs for seedling production. This research focuses on identifying the impacts of global warming on seedling phase duration and analyzing the financial feasibility of the seedling production of Cybistax antisyphilitica (Mart.) Mart. and Platycyamus regnellii Benth. in a forest nursery when adopting adaptation measures to cope with the impacts of these increases. The Wang and Engel (WE) development model was fed with air temperature data from 13 earth system models from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6). The WE model was simulated for the current climate (1995–2014) and projected for two future climates (near future, 2041–2060 and far future, 2081–2100) under two Socioeconomic Pathway scenarios (SSP2-4.5 and SSP5-8.5), considering 12 sowing dates. The financial feasibility of producing seedlings of both species in the current climate, near future, and far future was based on current operating costs and capital expenditures, evaluated using the net present cost approach. The projected increases of up to 4°C may alter the seedling phase duration of both tree species, resulting in higher seedling production costs for forest nurseries. Simulations performed from January to June show seedling phase duration reductions of ~15 days for C. antisyphilitica and ~ 28 days for Paspalum regnellii, while the simulations performed from July to December show slight increases for C. antisyphilitica (from 1 to 10 days) and P. regnellii (from 1 to 5 days). Adopting adaptation measures to ensure seedling quality and vigor in the future may increase the production costs by up to 137% in both species mainly due to required use of controlled-release fertilizers and larger containers (tube and tray). The results of this study could serve as an initial step in developing an alert system for forest nurseries to address the challenges posed by global warming.