Seed germination is a key factor in the success of forest regeneration and nursery production; however, its performance depends on the interactions among seed physiology, pre-germination treatments, and environmental conditions. We evaluated how eight pre-germination treatments and two contrasting environments affected germination capacity, vigor, and kinetics in seed lots (provenances) of Pinus hartwegii, P. montezumae, and P. pseudostrobus. The seeds were subjected to hydration, H₂O₂, mechanical scarification, or GA₃ treatments and were germinated in a controlled chamber and a greenhouse; the responses were analyzed using generalized linear mixed models. Species × environment interactions were significant for all germination parameters. Final germination was higher in the greenhouse than in the chamber (81% vs. 72%), while germination was faster in the chamber. P. pseudostrobus achieved the highest germination rate (96%), P. montezumae showed the greatest stability across environments, and P. hartwegii exhibited a relatively stable final germination capacity across environments but greater kinetic sensitivity. Among the treatments evaluated, 2% H₂O₂ and 200 mg L⁻¹ GA₃ showed the most favorable balance between germination capacity and rate, while scarification accelerated germination but reduced its final percentage.

Introduction Growth dynamics or tree growth response to management in forest plantations can be projected using a Growth and Yield System (TGYS), a useful quantitative silvicultural tool. Objective To develop a TGYS that includes site orientation as a random effect for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. in Nuevo San Juan Parangaricutiro, Michoacán, Mexico. Materials and methods Data from 58 re-measured sampling plots (400 m2) of P. montezumae and 96 re-measured sampling plots of Pinus pseudostrobus were used. Using a mixed-effects modeling approach, a base model and an algebraic difference approach were simultaneously fitted for each tree measurement variable of interest. Results The growth pattern of dominant height of P. montezumae (polymorphic) and that of P. pseudostrobus (anamorphic) influenced the forecasted trends of basal area and volume when using the fixed parameters of each compatible expression. The annual mortality rate for P. montezumae and P. pseudostrobus was 3.14 % and 3.35 %, respectively. The maximum current annual increment in volume at the best site index was 13.717 m3∙ha-1 at 12 years for P. montezumae, and 23.072 m3∙ha-1 at 15 years for P. pseudostrobus, while volume rotation age happened at 26 years (162.462 m3) and 22 years (321.66 m3), respectively. Conclusions With the developed system, it will be possible to simulate growth scenarios for each forest plantation and support species-specific management strategies.