Germination Behavior and Early Seedling Growth in Abies pinsapo Boiss. Seeds

Abies pinsapo Boiss. is a conifer endemic to southern Spain. It is categorized as an endangered species in the IUCN list and the plant communities it forms are considered unique ecosystems, being the remains of fir forests occupying the Mediterranean basin during the last glaciations. Understanding seed germination and plant production is essential for the management and conservation of A. pinsapo stands. The objective of this work was to investigate the effect of temperature and light on germination behavior and early seedling growth of A. pinsapo seeds from different populations. The results obtained reveal a significant influence of seed origin on germination percentage. Temperature played a critical role on germination rate, with optimal results at 15 °C. Light only significantly affected germination in seeds from Grazalema, although significant population × light and temperature x light interactions could be inferred. In relation to germination kinetics, different responses to the environmental factors tested were observed among seeds from different provenances. Globally, the temperature influenced all the germination parameters, except germination onset. However, light affected germination initiation and speed. Early seedling growth depended on seed origin and temperature. The temperature played a determinant role as temperatures above 15 °C strongly limited plantlets development. Light only significantly influenced root length in plantlets obtained from Grazalema seeds.