Unraveling fruit and seed morphology and seedling establishment of a narrow endemic tree species

Desentrañando la morfología de frutas y semillas, así como el establecimiento de plántulas de una especie de árbol estrechamente endémica

Abstract

Montane ecosystems in South America harbor high levels of endemism typically with species that are often threatened. Here we investigated fruit and seed morphology, germination, and early growth parameters of Crinodendron brasiliense, an endangered and narrow endemic tree species of subtropical montane cloud forests in Southern Brazil. We obtained fruit and seed size and shape, number of lobes and number of seeds per fruit and evaluated germination and early growth parameters in a greenhouse. We tested the effect of different container types and parent plant on seed morphology, germination, and early growth. We also tested whether thermal scarification would improve germination rates. We showed that parent plant significantly influenced fruit and seed morphology as well as early growth rates. The germination rate of the species was extremely low (0.003–0.004%), which may be one important underlying cause of its small population size and restricted distribution. Thermal scarification was ineffective to improve the germination of seeds. Unexpectedly, container type significantly affected germination success, as seeds in trays germinated faster and in higher rates than seeds planted in seedbeds. Such result suggests a higher soil moisture could improve germination success. Our study is the first documented propagation of the species and provides essential aspects on the reproductive biology and early development of Crinodendron brasiliense. We highlight the urgent need for further research and collaborative conservation initiatives to prevent the extinction of this species.

Keywords
Araucaria Forest; Brazil; Cloud Forest; Conservation; Crinodendron brasiliense; Elaeocarpaceae; Montane Forest