Reference values for germination and emergence measurements

Abstract

Why should we care about reference values for germination and emergence measurements? Because they can help in the conservation of species and thus the recovery or restoration of altered areas. Therefore, for the first time, we evaluated the germination and emergence processes of diaspores of five Cerrado species to propose reference values for the germination and emergence measurements to enable species comparison, and consequently, facilitate better conservation decisions. The five species have diaspores with high physiological quality and intraspecific variability in relation to most of the germination and emergence measurements, showing that they still retain their reproductive potential. The processes of seed germination and seedling emergence in Anadenanthera colubrina (Vell.) Brenan and Ceiba speciosa (A.St.-Hil.) Ravenna and seedling emergence in Astronium urundeuva Engl. were faster and more synchronised than those of Cedrela fissilis Vell. (emergence) and Lithraea molleoides (Vell.) Engl. (germination and emergence), indicating the presence of dormancy in the diaspores of the last two species. However, considering the reference values determined here, all the species could be considered very slow and very asynchronous. This means that all the species use large environmental windows to establish themselves, where the spreading of seed germination and seedling emergence over time is an important survival advantage.