Restoration implications of the germination ecology of six dry-forest woody Fabaceae species in Mexico

Key message

Seed germination responses to variation in temperature and light differed among six dry forest species, results that will inform ecological restoration and climate change adaptation projects.

In dry forests, where opportunities for plant establishment occur in a narrow window of opportunity, seeds must respond to cues to germinate when conditions for growth are suitable. Knowledge of the strategies and adaptations of seeds to the seasonal dry-forest ecosystems, being under constant threat, is needed to guide restoration and management actions in the face of climate change. We investigated the effects of scarification, temperature and light in germination percentage, germination time and synchrony of six woody Fabaceae species. The species have ecological potential for restoration and are of cultural or economic importance for the local people in the Tehuacán-Cuicatlán Valley, Mexico. We carried out a multifactorial germination experiment with five temperatures, two light regimes and two scarification conditions for Mimosa luisana, M. polyantha, M. adenantheroides, M. lactiflua, Acaciella angustissima and Vachellia constricta. All germinated in a wide range of temperatures (10–40 °C), and mechanical scarification highly increased the germination percentage. Higher temperature increased and speeded up germination in dark conditions for most of the species, but they exist heterogeneous responses in their germination synchrony. Studied species had high germination percentages in warm temperatures, but their recruitment in nature might be negatively affected by warmer and drier conditions, and by the loss of shade and seed dispersers due to deforestation and changes in land use. It is crucial to study not just germination percentage and time but also other aspects of the germination process such as the germination synchrony, since it might reveal useful information for management actions.