Mediterranean annual seedlings need to survive winter freezing temperatures to produce seeds in the spring. Pescador et al. test whether functional structure related to plant freezing resistance is structured according to abiotic and biotic filters.

High freezing resistance is extended among studied species, suggesting the presence of an historical environmental filtering. Density of rabbits and presence of Stipa tenacissima L. tussocks also modulate resistance to freezing events. Therefore, traits that allow plants to deal with herbivory may also promote freezing resistance, and tussocks can act as nurses via amelioration of harsher winter conditions. The study represents a significant advance in understanding the assembly of winter annual communities.