LAUSR

PREMISE In temperate climates, reductions in snow cover are expected, likely leading to more soil freezing events and damage to plant tissues. However, whether and how plants can compensate for this damage may depend on the timing of damage and plant allocation to seed size and number. We need more information about how seed production, germination, and seedling recruitment might respond to changes in snow cover. METHODS We manipulated snow cover over three seasons in a common garden experiment with four treatments: (1) control, (2) a consistent removal treatment of winter snow, which increased soil freezing ("freeze"), and (3) a single late season snow removal treatment ("removal"), and (4) a single late season snow addition ("addition") treatment. We measured survival, growth, reproduction, and recruitment of a native perennial herb, Thalictrum dioicum. RESULTS Reduced snow cover minimally influenced adult survival. Instead, individuals that experienced reduced snow cover throughout the winter produced more massive seeds, whereas individuals that experienced a single snow removal at the end of the season produced less massive seeds. Seedling recruitment was lower in snow reduction than control treatments, as a result of failure to germinate in the freeze treatment and seedling mortality in the late removal treatment. CONCLUSIONS Both reduced snow cover throughout the winter and a single late snow removal in the spring reduced seedling recruitment, but for different reasons, suggesting that a holistic approach to the life cycle is needed to understand responses to shifting climates. This article is protected by copyright. All rights reserved.