Early spring warming may hasten leaf emergence in Erythronium americanum.

Abstract

Climate change is making spring arrive earlier than in the past, causing some species to alter the timing of their spring activities. This study addressed whether Erythronium americanum Ker Gawl. (trout lily), a common spring ephemeral, can emerge earlier if exposed to early spring warming. I collected corms of Erythronium americanum in the fall, overwintered them in soil, and exposed them to warming in either mid (early treatment) or late (late treatment) February. The timing of leaf emergence was monitored and compared between treatments. Leaves exposed to early warming emerged earlier than those in the late treatment. Bud break happened closer to date of exposure to warming in the late treatment than in the early treatment. Spring ephemerals may be able to produce leaves early in response to early spring warming induced by climate change. Risk of late frost and eventual shading by the canopy may limit the duration of a potentially extended growing season.