Soil Compaction Causes Erythronium americanum(Liliaceae) to Produce Aboveground Droppers.

Erythronium americanum (trout lily) is a common spring ephemeral in the deciduous forests of the northeastern United States. Toward the end of its growing season in late spring, senescing corms produce a dropper (modified rhizome) to reposition one or more new corms within the soil profile. These droppers usually place the new corms deeper in the soil than the senescing corm, but occasionally and near hiking trails, the dropper goes aboveground. This study addressed the cause of this aboveground pattern. When corms were grown experimentally in compacted soil and drought conditions, only the compacted soil resulted in shallower droppers than the control. In a descriptive field study, aboveground droppers were significantly more common near trails where soil was more compacted than away from the trail. The results of this study suggest that soil compaction associated with hiking trails causes droppers to be shallower than away from the trail. This pattern may reduce survivorship and asexual reproduction in populations of E. americanum near hiking trails. [ABSTRACT FROM AUTHOR]