Magnitudes and Mechanisms of Shoot-damage Compensation in Annual Species of Linum (Linaceae) in Iowa

Abstract

ABSTRACT The effect of shoot damage on plant performance depends partly on a plant's ability to recover by growth compensation. Plant populations in tallgrass prairie likely experience, or historically experienced, high risks of damage and therefore might be expected to have evolved significant compensation ability. We investigated shoot damage and subsequent growth compensation in Iowa populations of the annuals Linum rigidum and L. sulcatum. To estimate damage rate and responses to damage under natural conditions, we collected two data sets. The first consisted of over 200 herbarium specimens collected over a 113-y period and the second consisted of field data for four populations in the same growing season. A companion experiment investigated damage responses under controlled greenhouse conditions and identified possible mechanisms of compensation. The study species frequently experience apical meristem removal in nature. Per-individual damage-rate estimates ranged from 33–54% in L. rigidum and from 12...