Morphological causes for the retention of precipitation in the crowns of alpine plants

Studies were conducted on 27 species of alpine plants to test the hypothesis that structural characteristics of leaves have a predictable influence on the amount of moisture retained by a plant crown following a simulated rain event. The retention of precipitation in crowns has been previously demonstrated as one factor potentially contributing to the direct effects of acid rain on alpine plants. The results of this study demonstrate that a significant share of the amount of water retained could be explained by general structural features of leaves and flowers common to all the diverse taxa studied. Water retained per unit leaf area was best explained by pubescence rank, number of leaves, petiole base width, flower mass, flower wettability and petiole base angle. Water retained per unit mass was best explained by pubescence ranking, number of leaves, petiole base width, leaf area, flower wettability, flower mass and number of flowers.