Effects of waves on the early growth of Vallisneria americana

Publisher Website
Google Scholar
Abstract
1. The impacts of 0.15‐m waves on the survival and short‐term growth and development of young Vallisneria americana plants were studied in experimental raceways. Young plants were planted at three depths within both wave and control raceways. Wave events were designed to simulate wave disturbances caused by boat traffic and were generated five or six times each day during the 67‐day experimental growth period. The 0.15‐m waves generated produced a maximum shear velocity of about 1.4 m s−1 as they swept over the plants. 2. All plants survived at all depths in both treatments. However, plants exposed to the waves accumulated significantly less total mass than controls. The total mass accumulation of wave‐exposed plants was only 50% of that of undisturbed plants. In addition, the plants experiencing the waves had significantly shorter leaves and produced significantly fewer daughter plants. 3. While plants under both wave and no wave treatments had a similar relative growth rate and both showed a net positive growth over the experimental period, those exposed to frequent wave energy developed more slowly due to continuous leaf loss caused by the waves. Plants exposed to even modest wave energy may spread more slowly and be less resilient to recovery from other forms of disturbance.