A plastochrone method for measuring leaf growth in eelgrass, Zostera marina L
Eelgrass, Zostera marina L., leaf growth measurement methods were investigated and compared in New Hampshire and Maine, USA. The commonly used leaf marking method, developed by Zieman (1974) and embraced by Dennison (1990), was found to underestimate leaf growth, particularly when measured over small time intervals, compared to a method developed by Short (1987) based on the weight of mature leaf tissue. Short's method (1987) was then compared to a modification of the plastochrone interval method of Jacobs (1979), giving very similar results. In our plastochrone method, leaf growth is calculated as the weight of a mature leaf divided by the time interval between initiation of two successive leaves on one shoot, the plastochrone interval. Our investigations demonstrate that the leaf plastochrone interval in eelgrass varies seasonally; to use the plastochrone method, the plastochrone interval must be measured for each growth determination. Based on our comparisons, we recommend what we call the 'plastochrone method' as a more efficient and accurate way to measure eelgrass leaf growth.
Bulletin of Marine Science
Gaeckle, J.L. and F.T. Short. 2003. A plastochrone method for measuring leaf growth in eelgrass, Zostera marina L. Bulletin of Marine Science 71:1237-1246.