Use of a video-imaging system for estimating leaf surface area of Pinussylvestris seedlings
A method is described for a rapid, nondestructive estimation of the surface area of the shoot system of intact pine seedlings. A video camera and image analyzer were used to quantify the area of a video image of pine seedling shoots. Surface area values were displayed in dimensionless units, referred to as silhouette area. Silhouette area was significantly correlated with several other methods of estimating needle surface area, including dry weight, calculation based on measurement of linear dimensions, volume displacement, and optical planimetry. Correspondence between dry weight, or surface area estimates based on dry weight, and silhouette area was relatively low (r2 < 0.9) but statistically significant. The correlation between shoot area and silhouette area were improved (r2 > 0.9) when shoot area was estimated from volume displacement or optical planimetry.