Foliage Attributes for Current-year Shoots of Fraser Fir

Abstract

Current-year shoots of Fraser fir [Abies fraseri (Pursh) Poir.] were sampled in Christmas tree plantations in western North Carolina. Needles were sampled at five positions on each shoot: 0% (proximal end), 25%, 50%, 75%, and 100% (distal end). At each position, needles were collected in a tight left-hand spiral beginning on the abaxial side (bottom) and ending on the adaxial side (top). Length, width, thickness, dry weight, and projected surface area were determined for each needle. Specific area (one-sided) averaged 45 cm2·g-1 and increased from the shoot base to the tip. On individual shoots, needle dimensions were maximal at the middle (50% position). Within sample positions, needle dimensions increased from the adaxial to the abaxial side. Needle length, weight, and area differed more than width or thickness by position. Needle surface area per centimeter of shoot was relatively stable. Regression models using shoot length, diameter, needle density, and average needle length or weight yielded good estimates of total foliage area and weight.