Early growth and yield of Albizia lebbeck at a coastal site in Puerto Rico.
Experimental plots of Albizia lebbeck [A. lebbek] were established in November 1984 at a northern coastal site in Puerto Rico on well drained, moderately alkaline (pH 7.9-8.4) soil low in organic matter and several macronutrients. The planting stock was 3-month-old seedlings produced from local seed from a single parent tree. There were 3 spacings, 0.5 × 0.5 m, 1.0 × 1.0 m and 2.0 × 2.0 m (corresponding, respectively, to 40 000, 10 000 and 2500 stems/ha). Six-monthly growth (height, diameter, crown width and depth) and biomass measurements are reported to 36 month old. Trees grown at high density were considerably smaller than those grown at wider spacings. Respective mean measurements at 36 month old, for low, medium and high densities, were: height, 4.35, 3.73 and 2.37 m; and stem basal diameter 7.52, 4.90 and 2.58 cm. While the individual tree growth rates were inversely related to tree density, values for biomass increased with density, up to 24 month old, after which the growth of the high density planting slowed considerably. The percentage of the above-ground biomass in the foliage increased with density.