WHICH CANOPY TIER SHOULD BE SAMPLED TO DETERMINE THE FERTILITY (NUTRITIONAL) STATUS OF ACACIA MANGIUM ON BRIS SOILS?

Abstract

Foliar elemental levels, determined in different canopy tiers of Acacia mangium growing on two different soil types, were compared with soil textural and chemical data. Foliage of trees growing on relatively fertile Jambu soils had higher elemental concentrations than
those growing on nutrient impoverished Rhudua soils. On both soil types, foliar elemental levels differed in the different canopy tiers, but their distributions among tiers did not conform with observed patterns in other taxa. It is recommended that for an evaluation of the fertility status of A. mangium, the lower tier of sun-exposed foliage should be sampled for N and P levels and the top tier for other elemental levels.