COMPETITION AMONG LATE·SUCCESSIONAL TREE SPECIES ACROSS DIFFERENT TOPOGRAPHIC POSITIONS OF A SRI LANKAN RAIN FOREST.

Abstract

The plant height growth, canopy expansion and foliar nutrients allocations provide theevidence to understand competitive role by canopy species in part of light and soilmoisture gradient. Experiments were designed to investigate competitive outcomes ofnine late-succesional tree seedlings in different light and soil moisture regimes. Treespecies were planted in the canopy gap and forest understory in different topographicpositions; valley, midslope and ridgetop. At the end of every year height, root collardiameter, leaf number and mortality were recorded. Results showed that Shoreatrapezifolia and Syzygium rubicundum can be regarded as the most light demandingspecies with competitive superiors as judged from its height increment, leaf and branchesincrements with crown structure, root collar diameter and leaf nutrients allocatingpattern. At other extremes are Mesua ferrea and Shorea worthingtonii, most which arethe most, shade tolerant and with lower competitive ability in this group. Patterns incompetitive hierarchy among late successional canopy species strongly support sitespecialisation and establishment of regeneration