RELATIONSHIP BETWEEN TOPOGRAPHY AND SOIL PROPERTIES IN A HILL DIPTEROCARP FOREST DOMINATED BY <em>SHOREA</em> <em>CURTISII</em> AT SEMANGKOK FOREST RESERVE, PENINSULAR MALAYSIA

Abstract

To obtain a better understanding of major tree species distribution in a hill dipterocarp forest, differences in soil properties and in topographical conditions were studied in the Semangkok Forest Reserve, Peninsular Malaysia, where Shorea curtisii was the dominant tree species on the ridges. The differences in nutrient status of S. curtisii saplings by topography were also examined. Shorea curtisii was absent in the valleys where the soil horizons with mottles of iron indicated the presence of seasonal anaerobic soil conditions. The soft soil was thin on ridges and convex slopes where S. curtisii was dominantly distributed. Differences in chemical properties of soil by topography were characterised by the surface soil. Surface soil with low pH, high contents of carbon, nitrogen and available phosphoric acid and high C-N ratio were distributed on the ridges and convex slopes. The soil acidity tended to increase as the C-N ratio increased. Differences in soil chemical properties by topography appeared to be strongly influenced by environmental conditions such as litter decomposition and soil moisture regime. As foliar nutrient contents of S. curtisii saplings did not differ with topography, the nutrient status of S. curtisii seemed to be little influenced by soil chemical properties.