A SHADING EXPERIMENT ON SOME TROPICAL RAIN FOREST TREE SEEDLINGS

Abstract

The growth of potted seedlings of Shorea curtisii, Shorea macroptera and Gluta curtisii was compared between three shade conditions. The treatments provided circa 1, 6 and 12% full sun photosynthetically active radiation (PAR) and altered the quality as well as the quantity of solar radiation reaching the plants, in order to simulate natural forest situations. All the species showed increased growth with increasing PAR. The two Shorea species grew better than G. curtisii in all the treatments. Whilst S. curtisii grew significantly better than S. macroptera in the 1 and 5% full sun treatments, the latter grew comparatively better in 12% full sun. This indicates that S. curtisii is more shade tolerant than S. macroptera.