01989naa a2200217 a 450000100080000000500110000800800410001910000190006024501490007926000090022852012770023765000120151465300250152665300290155165300150158065300220159565300140161770000230163170000200165477300970167416626132011-05-23       2009    bl uuuu     u00u1 u    #d1 aRONQUIM, C. C.  aGrowth, photosynthesis and leaf water potential in young plants of Copaifera langsdorffii Desf. (Caesalpiniaceae) under contrasting irradiances.  c2009  aGrowth and leaf nutrient content were compared in young potted plants of Copaifera langsdorffii in sunny and shaded areas without water stress. Besides, carbon assimilation and leaf water relations were evaluated by net photosynthesis, potential photochemical efficiency and water potential during dally courses in dry and rainy periods under natural conditions in both contrasting irradiances. Higher values of total biomass, height and leaf area occurred in sunny than in shaded area. On the other hand, all young plants survived in shade under natural water stress probably by reason of fast and intense biomass accumulation in favor of roots in early development. There was no significant difference about nutrient concentration in leaves between plnats growing in sunny and shaded areas. Net photosynthesis in shade increased occasionally when bunches of direct light reached the leaves. Theses sunflecks took place more frequently and high intensity in dry period but they were more effective for net photosynthesis in rainy period. The ability of young plants to persist under natural conditions in contrasting irradiance up to 1,230 days after sowing could explain the wide distribution of C. langsdorffii in Cerrado physiognomies and in different types of forest.  aCerrado  aBiomass partitioning  aChlorophyll fluorescense  aIrradiance  aLeaf gas exchange  aSunflecks1 aPRADO, H. B. A. P.1 aSOUZA, J. P. de  tBrazilian Journal of Plant Physiology, Campos dos Goytacazesgv. 21, n. 3, p. 197-208, 2009.