title: Leaf characteristics and chlorophyll concentration of Schyzolobium parahybum and Hymenaea stilbocarpa seedlings grown in different light regimes.
abstract: Light in the understory of a forest varies not only with season and solar elevation but also with vegetation dynamics. Seedlings of Schyzolobium parahybum (Vell) Blake, a fast-growing pioneer species, and Hymenaea stilbocarpa L., a slow-growing shade-tolerant species, were grown in pots for 90 days in a forest canopy gap (full sunlight) or in semi-shade (about 44% of full sunlight) beneath the canopy of a secondary forest. Both sites were located in Itaguai, RJ State, Brazil. Subsequently, half the seedlings grown in the canopy gap were moved to semi-shade and half the seedlings grown in semi- shade were moved to the canopy gap. After a further 90 days, seedling dry weight, height, leaf area, specific leaf area, leaf area ratio and concentration of chlorophyll a and b were measured. In response to increased irradiance, Schyzolobium parahybum responded by producing more leaf area, whereas Hymenaea stilbocarpa responded by increasing leaf mass per unit area and chlorophyll a concentration.
authors.affiliation: UNIOESTE-Centro de Ciencias Agrarias, Rua Pernambuco 1777, 85960-000 Mal.Cândido Rondon, PR Brazil.
authors.forename: U C
authors.initials: UC
authors.lastname: Malavasi
authors.forename: M M
authors.initials: MM
authors.lastname: Malavasi
mesh_terms: D029911:Caesalpinia / Q000502:physiology*; D002734:Chlorophyll / Q000032:analysis*; D008027:Light; D018515:Plant Leaves / Q000737:chemistry / Q000502:physiology*; D019685:Rosales / Q000502:physiology*; D014197:Trees / Q000502:physiology*
chemical_list: D002734:Chlorophyll