title: Spatial distribution patterns of trees at different life stages in a warm temperate forest.
abstract: We have investigated tree distributions in relation to topography between different tree life history stages, from the seed-dispersal stage to the adult stage in a warm temperate evergreen broadleaved forest on Yakushima Island, Japan, to clarify the critical stages in determining adult tree distributions. We conducted a census of all living trees > or =30 cm tall and collected seed falls over three years using 25 seed traps in a 50 m x 50 m quadrat. Four life stages were defined: stage 1, dispersed seed; stage 2, individuals taller than 30 cm and diameter at breast height (DBH) < 1 cm; stage 3, trunks 1 cm < or = DBH < 10 cm; stage 4, trunks with DBH > or = 10 cm. We classified 17 common tree species into three groups; group A was distributed mainly on the upper slope, group B on the lower slope, and group C on both. Most of group A and B trees at stages 2-4 showed an aggregated distribution along the topographical gradient. The densities at stage 1 showed weaker aggregations according to slope. Topography-specific tree distribution was probably determined at the regeneration stage, and later survival was less effective as a mechanism of vegetation differentiation.
authors: Research Institute for Humanity and Nature, 457-4, Motoyama, Kamigamo, Kita-ku, Kyoto, 603-8047, Japan. turi@chikyu.ac.jp
authors: Riyou
authors: R
authors: Tsujino
authors: Takakazu
authors: T
authors: Yumoto
mesh_terms: D000531:Altitude; D017753:Ecosystem; D005843:Geography; D007564:Japan; D012639:Seeds; D014197:Trees / Q000254:growth & development*
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references: 11027481
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references: 4859903