Abstract:Seedling growth of 42 woody species of subtropical forests in Guangdong Province was studied in relation to their ecological characteristics， growt h forms and seed weight． Seedlings of tree species had significantly higher stem and greater stem biomass than those of shrub species under high light(H，66．8 μmol m-2s-1)，but not low light intensity(L，33．7 μmol m-2s-1)．There was no significant diference among heliophilic species,shade-tolerant species and intermediate light-demanding species in stem height and stem biomass．Tree seedlings had more leaf area and leaf biomass per plant than shrub seedlings，but the latter had more leaves．Diference in leaf number and leaf area was generally not obvious between large-seeded and small-seeded species，and betw een diferent types of species based on light demand．Seedlings of heliophilic species had more lateral roots than those of shade-tolerant species．Seedlings of tree species had significantly greater root biomass and higher root／shoot ratio of biomass than those of shrub species．Seedlings of heliophilic species had also higher root／shoot ratio than those of shade-tolerant species under H as compared with L condition．Root biomass was sign ificantly positively correlated with seed weight for 45 d seedlings in both H and L light,but not for 90 d seedlings．Very significant linear correlation between seedling biomass and seed weight was found for 45 d seedlings under both H and L lightconditions，but not significant for 90 d seedlings under H light condition．Tree seedlings had significantly greater biomass per plant than shrub seedlings．Relative growt h rate and leaf area ratio of seedlings were foun d to be in order of heliophillc species>intermediate light-demanding species>shade-tolerant species，and there were significant difference between heliophilic species and shade-tolerant species．Difference in unit leaf rate was not significant among species ofvarious light-demanding types．
