ALLOMETRIC RELATIONSHIPS FOR BIOMASS AND LEAF-AREA OF BEECH (FAGUS-SYLVATICA L)

The objectives of this study were i) to establish allometric relations hips among stem and crown dimensions, biomass, and leaf area, ii) to d etermine the relative aboveground biomass distribution, iii) to quanti fy the relationship between leaf area and the water-conducting cross-s ectional stem area, iv) to determine the vertical gradient of the spec ific leaf area (SLA) and v) to estimate aboveground stand biomass and leaf area index (LAI). Thirty-eight trees were sampled, ranging in age from 8-59 years. Tree biomass amounts increased with increasing diame ter at breast height (dbh). Nonlinear models on dbh explained more tha n 90% of the biomass variance; regressions improved when tree height w as used as well. Crown dimensions increased with stem size. A linear r elationship was found between basal area and crown length. Crown proje ction area was nonlinearly related to leaf area and crown biomass. The fraction of dry matter present in the stem generally increased with t ree biomass, but differently for trees from different diameter classes . The ratio between leaf and branch biomass decreased significantly wi th increasing tree size. The ratio between leaf biomass and leaf area (SLA) was relatively constant for whole trees, amounting on average to 172 cm(-2) g(-1). SLA generally increased from the tree top down to t he crown base; this pattern did not significantly differ among trees w ithin a stand. The rate of change decreased with decreasing canopy clo sure. A strong linear relationship existed between leaf area and sapwo od area: the ratio was affected by the height of the crown base. Above ground stand biomass ranged from 6 to 167 ton ha(-1), and increased li nearly with stand age. LAI reached a maximum of seven; the leveling of f was ascribed to self-thinning.