TAILIEUCHUNG - Báo cáo khoa học: "Allometric relationships for biomass and leaf area of beech (Fagus sylvatica L)"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Allometric relationships for biomass and leaf area of beech (Fagus sylvatica L). | Ann Sci For 1997 54 39-50 Elsevier INRA 39 Original article Allometric relationships for biomass and leaf area of beech Fagus sylvatica L HH Bartelink Wageningen Agricultural University Department of Forestry PO Box 342 6700 AH Wageningen the Netherlands Received 13 September 1995 accepted 26 February 1996 Summary - The objectives of this study were i to establish allometric relationships among stem and crown dimensions biomass and leaf area ii to determine the relative aboveground biomass distribution iii to quantify the relationship between leaf area and the waterconducting cross-sectional stem area iv to determine the vertical gradient of the specific 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 diameter at breast height dbh . Nonlinear models on dbh explained more than 90 of the biomass variance regressions improved when tree height was used as well. Crown dimensions increased with stem size. A linear relationship was found between basal area and crown length. Crown projection area was nonlinearly related to leaf area and crown biomass. The fraction of dry matter present in the stem generally increased with tree biomass but differently for trees from different diameter classes. The ratio between leaf and branch biomass decreased significantly with increasing tree size. The ratio between leaf biomass and leaf area SLA was relatively constant for whole trees amounting on average to 172 cm2 g- . SLA generally increased from the tree top down to the crown base this pattern did not significantly differ among trees within a stand. The rate of change decreased with decreasing canopy closure. A strong linear relationship existed between leaf area and sapwood area the ratio was affected by the height of the crown base. Aboveground stand biomass ranged from 6 to 167 ton ha-1 and increased linearly with stand age. LAI .

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