V. Dvorak et al., RELATION BETWEEN LEAF BIOMASS AND ANNUAL RING SAPWOOD OF NORWAY SPRUCE ACCORDING TO NEEDLE AGE-CLASS, Canadian journal of forest research, 26(10), 1996, pp. 1822-1827
The relationship between leaf biomass and sapwood area was investigate
d in a 35-year-old Norway spruce (Picea abies (L.) Karst.) stand in mo
untainous conditions. Fifteen trees were destructively sampled to dete
rmine the needle biomass in several needle age-classes and whorls and
the corresponding sapwood areas at the whorl branch bases and in stems
at breast height. Leaf biomass/sapwood area ratio and specific leaf b
iomass (g . mm(-2)) were calculated for different needle age-classes a
nd also for different positions in the vertical profile of the crown.
The leaf biomass/sapwood area ratios were described by linear regressi
on with a high coefficient of determination. Specific leaf biomass ana
lysed in whorl branches was highest in the upper whorls but was decrea
sing downward through the profile; remained stable in the middle crown
layer; and decreased again in the lower crown parts. Specific leaf bi
omass assessments for stems showed the largest and most increasing val
ues in the youngest three needle age-classes followed by a decreasing
trend of the specific leaf biomass in older needle age-classes. The me
an values of specific leaf biomass were 1.08 g . mm(-2) for branches a
nd 1.02 g . mm(-2) for stems. The results of our study are consistent
with the ''pipe model theory.''