O. Eckmullner et H. Sterba, Crown condition, needle mass, and sapwood area relationships of Norway spruce (Picea abies), CAN J FORES, 30(10), 2000, pp. 1646-1654
Citations number
47
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
Crown-condition assessment, hypothesized to estimate needle losses followin
g damage from several sources, one of which might be air pollution, suffers
from the subjective notion of a standard "healthy" tree. On the other hand
, the foliage biomass - sapwood area ratios are reported to depend on a num
ber of factors, e.g., site quality, stand density, crown class, and tree ri
ng width conductivity. The authors hypothesize that early sapwood area migh
t help to even better estimate needle biomass of Norway spruce (Picea abies
(L.) Karst.) and to help standardize crown-condition assessment. Thirty-si
x Norway spruce trees at two Austrian sites, from three age-classes, three
crown classes, and two crown-condition classes were felled. Needle mass, cr
oss-sectional area, sapwood area, and early sapwood area (i.e., sapwood are
a excluding latewood) were measured. The results of this study indicate tha
t indeed early sapwood area is a good estimator of foliage, independent of
site, age, crown class, and crown condition. The ratio between early sapwoo
d area and cross-sectional area could be a good estimator for crown conditi
on and thus help to standardize crown-condition assessments by different su
rveyors.