Rolland C., Schweingruber F.H. (1999). Influence of species and abiotic
factors on extreme tree ring modulation: Picea abies and Abies alba in
Tarentaise and Maurienne (French Alps). Trees, Structure and Function 13:
- TITLE Influence of species and abiotic
factors on extreme tree ring modulation: Picea abies and Abies
alba in Tarentaise and Maurienne (French Alps)
- LANGUAGE English , with English abstract.
- SPECIES Abies alba Mill., Picea
abies (L.) Karst.
- KEY WORDS Silver fir, Norway spruce,
Dendroecology, Pointer years.
- MOTS CLES Sapin, Epicéa, Dendroécologie,
- SITES Tarentaise, Maurienne (France).
- ABSTRACT (English)
The influence of biotic (tree species) and abiotic factors (regional climate,
altitude and stand aspect) on extreme tree-ring widths was dendroecologically
investigated. Negative pointer years are observed when abrupt radial growth
reductions (exceeding 40%r) occurred synchronously in a given tree population.
Pointer year intensity is expected to follow several theoretical models when
tree are sampled along ecological gradients in various site conditions.
Hypotheses are made about expected patterns of pointer year spatial
distribution. They are compared with observed results obtained with Norway
spruce [Picea abies (L.) Karst.] and silver fir (Abies alba Mill.)
sampled in two French Alpine valleys (Tarentaise and Maurienne) with different
regiona1 climates, on two aspects and three altitude levels. Results reveal
that extreme years follow expected patterns well. Thus, clear site modulations
are observed in 1956 and 1986 (only trees located in Maurienne reacted).
Moreover, species differences are observed, with typical cases of single
species sensitivity (for spruce, occurring in 1962 and 1992). Abiotic factors
such as altitude and aspect also involve clear pointer year patterns, such as
narrow rings in 1976 due to summer drought that occurred especially at lower
altitudes. However, some observed extreme years sometimes appear to be a
combination of two (or three) of these one-factor theoretical models (e.g.
1921 with both lower altitude level and only observed in Tarentaise; l948
involving both higher altitude and northern slopes). These results demonstrate
the consistency of various tree-ring and climate relationships along