© 2006 Heron Publishing—Victoria, Canada
Selecting earlywood vessels to maximize their environmental signal
Ignacio García-González (1, 2) and Patrick Fonti (3)
1. Departamento de Botánica, Universidade de Santiago de Compostela, Escola Politécnica Superior, Campus de Lugo, E-27002 Lugo,
Spain / 2. Corresponding author (bvluigg@lugo.usc.es) / 3. WSL, Sottostazione Sud delle Alpi, Via Belsoggiorno 22, CH-6504 Bellinzona-Ravecchia, Switzerland / Received March 15, 2005; accepted December 19, 2005; published online June 30, 2006
Summary
The anatomical features of earlywood vessels often reflect information about past climatic conditions. We examined the relationships
between mean monthly temperature and mean vessel lumen area (MVA) in various categories of earlywood vessels. Subsets of earlywood
vessels of chestnut (Castanea sativa Mill.) were selected from a previously reported dataset based on several progressive size-related procedures. To include
all earlywood vessels, the minimum size considered was 10,000 µm2. Changes in the correlations between MVA and the mean air temperature in March are described and discussed. The results show
that not all vessels embody the same information. The MVA of a proportion of the largest earlywood vessels in each annual
ring was most closely related to March temperature, whereas MVA of the smallest earlywood vessels was better correlated with
June temperature. This difference is probably a result of the vessels being formed at different times: early spring for the
largest earlywood vessels and later in spring for the smallest earlywood vessels. Analyses combining large and small vessels
yielded lower correlations between MVA and monthly temperature. The number, size and distribution of vessels can vary greatly
from ring to ring. In making year-to-year comparisons, the best information is provided by observations on vessels of contemporaneous
ontogenesis. Criteria for the selection and analysis of vessels in the assessment of temperature during the season of wood
formation are proposed and discussed.
Keywords:
Castanea sativa, dendrochronology, dendroecology, ring-porous, tree rings, vessel size.
