TY - JOUR
T1 - The increase of atmospheric CO2 affects growth potential and intrinsic water-use efficiency of Norway spruce forests
T2 - insights from a multi-stable isotope analysis in tree rings of two Alpine chronosequences
AU - Giammarchi, Francesco
AU - Cherubini, Paolo
AU - Pretzsch, Hans
AU - Tonon, Giustino
N1 - Publisher Copyright:
© 2016, Springer-Verlag Berlin Heidelberg.
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Key message: Relevant CO2increase affects iWUE and growth potential of Alpine Norway spruce forests due to triggering of photosynthetic capacity. Minor effect on iWUE of tree size/age ontogenetic factors. Abstract: An increase in European forest productivity has been widely reported, but evidences on its causal relationship with climate change are still scarce, though they are crucial to understand the mitigation potential of forests and their future dynamics. In the present study, we first assessed the changes in forest productivity of two even-aged Norway spruce forests. Consequently, we investigated the role of several environmental drivers, such as atmospheric CO2 levels, temperature, and precipitation regimes on the intrinsic water-use efficiency (iWUE) temporal patterns of the above-mentioned forests. We applied a chronosequence approach, combining it with a multi-stable isotope analysis, including δ13C and δ18O, to infer tree responses to climate change over time in terms of iWUE changes. By this innovative methodology, we were able to separate environmental and age/size-related factors on iWUE changes. Results showed an increase in forest productivity in both sites, paralleled by a significant increase of iWUE, mainly triggered by a CO2-driven increase in photosynthetic capacity, rather than by a reduction of stomatal conductance. The paramount role of the increase in photosynthetic capacity was confirmed by a strong correlation between atmospheric CO2 concentration and iWUE temporal patterns. The effect of size/age of trees on iWUE temporal changes resulted to be less defining than that of climate change.
AB - Key message: Relevant CO2increase affects iWUE and growth potential of Alpine Norway spruce forests due to triggering of photosynthetic capacity. Minor effect on iWUE of tree size/age ontogenetic factors. Abstract: An increase in European forest productivity has been widely reported, but evidences on its causal relationship with climate change are still scarce, though they are crucial to understand the mitigation potential of forests and their future dynamics. In the present study, we first assessed the changes in forest productivity of two even-aged Norway spruce forests. Consequently, we investigated the role of several environmental drivers, such as atmospheric CO2 levels, temperature, and precipitation regimes on the intrinsic water-use efficiency (iWUE) temporal patterns of the above-mentioned forests. We applied a chronosequence approach, combining it with a multi-stable isotope analysis, including δ13C and δ18O, to infer tree responses to climate change over time in terms of iWUE changes. By this innovative methodology, we were able to separate environmental and age/size-related factors on iWUE changes. Results showed an increase in forest productivity in both sites, paralleled by a significant increase of iWUE, mainly triggered by a CO2-driven increase in photosynthetic capacity, rather than by a reduction of stomatal conductance. The paramount role of the increase in photosynthetic capacity was confirmed by a strong correlation between atmospheric CO2 concentration and iWUE temporal patterns. The effect of size/age of trees on iWUE temporal changes resulted to be less defining than that of climate change.
KW - CO increase
KW - Chronosequence
KW - Forest productivity
KW - Stable isotopes
KW - Tree size
KW - Water-use efficiency
UR - http://www.scopus.com/inward/record.url?scp=84991080360&partnerID=8YFLogxK
U2 - 10.1007/s00468-016-1478-2
DO - 10.1007/s00468-016-1478-2
M3 - Article
AN - SCOPUS:84991080360
SN - 0931-1890
VL - 31
SP - 503
EP - 515
JO - Trees - Structure and Function
JF - Trees - Structure and Function
IS - 2
ER -