TY - JOUR
T1 - Plant size, not age, regulates growth and gas exchange in grafted Scots pine trees
AU - Vanderklein, D.
AU - Martínez-Vilalta, J.
AU - Lee, S.
AU - Mencuccini, M.
PY - 2007/1
Y1 - 2007/1
N2 - We studied the effect of scion donor-tree age on the physiology and growth of 6- to 7-year-old grafted Scots pine (Pinus sylvestris L.) trees (4 and 5 years after grafting). Physiological measurements included photosynthethetic rate, stomatal conductance, transpiration, whole plant hydraulic conductance, needle nitrogen concentration and carbon isotope composition. Growth measurements included total and component biomasses, relative growth rates and growth efficiency. Scion donor trees ranged in age from 36 to 269 years at the time of grafting. Hydraulic conductance was measured gravimetrically, applying the Ohm's law analogy, and directly, with a high-pressure flow meter. We found no effect of scion donor-tree age on any of the variables measured. There was, however, great variation within scion donor-tree age groups, which was related to the size of the grafted trees. Differences in size may have been caused by variable initial grafting success, but there was no indication that grafting success and age were related. At the stem level, hydraulic conductance scaled with total leaf area so that total conductance per unit leaf area did not vary with crown size. However, leaf specific hydraulic conduc-tance (gravimetric), transpiration, photosynthesis and stomatal conductance declined with increasing total tree leaf area and needle width. We hypothesize that needle width is inversely re-lated to mesophyll conductance. We conclude that canopy and needle size and not scion donor-tree age determined gas ex-change in our grafted trees.
AB - We studied the effect of scion donor-tree age on the physiology and growth of 6- to 7-year-old grafted Scots pine (Pinus sylvestris L.) trees (4 and 5 years after grafting). Physiological measurements included photosynthethetic rate, stomatal conductance, transpiration, whole plant hydraulic conductance, needle nitrogen concentration and carbon isotope composition. Growth measurements included total and component biomasses, relative growth rates and growth efficiency. Scion donor trees ranged in age from 36 to 269 years at the time of grafting. Hydraulic conductance was measured gravimetrically, applying the Ohm's law analogy, and directly, with a high-pressure flow meter. We found no effect of scion donor-tree age on any of the variables measured. There was, however, great variation within scion donor-tree age groups, which was related to the size of the grafted trees. Differences in size may have been caused by variable initial grafting success, but there was no indication that grafting success and age were related. At the stem level, hydraulic conductance scaled with total leaf area so that total conductance per unit leaf area did not vary with crown size. However, leaf specific hydraulic conduc-tance (gravimetric), transpiration, photosynthesis and stomatal conductance declined with increasing total tree leaf area and needle width. We hypothesize that needle width is inversely re-lated to mesophyll conductance. We conclude that canopy and needle size and not scion donor-tree age determined gas ex-change in our grafted trees.
KW - Aging
KW - Caledonian pine
KW - Crown size
KW - Hydraulic limitation
KW - Leaf specific conductance
KW - Leaf-level adjustment
KW - Pinus sylvestris
UR - http://www.scopus.com/inward/record.url?scp=33846888528&partnerID=8YFLogxK
U2 - 10.1093/treephys/27.1.71
DO - 10.1093/treephys/27.1.71
M3 - Article
C2 - 17169908
AN - SCOPUS:33846888528
SN - 0829-318X
VL - 27
SP - 71
EP - 79
JO - Tree Physiology
JF - Tree Physiology
IS - 1
ER -