TY  - JOUR
AU  - Bosc, A.
AU  - De Grandcourt, A.
AU  - Loustau, D.
PY  - 2003//
TI  - Variability of stem and branch maintenance respiration in a Pinus pinaster tree
T2  - Tree Physiol.
JO  - Tree Physiology
SP  - 227
EP  - 236
VL  - 23
IS  - 4
PB  - HERON PUBLISHING
KW  - model
KW  - nitrogen
KW  - phloem
KW  - sapwood
KW  - temperature
N2  - The relationship between maintenance respiration (R.) of woody organs and their structural characteristics was explored in adult Pinus pinaster Ait. trees. We measured R-m on 75 stem and branch segments of different ages (from 3 to 24 years) and diameters (from 1 to 35 cm). The temperature response of R-m was derived from field measurements based on a classical exponential function with Q(10) = 2.13. Relationships between R-m and the dimensions of the woody organs were analyzed under controlled conditions in the laboratory. The surface area of a woody organ was a better predictor of R-m than volume, but surface area failed to account for the observed within-tree variability of R-m among stems, branches and twigs. Two simple models were proposed to predict the variability of R-m at 15 degreesC in an adult tree. Model 1, a linear function model based on the dry mass and nitrogen concentration of sapwood and phloem tissues, explained most of the variability of R-m in branches and stems (R-2 = 0.97). We concluded that the respective contributions of the phloem and sapwood depend on the location and diameter of the woody organ. Model 2, a power-law function model based on the length, diameter and age of the sample, explained the same variance of R-m as Model 1 and is appropriate for scaling R-m to the stand level. Models 1 and 2 appear to explain a larger variability of R-m than models based on stem area or sapwood mass.
SN  - 0829-318X
N1  - ISI:000181841200002
ID  - Bosc_etal2003
ER  -