TY - JOUR
T1 - Ecological implications of xylem cavitation for several Pinaceae in the Pacific Northern USA
AU - Piñol, J.
AU - Sala, A.
PY - 2000
Y1 - 2000
N2 - 1. Xylem hydraulic properties and vulnerability to cavitation (determined using the air-injection method) were studied in six Pinaceae of the northern Rocky Mountains: Pinus ponderosa, Pseudotsuga menziesii, Larix occidentalis, Pinus contorta, Pinus albicaulis and Abies lasiocarpa. We tested whether species extending into drier habitats exhibited increased resistance to water stress-induced cavitation, and whether there is a trade-off between xylem transport capacity and resistance to cavitation. 2. At lower elevations the more drought-tolerant P. ponderosa was much less resistant to cavitation than the codominant P. menziesii. Greater vulnerability to cavitation in P. ponderosa was compensated for, at least in part, by increased stomatal control of water loss (inferred from carbon isotope discrimination) and by increased sapwood to leaf area ratios. Similar differences, but less pronounced, were found in codominant species at higher elevations. 3. Leaf specific hydraulic conductivity was negatively correlated with mean cavitation pressure. When species were separated into pines and non-pines, sapwood specific conductivity and mean cavitation pressure were also negatively correlated within each of the two groups. 4. Our results indicate that within the evergreen conifers examined, greater resistance to water stress-induced cavitation is not required for survival in more xeric habitats, and that there is a trade-off between xylem conductance and resistance to cavitation.
AB - 1. Xylem hydraulic properties and vulnerability to cavitation (determined using the air-injection method) were studied in six Pinaceae of the northern Rocky Mountains: Pinus ponderosa, Pseudotsuga menziesii, Larix occidentalis, Pinus contorta, Pinus albicaulis and Abies lasiocarpa. We tested whether species extending into drier habitats exhibited increased resistance to water stress-induced cavitation, and whether there is a trade-off between xylem transport capacity and resistance to cavitation. 2. At lower elevations the more drought-tolerant P. ponderosa was much less resistant to cavitation than the codominant P. menziesii. Greater vulnerability to cavitation in P. ponderosa was compensated for, at least in part, by increased stomatal control of water loss (inferred from carbon isotope discrimination) and by increased sapwood to leaf area ratios. Similar differences, but less pronounced, were found in codominant species at higher elevations. 3. Leaf specific hydraulic conductivity was negatively correlated with mean cavitation pressure. When species were separated into pines and non-pines, sapwood specific conductivity and mean cavitation pressure were also negatively correlated within each of the two groups. 4. Our results indicate that within the evergreen conifers examined, greater resistance to water stress-induced cavitation is not required for survival in more xeric habitats, and that there is a trade-off between xylem conductance and resistance to cavitation.
KW - Drought tolerance
KW - Hydraulic conductance
KW - Montane conifers
KW - Sapwood to leaf area ratio
KW - Xylem cavitation
UR - http://www.scopus.com/inward/record.url?scp=0033729802&partnerID=8YFLogxK
U2 - 10.1046/j.1365-2435.2000.t01-1-00451.x
DO - 10.1046/j.1365-2435.2000.t01-1-00451.x
M3 - Article
AN - SCOPUS:0033729802
SN - 0269-8463
VL - 14
SP - 538
EP - 545
JO - Functional Ecology
JF - Functional Ecology
IS - 5
ER -