Tyree M T, Kolb K J, Rood S B, Patiño S
Aiken Forestry Science Laboratory, USDA Forest Service, 705 Spear St., P.O. Box 968, Burlington, VT 05402, USA.
Tree Physiol. 1994 May;14(5):455-66. doi: 10.1093/treephys/14.5.455.
Vulnerability of xylem to loss of hydraulic conductivity caused by drought-induced cavitation was determined for three riparian cottonwood species in Lethbridge, Alberta: Populus deltoides Bartr., P. balsamifera L., and P. angustifolia James. These species suffered 50% loss of hydraulic conductivity in one-year-old stem segments when xylem pressure potential fell to -0.7 MPa for P. deltoides and -1.7 MPa for P. balsamifera and P. angustifolia, making them the three most vulnerable tree species reported so far in North America. The possible contribution of drought-induced xylem dysfunction to the decline of riparian ecosystems in dammed rivers is discussed.
对加拿大艾伯塔省莱斯布里奇市的三种河岸杨属树种（三角叶杨Populus deltoides Bartr.、香脂杨P. balsamifera L.和狭叶杨P. angustifolia James）木质部因干旱诱导空化导致水力传导率丧失的脆弱性进行了测定。当木质部压力势降至三角叶杨为-0.7兆帕、香脂杨和狭叶杨为-1.7兆帕时，这些树种一年生茎段的水力传导率损失了50%，这使它们成为北美迄今报道的最脆弱的三种树种。文中讨论了干旱诱导的木质部功能障碍对筑坝河流沿岸生态系统衰退可能产生的影响。
