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Effects of mid-season frost and elevated growing season temperature on stomatal conductance and specific xylem conductivity of the arctic shrub, Salix pulchra.
- Source :
- Tree Physiology; Oct2002, Vol. 22 Issue 14, p1027-1034, 8p, 1 Chart, 5 Graphs
- Publication Year :
- 2002
-
Abstract
- An increased risk of frost is expected during the growing season, as climate warming increases spring temperatures in the Arctic. Because deciduous species have a growth season limited in length and also have generally larger conduit volumes, they are more likely than evergreens to be injured by freeze–thaw-induced cavitation during the growing season. To test whether growth at elevated temperature increases susceptibility to freeze–thaw damage, we grew a deciduous arctic shrub species (Salix pulchra Cham.) in simulated Alaskan summer temperatures and at 5 °C above the ambient simulation (+5 °C plants) in controlled environments. Stem specific hydraulic conductivity (ks) and leaf stomatal conductance (gs) were measured in plants grown at both temperatures before and after a freeze treatment simulating a mid-season frost. Before the freeze treatment, specific xylem conductivity was 2.5 times higher and stomatal conductances were 1.3 times higher in +5 °C plants than in ambient-grown plants. Reductions in hydraulic conductivity and stomatal conductance as a result of the freeze were 3.5 and 1.8 times greater respectively in +5 °C plants than in ambient-grown plants. Many of the +5 °C plants showed extensive leaf damage. Plants grown in the two treatments also differed in comparative xylem anatomy; +5 °C plants had larger vessel diameters (25.4 versus 22.6 μm) and higher vessel densities (71 versus 67.4 vessels mm−2) than ambient-grown plants. Our results suggest that higher growing season temperatures will increase the susceptibility of arctic deciduous shrubs to frost damage, which may offset their competitive growth advantage. [ABSTRACT FROM PUBLISHER]
Details
- Language :
- English
- ISSN :
- 0829318X
- Volume :
- 22
- Issue :
- 14
- Database :
- Complementary Index
- Journal :
- Tree Physiology
- Publication Type :
- Academic Journal
- Accession number :
- 51808227
- Full Text :
- https://doi.org/10.1093/treephys/22.14.1027