RECORD
The Consequences of Xylem Cavitation in Several North American Tree Species
- Title:
- The Consequences of Xylem Cavitation in Several North American Tree Species
- Creator:
- Sparks, Jed P.
- Date Created:
- 1998-08
- Description:
- Four experiments were conducted to investigate xylem cavitation in temperate trees. First, xylem cavitation, stomatal behavior, and hydraulic conductivity were examined in Populus trichocarpa. Cavitation occurred at less negative xylem water potentials in trees from wetter environments (−0.71 to −1.32 MPa) compared to trees from drier environments (−1.55 to −1.67 MPa). Additionally, trees from wetter environments exhibited higher stem hydraulic conductivities and limited stomatal control compared to trees from drier environments. Second, annual stem water contents, ice fractions, and xylem conductivities were monitored in Pinus contorta . Stem ice fractions and liquid water contents were measured using time domain reflectometry (TDR). Ice fractions during the winter varied from 0–75% and liquid water was in the xylem at temperatures <−20°C. Xylem conductivities decreased 70% through the winter and recovered to pre-winter values by May. No reductions in xylem conductivity were, observed during the summer. Third, xylem cavitation and stem water contents were monitored in conifers from upper and lower treeline. Species growing at lower treeline (Larix occidentalis and Pinus contorta) exhibited higher resistances to xylem cavitation (3.29 to 3.61 MPa) compared to species growing at upper treeline (Larix lyallii and Pinus albicaulis, 2.46 to 2.78 MPa). No species experienced losses in stem hydraulic conductivity during the summer. During the winter months, however, lower treeline species experienced 8–15% loss in conductivity compared to >30% for upper treeline species. Loss of stem hydraulic conductivity was correlated to winter freeze-thaw cycles, mid-winter warming and stem water contents in upper treeline species. However, the loss of conductivity was not correlated to environment or to stem water content in lower treeline species. Fourth, liquid water was measured using TDR in wood under otherwise frozen conditions. Four wood types were represented by Robinia pseudoacacia (ring-porous), Populus trichocarpa (diffuse-porous), Pinus contorta (evergreen conifer), and Larix occidentalis (deciduous conifer). R. pseudoacacia contained less liquid water at all temperatures below 0°C compared to the other species.
- Document Type:
- Dissertation
- Subjects:
- UIEF temperate trees xylem cavitation stomatal behavior respiration water behavior liquid water content silviculture
- Location:
- UIEF
- Latitude:
- 46.869607
- Longitude:
- -116.733856
- Publisher:
- ProQuest Dissertations Publishing
- Department:
- Forest, Rangeland, and Fire Sciences
- Type:
- Text
Source
- Preferred Citation:
- "The Consequences of Xylem Cavitation in Several North American Tree Species ", UIEF Research Exchange, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/uief/items/uief_0286.html
Rights
- Rights:
- In copyright, educational use permitted.
- Standardized Rights:
- http://rightsstatements.org/vocab/InC-EDU/1.0/