Root and leaf changes in Salix nigra cuttings in
response to increasing soil temperature
D. R. Baud* and S. R. Pezeshki
Department of Biological Sciences, University of Memphis,
Memphis, TN 38152, USA.
*Corresponding author. E-mail:
Accepted 10 February, 2012
black willow, is used for wetland restoration and streambank
stabilization and like other wetland species has the ability
to develop aerenchyma tissue to avoid root anoxia. Root
aerenchyma development could be affected if the temperature
of the rhizosphere increases as a result of climatic change.
Root porosity (used as an indication of aerenchyma tissue)
of S. nigra cuttings grown under three soil
temperature regimes was found to increase in response to
increases in temperature (F2,40 = 56.57; p <
0.0001). There was also an increase in internal C (carbon)
concentration (F2,27 = 27.36; P < 0.0001) and a
corresponding decrease in stomatal conductance (F2,27
= 3.728; P = 0.037), transpiration rate (F2,27
= 5.084; P = 0.013), and net photosynthesis (F2,27
= 14.07; P < 0.0001) in response to increased soil
temperature. The present research demonstrated that the
stress response of S. nigra to increased soil
temperature is similar to its response to anoxic conditions.
Key words: Aerenchyma, global warming, Salix nigra,
remediation, rhizospere, riparian systems.