Refer to the Figure

Multiple Choice

Refer to the figure.

- In soil, there can be layers with more or less available water. In the figure, there is a lower water potential in shallow soils than in deep soils. Considering this scenario, what will the stem water potential be in the middle of the night and why?

A) -3.0 MPa because the plant will equilibrate with the lowest water potential.
B) -0.5 MPa because the plant will equilibrate with the highest water potential.
C) Between -3.0 MPa and -0.5 MPa because the plant will average across all available water.
D) Between -3.0 MPa and -0.5 MPa because some of the water from the deep soil layers will move through the roots and then into the dry, shallow soils.