James Richards and Martyn Caldwell conducted an experiment to test the hypothesis that hydraulic lift occurs in Artemisia tridentata,a species of sagebrush common in the western United States.Each plant in the experimental group was covered with an opaque plastic bag for more than two days to prevent photosynthesis and greatly reduce transpiration,and control plants were left uncovered.Fluctuations in soil water potential were measured,and other aspects of the experimental systems were observed.Which of the following observations from such an experiment provides the strongest support for the occurrence of hydraulic lift in A.tridentata?

Question

Quizplus · Accepted Answer

The observation that the shallow soil beneath the experimental plants is moister than that beneath the control plants provides the strongest support for the occurrence of hydraulic lift in A. tridentata. Hydraulic lift involves the movement of water from deeper soil layers to shallower ones via the plant's roots. In this experiment, the plastic bags covering the plants prevented photosynthesis and greatly reduced transpiration, which would increase water availability in deeper soil layers. The fact that the soil beneath the experimental plants is moister than that beneath the control plants suggests that water was being lifted from deeper soil layers by the roots of the experimental plants and released into the shallower soil layers, consistent with hydraulic lift.

James Richards and Martyn Caldwell Conducted an Experiment to Test