Alma's mother keeps many potted plants. In the summer, she keeps the plants outside. Some of the plants are placed in full, direct sunlight. Others are placed in the shade under the trees. Alma has noticed that her mother gives the plants that are in the sun much more water than the ones in the shade. Alma asked her mother why some plants were in the sun and others in the shade. Her mother explained that some plants need more light than others. Alma concludes that plants that need more light also need more water. Which of the following is a possible alternative explanation for why the plants in the sun are given more water?