Have you ever heard of the xylem and phloem? The xylem and phloem are a tree’s transportation systems. The xylem and phloem are located in the cambium layer, which is just below the tree’s bark. The xylem is a tube, or pipe, for the transportation of water and nutrients. The xylem is the pipe that brings water from the ground up to the leaves of the tree where it is needed for the process of photosynthesis. The phloem transports sugar/ glucose to the needed parts of the tree. The glucose is the tree’s food that is made during the process of photosynthesis.
You can learn about xylem at home. To do this experiment you will need an adult to supervise, a cup, a stalk of celery, water, and food coloring. Fill the cup 1/4 way up with water, add in a few drops of food coloring, and finally add a stalk of celery with the leafy side up in the cup, and after a little while you will see the color of the food coloring rising through the xylem and into the leaf. This shows you that the water is being pulled up through the xylem, which are the pipes or tubes in the celery. You know this worked when you see the leafy part of celery turn the color of the food coloring you put in the cup. As you can see, the xylem and phloem are essential to a tree’s survival. Without xylem and phloem, there would be no photosynthesis and no life on earth. Pretty cool stuff if you ask me.
Here is another way to understand how xylem and phloem work. Imagine a train and train track; the people in the train are the water and the nutrients, the train track is the xylem, and the train travels one way on the track. When the train gets to a city, the people (or the water and nutrients) get off at the leaf station. Once at the leaf station, the sun hits them and they go through a process and they get changed into their carbohydrate uniform and board a local train where they go wherever they need to go to feed the tree. Any passengers left dressed in Carbohydrate uniforms, if not needed, get back on the local phloem express train to root town and stay there waiting to get on the train again when the tree calls them to work.
