Food is Comfort

Nutrients are brought into the plant by the roots and the leaves. Photosynthesis in the leaves allows for energy to be converted from solar energy to usable energy in the form of sugars. While water, which holds nutrients, is taken up by the root hairs; this helps with energy as well. Accumulated energy is stored in the form of starch.

To transport sugar and water from one end of the tree to the other, specific transport tissue is used. These tissues are called xylem and phloem. Xylem tissue is used for the transport of water; most commonly this is up the plant. Phloem tissue is used to move sugars, and this occurrence is usually down the plant.

The xylem is found on the inside of the vascular cambium. Xylem works very similar to a straw. As water is evaporated from the leaves (transportation), negative pressure is created. Because water travels from positive to negative pressure, water is pulled from the roots through the xylem up to the leaves. It is also assisted by adhesion, cohesion and tension.

Phloem tissue is a combination of sieve-tube elements and companion cells found outside of the vascular cambium. The transport of sugars that occurs in these cells are caused by pressure, causing the sugars to travel from the source to the sinks. Sugar is most often accumulated in the leaves, called the source, and then are actively transported into the phloem. This causes a high concentration of sugar compared to water in the phloem tissues resulting in water  diffusion from the xylem. The pressure created by all the sugars and water in the phloem tissue forces sugars to spread both up and down to the sinks. Sinks are areas of the plant that are actively growing or other areas in need of sugars.

Between these two tissues all water and food can be distributed to all the cells of Acer saccharinum.
Continue on and learn how Acer saccharinum has adapted to become such a prominent species.