Learn the Role of Nutrients in your trees by our Experts.

Over the next several months, we will share information that illustrates the role nutrients play in the health of our trees. Our goal is to educate you so you can become the best tree stewards you can be. Please enjoy the info and let us know if you have any questions.

There are 9 nutrients that are required in high concentrations in the tree. These concentrations are over 1000 parts per million and are highly mobile inside the tree. These nutrients are referred to as the macronutrients, and include Carbon, Oxygen, Hydrogen, Nitrogen, Potassium, Calcium, Magnesium, Phosphorus, and sulfur. There are also 7 nutrients that are just as essential as the macronutrients, but are only needed in concentrations of 100 parts per millions or more. These nutrients include Chlorine, Iron, Boron, Manganese, Zinc, Copper, and Molybdenum.

This month we will highlight the essential nutrient Carbon.

Carbon forms the skeleton of all the organic molecules in the tree including cellulose and lignin. Cellulose makes up the cell walls and lignin is the glue that fills the spaces between cells. Without carbon, trees would look like sponges rather than the towering figures we know them to be. Carbon, in the form of Carbon Dioxide, enters the tree through openings in the leaves known as stomata. During photosynthesis, when sunlight hits the leaf surface it reacts with the water and chlorophyll to form sugar and oxygen. Once reduced to a sugar, the carbon can be combined with other sugars in chains that form complex compounds such as glucose, cellulose, hemicellulose, and lignin. Carbon is such an important nutrient that it makes up nearly 50% of a tree’s total weight. This is an important fact when discussing the value of trees as “filters” for high levels of carbon in the atmosphere as a result of burning fossil fuels.

Carbon has only one route of entry into the tree: the stomata, pores that are found on leaves & stemsused to control gas exchange.

It is because of this limited entry that stomata become so crucial to the health of trees. When stomata do not function properly, carbon cannot enter the tree. Photosynthesis will not occur without the carbon and the tree will soon die. We often see non-functioning stomata for three reasons.

1) Drought: The first and most common reason for non-functioning stomata is due to drought. Water must enter the guard cells that surround the stomata for the stomata to open. During periods of drought water in the leaf is depleted and the stomata will not open.

2) Potassium Deficiency: The second reason for non-functioning stomata is linked to a lack of Potassium. Potassium accumulates in the guard cells and draws moisture into the cell. Without sufficient potassium, the cells cannot hydrate and the stomata will not open.

3) Sunlight: Finally, the third reason for stomata to close is the daily decrease in sunlight as nighttime approaches. This response to the sunlight moves water out of the guard cells and closes the stomata.

Next Month we will highlight Oxygen and Hydrogen in plants. Stay tuned….