Most everyone knows that we use proteins, carbohydrates and fats for energy. Calories are measurement of a unit of heat or food energy. For example, we can achieve four calories per gram of proteins and carbohydrates, and nine calories per gram from fats.
Tree Variety. Virginia pine (Pinus virginia) is the major Christmas tree species for the acidic soils found in East Texas. A grower can produce a 6- to 8-foot Virginia pine Christmas tree in 3 to 5 years, depending on soil and climatic conditions.
The Norway Spruce, a European native, was probably the original Christmas tree. The Blue Spruce is the state tree of Colorado and Utah, plus the U.S. National Christmas Tree is also a Blue Spruce. Description . Spruce trees are large, with some species maturing up to 200 feet tall. They have a strongly conical shape, especially when they are young.