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.
Fraser's fir is a narrow conical shaped tree that can grow to heights of 65 feet. Fraser's fir make the best Christmas tree and for this reason are raised and farmed in other regions. They are wonderful in the landscape or gardens. A Few Pines of the Southeast. Slash pine (Pinus elliottii) also called a swamp pine or lemon pine.