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.
In Alabama, for example, types of trees grown for use as Christmas trees include eastern white pine, redcedar, Virginia pine, Leyland cypress, and Arizona cypress. In Florida, the sand pine and spruce pine are among the 20,000 grown in the state each year.