Solar input and energy storage in a five-year-old American sycamore plantation

Energy stored in a 5-year-old American sycamore plantation grown in Mississippi was determined by bomb calorimetry of component parts of selected trees randomly sampled in autumn and spring. The results indicated significant differences among tree components. The caloric values were 4675.81 cal g^-1 for leaves, 4631.76 cal g^-1 for branch bark, 4489.12 cal g^-1 for branch wood, 4753.85 cal g^-1 for stem bark, and 4488.76 cal g^-1 for stem wood. Based on these caloric values, the total energy yeild for a 1-ha plantation, containing 1200 trees with a total above-ground biomass of 20.3 t, was computed at 9.22 × 10¹⁰ calories. The storage efficiency of the forest stand, which was calculated by dividing total energy yields by available photosynthetic solar radiation received during the growing season (168,462 × 10⁸ cal), was 0.55%. The biomass yield of this 5-year-old sycamore plantation is sufficient to supply the electrical energy needs of an average household for nearly 3 years.