Plant energy storage strategy and caloric value

Jørgensen [Jørgensen, S.E., 2002. Integration of Ecosystem Theories: A Pattern, 3rd ed. Kluwer Academic Publishers, The Netherlands] proposed: Ecosystem attempts to maximize their distance from a thermodynamic reference point by storing exergy. In this research a close relationship between energy storage strategies and caloric value was found. The caloric values of dominant plants in a 1-ha plot in a tropical seasonal rain forest (TSRF) and a 1-ha plot montane evergreen broad-leaved forest (MEBF) of Yunnan Province, southwest China were measured. We found plants growing in different environment and developing stage prefer different energy storage strategy. In the cold environment, plants prefer to condense energy in the limited volume which increases caloric value. And the same strategy is chosen by the top (sun) leaves, so they have higher caloric values than the bottom (shade) leaves. While in the warm environment, structure development dominates which abates caloric value. At the beginning of growth, plants prefer to develop structure. However after matured, they prone to condense energy in the full grown structure. So mature leaves maintain higher caloric values than young shoots do. On all accounts, the two exergy strategies – structural development that decreases caloric value and energy condensation that increases caloric value – interact each other to facilitate energy storage in plants.