The paper implemened forest resources data updated by designing survey database of resource (including subcompartment database and tree species database) and database of resource(including changed database of subcompartment and changed database of tree species) change,compartementalized database of resource survey into two processes—stand growing naturally without interference and stand changing caused by the interference of environment.The data of natural forest resources was updated by applying interrelation between database and adopting different types of growth and management models respectively on the base of network database language—PowerBulider and Visual C as well.
Leaf area is an important parameter for modeling tree growth and physiological processes of trees. The single young and mature leaf area estimation models of eucalyptus were developed based on leaf fresh weight. In total, leaf area and leaf weight were measured from 455 fresh leaves of 25 trees of eucalyptus in southern China. The majority of the data （80%） were used for model calibration, and the remaining data （20%） were used for model validation. The linear, compound and power models were tested. Based on goodness of fit, prediction ability and residual performance, we found that linear and power models could best describe the relationship between leaf area and weight for young leaf and mature leaf, respectively. The study provides a simple and reliable method for estimating single-leaf area, which has a good potential in the functional- structural model of eucalyptus.
