Abstract: As a carrier of ecological benefits, forest resources determine the value and services they provide. Based on forest area and forest volume, and the corresponding material quantity and values of forest ecological benefits of the 6th and 7th National Forest Inventory (NFI) in each province of China, we established an optimal prediction model of material quantity and values of forest ecological benefits, and applied this model to estimate the dynamics of material quantity and value of forest ecological benefits of the 2nd to 9th NFI in Shaanxi Province. The results showed that y=aS+bV+c was the optimal prediction model of the material quality and values of forest ecological benefits. The material quality of forest ecological functions in Shaanxi Province exhibited an obvious rising trend, especially in terms of nutrient accumulation and atmosphere environmental purification. The growth rate was high during the 5th NFI, between 9.45% and 30.35%. The simulated total values of forest ecological benefits in Shaanxi Province during the period from the 2nd to 9th NFI were 1979.66×10⁸, 2061.41×10⁸, 2064.46×10⁸, 2324.02×10⁸, 3085.11×10⁸, 2394.08×10⁸ (the actual value of 6th NFI), 3510.69×10⁸, 3896.77×10⁸,4069.95×10⁸ yuan·a^-1 respectively, showing an increasing trend. Among all forest ecological functions in Shaanxi Province, water conservation and biodiversity conservation accounted for a large proportion, which were 40.52%-40.70%, and 23.08%-26.50% respectively, followed by carbon sequestration and oxygen release, soil conservation, atmosphere purification, with the smallest proportion for nutrient accumulation. The optimal prediction model objectively reflected the synergy between forest ecological benefits and forest resources, providing an easy and feasible way to effectively estimate the dynamics of material quantity and values of forest ecological benefits in Shaanxi Province, and thus support for promoting the implementation of ecological GDP and ecological compensation system.

Key words: sugarcane, micropropagated plant, Klebsiella variicola DX120E, growth promoting effect.