[Objective]The aim was to reveal the spatial distribution characteristics of total nutrients in soil and provide a theoretical basis for farmland management and improvement of crop yield. [Method]GIS technique was used to analyze the spatial distribution characteristics of total C,total N,total P and total K for different soil layers in Liaoning Province. [Result]The results showed that the content of total C,total N,total P decrease from east to west,but the content of total K was high in north district of Liaoning Province. The content of total C,total N,total P and total K was higher in soil surface (0-20 cm) than the lower (20-40 cm). Total K varied less with soil depth,and its mean content was respectively 17.64 g/kg and 17.08 g/kg for soil surface and soil lower layer. [Conclusion]The results of the distribution of soil total nutrients in different soil layers supplied a theory basis for farmland management.
The interannual variation characteristics of NPP and carbon emission of Liaoning forest in recent 50 years (from 1961 to 2008) were analyzed based on the hydrothermal optimized NPP model and soil respiration Q10 model.The results showed that the total amount of annual NPP was increased in recent 50 years,in which the amount of NPP (83.9 Mt) in 2008 was 2.8 times as high as that in 1961.Amount of NPP per unit area changed with different years,and the maximum value was 36.5% more than the minimum one.The net carbon budget of Liaoning forest was carbon sink,with annual 2.1 t CO2/hm2.