Effects of elevated CO2 and temperature on soil enzymes of seedlings under different nitrogen concentrations.

Investigation of the response of seedling soil enzymes to climate changes may be beneficial for us to have comprehensive cognition of the influences climate changes brought to the process of forest soil ecology and forest productivity. Three-year-old seedlings of the two species were chosen in our experiment, using the FACE equipment,we studied the response of seedling soil enzymes-hydrolases and oxidoreductases to the elevated CO2and temperature under different nitrogen concentrations (N0-no added N,N1-25 kg/(hm2a),N2-50 kg/(hm2a), with nine treatments. The results showed that, under the elevated CO2, the activities of cellulose, intervase, urease, peroxidase and polyphenol oxidase were stimulated while the activity phosphatase was restrained, the reactions of amylase and hydrogen peroxidase were related to different kinds of plant species. Under the elevated temperature, those activities of intervase, phosphatase, urease, peroxidase and hydrogen peroxidase were stimulated while the activities of cellulose, amylase and polyphenol oxidase were related to different kinds of plant species. The reactions of cellulose activity of two seedlings to the elevated CO2 and the reactions of cellulose activity and urease activity of P. koraiensis seedling were significantly changed under different nitrogen concentrations. Therefore, different nitrogen concentrations may change the responses of soil enzymes to the elevated CO2 and temperature.