Abstract: Atmospheric nitrogen deposition contains both inorganic and organic nitrogen. How-ever, most of the previous studies focused on the effect of inorganic nitrogen deposition on soil organic carbon (SOC) mineralization; little information on how organic nitrogen deposition affects SOC mineralization is available. In this experiment, surface soils (0-10 cm) were collected in a longterm experiment of simulating nitrogen deposition that included the control (CK), inorganic nitrogen (IN), organic nitrogen (ON), and inorganic + organic nitrogen (IN∶ON=7∶3; MN) treatments in a larch (Larix gmelinii) plantation. These soil samples were divided into two groups with or without nematocide to investigate the role of soil nematode on SOC mineralization under the background of nitrogen deposition. All soils were incubated at 25 ℃ for 62 days, and the rate of SOC mineralization was measured. The results showed that the SOC mineralization was significantly suppressed by nitrogen deposition, and it was reduced by 15.7%, 23.9%, and 34.3% in IN, ON and MN treatments compared to CK treatment, respectively. This suggested that the suppression of mixed nitrogen deposition on SOC mineralization was higher than that of inorganic or organic nitrogen deposition alone. Thus, the suppression of atmospheric nitrogen deposition on SOC mineralization might be underestimated by using a single type of inorganic or organic nitrogen deposition. The rate of SOC mineralization increased when nematocide was added to soils. The effect value of nematocide increased by 0.08%, 42.40% and 29.0% in IN, ON and MN treatments compared with the CK treatment, respectively. The result indicated that the effect of soil nematode on SOC mineralization depended on the form of nitrogen deposition. Furthermore, cumulative amount of SOC mineralization was significantly positively related to C∶N ratio, available phosphorus concentration and the ratio of fungi to bacteria, but was significantly negatively correlated with NO₃^--N concentration and the ratio of grampositive bacteria to gramnegative bacteria. So, nitrogen deposition was helpful to decrease CO₂ emission from soil in temperate forest ecosystems under the background of global change.

Key words: landscape preference, stakeholders, agricultural landscape, photo elicitation interview