In order to study the effects of litter decomposition on soil nitrogen of Piceamongolica in different forest ages, young forest (0–5a), middle-aged forest (5–30a), and near-mature forest (30–40a) stands were selected in the Baiyinaobao National Nature Reserve. Litter decomposition was assessed using the decomposition bag method. The seasonal and vertical spatial variation characteristics of total N, NH₄⁺—N, and NO₃⁻—N caused by litter decomposition in P. mongolica forest soil were studied for different stand ages. Results showed that: (1) There was a positive correlation between litter N content and soil organic matter, total N content, and NO₃⁻—N content across different forest ages (p < 0.05). There was a negative correlation between litter N and NH₄⁺—N contents. A negative correlation between litter C content and soil organic matter, total N, and NO₃⁻—N contents was also observed. (2) In this study, the total N and NO₃⁻—N increased with the increase in N content during litter decomposition.NH₄⁺—N in the soil was positively correlated with sample date, soil NO₃⁻—N, and forest age (p < 0.05), and negatively correlated with soil depth (p < 0.01). NO₃⁻—N in the soil was negatively correlated with sample date and forest age (p < 0.05), and significantly negatively correlated with soil depth (p < 0.01). (3) the NH₄⁺—N content is greater than that of NO₃⁻—N in each soil layer for the three forest ages. The correlation analysis indicated which factors influenced NH₄⁺—N and NO₃⁻—N in the soil. The content decreased during February and November and increased in May and August. (4) The total N, NH₄⁺—N, and NO₃⁻—N in the forest soils across the three forest ages increased with the depth of the soil layer (0–50 cm) and showed an overall downward trend. The contents of NH₄⁺—N in the soil layer from the young forest (0–10 cm, 10–20 cm and 20–30 cm, 30–40 cm, and 40–50 cm) differed significantly (p < 0.05), as did the NO₃⁻—N results (p < 0.05), while results from the middle-aged forest and near-mature forest increased with soil layer depth. There was no significant difference in the NH₄⁺—N soil content. (5) The NH₄⁺—N in the forest soils showed a trend from mature forest > middle-aged forest > young forest. This trend for soil NO₃⁻—N content is consistent with that of the NH₄⁺—N content in the Picea mongolica forest soil.

The seasonal and vertical spatial variation characteristics of total N, NH4+—N and NO3-—N in the soil in Picea mongolica forest at different stand ages were studied. The results showed that: (1) NH4+ —N in the soil in Picea mongolica forest was positively correlated with sample date, soil NO3-—N and forest age (P <0.05), and negatively correlated with soil depth (P < 0.01). NO3-—N in the soil in Picea mongolica forest was negatively correlated with sample date and forest age (P < 0.05), and significantly negatively correlated with soil depth (P < 0.01); (2) the content of NH4+—N is greater than that of NO3-—N in each soil layer of Picea mongolica forest at three forest ages. The correlation analysis showed which had an impact on the content of NH4+—N and NO3-—N in the soil in Picea mongolica forest. The content was lower in February and November, and higher in May and August；(3) The contents of total N, NH4+—N and NO3-—N in the soil of Picea mongolica forest in the three forest ages increased with the depth of soil layer (0-50cm), and showed an overall downward trend. The contents of NH4+—N in the soil layer of young forest (0-10cm, 10-20cm and 20-30cm, 30-40cm and 40-50cm) were significantly different (P＜0.05), and the contents of NO3-—N were also significantly different (P＜0.05), while their contents of middle-aged forest and near mature forest increased with the depth of soil layer, There was no significant difference in the content of NH4+—N; (4) The content of NH4+—N in the soil in Picea mongolica forest generally showed the following change trend near mature forest > middle-aged forest > young forest. The change trend of soil NO3-—N content is consistent with that of the content of NH4+—N in the soil in Picea mongolica forest.

Based on the characteristics and layout of high-tech industry, this paper analyzes the factors of Chifeng City, Based on the theory of economic geography and industrial layout, the development ideas and theoretical basis for the development of high and New Technology Industrial Park in Chifeng area, which is the main function of the Chifeng University North Road, a financial Street area are proposed.