| Abstract:To address a series of ecological issues such as soil fertility decline caused by the uniform stand structure of pure forests of Pinus tabuliformis, the mixed coniferous and broad-leaved forest of P.tabuliformis and Q.wutaishansea (J1), P.tabuliformis pure forest (J2), and coniferous mixed forest of P.tabuliformis and P.armandi (J3) were selected as research subjects at the Shihe Forest Farm in Zhongtiao Mountain, Shanxi province.The soil chemical characteristics of three different mixed types of planted forests were explored, which can provide a scientific basis for the rational allocation of tree species in the region and the sustainable management of forests.The results showed that, in the same soil layer, the soil pH of J3 was significantly higher than that of J1 and J2; in the 0-10 cm surface layer, the soil nutrients of J1 were significantly increased, with the contents of organic matter, total N, total P, hydrolyzed N, and available P being 35.6%, 42.65%, 10.87%, 38.95% and 18.03% higher than J2, respectively.As the soil layers deepened, there was no significant change in soil pH among the three forest types; Except for available P, soil nutrients significantly decreased, exhibiting a clear surface aggregation effect.The effective nutrient ratio represents the forest’s ability to activate soil nutrients.J1 significantly increased the effective nutrient ratio of N element in the 10-20 cm soil layer, with an increase of 20.44% and 24.03% compared to J2 and J3, respectively.J1 significantly enhanced the activation ability of P element in the 10-20 cm and 20-40 cm soil layers.Correlation analysis showed significant or extremely significant positive correlations between soil organic matter, total N, total P, and hydrolyzed N, and significant or extremely significant negative correlations with pH.Soil organic matter is an important source of N and P nutrients, and their changes were often consistent.Soil pH indirectly affects soil nutrients by affecting microbial activity.In summary, the soil chemical properties of the mixed coniferous and broad-leaved forest of P.tabuliformis and Q.wutaishansea are significantly better than those of the pure P.tabuliformis forest, and coniferous mixed forest of P.tabuliformis and P.armandi.Therefore, we can improve the soil quality of pure forests of P.tabuliformis and enhance the stability of forest ecosystems by establishing a mixed forest model of P.tabuliformis and Q.wutaishansea. |
