Abstract:

In order to study the characteristics of P element background values, understand the P element cycling and its impact on the ecosystem in different forest types around Yuanyang terrace. The content of P element in dominant species leaves, soil and litter in nine forest communities around Yuanyang terrace area were studied, circulating factors and characteristics were analyzed. The results showed that: (1) In dominant species leaves, the average content of N was 1.69 g/kg ranging from 1.05 to 3.00 g/kg with the highest in Alnus nepalensis D. Don leaves and the lowest in Helilia Clivicola W. W. Smith.. In the litters, the average content of P was 1.51 g/kg ranging from 0.76 to 2.33 g/kg with the highest in Helilia Clivicola W. W. Smith. and the lowest in Clero dendrum banqei Steud. communities. The average contents of P in three forest types were plantation>broad-leaved forest>coniferous forest. (2) The average content of total P in 0-20 cm and 20-40 cm soil layers was 0.72 and 0.38 g/kg; The average soil available P contents were 3.50 mg/kg (0-20 cm) and 2.62 mg/kg (20-40 cm). The contents of total P and available P in 0-20 cm soil layer were higher than in 20-40 cm soil layer. P contents in surface soil in the three forest types were broad-leaved forest>plantation>coniferous forest. (3) The average enrichment factor, retention factor and coefficient of restitution of the soil were 2.63, 1.06 and 2.46. The sequence was enrichment factor of leaves>coefficient of restitution of soil>litter retention coefficient. The average restitution factor and retention factor in broad-leaved forest were high. The average enrichment factor in coniferous forest was high.