关键词: 山地森林土壤, 土壤pH值, 土壤有机质, 土壤全氮, 土壤有效磷, 北京

Abstract:

Variation of soil pH,and content of organic matter,nitrogen,phosphorus,and potassium in the soil was investigated in 53 forest soil plots in the mountainous areas from the southwest to the northeast of Beijing.The nutrient status was classified,and the correlation between soil organic matter and nutrients were analyzed.The plots were selected based on the representativeness of forest vegetation types.Coefficient of variation of the available phosphorus was the highest,while that of the total potassium and pH value was relatively lower.In the soil vertical profiles,the content of soil organic matter,total nitrogen,available nitrogen and potassium significantly decreased with increasing soil depth,the available phosphorus in the 0-10 cm layer was significantly higher than the other layers,but no significant difference was found with total phosphorus and potassium in different layers.Approximately 69.8% of the plots had their pH between 6.00 to 7.50,with a few of pH value <5.50.The total nitrogen content in 60.38% of the plots was less than 2.00 g·kg^-1 in the 0-20 cm layer,and the available nitrogen content in 73.59% of soil plots was between 50.1 to 150 mg·kg^-1.Total phosphorous content in 9.43% of the plots was above 0.8 g·kg^-1,and the available phosphorous content in 86.79% of soil plots was below 5 mg·kg^-1.Available potassium content in 37.74% of the plots was more than 150 mg·kg^-1，while that in 3.77% was below 50.0 mg·kg^-1.Soil organic matter was significantly correlated to total nitrogen,available nitrogen and potassium (P<0.01),while its correlation with available phosphorus was only found in 0－10 cm (P<0.05).Our results indicated that a few plots had a trend towards soil acidification,and a few soil plots were deficient in nitrogen and phosphorus.To improve forest health,attention should be paid to monitoring and managing soil acidity,nitrogen and phosphorus level.

Key words: forest soil in mountain areas, soil pH, soil organic matter, soil total nitrogen, soil available phosphorus, Beijing