Describes the seasonal variation of nutrient elements content of Chinese pine (Pinus tabulae formis) needles. nitrogen, phosphorus and potassium contents among different age needles were higher in early June and decreased gradually with growing season, whereas calcium content increased steadily. Magnsium content in one-year-old needles tended to increase and remained stable in 2 or 3 years old needles. The optimum sampling period and minimum sampling number of needles for analysis of the nutrient elements contents were also given.
Journal of Northwest Forestry University