Abstract:

For examining the variation of foliar mineral element concentration, the needle samples from ten sample trees in each of 26 seed sources within a 12-year old provenance trial located in Anhua County, Hunan Province were collected. For studying seasonal dynamics of mineral element concentrations the needles were collected on the following dates: April 30, July 30 and October 30 of 1991 and January 30 of 1992.At each sampling date the current and previous-year needls on the second whorl from crown top were sampled respectively.Thus at each sampling date there was one sample per needle age class from ten sample trees for analysis. Concentrations of N, P, K, Ca and Mg were determined by the Analysis Centre of Central-Southern Forestry College. The results showed that concentrations of all measured nutrient element among provenances varied significantly and the apparent geographic variation pattern was exist with significant correlation coefficients related to the latitudes and longitude of seed origins. The concentrations of N, P and Ca of northern seed source group were higher than those of southern seed source group and the K and Mg concentration were lower than those of southern seed source, but the pattern of seasonal change in concentration of mineral elements was similar for the two different distinct geographic regions, i. e. Yunnan-Guizhou Plateau and Qinling-Dabashan Mountains.

Key words: Pinus armandii, Seed source, Mineral element, Seasonal change