摘要
Through the content analysis of nutrient elements in the soil and in the needle at thedifferent site classes and periods of growth of P.koraiensis,and in a single growing season,someconclusions can be drawn below:Most of the soil nutrient elements were higher at the good sitesthan at the poor ones in an annua1 average concentration of them,i.e.,site class 1】site class2】site class 3.And for P.korarensis tree at every site class,the nutrient elements in their needles didthe same.However,each of the elements in the soil or in the need was seldom at the same level ofconcentration on the good or on the poor site during different periods of growth.There are no aninevitable relationship between the contents of the soil nutrient elements and the needle’s.Andwhether these elements are high or low within a tree body may depend on the physiogical require-ment of the tree,but not on their contents in the environment.Some nutrient elements repuired forP.koraiensis varied with growth periods during a whole growing
Through the content analysis of nutrient elements in the soil and in the needle at the different site classes and periods of growth of P. koraiensis, and in a single growing season, some conclusions can be drawn below: Most of the soil nutrient elements were higher at the good sites than at the poor ones in an annual average concentration of them, i.e., site class 1 > site class 2> site class 3. And for P. koraiensis tree at every site class, the nutrient elements in their needles did the same. However, each of the elements in the soil or in the need was seldom at the same level of concentration on the good or on the poor site during different periods of growth. There are no an inevitable relationship between the contents of the soil nutrient elements and the needle's. And whether these elements arc high or low within a tree body may depend on the physiogical requirement of the tree, but not on their contents in the environment. Some nutrient elements required for P. koraiensis varied with growth periods during a whole growing season. N, P and K, for example, were greatly needed only at the fast growth period, while Ca at the initial growth period; and on the contrary, Ca was needed less at the fast growth period. In intensive forest management, therefore, fertilizers with N, P and K should much be applied at the fast growth period, while fertilizer with Ca at the initial growth period to meet requirements of growth of P. koraiensis trees.
