Nutrient acquisition from different soil depths by pedunculate oak.

摘要

Eight oak trees (Quercus robur L.) received 32P at a soil depth of 50 cm and 33P at a soil depth of 15 cm at the end of June 2002 through plastic tubes inserted into the mineral soil. The phosphorus uptake from different soil depths was estimated by analysing the concentration of 32P and 33P in the foliage of oak growing in a mixed stand in southern Sweden. 32P and 33P were recovered in the leaveseedles after 21 and 39 days. The recovery of labelled P in oak was higher from 15 cm soil depth than from 50 cm, however, more than 4% of the total amount of labelled P was taken up from 50 cm. This indicates that oak can utilize deep soil layers for nutrient uptake. A study on the uptake of Cs (as an analogue to K) and 15N into the leaves was performed on the same trees and detectable amounts of 15N and Cs were recovered in leaves and buds. This indicates that 15N and Cs can be used to study nutrient uptake of mature trees from the mineral soil..