Stem productivity in relation to nitrogen concentration and carbon isotopic composition (δ^<13>C) in leaves of hinoki cypress (Chamaecyparis obtusa Endlicher) plantations in Shikoku district, Japan(Environment)

概要

論文の詳細を見る
The stem productivity of the hinoki cypress (Chamaecyparis obtusa Endlicher) in relation to plant nitrogen status and water-use efficiency was investigated in the Okuono (OKU) and Karakawa (KRK) areas in Shikoku district, Japan, where abundant precipitation occurs. The nitrogen concentration and carbon isotopic composition (δ^<13>C) in the leaves were used as indexes of plant nitrogen status and water-use efficiency, respectively. The leaf nitrogen concentration increased with decreasing soil carbon/nitrogen (C/N) ratio and with increasing soil pH. There was a marginally significant negative correlation between leaf δ^<13>C and soil water content in the KRK area, but leaf δ^<13>C in the OKU area did not correlate with the soil water condition, and increased on the upper slope. The results suggest that hinoki trees in the KRK area have higher water-use efficiency (high leaf δ^<13>C) under lower soil water conditions. In the OKU area, meanwhile, leaf δ^<13>C in the upper slope was higher due to adaptation to adverse conditions. When 12 plots in two areas were included, the mean height and stem increments increased with increasing leaf nitrogen concentration and with decreasing leaf δ^<13>C. These findings suggest that nitrogen acquisition is a primary factor for stem productivity in the areas concerned but the productivity of some forests is restricted by the soil water condition or other conditions, as indicated by the high value of leaf δ^<13>C. The measurement of nitrogen concentration and δ^<13>C in leaves can provide us with valuable insights into the relative importance of nitrogen, water and other conditions on stem productivity in the two areas.

Stem productivity in relation to nitrogen concentration and carbon isotopic composition (δ^<13>C) in leaves of hinoki cypress (Chamaecyparis obtusa Endlicher) plantations in Shikoku district, Japan(Environment)

スポンサーリンク

概要

著者

関連論文

スポンサーリンク