陕西黄土丘陵区金钱松和花旗松引种效果分析

对陕西延安树木园引种栽培的金钱松、花旗松及当地栽培树种油松的净光合速率（Pn）、蒸腾速率（Tr）和水分利用效率（WUE）等生理指标与生长状况进行了比较分析。结果表明,金钱松和花旗松的光合速率日进程均为单峰曲线， Pn小于油松；二者WUE日平均值分别为4.04 μmol·mmol-1和5.10 μmol·mmol-1，均高于油松(2.89 μmol·mmol-1)；生长量比油松小。金钱松和花旗松在黄土丘陵区表现良好，生长比油松缓慢，适宜作为园林绿化树种栽植。

Introduction Assess ment of Pseudolarix amabilis and Psedotsuga menziesii in the Loess Hilly Region of Shaanxi

The photosynthetic rate（Pn）, transpiration rate(Tr), water use efficiency （WUE） and growth situation of Pseudolarix amabilis,Psedotsuga menziesii and Pinus tabulaeformis introduced were measured and compared in Yanan arboretum of Shannxi. The results showed that the diurnal changes of Pn of the Pseudolarix amabilis,Psedotsuga menziesii were one peaked curves, and smaller than the Pinus tabulaeformis;but their WUE（4.04 and 5.10 μmol·mmol-1） were higher than that of Pinus tabulaeformis（2.89 μmol·mmol-1）;their growth was smaller than that of Pinus tabulaeformis. So Pseudolarix amabilis ,Psedotsuga menziesii may be utilized as gardening.