<正>应用Li-6400光合测定系统研究了贡嘎山地区不同海拔黄背栎（Quercus pannosa）幼树的光合生理特性。结果表明：（1）在8月晴天，不同海拔生长的黄背栎叶片净光合速率日变化均呈比较平稳的单峰曲线，无光合午休现象，随着海拔的升高，叶片净光合速率、蒸腾速率和水分利用效率均降低，而叶片气孔导度增加，有利于高海拔地区植物光合作用气体交换；（2）不同海拔试验点叶片净光合速率对光合辐射的响应有较大的差异，叶片光补偿点为39.16～68.06μmol/（m2?s），光饱和点为1124.78～1754.88μmol/（m2?s），表观光量子利用效率为0.02812～0.03173。随着海拔的升高，叶片光补偿点、光饱和点和最大净光合速率增加；（3）叶片CO2补偿点为68.47～105.21μmol/mol。随着海拔的升高，CO2补偿点降低，有利于植物对高海拔地区低CO2分压环境的适应。CO2饱和点在700μmol/mol左右，羧化效率为0.035～0.038。

The contents of 5 metal ions in root, shoot and leaf of three warm-season turfgrasses in soil salt stress were studied. The results showed that with salt stress aggrevating, content of Na+ increased in root, leaf and shoot, and the proportion of Na+ in shoot and leaf increased remarkably. Under the same concentration of salt stress, the content of Na+ of Centipedegrass was higher than those of Zoysiagrass and Manilagrass. The difference of Na+concentration between Zoysiagrass and Manilagrass was unremarkable with low concentration of salt treatment, but under 0.8G salt treatment, the content of Na+ in Zoysiagrass was higher than that in Manilagrass. Keeping high K+ concentration could be one way to get high salt tolerance of Zoysiagrass and Manilagrass, while Centipedegrass declined in its salt tolerance with the K+ concentration decreased under salt stress, and its salt tolerance was poor. Fe3+ concentration and RS (K+.Na+) changed trend could be used to estimate the turfgrass salt tolerance.