Wallace C S, Szarek S R
Department of Botany and Microbiology, Arizona State University, 85287, Tempe, Arizona, USA.
Oecologia. 1981 Oct;51(1):57-61. doi: 10.1007/BF00344653.
A comparison of photosynthetic adaptations of desert ephemerals from sun and shade environments has shown differences in the magnitude and timing of maximum CO assimilation. Photosynthetic rates of species from the sun environment were significantly higher, and maximum observed levels occurred both earlier in the day and earlier in the growing season. For plants of both sites the CO assimilation rates were relatively low when the soil water content was highest in the winter months. Anatomical modifications of specific leaf weight occurred for species of both environments, but were not correlated with improved water use efficiency. Throughout the growing season the stomatal conductance of most species was higher than 0.30 cm/s and effects a maximization of photosynthesis when water is available, at the expense of water use efficiency.
对来自阳光充足和阴凉环境的沙漠短命植物光合适应性的比较表明，最大二氧化碳同化的幅度和时间存在差异。来自阳光充足环境的物种光合速率显著更高，观察到的最高水平在一天中更早以及生长季节更早出现。对于两个地点的植物来说，在冬季土壤含水量最高时，二氧化碳同化率相对较低。两种环境中的物种都出现了比叶重的解剖学变化，但与水分利用效率的提高无关。在整个生长季节，大多数物种的气孔导度高于0.30厘米/秒，在有水可用时实现光合作用最大化，但以水分利用效率为代价。
