Lüttge U, Medina E, Cram W J, Lee H S J, Popp M, Smith J A C
Institut für Botanik, Technische Hochschule Darmstadt, D-6100 Darmstadt, FRG, Venezuela.
Centro de Ecologia y Ciencias Ambientales, Instituto Venezolano de Investigaciones Cientificas, Caracas 1020-A, Venezuela.
New Phytol. 1989 Feb;111(2):245-251. doi: 10.1111/j.1469-8137.1989.tb00689.x.
In an ecophysiological field investigation of plant communities of vegetation islands of an alluvial plain in northern Venezuela the members of the Cactaceae, Pereskia guamacho, and a columnar ceroid cactus, Subpilosocereus ottonis, were studied. The alluvial plain was flooded by fresh water in the rainy season in November/December 1985 and was dry and saline in the dry season in March/April 1986. The highly succulent leaves of P. guamacho were shed in the dry season. They performed C photosynthesis in the wet season and did not show signs of considerable salt accumulation. P. guamacho avoids stress due to drought and salinity by leaf-shedding. The columnar stem succulent ceroids are salt-excluding plants with crassulacean acid metabolism (CAM). Rapid die back and regeneration of absorptive roots, water parenchyma and CAM, with the possibility of nocturnal stomatal closure and CO recycling, are traits of adaptive value under fluctuating conditions between rainy and dry seasons on the alluvial plain.
在对委内瑞拉北部冲积平原植被岛植物群落进行的生态生理学实地调查中，研究了仙人掌科的成员、胭脂掌以及一种柱状蜡质仙人掌奥托尼斯柱丽花。该冲积平原在1985年11月/12月的雨季被淡水淹没，在1986年3月/4月的旱季则干燥且盐碱化。胭脂掌的高度肉质化叶片在旱季脱落。它们在雨季进行C光合作用，且未表现出明显的盐分积累迹象。胭脂掌通过落叶来避免干旱和盐碱胁迫。柱状茎肉质蜡质植物是具有景天酸代谢（CAM）的排盐植物。吸收根、贮水薄壁组织和CAM的快速枯死和再生，以及夜间气孔关闭和CO循环的可能性，是在冲积平原雨季和旱季波动条件下具有适应价值的特征。
