Squeo F A, Rada F, Azocar A, Goldstein G
Departamento de Biologia y Quimica, Facultad de Ciencias, Universidad de La Serena, Casilla 599, La Serena, Chile.
CIELAT, Facultad de Ciencias, Universidad de los Andes, Merida, Venezuela.
Oecologia. 1991 May;86(3):378-382. doi: 10.1007/BF00317604.
Freezing tolerance and avoidance were studied in several different sized species of the tropical high Andes (4200 m) to determine whether there was a relationship between plant height and cold resistance mechanisms. Freezing injury and supercooling capacity were determined in ground level plants (i.e. cushions, small rosettes and a perennial herb), intermediate height plants (shrubs and perennial herbs) and arborescent forms (i.e. giant rosettes and small trees). All ground-level plants showed tolerance as the main mechanism of resistance to cold temperatures. Arborescent forms showed avoidance mechanisms mainly through supercooling, while intermediate plants exhibited both. Insulation mechanisms to avoid low temperatures were present in the two extreme life-forms. We suggest that a combination of freezing tolerance and avoidance by insulation is least expensive and is a more secure mechanism for high tropical mountain plants than supercooling alone.
对热带高海拔安第斯山脉（4200米）几种不同大小的物种进行了抗冻性和避冻性研究，以确定株高与抗寒机制之间是否存在关联。测定了地被植物（即垫状植物、小型莲座丛植物和一种多年生草本植物）、中等高度植物（灌木和多年生草本植物）以及乔木状植物（即巨型莲座丛植物和小树）的冻害和过冷却能力。所有地被植物均表现出以耐受性作为抵御低温的主要机制。乔木状植物主要通过过冷却表现出避冻机制，而中等高度植物则兼具两者。两种极端生活型都存在避免低温的绝缘机制。我们认为，对于热带高山植物而言，抗冻性与通过绝缘实现的避冻性相结合成本最低，且比单纯的过冷却更为可靠。
