Abstract
Traditionally, plant distribution is thought to be closely related to environmental factors. But recently, it is found that Populus, quite different from other plant taxa, adapted to negative environmental changes, and successfully migrated to different climate zones from its origin places of warm temperate zone. Conversely, Metasequoia is gradually tending to extinction from the Miocene to Quaternary. Based on above contrary cases, two response patterns of plant to negative environmental changes are proposed. One is active adaptation represented by Populus, the other is passive adaptation represented by Metasequoia. The plants of passive strategy characterized for desert prevention might be easily replaced by those of active strategy characterized for desert utilization. Fast growing plants, such as Populus with characteristics of drought and salt tolerance, wind and sand resistance, are selected in Tarim Basin in southern Xinjiang, China, as a good example of desert utilization in the construction of new highways and towns, not only serve as farmland shelterbelt in sandy area. In addition, Populus with high-altitude and cold adaptation has also been selected as an ideal tree planted in Tibet. Therefore, the idea of using Populus as one of the preferred pioneer trees to colonize Mars is proposed.
