Rothschild L J
Ecosystem Science and Technology Branch, NASA/Ames Research Center, Moffett Field, CA 94035, USA.
Adv Space Res. 1995 Mar;15(3):223-8. doi: 10.1016/s0273-1177(99)80088-x.
If life were present on Mars to day, it would face potentially lethal environmental conditions such as a lack of water, frigid temperatures, ultraviolet radiation, and soil oxidants. In addition, the Viking missions did not detect near-surface organic carbon available for assimilation. Autotrophic organisms that lived under a protective layer of sand or gravel would be able to circumvent the ultraviolet radiation and lack of fixed carbon. Two terrestrial photosynthetic near-surface microbial communities have been identified, one in the inter- and supertidal of Laguna Ojo de Liebre (Baja California Sur, Mexico) and one in the acidic gravel near several small geysers in Yellowstone National Park (Wyoming, U.S.A.). Both communities have been studied with respect to their ability to fix carbon under different conditions, including elevated levels of inorganic carbon. Although these sand communities have not been exposed to the entire suite of Martian environmental conditions simultaneously, such communities can provide a useful model ecosystem for a potential extant Martian biota.
如果如今火星上存在生命，它将面临潜在的致命环境条件，如缺水、严寒温度、紫外线辐射和土壤氧化剂。此外，海盗号任务未检测到可供同化的近地表有机碳。生活在沙子或砾石保护层下的自养生物将能够规避紫外线辐射和固定碳的缺乏。已鉴定出两个陆地光合近地表微生物群落，一个位于Laguna Ojo de Liebre（墨西哥南下加利福尼亚州）的潮间带和潮上带，另一个位于美国怀俄明州黄石国家公园几个小间歇泉附近的酸性砾石中。对这两个群落都进行了研究，考察它们在不同条件下，包括无机碳水平升高时固定碳的能力。尽管这些沙地群落尚未同时暴露于火星的全套环境条件下，但这样的群落可为潜在现存的火星生物群提供一个有用的模型生态系统。
