Edwards Erika J, Still Christopher J
Department of Geography and the Institute for Computational Earth System Science University of California at Santa Barbara, Santa Barbara, CA 93106 USA.
Ecol Lett. 2008 Mar;11(3):266-76. doi: 10.1111/j.1461-0248.2007.01144.x. Epub 2008 Jan 14.
'C4 photosynthesis' refers to a suite of traits that increase photosynthesis in high light and high temperature environments. Most C4 plants are grasses, which dominate tropical and subtropical grasslands and savannas but are conspicuously absent from cold growing season climates. Physiological attributes of C4 photosynthesis have been invoked to explain C4 grass biogeography; however, the pathway evolved exclusively in grass lineages of tropical origin, suggesting that the prevalence of C4 grasses in warm climates could be due to other traits inherited from their non-C4 ancestors. Here we investigate the relative influences of phylogeny and photosynthetic pathway in determining the ecological distributions of C4 grasses in Hawaii. We find that the restriction of C4 grasses to warmer areas is due largely to their evolutionary history as members of a warm-climate grass clade, but that the pathway does appear to confer a competitive advantage to grasses in more arid environments.
“C4光合作用”指的是一系列能在高光和高温环境下增强光合作用的特性。大多数C4植物是禾本科植物，它们在热带和亚热带草原及稀树草原占主导地位，但在寒冷生长季节的气候中却明显不存在。C4光合作用的生理特性已被用来解释C4禾本科植物的生物地理学；然而，该途径仅在热带起源的禾本科谱系中进化，这表明C4禾本科植物在温暖气候中的普遍存在可能归因于从其非C4祖先继承的其他特性。在这里，我们研究系统发育和光合途径在决定夏威夷C4禾本科植物生态分布方面的相对影响。我们发现，C4禾本科植物局限于较温暖地区主要是由于它们作为暖气候禾本科分支成员的进化历史，但该途径似乎确实赋予了禾本科植物在更干旱环境中的竞争优势。
