Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.
Ecol Lett. 2018 Mar;21(3):376-383. doi: 10.1111/ele.12905. Epub 2018 Jan 10.
C photosynthesis is considered an adaptation to warm climates, where its functional benefits are greatest and C plants achieve their highest diversity and dominance. However, whether inherent physiological barriers impede the persistence of C species in cool environments remains debated. Here, we use large grass phylogenetic and geographical distribution data sets to test whether (1) temperature influences the rate of C origins, (2) photosynthetic types affect the rate of migration among climatic zones, and (3) C evolution changes the breadth of the temperature niche. Our analyses show that C photosynthesis in grasses originated in tropical climates, and that C grasses were more likely to colonise cold climates. However, migration rates among tropical and temperate climates were higher in C grasses. Therefore, while the origins of C photosynthesis were concentrated in tropical climates, its physiological benefits across a broad temperature range expanded the niche into warmer climates and enabled diversification into cooler environments.
C 光合作用被认为是对温暖气候的一种适应，在这种气候下，它的功能效益最大，C 植物的多样性和优势达到最高。然而，内在的生理障碍是否会阻碍 C 物种在凉爽环境中的持续存在，这一问题仍存在争议。在这里，我们利用大型禾本科植物的系统发育和地理分布数据集来检验以下三个假说：（1）温度是否影响 C 起源的速度；（2）光合作用类型是否影响不同气候带之间的迁移率；（3）C 进化是否会改变温度生态位的宽度。我们的分析表明，禾本科植物中的 C 光合作用起源于热带气候，而 C 禾本科植物更有可能在寒冷的气候中殖民。然而，C 禾本科植物在热带和温带气候之间的迁移率更高。因此，虽然 C 光合作用的起源集中在热带气候，但它在广泛的温度范围内的生理效益将生态位扩展到了更温暖的气候，并使多样化进入了更凉爽的环境。
