Vogel J C, Fuls A, Danin A
National Physical Research Laboratory, CSIR, PO Box 395, Pretoria, South Africa.
Department of Botany, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel.
Oecologia. 1986 Sep;70(2):258-265. doi: 10.1007/BF00379249.
The relation between photosynthetic pathway and habitat of the grass species recorded in the desert regions of Sinai, Negev, and Judea was investigated. The climatic conditions and micro-environments in the study area vary considerably, and the distribution of the various species is found to conform to specific patterns which reveal the adaptive advantages of the different photosynthetic pathways. There is also a distinct correlation between the phytogeographic origin of the grass species and the photosynthetic pathways that they utilize.The survey shows that the majority of the grass species in the region are of the C type and all except one of these species belong to the Holarctic domain. This is in accordance with the fact that the region forms part of the Mediterranean winter rainfall regime and that C species have an adaptive advantage where minimum temperatures are low during the winter growing season.The occurence of C species increases with decreasing rainfall and they dominate in those districts where temperatures are high throughout the year. These C grasses are of both Holarctic and Palaeotropic origin according to the classification adopted here, but they are essentially all elements of the Saharo-Arabian, Irano-Turanian, Sudanian, or Tropical phytogeographic regions and are not typical of the Mediterranean or Euro-Siberian floras. The plants with multi-regional distributions that occur in Mediterranean communities may well be intrusive.Analysis of the three subtypes of the C species suggests that the malate-forming NADP-me grasses grow where water stress is not a dominating factor, while the aspartateforming NAD-me grasses are more successful under xeric conditions. The PEP-ck species are not abundant and form an intermediate group between the NADP-me and NAD-me subtypes.
研究了西奈半岛、内盖夫沙漠和朱迪亚沙漠地区所记录的禾本科物种的光合途径与栖息地之间的关系。研究区域的气候条件和微环境差异很大，发现各种物种的分布符合特定模式，这些模式揭示了不同光合途径的适应性优势。禾本科物种的植物地理起源与其所利用的光合途径之间也存在明显的相关性。调查显示，该地区的大多数禾本科物种属于C型，除一种外，所有这些物种都属于全北区。这与该地区是地中海冬雨区的一部分这一事实相符，并且C类物种在冬季生长季节最低温度较低的地方具有适应性优势。C类物种的出现随着降雨量的减少而增加，并且它们在全年温度较高的地区占主导地位。根据此处采用的分类，这些C类禾本科植物既有全北区的起源，也有古热带的起源，但它们基本上都是撒哈拉 - 阿拉伯、伊朗 - 图兰、苏丹或热带植物地理区域的元素，并非地中海或欧洲 - 西伯利亚植物区系的典型代表。在地中海群落中出现的具有多区域分布的植物很可能是入侵物种。对C类物种的三个亚型的分析表明，形成苹果酸的NADP - me禾本科植物生长在水分胁迫不是主导因素的地方，而形成天冬氨酸的NAD - me禾本科植物在干旱条件下更具优势。PEP - ck物种数量不多，形成了介于NADP - me和NAD - me亚型之间的中间群体。
