Extra carbon to beat salt as opposed to heat
Atriplex canescens photo © Stan Shebs
Vegetation of Great Basin in winter photo © Qfl247
The C4-photosynthetic pathway is typical of tropical grasses because it allows the fixation of more carbon under hot, desiccating conditions than the C3 pathway would. It is surprising that saltbushes (belonging to the worldwide genus Atriplex) use the C4 pathway because these dicotyledonous shrubs extend into cold climates with winter snow. A possible explanation is that saltbushes, like tropical grasses, risk desiccation – in this case owing to salinity.
Robin and the Honey Badger, 8 January 2017
Vegetation of Great Basin in winter