Fig. 1

Microclimatic niches in Sahara Desert dune and belowground speargrasses. a Representative image of wild speargrass Stipagrostis pungens growing in the sandy dunes of the Sahara Desert in Ksar Ghilane, Tunisia; portion of the plant belowground rhizosheath–root system sampled is shown. b, c Temperature (ºC) and d, e relative humidity (%) experienced by bulk sand (surface and deep) and belowground plant (i.e., rhizosheath–root system; surface and deep) throughout the day at 6:00, 12:00, 18:00, 24:00 h. Values are expressed as means (n = 7). c and e Box plots showing details of temperature (ºC) and relative humidity (%), respectively, measured at midday (12:00) in barren sand (surface and deep) and belowground plant (surface and deep) in summer and winter; lowercase letters indicate the results of the post-hoc multiple comparison Tukey’s test among sand and belowground plant separately in the two seasons