Water using source of a perennial semi-shrub Reaumuria soongorica as measured by water isotopes in Gobi Desert, Inner Mongolia, China

Abstract

Aim: Reaumuria soongorica plays significant role in wind induced soil erosion and combating desertification due to its unique adaptation mechanisms in the Gobi Desert. This study was conducted to investigate its water using sources revealed by hydrogen and oxygen stable isotope as one of its adaptive strategies in Gobi Desert. Methodology: Field experiment was designed in Alashan Desert, China to evaluate the soil and plant water conditions from two R. soongorica sampling sites. Plant and soil water potential were measured by using the Psypro dew point water potential meter equipped with C-52 sample chamber. Water isotopes was measured based on hydrogen (Δ2H) and oxygen (δ18O) stable isotopes. Results: The results showed that the highest soil moisture content in both sites at 70~100 cm was 2.08% and 1.28%, respectively. The average leaf water content of R. soongorica ranged from 18.032% to 38.063% and the average water potential of its root, stem, and leaf was -8.89 and -9.71 MPa for site I and II, respectively. Δ2H and δ18O stable isotope analysis showed that soil water source for R. soongorica for both sites was from layer of 70~100 cm. Interpretation: R. soongorica uses water mainly from the medium soil layer and the results uncover its water using strategies as one of adaptive mechanism in Gobi Desert.