Mongolian pine is widely planted in arid and semi-arid regions, and serves as an important wind control and sand fixation species.
The root distribution pattern determines the range of resources that plants can absorb and utilize. The root distribution pattern of Mongolian pine plantations, according to some studies, can be affected by soil moisture and groundwater table. To reveal the mechanism controlling this relationship is necessary.
In a study published in Trees Structure and Function, Ala Musa and his colleagues from the Institute of Applied Ecology of the Chinese Academy of Sciences examined the root distribution characteristics of Mongolian pines in relation to soil water content and groundwater table. They found that fine roots which show an hourglass-shape distribution have a strong relationship with water utilization.
The proportion of fine roots is much higher in shallow (5–35 cm; 44.67%) and deep (85–145 cm; 43.53%) soil layers than that in the middle layer (35–85 cm; 11.8%), displaying a pattern that is consistent with the vertical distribution pattern of soil water content.
The depth of groundwater table in the Mongolian pine plantation increases from May to October, with an average depth of 251 cm, showing a seasonal pattern.
Rainfall and groundwater control the pattern of soil moisture in Mongolian pine plantations, and in turn affect the root distribution characteristics of these pines.
This study showed that whether deep roots of Mongolian pines can effectively obtain water underground determines the survival and growth of these pine plantations in the western Horqin Sandy Land.