Abstract: To study the spatial distribution pattern of plant fine root is the basis of constructing water uptake model of plant roots. The study on the spatial distribution pattern of Populus euphratica fine roots in desert riparian forest showed that horizontally, the distribution of P. euphratica root length density presented a parabola curve. The fine roots were concentrated within the range of 0-350 cm from the tree trunk, and their amount occupied 91.88% of the total within 0-500 cm. In vertical direction, the distribution of the fine rootlength density showed a negative exponent correlation with soil depth. The fine roots were concentrated in 0-80 cm soil layer, and their amount accounted for 96.8% of the total in 0-140 cm soil layer.

Key words: Plant, Root exudates, Methane production, Methane oxidation, Methane emission