The Relation between Water Supply and Tree Growth of High-Yield Poplar Plantation in Dry Area

Irrigation trial was conducted in a 3-year-old poplar plantation (Populus simonii × P. pyramidalis cv. 'Opera 8277') to study the effects of irrigation on the growth of the plantation. The results reveal that the growth of poplar plantation was promoted by rational irrigation and the increments in height, DBH and volume raised by 14.7%, 14.7% and 27.2% respectively. Irrigation brought about the expansion of leaf area and as a result increased the volume increment. The annual volume increment produced by per unit leaf area is more or less stable, approximately varied from 0.00050~0.000 58 m3/m2 and it is not influenced by the quantity of supplied water.