Ecological characteristics of cultivated Haloxylon ammodendron communities in Gurbantunggut Desert

The ecological characteristics of Haloxylon ammodendron communities cultivated under rainfed conditions for 33 years in Mosuowan of Southern Gurbantunggut Desert were analyzed under two afforestation techniques-snow-sand dressing afforestation and autumn-irrigated afforestation. The growth potential, understory vegetation and soil water content were monitored and recorded. Results showed that:1) H. ammodendron had strong growth with an average plant height and canopy spread under both cultivation techniques exceeding 2 m and 2 m², respectively. The average length of new branches was more than 20 cm, with a survival rate of afforestation of 40% under snow-sand dressing and 63% under autumn irrigation. The den-sity was enhanced and uneven-aged mixed forest was formed due to natural regeneration. There were different kinds of dominant species herbs in the forest. The average soil water content under the two forest treatments both exceeded 2.00%, which was enough to support H. ammodendron growth. 2) There were obvious differences between the two forests cultivation techniques in terms of vegetation cover and species diversity and natural regeneration of H. ammodendron due to the differences in the treatments, site conditions and initial water supply. 3) The two communities were highly adaptable to the local ecological conditions. Compared with autumn irrigated afforestation, the density, vegetation cover and number of natural regeneration were lower in snow-sand dressing afforestation. The cost also was lower, but grew slowly under autumn irrigated afforestation after irrigated was stopped. There was the need for effective artificial measures to reduce the density of H. ammodendron. In conclusion, H. ammodendron growth under snow-sand dressing and autumn irrigated afforestation was both stable with the latter well-adapted to the local ecological conditions.