Responses of Haloxylon ammodendron potential geographical distribution to the hydrothermal conditions under MaxEnt model

The MaxEnt model and GIS technology were employed to study the responses of Haloxylon ammodendron potential geographical distribution to the hydrothermal conditions in China and the main factors and threshold based on collected geographical distribution of the known coordinates and 20 high-resolution environmental factor layers. The results showed that the potential geographical distribution range were Xinjiang except small amounts in the south and center of Hotan, the southwest of Inner Mongolia, the north of central Gansu, the northwest of Ningxia, the middle of Qinghai Hercynian Mongolian and Tibetan autonomous prefecture and the southwest of Tibetan autonomous prefecture. Among them, the most suitable distribution region were the most regions of Junggar Basin, the southwest of Boluo wild mountain, the southeast of Halitosan mountain and little region in Turpan and Korla. There were scattered distribution in the southeast of Alxa Left Banner, Ordos, Hohehot Municipality and Wulanchabu, the northeast of Wu wei, the most region of Zhang ye, the east of Golmud, the northwest of Ulan and Dulan County. The total area was 2.95×105 km2. The dominate climatic factors influencing potential distribution of H. ammodendron in China were annual precipitation, precipitation of wettest month, annual mean temperature and mean temperature of driest season which had contribution rate of 27.5%, 20.3%, 14.2% and 10.1%, and threshold of 15.0~114.5 mm, 8.0~59.5 mm, -12.7~29.2 ℃ and -33.3~35.9 ℃, respectively. These research results can be applied to the suitable and reserve areas classification and provide reference for management decisions.