Distribution patterns and characteristics of Nitraria tangutorun nebkha at its different evolvement stages in the Minqin County of Gansu Province
甘肃民勤不同演化阶段白刺灌丛沙堆分布格局及特征

After a thorough investigation on the Nitraria tangutorun nebkhas at its different evolvement stages in the Minqin County of Gansu Province, this paper studied the spatial pattern and shape index of the nebkha, with the local environmental conditions analyzed. The results showed that the N. tangutorun nebkha in Minqin County was mainly at its stable stage, although this stage could not last too long. With the increase of the distance from dune, the nebkha at its different evolvement stages had a regular distribution, and the main reason for this was the interaction among vegetation, surface soil water, and wind. The shape index of the nebkha showed different variation trends with evolvement stage, i.e., no obvious correlation between height and horizontal component at rudimental stage, a second-order polynomial increase of height with increasing horizontal component at developing stage, a logarithmic increase of height with increasing horizontal component at stabilizing stage, and poor correlation between height and horizontal component at degrading stage.