Chin J Plant Ecol ›› 2023, Vol. 47 ›› Issue (4): 506-514.DOI: 10.17521/cjpe.2022.0319

• Research Articles • Previous Articles     Next Articles

Population structure and point pattern analysis of rare and endangered plant Potaninia mongolica in eastern Alxa, China

LI Xiao-Tian, WANG Tie-Juan*(), HAN Wen-Juan, ZHANG Li, ZHANG Hui, LIU Xiao-Ting, LIU Ya-Jie   

  1. College of Life Science and Technology, Inner Mongolia Normal University, Key Laboratory of Biodiversity Conservation and Sustainable Utilization for College and University of Inner Mongolia Autonomous Region, Hohhot 010022, China
  • Received:2022-07-27 Accepted:2022-12-09 Online:2023-04-20 Published:2022-12-10
  • Contact: *(
  • Supported by:
    Nei Mongol Autonomous Region Science and Technology Plan Project(2020GG0124)


Aims Potaninia mongolica, as a remnant species of ancient monospecific genus distributed in the northwest desert area, belongs to the category of national secondary key protected plants in China. The present study aims to investigate the structure, intra- and interspecific relationships, as well as the adaptation strategies to the environment of different types of P. mongolica populations. In particular, the age structure, spatial distribution patterns, and spatial correlations between size classes of P. mongolica populations were analyzed.

Methods Potaninia mongolica population concentrated in the gravel land (referred to as the Alxa population) and distributed in sandy soil in the eastern marginalia of distribution area (referred to as Erdos population) were selected. Through the size structure analysis method, P. mongolica individuals were categorized into three size classes, namely class I: d ≤ 10 cm; class II: 10 cm < d ≤ 30 cm; and class III: d > 30 cm, where d stands for the cubic root of the product of crown length, crown width and plant height. Moreover, the age structure, spatial distribution patterns, and spatial correlations between size classes of the selected P. mongolicapopulations were analyzed using the Ripley’s K-function through spatial point pattern analysis.

Important findings Results of the study include: 1) The Alxa population of P. mongolica was dominated by class II plants, accounting for 69%, whereas class I plants accounting for only 5% of the total population. However, the Alxa population was observed to be stable because of asexual reproduction. On the other hand, for the Erdos population, the proportion of class II and III plants were similar, and no class I plants were observed, which resulted in limited population renewal by seed propagation. 2) The Alxa population was randomly distributed, with class I and II plants predominantly distributed in clusters at small and medium scales and randomly distributed at large scales. Nevertheless, the Erdos population was predominantly distributed in clusters, both in general and at all size scales, which was strongly related to interspecific competition. 3) There was a significant negative correlation between class III and I individuals of the Alxa population at small and medium scales, reflecting the inhibition effect of the senior individuals on the young individuals. However, class II and III plants of the Erdos population showed a positive association with increasing scale range, suggesting a positive interaction between mature age classes of P. mongolica.

Key words: eastern Alxa, Potaininia mongolica, spatial distribution pattern, spatial association, size structure