Chin J Plant Ecol ›› 2015, Vol. 39 ›› Issue (10): 980-989.DOI: 10.17521/cjpe.2015.0095

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Structure and dynamic characteristics of Gymnocarpos przewalskii in different habitats

Li-Long WANG1, Liang WANG2, Li-Fang ZHANG1, Yu-Yang LIU1, Shi-Jian XU1,*()   

  1. 1School of Life Sciences, Lanzhou University, Lanzhou 730000, China
    2Administration of Anxi Extra-arid Desert National Nature Reserve, Jiuquan, Gansu 736100, China
  • Online:2015-10-20 Published:2015-10-24
  • Contact: Shi-Jian XU

Abstract: Aims

Gymnocarpos przewalskii is a relict plant of the Tethys flora, which is also one of the constructive species in stony desert. Our objective was to determine the structure and dynamic characteristics of G. przewalskii in different habitats.

Methods

Based on the equal-area plot investigations in three habitats of G. przewalskii, the static life table was established, survival curves and the function curves derived from the survival analysis were also constructed to evaluate the population characteristics. The population dynamics were predicted by a time-sequence model.

<i>Important findings</i>

The survival curves of G. przewalskii appear to approach the Deevey-II type, which indicate that the mortality rate in different size classes was similar, and the population fit in with the growing type in all habitats, but sensitive to environment disturbances. The population size of G. przewalskii was largest in flooding lands, medium in gullies and smallest in the flat desert and the age structure showed that the flooding lands and gullies are better habitats for the growth of G. przewalskii. The survival analysis and the time-sequence model demonstrated that the lack of young individuals could be the major cause for population declines of G. przewalskii in all habitats; moreover, a decline is likely to occur in the flat desert earlier and quicker.

Key words: Gymnocarpos przewalskii, habitat, life table, survival analysis, time sequence analysis