Open Access

ARTICLE

Potential spatial expansion of Ulmus macrocarpa population in Keerqin sandy lands, China

by Jianar A, JH Yuan, YF Yang

Key Laboratory of Vegetation Ecology, Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun, China 130024.
This work was funded by the National Key Research and Development Program of China (2016 YFC0500602), Natural Science Foundation of China (31472134, www.nsfc.gov. cn, YFY), and the Program of Introducing Talents of Discipline to Universities (B16011).

Address correspondence to: Prof. Yunfei Yang, Fax 086-431-85695065; Phone 086-431-85098994; e-mail: ; ;

Phyton-International Journal of Experimental Botany 2018, 87(all), 32-39. https://doi.org/10.32604/phyton.2018.87.032

Abstract

Ulmus macrocarpa Hance can form monodominant woodlands in the semiarid Keerqin sandy lands, China. Methods of sampling at meter intervals from the bases of trees at the woodland edges and isolated trees, respectively, were employed along vertical sections in different directions. Using statistical methods based on the density function of the Weibull distribution, the patterns of seed dispersal and the spatial expansion response of U. macrocarpa, which is a typical anemochorous plant, were analyzed. Although as an effect of the wind direction varying owing to the monsoon, there were differences in the degree of dispersal of seeds in terms of distance, and cumulative seed number for the woodland edges and isolated trees, the seed dispersal patterns were all the same. That is, the seed dispersal patterns can be described by density functions of the Weibull distribution (P<0.01) for the frequencies of the number of seeds per unit area away from the tree bases. The shape parameter (α) of the Weibull distribution associated with the mechanism of seed dispersal always had values of α>1 in different directions. Therefore, it is proposed that U. macrocarpa always displays a “long-distance” seed dispersal pattern, whether from isolated trees or those at woodland edges, or whether with or against the wind direction under natural conditions in the Keerqin sandy lands. This could be understood as the potential spatial expansion of U. macrocarpa populations in different directions always following the same pattern.

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