Structure and Dynamic of Populus euphratica Population along Tarim River

The population structure of plant species, especially long-lived ones is considered as indicators of vegetation succession as well as climate changes along the tree lined ecotone. Describing the population structure is a well-known method for analyzing population dynamics. Age is one of the important elements to evaluate the structure of plant populations. Moreover, the life table and survivorship curve are very important tools for the study of population structures and dynamics.

Populus euphratica Oliv. is the dominant tree species and exclusive germplasm resource in the Tarim Basin. During the last five years, the area of the P. euphratica population has been reduced considerably in the upper and lower reaches of the Tarim River. There were many studies on the distribution and differentiation of biological characteristics of P. euphratica. However, few discussions were conducted on the structure and dynamics of P. euphratica population.

To explore the population structure, quantitative dynamics, living status and future developmental trends of P. euphratica population, researchers did field investigation in the upper and lower reaches of the Tarim River. The results showed that young individuals were dominant in the upper reaches of the P. euphratica population, with the survivor curve belonging to the Deevey C type category. The time sequence model demonstrated that the number of mid-aged individuals in the upper reaches of the river will increase in population over the next 20-40 years. In contrast, young individuals were rare in the lower reaches, and mid-aged individuals comprised the largest proportion of the population. The time sequence model for this population demonstrated that the number of old individuals will increase and young individuals will decrease during the next 20-40 years. The main cause of this difference between the upper and lower reaches of the Tarim River is connected mostly to the level of ground water, which plays an important role in the determination of age structure. Therefore, the crucial factors for the natural regeneration and restoration of P. euphratica were the ground water level and their habitat.

The result was published in Pakistan Journal of Botany, 2012, 44(5): 1651-1656. The paper can be downloaded from http://www.pakbs.org/pjbot/PDFs/44(5)/24.pdf.

Contact:

LIU GuoJun

Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China

E-mail: lgjs96@sohu.com