Life-form composition of alpine plant communities at the Eastern Qinghai-Tibetan plateau

Abstract

Alpine plants of the eastern Qinghai-Tibetan plateau (Sichuan, China) are developed under long-lasting grazing by wild and domestic yaks. Among morphological features of plants, life forms may reflect their adaptation to grazing. We studied life-form composition of four typical communities within the alpine belt (3930–3960 m a.s.l.) subjected to grazing of various intensity: alpine fen (heavily grazed), alpine shrub meadow (heavily grazed), Spiraea alpina thicket (grazed), and Rhododendron thicket (practically not grazed). The following morphological traits were studied: (1) life form according to Raunkiaer, (2) life form according to Serebryakov, (3) canopy structure, and (4) rate of lateral spreading. We derived life-form spectra based on (1) the number of species per life form and (2) the cumulative abundance of species which have the same life form. One-way ANOVA and nonparametric ANOVA were run to test for significance of differences between spectra. The studied communities differed significantly by the proportion of different life forms. The main life forms are caudex and short rhizome hemicryptophytes, nonclonal species, or species with a low rate of lateral spreading. Therophytes made up 10–11% of the communities except in Rhododendron thickets, where such were absent. These life forms can indicate grazing in the study area.

Keywords::

• Alpine vegetation
• life form
• yak grazing
• canopy structure
• lateral spreading

Acknowledgements

The authors thank their colleagues P.Yu. Zhmylev for consultations concerning life forms, M.G. Pimenov, Yu.E. Alekseev, and M.N. Kozhin for identification of several groups of plants, and Ken Thompson for comments to the first draft, M.S. Blinnikov on the second draft, and the anonymous reviewer.

Additional information

Funding

This work was supported by RFBR [grant numbers 08-04-00344, 08-04-92206], Grant of Minobrnauka RF [grant number 16.740.111.0177], Grants of Chinese Academy of Sciences Fellowships for Young International Scientists [grant number 2011Y1SA01], Grant of the National Natural Science Foundation of China [grant numbers 30870396, 40971178, and 31150110471], and Ministry of Science and Technology [grant number 2009BA184B02].