Authors who contributed equally to the work presented in this article.
Tree endurance on the Tibetan Plateau marks the world’s highest known tree line of the Last Glacial Maximum
Article first published online: 15 SEP 2009
© The Authors (2009). Journal compilation © New Phytologist (2009)
Volume 185, Issue 1, pages 332–342, January 2010
How to Cite
Opgenoorth, L., Vendramin, G. G., Mao, K., Miehe, G., Miehe, S., Liepelt, S., Liu, J. and Ziegenhagen, B. (2010), Tree endurance on the Tibetan Plateau marks the world’s highest known tree line of the Last Glacial Maximum. New Phytologist, 185: 332–342. doi: 10.1111/j.1469-8137.2009.03007.x
- Issue published online: 1 DEC 2009
- Article first published online: 15 SEP 2009
- Received: 28 April 2009, Accepted: 12 July 2009
- glacial refugia;
- high-mountain areas;
- Juniperus tibetica complex;
- orographic leading edge;
- orographic rear edge;
- Tibetan Plateau
- • Because of heterogeneous topographies, high-mountain areas could harbor a significant pool of cryptic forest refugia (glacial microrefugia unrecognized by palaeodata), which, as a result of poor accessibility, have been largely overlooked. The juniper forests of the southern Tibetan Plateau, with one of the highest tree lines worldwide, are ideal for assessing the potential of high-mountain areas to harbor glacial refugia.
- • Genetic evidence for Last Glacial Maximum (LGM) endurance of these microrefugia is presented using paternally inherited chloroplast markers. Five-hundred and ninety individuals from 102 populations of the Juniperus tibetica complex were sequenced at three polymorphic chloroplast regions.
- • Significant interpopulation differentiation and phylogeographic structure were detected (GST = 0.49, NST = 0.72, NST > GST, P < 0.01), indicating limited among-population gene flow. Of 62 haplotypes recovered, 40 were restricted to single populations. These private haplotypes and overall degrees of diversity were evenly spread among plateau and edge populations, strongly supporting the existence of LGM microrefugia throughout the present distribution range, partly well above 3500 m.
- • These results mark the highest LGM tree lines known, illustrating the potential significance of high-mountain areas for glacial refugia. Furthermore, as the close vicinity of orographic rear-edge and leading-edge populations potentially allows gene flow, surviving populations could preserve the complete spectrum of rear-edge and leading-edge adaptations.