Tree endurance on the Tibetan Plateau marks the world's highest known tree line of the Last Glacial Maximum.
New Phytol
; 185(1): 332-42, 2010 Jan.
Article
em En
| MEDLINE
| ID: mdl-19761444
ABSTRACT
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 (G(ST) = 0.49, N(ST) = 0.72, N(ST) > G(ST), 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.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Polimorfismo Genético
/
Árvores
/
Adaptação Fisiológica
/
Ecossistema
/
Juniperus
/
Camada de Gelo
País/Região como assunto:
Asia
Idioma:
En
Revista:
New Phytol
Assunto da revista:
BOTANICA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Alemanha