Fine-scale genetic structure of Nothofagus pumilio (lenga) at contrasting elevations of the altitudinal gradient

Montane forests provide the natural framework to test for various ecological settings at distinct elevations as they may affect population demography, which in turn will affect the spatial genetic structure (SGS). We analyzed the fine-scale SGS of Nothofagus pumilio, which dominates mountain areas o...

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Bibliographic Details
Authors: Mathiasen, Paula, Premoli Il'grande, Andrea Cecilia
Format: article
Status:Published version
Publication Date:2013
Country:Argentina
Institution:Consejo Nacional de Investigaciones Científicas y Técnicas
Repository:CONICET Digital (CONICET)
Language:English
OAI Identifier:oai:ri.conicet.gov.ar:11336/6815
Online Access:http://hdl.handle.net/11336/6815
Access Level:Open access
Keyword:Clonality
Isozymes
Microsatellites
Nothofagus
Sgs
South American Beech
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Description
Summary:Montane forests provide the natural framework to test for various ecological settings at distinct elevations as they may affect population demography, which in turn will affect the spatial genetic structure (SGS). We analyzed the fine-scale SGS of Nothofagus pumilio, which dominates mountain areas of Patagonia, in three pairs of sites at contrasting elevations (low- vs. high-elevation). Within a total area of 1 ha fresh leaf tissue from 90 individuals was collected at each of the six studied stands following a spatially explicit sampling design. Population genetic diversity parameters were analyzed for all sampled individuals using five polymorphic isozyme loci, and a subset of 50 individuals per stand were also screened for five microsatellite loci. The SGS was assessed on 50 individuals / stand, using the combined datasets of isozymes and microsatellites. Most low-elevation stands consisted of older individuals with complex age structures and genetically diverse plots. In contrast, high-elevation stands and one post-fire low-elevation population yielded even-aged structures with evidence of growth suppression, and were genetically homogeneous. All stands yielded significant SGS. Similarly to mature stands of the non-sprouter congener N. dombeyi, multi-age low-altitude N. pumilio yielded significant SGS weakened by competing species of the understory and the formation of seedling banks. Alike the sprouter N. antarctica, high-altitude stands produced significant SGS as a consequence of occasional seedling establishment reinforced by vegetative spread.