40
populations were significantly different (Allnutt et al. 1999). The populations from
eastern slopes of the Andes (Argentinean populations) were more variable than
those of the west and suggested an origin from different glacial refugia (Premoli
et al. 2000b).
Another group of tree conifers inhabiting these forests belong to the Podocarpaceae
family: Podocarpus nubigenus, Saxegothaea conspicua, and Prumnopitys andina.
All these species are more abundant in Chile and occur in very humid sites in
Argentina, near the border. Podocarpus nubigenus has a widespread latitudinal
range (between 39° 50′ and 50° 23′ S) but occurs in small and isolated populations
with low density, under climatic conditions of high precipitation. While in Chile it
grows at the Coastal Range, the Andes, and the Central Valley, in Argentina, it is
restricted to the region of the Valdivian rainforests (Donoso et al. 2006b). It usually
forms mixed forests with other conifers like S. conspicua, F. cupressoides, and
P. uviferum, as well as some broadleaf species like Nothofagus dombeyi, Drimys
winteri, or Embothrium coccineum. Genetic diversity was studied in this species
through isozyme markers (Quiroga and Premoli 2010). A moderate genetic diversity was detected within populations (H T = 0.275) and a significant genetic differentiation (F ST = 0.18). Cluster analysis showed latitudinal divergence at around 43° S
associated to a paleobasin that would have impeded gene flow among northern and
southern populations (Quiroga and Premoli 2010). Saxegothaea conspicua is found
between 36° and 49° S mainly in Chile, at low altitudes on poorly drained marine
deposits in the Coastal and Andes Mountains and also at mid to high altitudes
(400–950 m asl) on shallow soils (Veblen et al. 1981). Prumnopitys andina has a
restricted distribution along the Andes Range between 35° 52′ and 39° 30′, with a
high degree of fragmentation and degradation (Hechenleitner et al. 2005). A genetic
analysis of few populations using AFLP markers revealed low levels of diversity
(He = 0.011) and very high differentiation (F ST = 0.608) (Hernández et al. 2012 cit.
in González 2019).
Among the angiosperms, Nothofagus is the highly dominant genus conforming
about 80% of the Andean-Patagonian forests. This genus has a disjunct distribution
with more than 40 species in the world occurring in New Zealand, Australia, New
Guinea, New Caledonia, and South America (Wardle 1984). In South American
temperate forests, we can find ten species and three recognized hybrids, with six of
these species occurring in Argentina Nothofagus obliqua, N. alpina (= N. nervosa),
N. pumilio, N. antarctica, N. dombeyi, and N. betuloides. The most relevant of these
Nothofagus species are described in detail in the specific chapters of this section of
the book (Chaps. 3, 4 and 5).
Some small trees of the Proteaceae family can also be mentioned: Lomatia hirsuta, remarkable due to its fine wood used in carpentry and joinery work; Gevuina
avellana, cultivated (not in Argentina) for the production of its edible fruits; and
Embothrium coccineum (Fig. 2.5), whose abundant and colorful flowering causes it
to be frequently planted with ornamental purposes. Gevuina avellana grows mainly
on the western slopes of the Andes between 35° and 44° S, from sea level till 700 m
asl, as an understory species usually associated with N. obliqua and N. alpina
(Donoso 1978). Molecular markers (EST-SSRs) were developed and used to
P. Marchelli et al.
populations were significantly different (Allnutt et al. 1999). The populations from
eastern slopes of the Andes (Argentinean populations) were more variable than
those of the west and suggested an origin from different glacial refugia (Premoli
et al. 2000b).
Another group of tree conifers inhabiting these forests belong to the Podocarpaceae
family: Podocarpus nubigenus, Saxegothaea conspicua, and Prumnopitys andina.
All these species are more abundant in Chile and occur in very humid sites in
Argentina, near the border. Podocarpus nubigenus has a widespread latitudinal
range (between 39° 50′ and 50° 23′ S) but occurs in small and isolated populations
with low density, under climatic conditions of high precipitation. While in Chile it
grows at the Coastal Range, the Andes, and the Central Valley, in Argentina, it is
restricted to the region of the Valdivian rainforests (Donoso et al. 2006b). It usually
forms mixed forests with other conifers like S. conspicua, F. cupressoides, and
P. uviferum, as well as some broadleaf species like Nothofagus dombeyi, Drimys
winteri, or Embothrium coccineum. Genetic diversity was studied in this species
through isozyme markers (Quiroga and Premoli 2010). A moderate genetic diversity was detected within populations (H T = 0.275) and a significant genetic differentiation (F ST = 0.18). Cluster analysis showed latitudinal divergence at around 43° S
associated to a paleobasin that would have impeded gene flow among northern and
southern populations (Quiroga and Premoli 2010). Saxegothaea conspicua is found
between 36° and 49° S mainly in Chile, at low altitudes on poorly drained marine
deposits in the Coastal and Andes Mountains and also at mid to high altitudes
(400–950 m asl) on shallow soils (Veblen et al. 1981). Prumnopitys andina has a
restricted distribution along the Andes Range between 35° 52′ and 39° 30′, with a
high degree of fragmentation and degradation (Hechenleitner et al. 2005). A genetic
analysis of few populations using AFLP markers revealed low levels of diversity
(He = 0.011) and very high differentiation (F ST = 0.608) (Hernández et al. 2012 cit.
in González 2019).
Among the angiosperms, Nothofagus is the highly dominant genus conforming
about 80% of the Andean-Patagonian forests. This genus has a disjunct distribution
with more than 40 species in the world occurring in New Zealand, Australia, New
Guinea, New Caledonia, and South America (Wardle 1984). In South American
temperate forests, we can find ten species and three recognized hybrids, with six of
these species occurring in Argentina Nothofagus obliqua, N. alpina (= N. nervosa),
N. pumilio, N. antarctica, N. dombeyi, and N. betuloides. The most relevant of these
Nothofagus species are described in detail in the specific chapters of this section of
the book (Chaps. 3, 4 and 5).
Some small trees of the Proteaceae family can also be mentioned: Lomatia hirsuta, remarkable due to its fine wood used in carpentry and joinery work; Gevuina
avellana, cultivated (not in Argentina) for the production of its edible fruits; and
Embothrium coccineum (Fig. 2.5), whose abundant and colorful flowering causes it
to be frequently planted with ornamental purposes. Gevuina avellana grows mainly
on the western slopes of the Andes between 35° and 44° S, from sea level till 700 m
asl, as an understory species usually associated with N. obliqua and N. alpina
(Donoso 1978). Molecular markers (EST-SSRs) were developed and used to
P. Marchelli et al.