80
3.8 Conservation and Management of Raulí Forests
in Argentina
In Argentina, N. alpina has been protected since the creation of the National Park
Lanín in 1937, and, although devastated in some areas in the past because of its
valuable wood, now it is not threatened by logging. The current tendency in
Argentine Nothofagus mixed forest (N. alpina, N. obliqua and N. dombeyi) is to
extract every time less wood from the native forests due to social pressures. Actually,
the main threat for this species is climate change. As has been shown by Marchelli
et al. (2017; see Chap. 18 for details), according to the more plausible climate
change scenarios for the mountainous zone of North Patagonia, the distribution of
raulí will be seriously reduced. This species has very specific autoecological requirements for germination and establishment of regeneration, among which humidity
and shadow protection counts as the most important. Therefore, forest management
in the coming decades should consider the effects of global climate change in
N. alpina forests.
Assisted migration activities are often proposed for mitigation of the effects of
climate change in endangered species (Vitt et al. 2009; Williams and Dumroese
2013). In this sense, large areas of suitable habitat are predicted to appear in the
future at southern latitudes, outside of the species’ current distribution ranges, as
well as locally but at higher altitudes in western sites (Marchelli et al. 2017).
However, assisted migration can have unintended and unpredictable consequences
(Fady et al. 2016), and caution is in place before introducing a species to areas
where is considered as exotic. To maintain the native forest with all its production
and ecosystem functions, in situ conservation strategies are the best choice. These
strategies might be enhanced by promoting ecological connectivity to expedite natural migration of high diversity populations to new suitable areas. Also management practices should promote the persistence of ecosystem functionality.
Silvicultural practices that involve natural regeneration, regulation of species
mixtures, thinning and harvesting operations could have a strong influence on the
genetic variation of the populations (Finkeldey and Ziehe 2004), which is essential
to preserve the adaptation capacity (Lefèvre et al. 2013). Silvicultural management
of Nothofagus mixed forests (N. dombeyi, N. alpina and N. obliqua) has been carried
out within Lanín National Park (40° 9′ S, 71° 21′ W) since late 1980, mainly
following the shelterwood system. This system consists in successive regeneration
cuttings that retain partial forest cover (canopy cover of around 30–40%) until the
regeneration phase is complete (approximately 20 years, Chauchard 1989).
In order to evaluate the effects of a seed cut (cut performed with the purpose of
seed dissemination) on the regeneration dynamics, Sola et al. (2015, 2016, 2020a)
studied the genetic diversity and gene flow at different spatial scales in Nothofagus
mixed forests after about 20 years of seed cut implementation. At microsite scale (a
2.85 ha plot), an intensive sampling of pre- (mature trees) and post- (regeneration)
harvest individuals of all three species (N. alpina, N. obliqua and N. dombeyi) was
combined with microsatellite genotyping (>2000 individuals and 15 microsatellite
P. Marchelli et al.
3.8 Conservation and Management of Raulí Forests
in Argentina
In Argentina, N. alpina has been protected since the creation of the National Park
Lanín in 1937, and, although devastated in some areas in the past because of its
valuable wood, now it is not threatened by logging. The current tendency in
Argentine Nothofagus mixed forest (N. alpina, N. obliqua and N. dombeyi) is to
extract every time less wood from the native forests due to social pressures. Actually,
the main threat for this species is climate change. As has been shown by Marchelli
et al. (2017; see Chap. 18 for details), according to the more plausible climate
change scenarios for the mountainous zone of North Patagonia, the distribution of
raulí will be seriously reduced. This species has very specific autoecological requirements for germination and establishment of regeneration, among which humidity
and shadow protection counts as the most important. Therefore, forest management
in the coming decades should consider the effects of global climate change in
N. alpina forests.
Assisted migration activities are often proposed for mitigation of the effects of
climate change in endangered species (Vitt et al. 2009; Williams and Dumroese
2013). In this sense, large areas of suitable habitat are predicted to appear in the
future at southern latitudes, outside of the species’ current distribution ranges, as
well as locally but at higher altitudes in western sites (Marchelli et al. 2017).
However, assisted migration can have unintended and unpredictable consequences
(Fady et al. 2016), and caution is in place before introducing a species to areas
where is considered as exotic. To maintain the native forest with all its production
and ecosystem functions, in situ conservation strategies are the best choice. These
strategies might be enhanced by promoting ecological connectivity to expedite natural migration of high diversity populations to new suitable areas. Also management practices should promote the persistence of ecosystem functionality.
Silvicultural practices that involve natural regeneration, regulation of species
mixtures, thinning and harvesting operations could have a strong influence on the
genetic variation of the populations (Finkeldey and Ziehe 2004), which is essential
to preserve the adaptation capacity (Lefèvre et al. 2013). Silvicultural management
of Nothofagus mixed forests (N. dombeyi, N. alpina and N. obliqua) has been carried
out within Lanín National Park (40° 9′ S, 71° 21′ W) since late 1980, mainly
following the shelterwood system. This system consists in successive regeneration
cuttings that retain partial forest cover (canopy cover of around 30–40%) until the
regeneration phase is complete (approximately 20 years, Chauchard 1989).
In order to evaluate the effects of a seed cut (cut performed with the purpose of
seed dissemination) on the regeneration dynamics, Sola et al. (2015, 2016, 2020a)
studied the genetic diversity and gene flow at different spatial scales in Nothofagus
mixed forests after about 20 years of seed cut implementation. At microsite scale (a
2.85 ha plot), an intensive sampling of pre- (mature trees) and post- (regeneration)
harvest individuals of all three species (N. alpina, N. obliqua and N. dombeyi) was
combined with microsatellite genotyping (>2000 individuals and 15 microsatellite
P. Marchelli et al.