498
Despite all these additional factors, the wide range of germination temperatures
shown by Nothofagus seeds during dormancy alleviation (Fig. 18.6) suggests that
germination behavior could adapt quickly to climate change, what would have
strong consequences on plant distribution shift. These observations have important
implications in the context of future climate scenarios because they indicate that the
predicted shifts in temperature for the Patagonian Andes (Barros et al. 2015) will
affect the timing of germination in their current distribution areas. Since the phenology of germination influences plant survival and the selection of post-germination
traits (Donohue et al. 2010), it is possible that the observed changes in the timing of
germination will affect seedling survival, with consequences in plant recruitment,
which may affect the current pattern of abundance and distribution of Nothofagus
spp. across environmental gradients. In fact, the transition from germinated seed to
seedling constitutes one of the most susceptible developmental stages during the
early steps of the regeneration process of these species. The most critical temporal
window for survival corresponds to the first 60 days after germination. In this
period, the survival is highly influenced by the environment, particularly by temperature (Cagnacci et al. 2020). In this context, shift in the timing of germination
due to changes in the climate can modify the environment perceived by the seedlings in this first critical period, with strong consequences on their survival ability.
18.5 Assisted Migration: Breeding for the Present or
for the Future Climate?
Due to their longevity, the trees we plant today will have to adapt to the environmental conditions of the future. On the other hand, we can predict in which direction the
climate will change. Therefore, it becomes evident to wonder if we should select the
trees according to the current conditions or to the conditions of the future. In other
words, should we plant the species and the provenances adapted to the current or to
the future climate?
Since the beginning of the century and as the evidence of climate change became
more obvious, there has been a debate in the scientific community about the risks
and potential benefits of an assisted migration (AM) strategy for the persistence of
threatened species (Lawler and Olden 2011). AM involves the intentional translocation of specimens of a certain species into an area outside its natural distribution in
order to protect the species from anthropogenic threats that can lead to its extinction
(Seddon 2010). While some authors argue that AM is an essential tool for species
conservation in the face of a changing climate, others highlight the unpredictable
risk of biological invasions that could have a devastating impact of the translocated
species on the recipient ecosystems (Ricciardi and Simberloff 2009).
There are undoubtedly examples for both extremes: species on the way to extinction due to the absence of actions to mitigate the effects of climate change and also
ecosystems that are strongly impacted, and even lost, by the invasion of exotic species. As examples of invasions of tree species in Argentinean forests, we can menM. J. Pastorino et al.
Despite all these additional factors, the wide range of germination temperatures
shown by Nothofagus seeds during dormancy alleviation (Fig. 18.6) suggests that
germination behavior could adapt quickly to climate change, what would have
strong consequences on plant distribution shift. These observations have important
implications in the context of future climate scenarios because they indicate that the
predicted shifts in temperature for the Patagonian Andes (Barros et al. 2015) will
affect the timing of germination in their current distribution areas. Since the phenology of germination influences plant survival and the selection of post-germination
traits (Donohue et al. 2010), it is possible that the observed changes in the timing of
germination will affect seedling survival, with consequences in plant recruitment,
which may affect the current pattern of abundance and distribution of Nothofagus
spp. across environmental gradients. In fact, the transition from germinated seed to
seedling constitutes one of the most susceptible developmental stages during the
early steps of the regeneration process of these species. The most critical temporal
window for survival corresponds to the first 60 days after germination. In this
period, the survival is highly influenced by the environment, particularly by temperature (Cagnacci et al. 2020). In this context, shift in the timing of germination
due to changes in the climate can modify the environment perceived by the seedlings in this first critical period, with strong consequences on their survival ability.
18.5 Assisted Migration: Breeding for the Present or
for the Future Climate?
Due to their longevity, the trees we plant today will have to adapt to the environmental conditions of the future. On the other hand, we can predict in which direction the
climate will change. Therefore, it becomes evident to wonder if we should select the
trees according to the current conditions or to the conditions of the future. In other
words, should we plant the species and the provenances adapted to the current or to
the future climate?
Since the beginning of the century and as the evidence of climate change became
more obvious, there has been a debate in the scientific community about the risks
and potential benefits of an assisted migration (AM) strategy for the persistence of
threatened species (Lawler and Olden 2011). AM involves the intentional translocation of specimens of a certain species into an area outside its natural distribution in
order to protect the species from anthropogenic threats that can lead to its extinction
(Seddon 2010). While some authors argue that AM is an essential tool for species
conservation in the face of a changing climate, others highlight the unpredictable
risk of biological invasions that could have a devastating impact of the translocated
species on the recipient ecosystems (Ricciardi and Simberloff 2009).
There are undoubtedly examples for both extremes: species on the way to extinction due to the absence of actions to mitigate the effects of climate change and also
ecosystems that are strongly impacted, and even lost, by the invasion of exotic species. As examples of invasions of tree species in Argentinean forests, we can menM. J. Pastorino et al.