Fire management is a complex management goal that involves several of these
issues: synergies between management options, interacting agents and time lags.
Although weather conditions and a low fuel load overall constrain wildfires in high
mountain ecosystems, their incidence is far from negligible. They can lead to the
lowering of the treeline (Nagy and Grabherr 2009) and constitute a natural disturbance in the conifer forests of the mountains of western North America (Sibold
et al. 2006), where fire regime has been heavily altered by active fire suppression
policies over the past century (Donovan and Brown 2007). In fact, in many of the
world’s mountain regions, the fire has been used as a major management tool to
foment grasslands, eventually determining ecotones (Nagy and Grabherr 2009). In
recent decades, the loss of local population in mountain areas, at least in developed
countries, is leading to encroachment onto former grasslands, and the consequences
on biodiversity and ecosystem functioning have yet to be fully explored
(Roura-Pascual et al. 2005; Brandt et al. 2013; Formica et al. 2014).
Fire management, and particularly fire suppression, consumes a large proportion of the resources devoted to forest management in countries with a high
climatic fire risk, dense populations in the wildland–urban interface or substantial
forest revenues. Fire management is therefore suited to an analysis based on
trade-offs. Both actions aiming to reduce ignition—i.e. public information, regulation of access to forests, lighting restrictions—and to suppress fires share the
goal of minimising burned areas. A cost-efficiency analysis in both the ecological
and social contexts may help to optimise the contribution of each different action
to the common goal. Paradoxically, however, the reduction of burned surface area
implies further development of vegetation and subsequently the accumulation of
fuel for the future, which will likely produce more intense and extensive fires
(Donovan and Brown 2007; Lloret et al. 2009; Loepfe et al. 2012, but see Odion
et al. 2004). This situation illustrates the temporal dimension of conservation
practices and how they modify the future environment. It also reveals the existence
of feedbacks regulating ecological systems; in this case vegetation growth and
wildfires are mutually regulated by negative feedback. Fire suppression policies
may lead the system to a structure of fire sizes that tends to be less equitative, with
many small fires—which are rapidly extinguished—and very few extremely large
ones, although these are usually very intense (Lloret et al. 2009). In terms of
ecological trade-offs, and in the context of prolonged periods, investment in a
reduction to fire exposure—limitations on lightning and fire propagation caused by
humans—corresponds with increasing future fire sensitivity—associated with more
intense and severe fires—. Assuming that management resources are limited, if
one major goal is the minimisation of megafires of extreme extension and intensity, a strict fire extinction policy is not in itself the best long-term solution, and it
may have strong consequences for the long-term structural and functional properties of ecosystems (Donovan and Brown 2007). Given that fire extinction is
mandatory in some areas close to populated areas or installations, and in areas with
specific conservation values, explicit geographical models can be developed to
establish areas in which fuel load accumulation resulting from fire suppression
should be counterbalanced by mechanical fuel reduction or by restoring
2 Trade-offs in High Mountain Conservation
53
issues: synergies between management options, interacting agents and time lags.
Although weather conditions and a low fuel load overall constrain wildfires in high
mountain ecosystems, their incidence is far from negligible. They can lead to the
lowering of the treeline (Nagy and Grabherr 2009) and constitute a natural disturbance in the conifer forests of the mountains of western North America (Sibold
et al. 2006), where fire regime has been heavily altered by active fire suppression
policies over the past century (Donovan and Brown 2007). In fact, in many of the
world’s mountain regions, the fire has been used as a major management tool to
foment grasslands, eventually determining ecotones (Nagy and Grabherr 2009). In
recent decades, the loss of local population in mountain areas, at least in developed
countries, is leading to encroachment onto former grasslands, and the consequences
on biodiversity and ecosystem functioning have yet to be fully explored
(Roura-Pascual et al. 2005; Brandt et al. 2013; Formica et al. 2014).
Fire management, and particularly fire suppression, consumes a large proportion of the resources devoted to forest management in countries with a high
climatic fire risk, dense populations in the wildland–urban interface or substantial
forest revenues. Fire management is therefore suited to an analysis based on
trade-offs. Both actions aiming to reduce ignition—i.e. public information, regulation of access to forests, lighting restrictions—and to suppress fires share the
goal of minimising burned areas. A cost-efficiency analysis in both the ecological
and social contexts may help to optimise the contribution of each different action
to the common goal. Paradoxically, however, the reduction of burned surface area
implies further development of vegetation and subsequently the accumulation of
fuel for the future, which will likely produce more intense and extensive fires
(Donovan and Brown 2007; Lloret et al. 2009; Loepfe et al. 2012, but see Odion
et al. 2004). This situation illustrates the temporal dimension of conservation
practices and how they modify the future environment. It also reveals the existence
of feedbacks regulating ecological systems; in this case vegetation growth and
wildfires are mutually regulated by negative feedback. Fire suppression policies
may lead the system to a structure of fire sizes that tends to be less equitative, with
many small fires—which are rapidly extinguished—and very few extremely large
ones, although these are usually very intense (Lloret et al. 2009). In terms of
ecological trade-offs, and in the context of prolonged periods, investment in a
reduction to fire exposure—limitations on lightning and fire propagation caused by
humans—corresponds with increasing future fire sensitivity—associated with more
intense and severe fires—. Assuming that management resources are limited, if
one major goal is the minimisation of megafires of extreme extension and intensity, a strict fire extinction policy is not in itself the best long-term solution, and it
may have strong consequences for the long-term structural and functional properties of ecosystems (Donovan and Brown 2007). Given that fire extinction is
mandatory in some areas close to populated areas or installations, and in areas with
specific conservation values, explicit geographical models can be developed to
establish areas in which fuel load accumulation resulting from fire suppression
should be counterbalanced by mechanical fuel reduction or by restoring
2 Trade-offs in High Mountain Conservation
53