have had a different profile in the past (Fig. 5.3a). When these pioneer formations
are being analyzed, the problem is greatest when attempting to define the ecological
baseline and RNV. As indicated by Alagona et al. (2012: 65): “Restoration requires
historical baseline targets, but all such targets are arbitrary for ecosystems that are
constantly changing and have always been doing so (…) Recasting historical
knowledge not as a narrow search for singular baseline conditions or specific
population figures, but as a way to track multifaceted ecological changes over time,
offers a middle ground where the past may inform but not determine the ecosystems
of the future. The past may be imperfect as a model for the future, but it is an
indispensable guide for understanding a world in flux.”
At present, there is no special management of birch in the National Park. It is an
opportunistic pioneer species that has adapted to colonizing unstable settings such
as landslide channels and places with limited soil. Both species mentioned above,
Betula pendula and B. pubescens, are found in this zone; the first is much more
abundant now. We do not know whether this was also the case in the past, but it
seems clear that B. pubescens must have a certain priority for conservation because
it represents a relic of the past.
5.2.3 How Should Open Spaces Cleared for Human
Activities Be Managed When They Have
a Semi-natural Function?
The European Community’s Directive 97/62/EC defines 198 habitats of community
interest. In Catalonia, 94 habitats of community interest have been identified, of
which 22 are prioritized. Among these habitats we find the acidic peat bogs of
Sphagnum (see Sect. 2.5), natural and semi-natural grasslands (e.g., meadows
Fig. 5.3 a Holocene dynamic of the birch, the fir, and the pine at Burg Lake [partially published
in Pèlachs et al. (2011)]. b Local environment in Bassa Nera during the Holocene [partially
published in Pèlachs et al. 2016]
5 The Role of Environmental Geohistory …
119
are being analyzed, the problem is greatest when attempting to define the ecological
baseline and RNV. As indicated by Alagona et al. (2012: 65): “Restoration requires
historical baseline targets, but all such targets are arbitrary for ecosystems that are
constantly changing and have always been doing so (…) Recasting historical
knowledge not as a narrow search for singular baseline conditions or specific
population figures, but as a way to track multifaceted ecological changes over time,
offers a middle ground where the past may inform but not determine the ecosystems
of the future. The past may be imperfect as a model for the future, but it is an
indispensable guide for understanding a world in flux.”
At present, there is no special management of birch in the National Park. It is an
opportunistic pioneer species that has adapted to colonizing unstable settings such
as landslide channels and places with limited soil. Both species mentioned above,
Betula pendula and B. pubescens, are found in this zone; the first is much more
abundant now. We do not know whether this was also the case in the past, but it
seems clear that B. pubescens must have a certain priority for conservation because
it represents a relic of the past.
5.2.3 How Should Open Spaces Cleared for Human
Activities Be Managed When They Have
a Semi-natural Function?
The European Community’s Directive 97/62/EC defines 198 habitats of community
interest. In Catalonia, 94 habitats of community interest have been identified, of
which 22 are prioritized. Among these habitats we find the acidic peat bogs of
Sphagnum (see Sect. 2.5), natural and semi-natural grasslands (e.g., meadows
Fig. 5.3 a Holocene dynamic of the birch, the fir, and the pine at Burg Lake [partially published
in Pèlachs et al. (2011)]. b Local environment in Bassa Nera during the Holocene [partially
published in Pèlachs et al. 2016]
5 The Role of Environmental Geohistory …
119