Roots, relevance, aims and values
39
Relict communities have also been used as potential
reference sites for ecosystem and habitat restoration
projects. One example can be seen in attempts to
restore some of the ‘ lost ’ forests of Tenerife (Canary
Islands), where scientists are drawing upon data from
both palaeoecology and contemporary studies of relict
communities to provide a basis for restoration efforts.
Before human occupation, the island of Tenerife contained all of the main vegetation types of the Canarian
archipelago, from the hot, dry semi - desert scrub of the
coastal lowlands to the lush, green laurel forest that is
swathed in cloud for long periods every day (Fern á ndez -
Palacios et al ., 2004 ). These vegetation types occurred
in distinct climatic zones or bands stretching from sea
level to the top of Mount Teide, the 3,700 m dormant
volcano that dominates the Tenerife landscape.
As happened on many oceanic islands after occupation, agriculture began to expand from the coast to
higher elevations and, in the process, devastated or
completely removed several ‘ bands ’ of typical vegetation. In particular, the thermophilous forest was almost
completely destroyed (less than 1 per cent remains),
with only a few pockets of juniper ( Juniperus spp.) forest
clinging on to existence on exposed cliff sites. The
European Community has recently funded a pilot
conservation project to restore a 53 ha patch of
thermophilous woodland on the Teno peninsula
( www.tenerife.es/life/ ).
Scientists have based the replanting scheme on phytosociological analysis of tiny remnant fragments of
juniper forest in steep cliffs and remote gullies on
Tenerife and nearby La Gomera. Amazingly, a recent
analysis of pollen from sediments in a dried - up lake
in the city of La Laguna suggests that there may also
have been a native broad - leaved forest of hornbeam
( Carpinus ) and oak ( Quercus ), species now considered
as non - native on the archipelago, which was most
likely sandwiched somewhere between the laurel forest
and the pine zone on Tenerife. These fi ndings challenge
prior conceptions of indigenous ecological baselines on
the Canary Islands (de Nascimento et al ., 2009 ).
3.5.2 Baselines d erived from
l ong - t erm e cology
Current ecological understanding recognizes that
most ecosystems are dynamic, being subject to ongoing
processes of changing climate and other environmental disturbances, and that many landscapes have also
situations, to offer inspiration for ecological restoration
when historical data are missing. Relict sites are also
frequently the focus of conservation themselves, as
they often contain a high proportion of endemic or
endangered fauna and fl ora.
More generally, the analysis of relict or natural sites
through phytosociology has played a major role in
identifying sites for regional conservation, especially
in Europe. Phytosociology is a sub - discipline of plant
community ecology that seeks to describe and understand plant species co - occurrences – or, in the words of
Ewald ( 2003 , p. 291), it deals with the ‘ compositional
patterns and gradients at the “ grain ” of the plant community ’ . The tools of modern phytosociology are gradient analysis, classifi cation and other multivariate
methods used to identify characteristic plant assemblages that can be used as baselines for conservation.
In the UK, phytosociological data have been used
extensively to identify and assess natural and semi -
natural sites that qualify as Sites of Special Scientifi c
Interest (SSSIs), one of the key national protected area
designations in the UK (NCC, 1989 ) and a constituent
part of the larger Natura 2000 network of protected
areas in Europe. The desire to preserve ‘ semi - natural ’
habitats is interesting and could be interpreted as a
desire to protect and restore pre - industrial baselines (as
opposed to ‘ natural ’ habitats that are presumably pre -
human), although the UK ’ s national agency (now
agencies) was by no means explicit about this (e.g.
NCC, 1989 ).
A good example is the identifi cation and prioritization of woodlands in the UK. Only ancient ‘ semi -
natural woodland ’ is considered for conservation
(NCC, 1989 , p. 73) and this is identifi ed using the
National Vegetation Classifi cation (NVC) scheme, a
standardized classifi cation protocol for all the vegetation types in the UK. Under the NVC, each broad classifi cation (e.g. woodlands) is divided into communities,
sub - communities and sometimes variants based solely
on the presence or absence of species. UK woodlands
are divided into 25 communities which are further
divided into 73 sub - communities (Hall et al ., 2001 ).
These act as references against which new sites can be
assessed and existing protected sites can be monitored.
For instance, Upland Oak Woodland, defi ned as woodland within the ‘ upland region ’ of England generally
with at least 80 per cent oak or birch in the potential
canopy, is classifi ed as W11 or W17, depending on the
nature of the fi eld layer (see further discussion of these
approaches in Chapter 4 , Section 4.5.1 ).
39
Relict communities have also been used as potential
reference sites for ecosystem and habitat restoration
projects. One example can be seen in attempts to
restore some of the ‘ lost ’ forests of Tenerife (Canary
Islands), where scientists are drawing upon data from
both palaeoecology and contemporary studies of relict
communities to provide a basis for restoration efforts.
Before human occupation, the island of Tenerife contained all of the main vegetation types of the Canarian
archipelago, from the hot, dry semi - desert scrub of the
coastal lowlands to the lush, green laurel forest that is
swathed in cloud for long periods every day (Fern á ndez -
Palacios et al ., 2004 ). These vegetation types occurred
in distinct climatic zones or bands stretching from sea
level to the top of Mount Teide, the 3,700 m dormant
volcano that dominates the Tenerife landscape.
As happened on many oceanic islands after occupation, agriculture began to expand from the coast to
higher elevations and, in the process, devastated or
completely removed several ‘ bands ’ of typical vegetation. In particular, the thermophilous forest was almost
completely destroyed (less than 1 per cent remains),
with only a few pockets of juniper ( Juniperus spp.) forest
clinging on to existence on exposed cliff sites. The
European Community has recently funded a pilot
conservation project to restore a 53 ha patch of
thermophilous woodland on the Teno peninsula
( www.tenerife.es/life/ ).
Scientists have based the replanting scheme on phytosociological analysis of tiny remnant fragments of
juniper forest in steep cliffs and remote gullies on
Tenerife and nearby La Gomera. Amazingly, a recent
analysis of pollen from sediments in a dried - up lake
in the city of La Laguna suggests that there may also
have been a native broad - leaved forest of hornbeam
( Carpinus ) and oak ( Quercus ), species now considered
as non - native on the archipelago, which was most
likely sandwiched somewhere between the laurel forest
and the pine zone on Tenerife. These fi ndings challenge
prior conceptions of indigenous ecological baselines on
the Canary Islands (de Nascimento et al ., 2009 ).
3.5.2 Baselines d erived from
l ong - t erm e cology
Current ecological understanding recognizes that
most ecosystems are dynamic, being subject to ongoing
processes of changing climate and other environmental disturbances, and that many landscapes have also
situations, to offer inspiration for ecological restoration
when historical data are missing. Relict sites are also
frequently the focus of conservation themselves, as
they often contain a high proportion of endemic or
endangered fauna and fl ora.
More generally, the analysis of relict or natural sites
through phytosociology has played a major role in
identifying sites for regional conservation, especially
in Europe. Phytosociology is a sub - discipline of plant
community ecology that seeks to describe and understand plant species co - occurrences – or, in the words of
Ewald ( 2003 , p. 291), it deals with the ‘ compositional
patterns and gradients at the “ grain ” of the plant community ’ . The tools of modern phytosociology are gradient analysis, classifi cation and other multivariate
methods used to identify characteristic plant assemblages that can be used as baselines for conservation.
In the UK, phytosociological data have been used
extensively to identify and assess natural and semi -
natural sites that qualify as Sites of Special Scientifi c
Interest (SSSIs), one of the key national protected area
designations in the UK (NCC, 1989 ) and a constituent
part of the larger Natura 2000 network of protected
areas in Europe. The desire to preserve ‘ semi - natural ’
habitats is interesting and could be interpreted as a
desire to protect and restore pre - industrial baselines (as
opposed to ‘ natural ’ habitats that are presumably pre -
human), although the UK ’ s national agency (now
agencies) was by no means explicit about this (e.g.
NCC, 1989 ).
A good example is the identifi cation and prioritization of woodlands in the UK. Only ancient ‘ semi -
natural woodland ’ is considered for conservation
(NCC, 1989 , p. 73) and this is identifi ed using the
National Vegetation Classifi cation (NVC) scheme, a
standardized classifi cation protocol for all the vegetation types in the UK. Under the NVC, each broad classifi cation (e.g. woodlands) is divided into communities,
sub - communities and sometimes variants based solely
on the presence or absence of species. UK woodlands
are divided into 25 communities which are further
divided into 73 sub - communities (Hall et al ., 2001 ).
These act as references against which new sites can be
assessed and existing protected sites can be monitored.
For instance, Upland Oak Woodland, defi ned as woodland within the ‘ upland region ’ of England generally
with at least 80 per cent oak or birch in the potential
canopy, is classifi ed as W11 or W17, depending on the
nature of the fi eld layer (see further discussion of these
approaches in Chapter 4 , Section 4.5.1 ).