Environmental Engineering Reference
In-Depth Information
Considering all these factors results in a matrix
within which management categories can be recog-
nized based on the degree of urgency and the level of
intervention required. While such a scheme might
seem logical, there are, in fact, endless complications
involved in actually applying it. Considering more than
one or a few threats at a time (e.g. excessive nitrogen
input, or the presence of invasive alien species) quickly
makes the assessment very complex. Assigning degrees
of urgency and estimating likelihood of success are
diffi cult, as is the assignment of value. Finally, desig-
nating some areas or actions as having higher priority
than others immediately leads to there being 'winners'
and 'losers'. In other words, consigning some areas to
a low priority status inevitably has economic, social
and political consequences, which may be unpalatable
to the local community or portions thereof, and there-
fore untenable politically. Hence, it is essential to con-
sider how to set priorities, but socially and politically
tricky to do so effectively.
5.5.2
Perspectives
At a world scale, two opposite landscape development
trends seem to be occurring simultaneously. On the
one hand, all models predict a continuation of human
population growth in the coming century, especially in
developing countries. In combination with economic
developments in the same countries, this implies
increasing land use pressure there. Intact and varie-
gated landscapes are likely to change into fragmented
and relictual landscapes with associated ecological and
biodiversity losses. The reverse trend seems to occur in
developed countries. Here it is increasingly recognized
that local conservation and restoration activities alone
are not suffi cient to safeguard biodiversity and that
spatial connections are essential. Programmes such as
the creation of the network of protected areas, Natura
2000, in the European Union (Box 5.1), or improving
connectivity in south - western Australia ( ' Gondwana
Link'; see website in the appendix) are now being
Box 5.1 Natura 2000 and National Networks in the European Union
The fi rst offi cial declaration by the European Commis-
sion (EC) of the need for ecological restoration is to be
found in the Habitats Directive of 1992 (EC 1992a).
Together with the much older Birds Directive (from
1979), the Habitats Directive establishes the legal base
for the creation of the worlds largest and most ambi-
tious network of protected areas, which is called
Natura 2000 (see website in the appendix). The goal
is not only to preserve certain areas for nature conser-
vation, but also to achieve a so-called favourable con-
servation status of species and habitats. Natura 2000
consists in fact of two different, often broadly overlap-
ping types of areas. 'Specially Protected Areas' (often
called 'bird areas') were proposed in the Birds Directive
of 2009 for the designation of 'International Bird Areas'.
Areas of the second type ('Natura sites') are proposed
by member states abitats Directive as so-called Sites
of Conservation Interest. After inclusion in the Euro-
pean list they must be legally established by the rel-
evant EU member country, and then become so-called
Special Areas of Conservation. Natura sites are des-
ignated to biogeographic regions, rather than just to a
particular state, and may be terrestrial, marine or both.
The terrestrial part of the Natura 2000 network was
largely completed in 2010, while completion of the
marine part is foreseen in 2012. The network covers
17.6% of the European Union's total land area and
100 000 km
2
of its marine environment; it consists of
almost 26,000 sites and includes more than 922 000 km
2
(see website in the appendix). The new European bio-
diversity target, adopted in March 2010, explicitly
addresses the need to restore ecosystems by 2020
where feasible. This means that further development
of the Natura 2000 network will use all possible
approaches - that is, full protection (non-intervention)
in wilderness or near-natural sites, active management
in human-induced and human-dependent ecosys-
tems, and restoration in damaged sites or sites con-
verted into an unfavourable conservation status. The
new strategy also addresses the issues of fragmenta-
tion and connectivity, by proposing a 'green infrastruc-
ture' in the wider countryside, that is, also outside
Natura 2000 sites. The strategy intentionally utilizes
the concept of ecosystem services to address prob-
lems like water retention, fl ood prevention, erosion
control, carbon sequestration and so on, and com-
bines this with biodiversity conservation and the crea-
tion of a functional network of protected sites.
