Environmental Engineering Reference
In-Depth Information
Hydrology
- See
ecohydrology
.
Hysteresis
Due to myriad internal and external
factors, the route to recovery or restoration of an
ecosystem often takes much longer than, and differs
from, the initial route of
degradation
. This discrep-
ancy is called hysteresis.
Indicator (ecological indicator)
Variables that
can be readily identifi ed, and are relatively easy to
measure or monitor and that serve as synthetic re-
presentatives or signals of changes in ecological or
environmental conditions (Dale & Beyeler 2001).
For example, characteristic species or species combi-
nations can be used as a sign of
ecosystem health
or
degradation
, and are also applicable to evaluate the
success of
ecological restoration
.
Indigenous species
- See
native species
.
Intervention
A specifi c action or intentional strat-
egy that will bring about an action, such as site
preparation,
invasive species
removal, desirable
species
systems
and spaces or landscape units managed
for social and economic use without any specifi c
systems thinking. The size of the landscape in a
given restoration project is determined mostly by the
scale of the restoration initiative, and the likely or
hoped-for geographic extent of its impacts (see Riet-
bergen - McCracken
et al
. 2008). See also
cultural
landscape
.
Livelihood
The capabilities, assets (stores, resources,
claims and access) and activities required for a
means of earning a living. A livelihood is sustainable
when it can cope with and recover from stress and
shocks, maintain and enhance its capabilities and
assets, provide sustainable livelihood opportunities
for the next generation, and contribute net benefi ts
to other livelihoods at the local and global levels in
the long and short terms.
Local adaptation
Process by which populations dif-
ferentiate genetically in response to selective pres-
sure acting on their respective
habitats
.
Local Ecological Knowledge (LEK)
(synonym: local
environmental knowledge)
Useful knowledge about
species and
ecosystems
gathered by people who live
in rural
landscapes
and manage their land to mini-
mize detrimental impacts. See also
Traditional Eco-
logical Knowledge
.
Metapopulation
A set of interacting local popula-
tions of a plant or animal species within a larger
area of space, with long-term survival of the species
depending on a shifting balance between local
extinctions and recolonizations in the patchwork of
an heterogeneous
landscape
or
habitat
(cf. Hanski
1999). More simply, they are assemblages of local
populations connected by mutually dispersing indi-
viduals in a network of
habitat
patches.
Mires
reintroductions
,
biomanipulation
,
altering
canopy structure or reintroducing fi re.
Invasive species
A non - native or
alien species
that
has become naturalized in an area, and whose dis-
tribution, reproduction and spread are no longer
restrained by soil parameters, natural predators and
so on and thus rapidly expand its distribution and
abundance regardless of
habitat
(Py š ek 1995 ; Rich-
ardson
et al
. 2000). If this process threatens
ecosys-
tems
,
habitats
or humans, domesticated species or
wild species with health-related, economic or envi-
ronmental harm, the species can be called noxious,
as noted under Article 8(h) of the Convention on
Biological Diversity (http://www.cbd.int/conven-
tion). In contrast, a
native species
whose distribution
and/or abundance in the wild is increasing should
be described simply as increasing, colonizing or
spreading, not as invading.
Keystone species
A species that has a substantially
greater infl uence on other species in the food web of
an ecosystem than would be predicted by its abun-
dance or size (Paine 1966). Cf.
foundation species.
Lake biomanipulation
- See
biomanipulation
.
Landscape
Many acceptable defi nitions exist for this
concept. Here we use the ecological defi nition,
namely an assemblage of
ecosystems
that are
arranged in recognizable patterns and that exchange
organisms and materials such as nutrients and
water (Forman & Godron 1986). Today, most land-
scapes are mosaics of interacting systems that may
be natural or
seminatural ecosystems
,
Peatlands
where
peat
is
currently
being
formed (Joosten & Clarke 2002 ).
Mitigation
Compensation in terms of enhancement
of an
ecosystem function
,
rehabilitation
,
ecological res-
toration
and so on that is required by government
agencies, or international treaties and agreements,
for permission to undertake or continue develop-
ment projects, or other economic activities (e.g. fossil
fuel extraction or refi nement, the manufacture of
cement or high-speed travel) that cause signifi cant
environmental harm.
Native species
(synonym:
indigenous species
)
Biolo-
gical species that evolved in a specifi ed region, or
that arrived there before the beginning of the Neo-
lithic period (Pyšek 1995), or that arrived there
production
