285
vast areas of wetlands. Many wetlands in the
world had been drained centuries ago. It is, probably, not unjustifi ed to assume that we are still
losing wetlands at a fairly rapid rate globally. We
have, perhaps, lost c 50 % of the original wetlands by this time on the face of the earth (Dugan
1993 ). However, there are a number of areas
where the loss rate of the wetlands has been documented. Threats to wetlands are displayed in
many forms (Williams 1990 ; Dugan 1993 ). In the
USA, the estimates of c 50 % loss of wetlands
since European settlement in the lower 48 states
is said to be fairly accurate. Similarly, c 90 % loss
of wetlands in New Zealand is, perhaps, well
documented. China has perhaps lost c 60 % of its
wetlands. It is said to be based on the present estimate of 250,000 km
2 of natural wetlands in the
country out of total of 620,000 km
2 including
artifi cial wetlands (Lu 1995 ).
Coastal wetlands have long been destroyed
through a combination of excessive harvesting,
hydrologic modifi cation and seawall construction, coastal development, pollution and other
human activities. It may be noted here that >70 %
of the world’s population live on or near the
coastlines. Similarly, the inland wetlands have
also been continually affected, particularly,
through hydrologic modifi cations and agricultural and urban development. The inland wetlands are generally lost due to a number of causes.
Some of the signifi cant causes are drainage for
agriculture, forestry, fi lling for urbanisation, solid
waste disposal, mining, etc.
Contrary to the west, the propensity of the east
was not to drain the valuable wetlands entirely
but to work within the aquatic landscape, albeit in
a heavily managed way. Dugan ( 1993 ) makes an
interesting comparison between hydraulic civilisation (European in origin) and aquatic civilisation (Asian in origin). The former had controlled
water fl ow, perhaps, through the use of dykes,
dams, pumps, drainage tile, etc. On the other
hand, the latter was better adapted to their surroundings consisting of water-abundant fl oodplains and deltas. They took advantage of nature’s
pulses, such as fl ooding. The main reason for
high losses of wetlands worldwide is the dominance of approach of controlling nature rather
than working with it.
19.4 Wetland Terms and Types
A number of common terms, such as swamps,
marsh and mire, have been used over the years to
describe different types of wetlands. The history
of the use and misuse of these words has often
revealed a decidedly regional or at least continental origin. Many of these terms have their own
meanings. A marsh is known by most as a herbaceous plant wetland. A swamp has woody vegetation, either shrubs or trees. Further, a marsh with
a signifi cant (>30 cm) standing water throughout
much of the year is often called a deepwater
marsh. Conversely, a shallow marsh with waterlogged soil or shallow standing water is sometimes called a sedge meadow or a wet meadow.
Further, intermediate between a marsh and
meadow is a wet prairie. The term peatland is
said to be synonymous with moor and muskeg.
There are many types of peatlands. However, the
most general being the fens and bogs.
These common terms do not always convey
the same meaning regarding specifi c type of wetland amongst the international scientifi c community. In fact, there is no direct equivalent of
certain kinds of wetlands in some languages. The
term swamp has no direct equivalence in Russian
language. The word ‘swamp’ clearly refers to a
wetland dominated by woody plants in North
America. In Europe, reed swamps are dominated
by reed grass ( Phragmites). The ‘marsh’ in the
USA is referred to as ‘swamp’ in Africa. A cutoff
meander of a river is called ‘billabong’ in
Australia ( Shiel 1994) and oxbow in India and
North America. Further, the words ‘Beel’ and
‘Haor’, perhaps, have no equivalence in English
language. ‘Beel’ and ‘Haor’ are typical and peculiar wetlands in the Indian subcontinent and
Bangladesh. The former is referred to as a
‘perennial’ wetland, while the latter is related to
as a ‘seasonal fl oodplain’ wetland. And, further,
the term ‘Anua’ is used in Barak valley region of
Assam to denote a river-formed oxbow wetland
formed due to change of course of a river due to
meandering (Kar 2007a , b , 2010 , 2012 ).
In addition to the above, the common as well
as the scientifi c names of the plants and animals
may become confusing on a global scale, e.g.
19.4 Wetland Terms and Types
vast areas of wetlands. Many wetlands in the
world had been drained centuries ago. It is, probably, not unjustifi ed to assume that we are still
losing wetlands at a fairly rapid rate globally. We
have, perhaps, lost c 50 % of the original wetlands by this time on the face of the earth (Dugan
1993 ). However, there are a number of areas
where the loss rate of the wetlands has been documented. Threats to wetlands are displayed in
many forms (Williams 1990 ; Dugan 1993 ). In the
USA, the estimates of c 50 % loss of wetlands
since European settlement in the lower 48 states
is said to be fairly accurate. Similarly, c 90 % loss
of wetlands in New Zealand is, perhaps, well
documented. China has perhaps lost c 60 % of its
wetlands. It is said to be based on the present estimate of 250,000 km
2 of natural wetlands in the
country out of total of 620,000 km
2 including
artifi cial wetlands (Lu 1995 ).
Coastal wetlands have long been destroyed
through a combination of excessive harvesting,
hydrologic modifi cation and seawall construction, coastal development, pollution and other
human activities. It may be noted here that >70 %
of the world’s population live on or near the
coastlines. Similarly, the inland wetlands have
also been continually affected, particularly,
through hydrologic modifi cations and agricultural and urban development. The inland wetlands are generally lost due to a number of causes.
Some of the signifi cant causes are drainage for
agriculture, forestry, fi lling for urbanisation, solid
waste disposal, mining, etc.
Contrary to the west, the propensity of the east
was not to drain the valuable wetlands entirely
but to work within the aquatic landscape, albeit in
a heavily managed way. Dugan ( 1993 ) makes an
interesting comparison between hydraulic civilisation (European in origin) and aquatic civilisation (Asian in origin). The former had controlled
water fl ow, perhaps, through the use of dykes,
dams, pumps, drainage tile, etc. On the other
hand, the latter was better adapted to their surroundings consisting of water-abundant fl oodplains and deltas. They took advantage of nature’s
pulses, such as fl ooding. The main reason for
high losses of wetlands worldwide is the dominance of approach of controlling nature rather
than working with it.
19.4 Wetland Terms and Types
A number of common terms, such as swamps,
marsh and mire, have been used over the years to
describe different types of wetlands. The history
of the use and misuse of these words has often
revealed a decidedly regional or at least continental origin. Many of these terms have their own
meanings. A marsh is known by most as a herbaceous plant wetland. A swamp has woody vegetation, either shrubs or trees. Further, a marsh with
a signifi cant (>30 cm) standing water throughout
much of the year is often called a deepwater
marsh. Conversely, a shallow marsh with waterlogged soil or shallow standing water is sometimes called a sedge meadow or a wet meadow.
Further, intermediate between a marsh and
meadow is a wet prairie. The term peatland is
said to be synonymous with moor and muskeg.
There are many types of peatlands. However, the
most general being the fens and bogs.
These common terms do not always convey
the same meaning regarding specifi c type of wetland amongst the international scientifi c community. In fact, there is no direct equivalent of
certain kinds of wetlands in some languages. The
term swamp has no direct equivalence in Russian
language. The word ‘swamp’ clearly refers to a
wetland dominated by woody plants in North
America. In Europe, reed swamps are dominated
by reed grass ( Phragmites). The ‘marsh’ in the
USA is referred to as ‘swamp’ in Africa. A cutoff
meander of a river is called ‘billabong’ in
Australia ( Shiel 1994) and oxbow in India and
North America. Further, the words ‘Beel’ and
‘Haor’, perhaps, have no equivalence in English
language. ‘Beel’ and ‘Haor’ are typical and peculiar wetlands in the Indian subcontinent and
Bangladesh. The former is referred to as a
‘perennial’ wetland, while the latter is related to
as a ‘seasonal fl oodplain’ wetland. And, further,
the term ‘Anua’ is used in Barak valley region of
Assam to denote a river-formed oxbow wetland
formed due to change of course of a river due to
meandering (Kar 2007a , b , 2010 , 2012 ).
In addition to the above, the common as well
as the scientifi c names of the plants and animals
may become confusing on a global scale, e.g.
19.4 Wetland Terms and Types