221
4. Further, wetlands form the aquatic boundary of the habitats of many terrestrial plants
and animals. As such, small changes in
hydrology may result in significant changes
in biology.
5. The starting point for the hydrology of a wetland is the climate and basin morphology. The
second significant factor is the geomorphology of the landscape and basin. When climate,
basin geomorphology and hydrology are considered as one unit, it is referred to as ‘wetland’s hydro geomorphology’.
6. Further, wetland biota are not passive to their
hydrologic conditions. They exert feedback
(cybernetic) control over their physical/
environments just as many other ecosystems.
Plants, animals and microbes, which use the
essential biological feedback mechanisms,
have been formally recognised as ‘ecosystem
engineers’ in the ecological literature. Further,
a number of animals are particularly important for their contributions to hydrologic
modifications and subsequent changes in
wetlands.
7. Studies on wetland hydrology are not new.
Many earlier studies on wetlands had dealt
with the relationship between hydrologic variables (usually water depth) and wetland productivity and species composition. The
seasonal pattern of water level of a wetland is
called its ‘hydro-period’. The hydro-period is
not the same each year. The ‘renewal rate’ or
‘turnover rate’ of water is generally a useful
concept of wetland hydrology. It may be
defined as the ratio of throughput to average
volume within the system. The water which
vaporises from water or soil in a wetland is
called evaporation. And the moisture which
passes through vascular plants to the atmosphere
is called transpiration. Evapotranspiration is a
combination of the two.
8. Excess organic matters may be accumulated
in the wetlands. This could be as a result of
increase primary productivity or decreased
decomposition and export.
9. Hydrology is said to stimulate diversity when
the action of water and transported sediments
creates spatial heterogeneity, thus opening up
additional ecological niches.
Suggested Readings
Alper J (1998) Ecosystem “engineers” shape habitats for
other species. Science 280:1195–1196
Bay RR (1967) Groundwater and vegetation in two peat
bogs in northern Minnesota. Ecology 48:308–310
Bay RR (1969) Runoff from small peatland watersheds.
J Hydrol 9:90–102
Brinson MM (1977) Decomposition and nutrient
exchange of litter in an alluvial swamp forest. Ecology
58:601–609
Deghi GS, Ewel KC, Rudis DD (1980) Effects of sewage
effluent application on litterfall and litter decomposition in cypress swamps. J Appl Ecol 17:397–408
Doss PK (1993) The nature of a dynamic water table in a
system of non-tidal, freshwater coastal wetlands.
J Hydrol 141:107–126
Eggelsmann R (1963) Die Potentielle und Aktuelle
Evaporation eines Seeklimathochmoore. Publication
62. International Association of Hydrological Science,
pp 88–97
Eisenlohr WS (1976) Water loss from a natural pond
through transpiration by hydrophytes. Water Resour
Res 2:443–453
Ford J, Bedford BL (1987) The hydrology of Alaskan
wetlands, U.S.A.: a review. Arctic Alpine Res
19:209–239
Glaser PH (1997) The ecology of Patterned Boreal
Peatland, of Northern Minnesota: a community profile. Biological report 85(7.14). U.S. Fish and Wildlife
Service, Washington, DC, 98 pp
Golet FC, Calhoun AJK, Deragon WR, Lowry DJ, Gold
AJ (1993) Ecology of Red Maple Swamps in the
Glaciated Northeast: a community profile. Biological
report 12. U.S. Fish and Wildlife Service, Washington,
DC, pp 151
Hall FR, Rutherford RJ, Byers GL (1972) The influence of
a New England wetland on water quantity and quality.
New Hampshire, Water Resource Center research
report 4. University of New Hampshire, Durham, pp 51
Heimburg K (1984) Hydrology of north-central Florida
cypress domes. In: Ewel KC, Odum HT (eds) Cypress
swamps. University Presses of Florida, Gainesville,
pp 72–82
Hemond HF, Fifield JL (1982) Subsurface flow in salt
marsh peat: a model and field study. Limnol Oceanogr
27:126–136
Johnston CA (1994) Ecological engineering of wetlands
by beavers. In: Mitsch WJ (ed) Global wetlands: old
world and new. Elsevier, Amsterdam, pp 379–384
Johnston CA, Naiman RJ (1990) Aquatic patch creation
in relation to beaver population trends. Ecology
71:1617–1621
Jones CG, Lawton JH, Shachak M (1994) Organisms as
ecosystem engineers. Oikos 69:373–386
Junk WJ, Bayley PB, Sparks RE (1989) The flood pulse
concept in river-floodplain systems. In: Dodge DP
(ed) Proceedings of the international large river
symposium. Special Issue of J Can Fish Aquat Sci
106:11–127
Suggested Readings
4. Further, wetlands form the aquatic boundary of the habitats of many terrestrial plants
and animals. As such, small changes in
hydrology may result in significant changes
in biology.
5. The starting point for the hydrology of a wetland is the climate and basin morphology. The
second significant factor is the geomorphology of the landscape and basin. When climate,
basin geomorphology and hydrology are considered as one unit, it is referred to as ‘wetland’s hydro geomorphology’.
6. Further, wetland biota are not passive to their
hydrologic conditions. They exert feedback
(cybernetic) control over their physical/
environments just as many other ecosystems.
Plants, animals and microbes, which use the
essential biological feedback mechanisms,
have been formally recognised as ‘ecosystem
engineers’ in the ecological literature. Further,
a number of animals are particularly important for their contributions to hydrologic
modifications and subsequent changes in
wetlands.
7. Studies on wetland hydrology are not new.
Many earlier studies on wetlands had dealt
with the relationship between hydrologic variables (usually water depth) and wetland productivity and species composition. The
seasonal pattern of water level of a wetland is
called its ‘hydro-period’. The hydro-period is
not the same each year. The ‘renewal rate’ or
‘turnover rate’ of water is generally a useful
concept of wetland hydrology. It may be
defined as the ratio of throughput to average
volume within the system. The water which
vaporises from water or soil in a wetland is
called evaporation. And the moisture which
passes through vascular plants to the atmosphere
is called transpiration. Evapotranspiration is a
combination of the two.
8. Excess organic matters may be accumulated
in the wetlands. This could be as a result of
increase primary productivity or decreased
decomposition and export.
9. Hydrology is said to stimulate diversity when
the action of water and transported sediments
creates spatial heterogeneity, thus opening up
additional ecological niches.
Suggested Readings
Alper J (1998) Ecosystem “engineers” shape habitats for
other species. Science 280:1195–1196
Bay RR (1967) Groundwater and vegetation in two peat
bogs in northern Minnesota. Ecology 48:308–310
Bay RR (1969) Runoff from small peatland watersheds.
J Hydrol 9:90–102
Brinson MM (1977) Decomposition and nutrient
exchange of litter in an alluvial swamp forest. Ecology
58:601–609
Deghi GS, Ewel KC, Rudis DD (1980) Effects of sewage
effluent application on litterfall and litter decomposition in cypress swamps. J Appl Ecol 17:397–408
Doss PK (1993) The nature of a dynamic water table in a
system of non-tidal, freshwater coastal wetlands.
J Hydrol 141:107–126
Eggelsmann R (1963) Die Potentielle und Aktuelle
Evaporation eines Seeklimathochmoore. Publication
62. International Association of Hydrological Science,
pp 88–97
Eisenlohr WS (1976) Water loss from a natural pond
through transpiration by hydrophytes. Water Resour
Res 2:443–453
Ford J, Bedford BL (1987) The hydrology of Alaskan
wetlands, U.S.A.: a review. Arctic Alpine Res
19:209–239
Glaser PH (1997) The ecology of Patterned Boreal
Peatland, of Northern Minnesota: a community profile. Biological report 85(7.14). U.S. Fish and Wildlife
Service, Washington, DC, 98 pp
Golet FC, Calhoun AJK, Deragon WR, Lowry DJ, Gold
AJ (1993) Ecology of Red Maple Swamps in the
Glaciated Northeast: a community profile. Biological
report 12. U.S. Fish and Wildlife Service, Washington,
DC, pp 151
Hall FR, Rutherford RJ, Byers GL (1972) The influence of
a New England wetland on water quantity and quality.
New Hampshire, Water Resource Center research
report 4. University of New Hampshire, Durham, pp 51
Heimburg K (1984) Hydrology of north-central Florida
cypress domes. In: Ewel KC, Odum HT (eds) Cypress
swamps. University Presses of Florida, Gainesville,
pp 72–82
Hemond HF, Fifield JL (1982) Subsurface flow in salt
marsh peat: a model and field study. Limnol Oceanogr
27:126–136
Johnston CA (1994) Ecological engineering of wetlands
by beavers. In: Mitsch WJ (ed) Global wetlands: old
world and new. Elsevier, Amsterdam, pp 379–384
Johnston CA, Naiman RJ (1990) Aquatic patch creation
in relation to beaver population trends. Ecology
71:1617–1621
Jones CG, Lawton JH, Shachak M (1994) Organisms as
ecosystem engineers. Oikos 69:373–386
Junk WJ, Bayley PB, Sparks RE (1989) The flood pulse
concept in river-floodplain systems. In: Dodge DP
(ed) Proceedings of the international large river
symposium. Special Issue of J Can Fish Aquat Sci
106:11–127
Suggested Readings