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F029 Tropical Flooded & Swamp Forest Formation
Type Concept Sentence: Tropical Flooded & Swamp Forest is a forested or wooded wetland and peatland found in margins of freshwater lakes, alluvial plains, rivers and depressions around the globe.
Common (Translated Scientific) Name: Tropical Flooded & Swamp Forest Formation
Colloquial Name: Tropical Flooded & Swamp Forest
Hierarchy Level: Formation
Type Concept: Tropical Flooded & Swamp Forest is a forested or wooded wetland and peatland. Structural characteristics that recur in flooded forests are presence of monospecific stands such as palm swamp, even-canopied forests, and sharp vegetation zonation. Trees in flooded tropical forests may develop sclerophylly (firm, thickened leaves) due to poor nutrition or water limitations, gas exchange structures (e.g., pneumatophores, lenticels, knees, aerial roots, swelling of base of trees, surface or aerial roots) in order to overcome poor soil aeration, or support structures (e.g., plank buttresses and stilt roots) to provide stability in muddy or steep conditions. Tree heights can vary greatly, from 1 to 50 m. Tropical swamp forests can be divided into freshwater swamp or floodplain forest (along rivers and lakes) and peat swamp forest (formed behind natural floodplain levees), where peat layers may be well in excess of 1 m thick. The floodplain forests are found along rivers, streams and lakes. They have a dynamic water table, with seasonal flooding inundating the vegetation for short (<7 days) to long (>1 month) periods, leading to an influx of sediment and mineral enrichment during high water periods.
Floristic composition, diversity and structure of these forests can vary considerably depending on the characteristics of the flood. For example, in the Neotropics, turbid white-water flooded forests may be distinguished from limpid black- and clear-water flooded forests based on the significant amount of suspended sediment and dissolved calcium in white water, as compared to the low sediment load and low concentration of calcium in black and clear waters. Also, the black waters typically contain significant amounts of humic acid substances in colloidal suspension. Another important cause of ecological variation in these forests is related to the type of flooding, mainly flooded regime (inundation by waters flowing from the overflow of rivers and relatively fast drainage) versus stagnant waters that accumulate in large shallow topographic depressions and that are only slowly removed by evaporation (ponded regime).
Floristic composition, diversity and structure of these forests can vary considerably depending on the characteristics of the flood. For example, in the Neotropics, turbid white-water flooded forests may be distinguished from limpid black- and clear-water flooded forests based on the significant amount of suspended sediment and dissolved calcium in white water, as compared to the low sediment load and low concentration of calcium in black and clear waters. Also, the black waters typically contain significant amounts of humic acid substances in colloidal suspension. Another important cause of ecological variation in these forests is related to the type of flooding, mainly flooded regime (inundation by waters flowing from the overflow of rivers and relatively fast drainage) versus stagnant waters that accumulate in large shallow topographic depressions and that are only slowly removed by evaporation (ponded regime).
Diagnostic Characteristics: This formation is dominated by mesophyll, broad-leaved, evergreen trees, with soils saturated to flooded for all or parts of the year, varying from peat to mineral soil textures. Climates are consistently warm (seasonal daily temperatures with minimal variation).
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Forests may vary from deciduous to evergreen. Further review is needed of the degree of variation in evergreen versus deciduous-leaved trees between floodplains and swamps in tropical dry versus moist-wet climates.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Tropical Flooded & Swamp Forest is a forested or wooded wetland and peatland. Structural characteristics that recur in flooded forests are presence of monospecific stands such as palm swamp, even-canopied forests, and sharp vegetation zonations. It is common to find that trees in flooded tropical forests develop sclerophylly (firm, thickened leaves) due to poor nutrition or water limitations, or gas exchange structures (e.g., pneumatophores, lenticels, knees, aerial roots, swelling of base of trees, surface or aerial roots) in order to overcome poor soil aeration, or support structures (e.g., plank buttresses and stilt roots) to provide stability in muddy or steep conditions. Tree heights can vary greatly, from 1 to 50 m.
Based on the type of dominant species, swamp forests can be conveniently divided into two types: forests dominated by broad-leaved evergreen hardwood species and those dominated by palms. Dominance by palms becomes stronger with increasing hydroperiod or soil moisture conditions. Species richness generally decreases with increasing hydroperiod. One formation that covers large areas in western Amazonia and in the Orinoco River basin is the often monodominant "aguajales" or Mauritia flexuosa stands. These palm swamps may be regularly affected by riverine floods, but they mostly occur farther from current river channels, the water-logged condition then being maintained by a combination of high precipitation and poor drainage in depressional terrain. Other palm-associated (Raphia, Manicaria) swamps are typical of the coastal regions of Central America and northern South America along estuarine channels, sometimes in mixed stands with a few mangrove species.
Based on the type of dominant species, swamp forests can be conveniently divided into two types: forests dominated by broad-leaved evergreen hardwood species and those dominated by palms. Dominance by palms becomes stronger with increasing hydroperiod or soil moisture conditions. Species richness generally decreases with increasing hydroperiod. One formation that covers large areas in western Amazonia and in the Orinoco River basin is the often monodominant "aguajales" or Mauritia flexuosa stands. These palm swamps may be regularly affected by riverine floods, but they mostly occur farther from current river channels, the water-logged condition then being maintained by a combination of high precipitation and poor drainage in depressional terrain. Other palm-associated (Raphia, Manicaria) swamps are typical of the coastal regions of Central America and northern South America along estuarine channels, sometimes in mixed stands with a few mangrove species.
Floristics: No Data Available
Dynamics: No Data Available
Environmental Description: Soil/substrate/hydrology: Tropical swamp forests can be divided into freshwater or brackish swamp or floodplain forest (along rivers and lakes) and peat swamp forest (formed behind natural floodplain levees), where peat layers may be well in excess of 1 m thick (Whitmore 1984). The floodplain forests are found along rivers, streams, coasts, and lakes. They have a dynamic water table, with seasonal flooding inundating the vegetation for short (<7 days) to long (>1 month) periods, leading to an influx of sediment and mineral enrichment during high water periods. Information about underlying soils is scarce.
Many floodplain swamp forests are potentially peat-accumulating, but, although studies on this subject exist in Southeast Asia, they have apparently never been published for the Amazon basin (Whitmore 1998). Swamps and other types of wetlands in the Neotropics have been described in terms of their vegetation composition, structure, and geomorphology, but studies have failed to deal with peat formation or detailed descriptions of the underlying soils. There is evidence that at least the Mauritia swamps frequently accumulate peat of some kind.
The lowland tropical peat swamps are formed from layers of woody debris too waterlogged to fully decompose. Slowly deposited over thousands of years, the carbon-rich peat strata have been known to reach a thickness of up to 20 m. In Indonesia the ombrogenous peatlands are mostly formed on the inward edge of the mangroves. They are usually dome-shaped and several meters thick overlying the mangrove mineral soil; the whole sequence taking several thousand years. Periods with rising sea levels promote the formation of very deep peat layers up to 20 m thickness with the alluvial soil far below present sea levels. Peat domes younger than 3000 years do have the alluvial soil at about present mean sea level.
The initial rate of vegetation growth and peat build-up is rapid, as the alluvial mangrove soils are nutrient-rich. As the peat accumulates, it builds up above the level of the nutrients in the alluvial soils that are accessible for the plant roots. In that case, the mineral supply to the vegetation depends on the minerals in the rainwater and available nutrients of the decaying vegetation in the surface layer. As the swamp ages and the peat layer increases, nutrients become increasingly scarce, tree growth and litter production are reduced, and growth of the whole formation slows down.
Besides its association with mangroves, the lowland Neotropical peatlands are associated with palm swamps and open herbaceous marshes. The latter apparently are relatively nutrient-rich, since surface runoff water easily reaches all parts of the swamps. Furthermore, the layer of organic material is usually thin enough for the roots of the plants to have direct contact with the underlying mineral soil. In the case of palm swamps, they may be regularly affected by riverine floods, but for most of their extent they occur farther from current river channels, the water-logged condition then being maintained by a combination of high precipitation and poor drainage, which makes them ombrogenous types of peatlands.
Many floodplain swamp forests are potentially peat-accumulating, but, although studies on this subject exist in Southeast Asia, they have apparently never been published for the Amazon basin (Whitmore 1998). Swamps and other types of wetlands in the Neotropics have been described in terms of their vegetation composition, structure, and geomorphology, but studies have failed to deal with peat formation or detailed descriptions of the underlying soils. There is evidence that at least the Mauritia swamps frequently accumulate peat of some kind.
The lowland tropical peat swamps are formed from layers of woody debris too waterlogged to fully decompose. Slowly deposited over thousands of years, the carbon-rich peat strata have been known to reach a thickness of up to 20 m. In Indonesia the ombrogenous peatlands are mostly formed on the inward edge of the mangroves. They are usually dome-shaped and several meters thick overlying the mangrove mineral soil; the whole sequence taking several thousand years. Periods with rising sea levels promote the formation of very deep peat layers up to 20 m thickness with the alluvial soil far below present sea levels. Peat domes younger than 3000 years do have the alluvial soil at about present mean sea level.
The initial rate of vegetation growth and peat build-up is rapid, as the alluvial mangrove soils are nutrient-rich. As the peat accumulates, it builds up above the level of the nutrients in the alluvial soils that are accessible for the plant roots. In that case, the mineral supply to the vegetation depends on the minerals in the rainwater and available nutrients of the decaying vegetation in the surface layer. As the swamp ages and the peat layer increases, nutrients become increasingly scarce, tree growth and litter production are reduced, and growth of the whole formation slows down.
Besides its association with mangroves, the lowland Neotropical peatlands are associated with palm swamps and open herbaceous marshes. The latter apparently are relatively nutrient-rich, since surface runoff water easily reaches all parts of the swamps. Furthermore, the layer of organic material is usually thin enough for the roots of the plants to have direct contact with the underlying mineral soil. In the case of palm swamps, they may be regularly affected by riverine floods, but for most of their extent they occur farther from current river channels, the water-logged condition then being maintained by a combination of high precipitation and poor drainage, which makes them ombrogenous types of peatlands.
Geographic Range: Flooded forest systems are a regular feature of the low-lying coastal areas in the West Indies, southern Mexico, Central America, and northern South America. In South America, the greatest extent of flooded forest occurs in Amazonia, and in the basins of other important rivers, such as the Orinoco and the Atrato. However, the most complex mosaics of wetlands, savannas, and flooded forests are maybe those of the Beni in Bolivia and the Brazilian Pantanal, on very extensive flat basins subject to a strong seasonality in the precipitation. Some of the extensive floodplains of South America include treed and shrub swamps that are located off the direct influence of the main river channels, usually occupying past, silted up river arms or depressed areas with inflows product of runoff and seepage or only sporadic, extreme river floods.
Nations: AS,FM,MP,MX,PR,PW,US,WS
States/Provinces: No Data Available
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860267
Confidence Level: High
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.A Tropical Forest & Woodland Subclass | S17 | 1.A |
| Formation | 1.A.4 Tropical Flooded & Swamp Forest Formation | F029 | 1.A.4 |
| Division | 1.A.4.Ed Caribbean-Central American Flooded & Swamp Forest Division | D093 | 1.A.4.Ed |
| Division | 1.A.4.Ob Polynesian Flooded & Swamp Forest Division | D003 | 1.A.4.Ob |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Freshwater swamp forest (Whitmore 1998) [Whitmore divides the Tropical Swamp & Flooded Forest into two formations based on peat or mineral soils.]
> Peat swamp forest (Whitmore 1998) [Whitmore divides the Tropical Swamp & Flooded Forest into two formations based on peat or mineral soils.]
> Peat swamp forest (Whitmore 1998) [Whitmore divides the Tropical Swamp & Flooded Forest into two formations based on peat or mineral soils.]
- Faber-Langendoen, D., T. Keeler-Wolf, D. Meidinger, C. Josse, A. Weakley, D. Tart, G. Navarro, B. Hoagland, S. Ponomarenko, J.-P. Saucier, G. Fults, and E. Helmer. 2015c. Classification and description of world formation types. General Technical Report RMRS-GTR-000. USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO.
- Irmler, U. 1977. Inundation forest types in the vicinity of Manaus. Biogeographica 8:17-29.
- Kubitzki, K. 1989. The ecogeographical differentiation of Amazonian inundation forests. Plant Systematics and Evolution 162:285-304.
- Prance, G. T. 1979. Notes on the vegetation of Amazonia. III. The terminology of Amazonian forest types subject to inundation. Brittonia 31(1):26-38.
- Whitmore, T. C. 1984. Tropical rain forests of the Far East. Second edition. Clarendon Press, Oxford.
- Whitmore, T. C. 1998. An introduction to tropical rain forests. Second edition. Oxford University Press, Oxford.