NEC1006: Hydropedology: Genesis, properties, and distribution of hydromorphic soils.
(Multistate Research Coordinating Committee and Information Exchange Group)
Status: Inactive/Terminating
NEC1006: Hydropedology: Genesis, properties, and distribution of hydromorphic soils.
Duration: 10/01/2002 to 09/30/2004
Administrative Advisor(s):
NIFA Reps:
Non-Technical Summary
Statement of Issues and Justification
Water plays an essential role in many processes taking place in the soil environment. Wetlands are characterized by having saturated conditions to the soil surface during some part of the growing season. This strongly affects the ability of microorganisms to break down the organic materials. This results in accumulation of organic matter in the form of bogs, swamps, and marshes. Even mineral wetland soils undergo microbial processes that make these soils unique. Knowledge of these processes is important to elucidate, among other things, the effects of global warming on the distribution of coastal wetlands and to study the processes that result in the sequestration of carbon, iron, sulfur, and other compounds associated with wetlands. Others want to study wetland soils because of regulatory complications, in which certain soils do not display characteristics typically associated with long-term soil saturation.
Not much is known about the pedological effects of rising sea levels, but soils of coastal wetlands potentially can store large amounts of carbon which may affect the atmospheric carbon balance. Although some estimates have been made about the amount of carbon sequestration in coastal wetlands, these estimates do not take into account that formerly dry soils can become submerged and that these soils will contribute strongly to carbon immobilization. Rising sea levels also create shallow estuarine substrates which properties are controlling the plants and animals living in this environment. Subaqueous soils can be classified and delineated into units with similar physical and chemical characteristics. The properties of these submerged sediments have a significant effect on subaqueous vegetation (SAV) which serve as an important breeding and feeding locale for fish. A healthy coastal fisheries industry largely depends on the quality and distribution of the SAV.
Seasonal high water tables generally result in distinct patterns of colored spots often referred to as redoximorphic features. Various wetland regulations define the occurrence of hydric soils as an indicator of jurisdictional wetlands, particularly when the redoximorphic features are present in the upper 30 cm of the soil. While this concept is valid for the majority of soils, there are situations where redox features are lacking, yet the site may exhibits extensive periods of saturation. New indicators need to be developed for these problem soils, to allow for a reliable and reproducible determination of wetland boundaries. In fact, it would be helpful to monitor
seasonal water table fluctuations in selected soils over a long time period to allow for a better understanding of the genesis of these redoximorphic features. This would also help in providing more realistic estimates about the degree of seasonal soil wetness. This would contribute to much improved soil survey interpretations of the hydrology of specific soils. This would aid land use decisions for a wide variety of purposes including agriculture, building construction, and on-site sewage disposal.
The Northeast region recently has seen a rise in the number of active pedology researchers. The common threat in the research interests of these individuals is water. This project is an attempt to consolidate the study of wetland soils in a more organized fashion thereby allowing soil scientists from the entire region and beyond to focus on processes unique to wetlands and to study the physical, chemical and morphological characteristics that result from these distinct processes.
Objectives
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to quantify carbon sequestration in soils of coastal wetlands and near shore environments of the northeastern US, and to estimate changes in C-storage and other pedological process in response to predicted sea-level rise.
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to identify, characterize, and further the knowledge of subaqueous soils.
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to address interpretation problems between measured hydrology and vegetation characteristics, and field hydric soil indicators as used by regulatory personnel.
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to determine frequency and duration of water table depths of wetland and agriculturally important soils.
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Procedures and Activities
Expected Outcomes and Impacts
- Products generated by this research have a direct impact on the general knowledge of the genesis, and physical and chemical properties of wetland soils. Specifically they allow for better prediction models of the fate of carbon in recently submerged wetlands. Thereby improving the current, rather coarse, prediction models of the role of carbon sequestration in wetlands, specifically in coastal wetlands
- Subaqueous soils affect the productivity of subaqueous vegetation. Pollution has wiped out significant portions of SAV. The results of this research will identify those sediments with superior characteristics for the reestablishment of this type of vegetation. Furthermore, the research will provide an improved understanding of the chemical and morphological alterations taking place in these soils, which is important to predict behavior of these soils when disturbed.
- Wetland delineation is a million dollar industry. Its impact on construction and overall land use easily runs into the multi-million dollars. Identification of hydric soils is essential in the delineation process. This research will result in an improved assessment procedure allowing delineations, even in soils that traditionally do not display the typical redoximorphic features associated with so-called problem hydric soils. These include the sandy soils supporting evergreen vegetation along the eastern sea board from Maine to Florida, soils derived from Triassic redbed sediments, soils high in black phyllitic materials, hydrologically discharging soils, pre-weathered parent materials, and soils in floodplains.
- Soil survey inventories and reports are used for a wide variety of land use purposes, including agriculture, construction, recreational use, forestry, etc. Most of the interpretations for various land-uses are emperical, i.e. they are not based on actual measurements. Obtaining better data about the physical and chemical characteristics of hydric soils and soils of local, regional, or national importance will greatly improve the reliability of soil survey products, particularly the variation in seasonal groundwater tables in different soil series.
Projected Participation
View Appendix E: ParticipationEducational Plan
Organization/Governance
The recommended Standard Governance for multistate research activities include the election of a Chair, a Chair-elect, and a Secretary. All officers are to be elected for at least two-year terms to provide continuity. Administrative guidance will be provided by an assigned Administrative Advisor and a CSREES Representative.
Literature Cited