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Intro > Classification > Depressions > Sand Pond
Sand Pond
Wetland Class: Depressions
Wetland SubClass: Isolated Depression
Introduction: Sand Pond
Landscape Setting and Hydrology
Sand ponds are depressions formed among dune fields on glacial outwash (also known as "valley train") deposits within the Delta region. Within the extensive dune fields, individual dunes typically are 3 to 5 meters high and consist of fine-sands. They are wind-blown deposits of sediments that were first carried to Arkansas by braided stream channels flowing from melting continental glaciers. The dune fields are estimated to be between 12,000 and 30,000 years old. Each dune field includes numerous small enclosed depressions which are underlain by fine-grained valley train deposits, resulting in a poorly-drained environment that ponds rainwater and intercepts or collects perched groundwater for extended durations. As a result, distinctive, isolated wetlands occur that range from very small swale-like features to relatively large and deep depressions tens of acres in size. Most sand pond wetlands have standing water through the winter, and gradually dry during the growing season. They likely are sources for groundwater recharge in some locations. Individual storms may rapidly re-flood these wetlands at any time of year.
Many of the sand ponds have been drained or filled for agriculture, and drainage water is sometimes directed into the remaining large, deep depressions, changing their hydrology and accelerating sedimentation. Vegetation
Large sand pond basins may be microcosms of floodplain systems, having swamp species in the deepest interior areas with extended inundation, and successively less water-tolerant species around the perimeter of the depression. Small sand ponds may have abrupt transitions to uplands. Few remaining sand ponds have any significant upland buffer, as most of the surrounding landscape is typically in agriculture.
The isolation of individual sand ponds contributes to a unique composition and structure in many cases. Many sand ponds, particularly those in the northern part of their distribution, contain two unusual shrub species: Lindera melissifolia (pondberry) and Leitneria floridana (corkwood). Both of these species are clonal, and typically occur as localized colonies consisting of multiple individual stems. Characteristic Plants
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| Acer rubrum var. drummondii | swamp red maple | | Carpinus caroliniana | ironwood | | Carya aquatica | water hickory | | Carya illinoensis | pecan | | Celtis laevigata | sugarberry | | Diospyros virginiana | persimmon | | Fraxinus pennsylvanica | green ash | | Fraxinus tomentosa (profunda) | pumpkin ash | | Gleditsia aquatica | water locust | | Ilex decidua | deciduous holly | | Liquidambar styraciflua | sweetgum | | Populus heterophylla | swamp cottonwood | | Quercus lyrata | overcup oak | | Quercus nigra | water oak | | Quercus nuttallii | Nuttall oak | | Quercus palustris | pin oak | | Quercus phellos | willow oak | |
| Berchemia scandens | rattan vine | | Brunnichia ovata | ladies' eardrops | | Carex sp. | sedges | | Impatiens capensis | jewelweed | | Juncus effusus | soft rush | | Leitneria floridana | corkwood | | Lindera melissifolia | pondberry | | Parthenocissus quinquefolia | Virginia creeper | | Saururus cernuus | lizard's tail | | Smilax rotundifolia | greenbrier | | Styrax americana
Vitis sp. | snowbell | | Vitis sp. | grapes |
Distribution
Sand pond wetlands occur in several distinct bands within the Delta region. They are associated with a series of ancient dune fields each of which covers 5 to 25 square miles. Approximately 75 such dune fields have been identified in three general groupings or trend lines: immediately east of the Current, Spring, and White Rivers; along both sides of the Cache River, and; immediately east of Sikeston Ridge in southeastern Missouri. The only publicly-accessible example of this type is just outside the Arkansas State line in Ripley County, Missouri, at the Missouri Department of Conservation Pondberry Natural Area.
Other Isolated Depression Community TypesMountaintop Depression
Sinkhole
Unconnected Alluvial Depression
Valley Train Pond
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