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The northern floodplain of Walnut Creek between Garner Road and State Street is described as an alluvial forest because it lies in the floodplain of Walnut Creek. Each time Walnut Creek floods above its banks soil and sand particles wash into the flood plain, creating a unique habitat for plants and animals.
The most common types of trees that grow in floodplain areas are bottomland hardwoods. These are deciduous trees, including many oaks that have very dense wood. A silhouette of Water Oak, Quercus nigra, on floodplain is seen below. The leaves and bark of water oak are helpful for identification.
Swamp Chestnut Oak, Quercus michauxii, has bark similar to the common white oak that grows in drier soils. However, its leaf shape is quite different.
Sycamore, Platanus occidentalus, known by its white and peeling bark, is also found on the Walnut Creek floodplain.
The seeds of Box Elder, Acer negundo, are easy to identify due to their large size and winged structure.
One problem that occurs in urban natural areas is that non-native plant seeds are carried into areas where they grow easily and out compete native plants. The northern flood plain has extensive patches of Chinese Privet, Ligustrum sinense, whose seed was likely carried here from yard plantings. Some exotic species become very invasive and can destroy native plant populations. In the photo below an invasive ground cover has spread over a large area. Even though it looks nice and green it will keep native wildflowers from growing by not allowing them to get enough sunlight, water and nutrients.
Invasive vines are also very prominent in the northern floodplain . The close up below shows how invasive vines can smother a tree.
The wild rosebush makes travelers weary of its prickles but happy to see is brilliant fall leaf color. In the fall the tributary streams of Walnut Creek run clear as long as we keep them clean and free of trash.
Many animals live in the northern floodplain along Walnut Creek. A small pond created by a fallen tree provides habitat for frogs, salamanders and a water source for mammals and birds. This lush meadow of sedges and grasses inside the flood plain forest provides food for many animals.
After browsing on grass, a white tailed deer left its footprint in the mud.
<Deer tracks in floodplain mud.
|Website created by Frank Koch, Ross Andrews, and Chris Murray. All pictures taken by Ross Andrews at the Walnut Creek Wetlands in Southeast Raleigh. Maps generated by Frank Koch using ESRI ArcGIS 8.1. Soil profiles and their descriptions completed by Chris Murray. For more information on how you can help preserve this vital urban resource please write to Partners For Environmental Justice, c/o St. Ambrose Episcopal Church, 813 Darby Street, Raleigh, North Carolina, 27610.|