River cane has variably been considered two species or a species with subspecies:
- Arundinaria gigantea – also known as giant cane, large cane, river cane, Southern cane
- A.tecta or A gigantea tecta – also small cane or switch cane
The two types share similar habitats and physiologies, and often grow together in the wild. As a member of the bamboo family, river cane is a true grass with a perennial woody stem. The larger variety typically grows to 3-5 meters, whereas the smaller cane may top off at 2 meters.
Current and Historic Distribution of Arundinaria
Arundinaria gigantea is found in 23 states and tecta in 14 of these states. River cane can be found as far west as Texas and as far north as New York, but is primarily distributed in the Southern and Southeastern US.
Rivercane is typically found in monodominant thickets or “brakes”. These were once a dominant part of the landscape. For instance in central Kentucky in 1790, one canebrake was reported to be ‘‘15 miles long and nearly half as wide.’’ Today it is estimated that less than 2% of original habitat remains.
Overgrazing and cultivation are the primary culprits of native Arundinaria’s habitat loss. Decades of fire suppression have also been harmful in two ways: the canopy grows too thick for understory plants like river cane, and when fires do occur, they tend to be catastrophic and leave too much sunlight for the cane to reestablish itself.
As the name implies, river cane is found in floodplains beneath sparse forest canopy. However, it will grow where there is the right mix of shadow and light, such as at the forests’ edge or in canopy gaps in upland forests and savannahs.
Economic and Ecological Value of Arundinaria
River cane has historically had a high forage value for livestock, particularly cattle. It also serves as an important habitat for wild animals. Small mammals, reptiles, birds, and insects live, nest, and forage within breaks of river cane. There are even species that are believed to be cane-dependent. Most notable of these is Bachman’s warbler, which is believed to be extinct. Other cane-dependent species include Swainson’s Warbler, St. Francis satyr butterfly, and the plants golden sedge (Carex lutea), Lilium iridollae and Lilium gazarubrum.
Arundinaria's Role in Riparian Ecosystems
The compact network of rhizomes and culms that characterize river cane provides:
- stream bank stabilization,
- sediment retention (decreased erosion), and
- bioaccumulation of nutrients and toxins
Studies have found that Arundinaria will uptake agricultural runoff such as nitrogen, orthophosphates, ammonium, nitrates, and sediments. A 2003 study by Schoonover et al. suggests that canebrakes can filter 130 times more nitrogen that regular hardwood forest.
Canebrake Propagation
It is unfortunately impractical to propagate Arundinaria using seeds. River cane seeds are produced only sporadically, are often not viable, and suffer from high rates of predation by rodents, birds, and insects. Most people therefore use either:
- clump division, which involves digging up and replanting intact culms, rhizomes, and roots, or
- rhizome cuttings, which can be surface planted provided there are at least 10 internodes in the cuttings
To thrive, river cane needs:
- to be transplanted after it has been well watered
- a light canopy
- no competition from fast-growing plants such as privet
- good drainage, as found in sloped areas
Arundinaria will also grow best in areas that have been mulched and fertilized.
Arundinaria gigantea and tecta play important roles in our ecosystems. Hopefully cane restoration programs will help bring back some of the massive canebrakes -- and the accompanying bird song and clean water -- of yore.
Estela Kennen - Estela is a doctoral student in Public Administration and a freelance writer and editor.
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