KUCHLER TYPE VALUE AND USE
KUCHLER TYPE: Northern floodplain forest



FORESTRY VALUES : 
Cottonwood is valued for sawtimber and pulp and is commercially
harvested on a small scale in central North Dakota [24].  Eastern
cottonwood is the fastest-growing bottomland species in the central
states and black willow grows almost as fast [25].  Eastern cottonwood
can be managed in short rotation even-aged stands [36], and is a good
candidate for plantation silviculture.  Light thinning is recommended at
5- to 10-year intervals beginning at age 5.  Most stands of eastern
cottonwood are harvested by age 50, although stands may remain healthy
until 75 years.  Black willow begins to deteriorate at around 35 years
and commercial value is low by 50 years [25].  Well-drained silt flats
are the most valuble timber and fiber producing areas.  Depressional
swamps do not produce commercial timber or fiber, but silver maple and
willow in these swamps provide cordwood and can be regenerated by
coppicing.  Silver maple is a valuable timber species in the Midwest and
is managed by clearcutting or group selection [36,37].

Other northern floodplain forest species valued for timber and fiber
production include American elm, green ash, sycamore, hackberry, red
maple, and river birch.  Site index curves for cottonwood, American elm,
silver maple, and green ash are available [37].


RANGE VALUES : 
In the Great Plains, many livestock grazing areas include patches of
northern floodplain forest.  These forests provide important shade and
shelter for cattle grazing on adjacent grasslands [16].


WILDLIFE VALUES : 
Riparian forests including northern floodplain forests are important
wildlife habitat, particularly for birds [8,36].  These forests are
complex due to the mixture of many physical and biological features.
There is substantial development of edge habitat at the interfaces
between stream and forest, and between forest and adjacent uplands.
Many species occur almost entirely in edge zones [8].

Open stands of northern floodplain forest with heavy herb cover are
ideal waterfowl nesting habitat.  Dead elms and cottonwoods provide food
and shelter for many species of songbirds [36].  Cottonwood plantations
provide excellent wildlife habitat [25].  On the Platte River, extensive
tracts of woodland are of benefit to many species of raptors including
bald eagle (Haliaeetus leucocephalus), peregrine falcon (Falco
peregrinus), prairie falcon (F. mexicanus), American kestrel (F.
sparverius), northern harrier (Circus cyaneus), red-tailed hawk (Buteo
jamaicensis), rough-legged hawk (B. lagopus), ferruginous hawk (B.
regalis), and golden eagle (Aquila chrysaetos) [48].

The Big Bend Reach of the Platte River is an area of great importance to
numerous species of migratory birds using the Central Flyway [47].  This
area is an important stopover site for sandhill crane (Grus canadensis),
which roost in the river and feed in nearby corn fields [56].

Threatened and endangered animals occurring in riparian ecosystems (some
of which are northern floodplain forests) include Indiana myotis (Myotis
sodalis), gray myotis (M. grisescens), whooping crane (G. americana),
bald eagle, peregrine falcon, and Bachman's warbler (Vermivora
bachmanii) [47].  Riparian ecosystems are important to at least
one-third of the species or subspecies listed as threatend or endangered
by the U.S. Fish and Wildlife Service.  Many riparian species are
candidates for future federal listing as threatened or endangered.
These species include Bell's vireo, western populations of yellow-billed
cuckoo, many invertebrates, and many plants [8].

Breeding birds along the Platte River, Nebraska, are diverse.  Some 142
species have been observed nesting in northern floodplain forest and
adjacent ecosystems.  In many areas, decreased flow due to dams and
irrigation has decreased meandering and increased land area.  Species
which nest in northern floodplain forest have increased because of the
extension of woody vegetation into former river channels.  However,
available nesting habitat for species such as least tern (Sterna
antillarum) and piping plover (Charadrius melodus), which nest on
sandbars, has decreased [48].  Breeding bird densities in some riparian
ecosystems (largely equivalent to northern floodplain forest) are as
follows (compiled by Brinson and others [8]):

                                  birds per 40 ha
willow, Colorado                    100
cottonwood-willow, Colorado         525-589
cottonwood-willow, Colorado         225-900
cottonwood, Colorado                319
bottomland forests, Oklahoma        400
riparian communities, Great Plains  137-748


Riparian bird population densities in winter are as follows [45]:

                                                  birds per 40 ha
floodplain forest, Illinois (2 locations)          148;226
mixed habitat-disturbed bottomland, Oklahoma       183
floodplain cottonwood, Colorado                    186
cottonwood-willow riverbottom, Colorado            311


OTHER VALUES : 
Floodplain forests help regulate water level, flow rate and direction,
bank stability, and potential evapotranspiration.  Changes in the
vegetation affect flood characteristics.  Flood damage to bridges and
other streamside structures can be reduced if open forests are
maintained adjacent to these structures [36].


MANAGEMENT CONCERNS : 
Floodplains are a mosaic of cultivated fields, marshes, sand dunes,
sandbars, brushland, and forest [24].  Klapotek and others [28] reported
in 1979 that the potential area of northern floodplain forest was over
17 million acres (7,171,000 ha) but that the actual area covered by
northern floodplain forests was less than 700,000 acres (279,000 ha).
Irrigation and flood control projects have resulted in a 70 percent
reduction in flow of the Platte River in Nebraska.  As a result woody
vegetation has encroached on thousands of hectares of former channel
area, contributing to changes in channel features and altering wildlife
habitat [56].  Petranka and Holland [39], however, reported that there
were only minor differences in plant species composition and structure
between channelized and undisturbed south-central Oklahoma gallery
forests (which contain predominately the same species as northern
floodplain forest but are not mapped as such) of various ages since
channelization.

Heavy use of floodplain forests by livestock can have severe detrimental
effects on the vegetation.  Concentrated use by cattle can result in
sparse stands of low vigor, much dead material on the ground, compacted
soils, and little or no seedling survival.  This type of damage is
particularly common when the forest occupies only a small portion of a
range.  Continuous summer grazing of these woodlands, even under good
conditions, will probably result in some degradation [58].

Riparian ecosystems are dependent on fluvial processes and drainage
density for soil moisture, nutrient availability, and community
stability and structure [8].  Usually, resilience of floodplain forests
to timber harvests is relatively high.  A combination of harvest and
site alteration (i.e., dam construction and irrigation projects) may,
however, increase regeneration time for many forests [13].  Many
riparian woodlands in the United States have been replaced by grasses;
many others are in a state of decline due to a number of factors.  Many
of the stands are exposed to concentrated use by livestock; some are
nearing the natural end of their lifespans and are vulnerable to
insects, disease, and mechanical stresses [7].  Heavy grazing and timber
cutting have reduced some central North Dakota floodplain forests to
brushlands [24].

A lack of eastern cottonwood seedling establishment along the Missouri
River in central North Dakota was attributed to a reduction in the
meandering rate following the construction of dams [24,53].  Lack of
cottonwood seedling establishment in other floodplains is also
attributed to flood control projects [7,24,26].  A decline in the
establishment of silver maple and elms, and a reduction in the diameter
growth rate for silver maple, elms, and ash is apparently related to
flood control which reduces the height and duration of spring flooding
[24,53].  Boxelder and sweet pecan also appear to depend on flooding for
reproduction.  Boxelder can even be used as an indicator of flooding
frequency [3].

Channelization of streams in south-central Oklahoma has contributed to
reductions in bottomland forest area of up to 93 percent.  These forests
are not included in northern floodplain forest maps but consist of the
species listed by Kuchler for northern floodplain forest.  On two study
sites, the combined floodplain areas were 76 percent forested in 1871
and only 10 percent forested in 1969.  Black willow and eastern
cottonwood seedlings are restricted to the channel zone.  Bird densities
were substantially lower on channelized sites than on unchannelized
sites.  Species that occurred only on unchannelized sites included
northern parula, Louisiana waterthrush (Seiurus motacilla), northern
cardinal, Carolina chickadee (Parus carolinensis), tufted titmouse,
brown-headed cowbird, red-bellied woodpecker, indigo bunting, painted
bunting, yellow-bellied cuckoo, Carolina wren, and American goldfinch
[3].

The widespread infection of American elm with Dutch elm disease has
important consequences for conservation, floodwater management, and
resource utilization in northern floodplain forests.  Loss of large
trees decreases bank stability, increases water availability (and flood
level), and decreases timber [46].

Wildlife species that require a combination of riparian habitat features
are more sensitive to alterations than those requiring only one
component [8].

Related categories for Kuchler Type: Northern floodplain forest