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Abstracts for Oral Presentations
Floodplain Ecosystems of the Southeast: Linkages
Between Forests and People
Dr. Graeme Lockaby
School of Forestry and Wildlife Sciences
Auburn University
Floodplain forests entail greater value to society than any other
type of forest ecosystem and that value will rise immensely in the
coming decades as water becomes the most critical natural resource
in our region. Although progress has been made in promoting the
importance of floodplain wetlands to the public and in successfully
manipulating systems toward particular goals, we are still quick to
generalize and may hurry past some of the complexities of these
systems during our research, management, and restoration efforts.
Within the Southeast, floodplain hydrology varies from constant to
no flooding and forest NPP ranges from near the highest of the
temperate zone to among the lowest. The complex entanglements
of hydrology and all other floodplain forest processes and traits
are daunting. Nevertheless, these do not represent our
greatest challenge, i.e. that of understanding and basing actions on
the influences of human society and landscape evolution within
watersheds and floodplains. It will become increasingly less
relevant to study, manage, or try to restore portions of floodplains
without due consideration of past, current, and future socioeconomic
drivers and land use trends within basins and watersheds. The human
footprint on these critical systems has been very distinct for the
last 200-300 years; now, it is becoming enormous and must be fully
taken into account if we are to be successful in maintaining
significant amounts of floodplain forests in the Southeast.
Guidelines for Effective Restoration of River-floodplain Ecosystems
David L. Galat
U. S. Geological Survey
Missouri Cooperative Research Unit
The Department of Fisheries and Wildlife Sciences
302 ABNR Building
University of Missouri
Columbia, MO 65211-7240
Email: galatd@missouri.edu
Phone: 573-882-9426
Fax: 573-884-5070
Multi-million dollar, ecosystem-scale river restoration programs are
underway for many of our nation’s largest rivers, including the
Colorado, Columbia, Mississippi, Missouri, and Rio Grande along with
similar programs for river associated wetlands in the California
Bay-Delta, Chesapeake Bay, coastal Louisiana, and Florida
Everglades. The diversity of competing issues, significant
social-ecological consequences of management decisions, and degree
of scientific knowledge required have resulted in numerous
uncertainties over what constitutes effective river-floodplain
restoration. The following attributes of effective restoration
are contrasted among Missouri River Biological Opinion Compliance,
Upper Mississippi River Navigation and Ecosystem Sustainability
Program (NESP), and other large-scale river-wetland restoration
programs in the U.S.
·
Understand principles for conflict resolution in high-profile water
disputes.
·
Set standards for ecologically successful restoration.
·
Formalize a collective vision and a hierarchy of goals and
objectives.
·
Implement a system versus a species perspective and restore
processes over places.
·
Target ecosystem sustainability over ecological integrity.
·
Adopt essential features of other successful large-scale
river-wetland restoration programs
·
Implement effective science and effective use of science.
Applying these attributes will increase the likelihood of achieving
socially and ecologically successful restoration programs that
secure authorization and maintain multiple-year funding.
Floodplain Geomorphic Processes, Sedimentation, and Ecological
Impacts of Hydrologic Alteration along Coastal Plain Rivers
Cliff R. Hupp, U.S. Geological Survey
Aaron R. Pierce, Nicholls State University
Phillip A. Townsend, University of Wisconsin
Rivers on the Coastal Plain of southeastern United States develop
the largest floodplains on the continent. The associated
forested wetlands reveal a template of the landforms of those
floodplains that represent in great ecological detail the ambient
hydrogeomorphic processes of the system. Thus, alterations in
the hydrogeomorphology of a reach can significantly affect these
forested ecosystems. Depending on the geomorphic setting, land
clearance and downslope aggradation, channelization, and flow
regulation may lead to channel incision or filling. Such
processes influence hydrogeomorphic thresholds and alter key
functions of floodplain forests, including sediment trapping (and
associated contaminants), which can subsequently initiate long-term
shifts in forest composition. Floodplain sedimentation rates
vary from 0 in levee crevasses to 400 mm/yr in backswamps with high
degrees of connectivity to sediment laden river water; some recent
historical sedimentation depths exceed 4m. In this paper we
integrate and interpret general results from intensive studies of
hydrogeomorphic processes, landforms, and riparian forests on the
Roanoke River, NC where flow is tightly regulated by dams,
throughout West Tennessee where most streams have been channelized,
and in the Atchafalaya Basin where hydrologic alteration has been
intense. Coastal Plain floodplains are especially significant
because they represent the last place for substantial sediment
trapping and biogeochemical amelioration of contaminants before
water enters critical estuarine habitats. The
functioning of Coastal Plain floodplain ecosystems may be critical
in the future to maintain water quality and quantity, as well as to
preserve biodiversity and other ecological and economic values of
riparian wetlands. Ultimately, data and models of the
hydrology and forests of these complex systems may be used to
facilitate understanding and management of important floodplain
ecosystem services.
Complex Effects of Channelization and Leveeing on Western Tennessee
Floodplain Forest Structure, Composition and Function
Scott B. Franklin1,5*, John A. Kupfer2,5, S. Reza Pezeshki1, Randy
Gentry3 & R. Daniel Smith4
1Department of Biology, University of Memphis, Memphis, TN
2Department of Geography & Regional Development, University of
Arizona, Tucson, AZ
3Southeastern Water Resources Institute, The University of
Tennessee, Knoxville, TN
4US Army Corps of Engineers Waterways Experiment Station, Vicksburg,
MS
5Edward J. Meeman Biological Field Station, Millington, TN
Abstract
In an effort to examine channelization effects on western Tennessee
floodplains, we selected six rivers reaches (3-8 km long), including
two non-channelized, two channelized and leveed, and two channelized
but non-leveed. Data on vegetation composition and structure,
herbaceous productivity, soil and leaf nutrient pools, soil redox
potential, and surface water hydrology were compared among
channelization treatments and floodplain microtopography (depression
and nondepressional sites). Hydrology was significantly affected by
channelization treatments, especially streams with levees.
Disconnected floodplains were drier, maintained higher nutrient
pools, and were more productive than floodplains still connected to
channel hydrology. Channelized reaches were flashy in their response
to rainfall events, their hydrologic stage rising quickly and
falling quickly. Channel and floodplain hydrology were most strongly
connected for unchannelized streams, and only connected during high
flow events for channelized streams. As a result, unchannelized
streams were extremely variable in soil redox potential and nutrient
pools, and showed the greatest differences among depression and
nondepression sites. Forest compositional differences among the
three types of river reaches were confounded by disturbances (e.g.,
channelized sites had 20-40% more of their basins in agriculture
than unchannelized sites) and the storage effect of long-lived tree
species, although significantly correlated to hydrology. Results
suggest both the subsidy (i.e., nutrient inputs) and the stress of
flood events have been altered by anthropogenic activities, but
these alterations were greatest in channelized systems compared to
unchannelized systems. A conceptual model of the complex floodplain
interactions due to anthropogenic alterations is offered.
Geomorphology, Plant Community Distribution, and Wetland Restoration
in the Mississippi Alluvial Valley
Charles Klimas[1], Elizabeth Murray[2],
Thomas Foti[3], Jody Pagan[4],
and Henry Langston[5]
Alternating braided-stream and meandering-stream regimes of the
Mississippi River throughout the Quaternary Period produced a subtly
complex landscape of depositional features within the Mississippi
Alluvial Valley (MAV), exhibiting highly variable soils and
hydrology. Prior to European settlement, those variations
produced tremendous spatial complexity and diversity within vast
forested wetlands and extensive fire-maintained prairies and
savannas, with the distribution of specific plant communities
largely driven by abiotic characteristics of the site:
geomorphology, soils, hydrology and topography. Agricultural
development over the past century ─ facilitated by river
engineering, flood protection, and drainage efforts ─ has destroyed
most of the natural vegetation and obscured the patterns of
community distribution.
The fundamental controlling influence of geomorphology in
determining the distribution of plant communities provided the basis
for a hydrogeomorphic classification and characterization of
vegetation for the Mississippi and Arkansas portions of the valley.
Detailed, spatially-explicit geomorphology and soils data are
available for the entire MAV, and hydrologic mapping has been
completed in many areas. Thus, the tools exist to apply the
hydrogeomorphic classification to the modern, highly modified
landscape, and to develop maps of potential plant community
distribution based on identifiable combinations of abiotic
characteristics of sites that are currently in agriculture.
These Potential Natural Vegetation (PNV) maps provide an indication
of the multi-scale complexity that once characterized the MAV, and
serve as planning tools for restoration. PNV maps have already been
completed in Arkansas; the approach currently is being applied to
northeastern Louisiana, and can be expanded to the entire MAV.
The Effects of Lateral Channel Migration Rates on Riparian Forest
Structure and Composition, Congaree River, Congaree National Park,
South Carolina
Kimberly Meitzen
Department of Geography
University of South Carolina
709 Bull Street, Rm 227
Columbia, SC 29208
(803) 210-5421
Blancas@mailbox.sc.edu
Lateral channel migration initiates complex and dynamic
biogeomorphic responses that are fundamental to the creation and
maintenance of riparian habitats along low-gradient, coastal plain
rivers. This research examines the effect of lateral channel
migration rates on structure and composition of pointbar and cutbank
forests along the Congaree River, Congaree National Park, SC.
Lateral channel migration rates were measured in a GIS using
geo-referenced aerial photos from 1938-2006. Forest structure and
composition were measured in the field from a stratified-random
sample of 50 sites, which included 25 paired edge-interior plots,
and analyzed using Mann-Whitney tests, Spearman’s Correlation
Coefficients, and DCA ordinations.
Lateral channel migration produced a significant directional control
on cutbank and pointbar forests through divergent successional
responses. Pointbar forests exhibited a classic forward successional
response, whereby one species assemblage replaced another dependant
on spatial and temporal controls related to micro-topography and
lateral migration rates. Cutbank forests exhibited a retrogressive,
reverse successional response and increased in structural complexity
with increasing proximity to the river; however vegetation indices
varied inversely with lateral migration rates. Cutbank edges with
low lateral migration rates allowed a longer time for trees to
colonize and they contained greater density, basal area, and
richness. Cutbanks characterized by high lateral migration rates
contained lower tree densities, basal area, and richness.
Habitat diversity and increased complexity along the river are
especially important for providing feeding, nesting, and corridor
habitat to a variety of riparian wildlife. Monitoring forest
responses to lateral migration rates is necessary for managing river
and floodplain resources.
Influence of Hydrologic Alteration on Floodplain Ecosystems in the
Connecticut River Basin, Northeastern U.S.
K. H. Nislow1,2, C.O. Marks3, F. J. Magilligan4, J. K. H. Zimmerman3
and K.A. Lutz3
1 USDA Forest Service Northern Research Station, Amherst, MA 01003
2 corresponding author email: knislow@fs.fed.us
3 The Nature Conservancy, Connecticut River Initiative, 5 Strong
Avenue, Suite 201, Northampton, MA 01060
4 Department of Geography, Dartmouth College, Hanover, NH 03755
The floodplain ecosystems of the Connecticut River in New England
share most of their species with the southeastern US. However,
important differences in hydroclimatology, geologic setting, and
patterns of hydrologic alteration, may provide insight into the
ecology of these shared floodplain species. Due to geologic
and topographic constraints, natural floodplain ecosystems are
generally limited to large tributary and mainstem locations with
highly altered hydrologic regimes. These threatened habitats, which
are diversity hotspots in the New England region, have been further
impacted by a suite of invasive species and by changes in land use.
In this paper, we outline an interdisciplinary framework designed to
evaluate the effects of hydrologic alteration on Connecticut River
floodplain ecosystems. Our goal is to extend our understanding
of population and ecosystem dynamics in diverse floodplain
environments, and to provide context-specific guidance for
ecological flow restoration.
Influence of Sediment Oxygen Demand in Seasonally Inundated
Floodplain Swamps of the Georgia Coastal Plain
M. Jason Todd1, George Vellidis2, R. Richard Lowrance3 and Catherine
M. Pringle1
1Odum School of Ecology, University of Georgia, Athens, GA
2Biological and Agricultural Engineering, University of Georgia,
Tifton, GA
3USDA-ARS, Southeast Watershed Research Lab, Tifton, GA
Blackwater streams are found throughout the Coastal Plain of the
southeastern United States. These streams are characterized by
low slopes, high summertime temperatures, and extensive inundation
of surrounding floodplains. Typically lasting from winter to
early spring, the long inundation period creates a multitude of
instream floodplain swamps that play a vital role in overall water
quality. Over 90% of the blackwater streams listed as impaired
on the Coastal Plain of Georgia are listed for violation of the
state’s dissolved oxygen (DO) standard. Generally assumed to
be a consequence of increased biological activity from nitrogen and
phosphorus enrichment, lowered DO may be a natural phenomenon within
this system. A key influence on the DO levels within these
floodplain swamps is sediment oxygen demand (SOD). Despite
being a critical and dominant sink of oxygen in many river systems,
SOD is often poorly investigated or estimated in oxygen budgets.
Results show SOD rates ranging from 0.491 – 15.836 g O2 m-2 d-1
which are up to 43 times higher than values reported for
southeastern sandy-bottomed streams. A key cause of these
elevated SOD rates may be the distribution of highly organic soils
across the river continuum. When developing water quality
models managers should pay closer attention to the influence of SOD,
as when coupled with long residence times, it likely plays a central
role in determining DO levels within these instream swamps and the
river system as a whole.
Retention of Riverine Nutrient and Sediment Loads by Floodplains in
the Chesapeake Bay Watershed
Gregory B. Noe and Cliff Hupp. U. S. Geological Survey
Few quantitative estimates exist for the percent retention of annual
river loads of nitrogen (N), phosphorus (P), and suspended sediment
by wetlands. We measured depositional fluxes of nutrients and
suspended sediment onto floodplain soil surfaces (g m-2 yr-1; 1-6
yrs of accumulation) over a sampling network that included the
Coastal Plain portion of seven rivers in the Chesapeake Bay
watershed. For each river, the average N, P, and sediment
depositional flux rates were multiplied by an estimate of floodplain
area to calculate floodplain trapping rates (kg yr-1), and then
compared to average river loads. Median material retention
among the rivers was 22% of N (range 5-150%), 59% of P (14-587%),
and 119% of suspended sediment (35-690%). Uncertainty in
retention estimates derive from several aspects related to
permanency of the sink of deposited nutrients and sediment, relative
importance of the rivers as the source of deposited material,
adequacy of sampling network, measurement of river loads, and
estimation of floodplain area. The percent retention of N, P,
and sediment among rivers increased with floodplain area and
decreased with river load. Coastal Plain floodplains in the
Chesapeake Bay watershed likely function as an important long-term
sink for material transported by rivers, greatly reducing loading
rates to the Bay. Restoration activities that increase
floodplain area or the hydraulic connectivity between floodplains
and river channels most likely would enhance nutrient and sediment
retention.
Nitrogen and Phosphorus Sequestration on the Floodplain: A
Case for Restoring the Ecological Functionality of the Lower
Mississippi River-Floodplain Ecosystem
Harold L. Schramm, Jr.
U.S. Geological Survey, Mississippi Cooperative Fish and Widlife
Research Unit, Mail Stop 9691, Mississippi State, MS 39762;
phone 662/325-7495;
hschramm@cfr.msstate.edu
Michael S. Cox
Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi
State, MS 39762; phone 662-325-2767; mcox@pss.msstate.edu
Andrew W. Ezell
Department of Forestry, Mail Stop 9681, Mississippi State, MS
39762; phone
662/325-1688;
aezell@cfr.msstate.edu
Todd E. Tietjen
Department of Wildlife and Fisheries, Mail Stop 9690, Mississippi
State, MS 39762; phone 662/325-2996;
ttietjen@cfr.msstate.edu
Alterations to the lower Mississippi River-floodplain ecosystem
(LMRFE) have changed the hydrology to facilitate commercial
navigation and to reduce flooding of agricultural lands and
communities in the historic floodplain. As a result the flood
pulse usually has a lower water level, is of shorter duration, has
colder water temperatures, and a smaller area of floodplain is
inundated. Several evaluations of the flood-pulse hypothesis in the
Mississippi River have failed to support the concept, but other
research that considered thermal coupling of the flood pulse found
the flood-pulse concept affects fish growth. This presentation
evaluates the effect of temperature and timing on nutrient dynamics
on the active floodplain of the lower Mississippi River.
Nitrogen (primarily as nitrate) and phosphorus transported by the
Mississippi River are important contributors to hypoxic conditions
in the Gulf of Mexico. Nitrogen and phosphorus sequestration
by plants and aquatic biota increases when the water on the
floodplain is warmer and the floodwaters remain on the floodplain
longer. Thus, the floodplain and associated water bodies may
provide an important management opportunity for limiting downstream
transport of nitrogen and phosphorus in Mississippi River waters.
Although restoring the historical hydrological conditions and
floodplain inundation is unlikely, modifications of the currently
active floodplain may restore ecological functionality to the LMRFE
and reduce nutrients discharged into the Gulf of Mexico.
Wetland Assimilation of Treated Municipal Effluent: Wetland
Restoration & Improved Water Quality in Louisiana
Robert R. Lane1,2, John W. Day1,2, Rachael Hunter1,2, Joel Lindsey1
1Comite Resources, Inc., Zachary, LA
2Department of Oceanography and Coastal Science, Louisiana State
University, Baton Rouge, LA
Cypress-Tupelo dominated wetlands in much of southern Louisiana
evolved with semi-annual flooding of nearby rivers, introducing
substantial amounts of nutrients and sediments that promoted wetland
growth and productivity. Relatively recent human modifications
to the landscape have impounded vast areas of wetlands,
hydrologically isolating them from riverine input, causing
widespread degradation. We have found that the addition of
nutrient rich treated municipal effluent to these wetlands
stimulates plant productivity, increases organic matter production
and deposition, and leads to increased wetland surface elevation
that can offset regional subsidence, which is as high as 10 mm/yr in
Louisiana. In addition, water exiting the wetlands has greatly
improved water quality compared to that entering. Normally,
treated municipal effluent is discharged directly into rivers and
streams, often causing water quality problems. When effluent
is discharged into wetlands first, water quality is greatly improved
prior to discharge to rivers and streams. We present results
from several wetlands in coastal Louisiana that have been receiving
secondarily treated municipal effluent for a number of years.
We have found increases in net aboveground primary productivity and
surface accretion, as well as greatly improved water quality.
The introduction of treated municipal effluent into the highly
perturbed wetlands of Louisiana is a major step towards their
ecological restoration, and is in addition to improving water
quality in surrounding rivers and streams, as well as providing
municipalities with an economical and energy efficient means to meet
more stringent water quality standards.
Multiple-gear Assessment of Floodplain Lake Fish Assemblages of a
Large River-floodplain Ecosystem
Michael A. Eggleton
Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff,
1200 N. University, Box 4912, Pine Bluff, Arkansas 71601 USA.
John R. Jackson
Arkansas Tech University, Department of Biological Sciences, McEver
Hall Rm 4, Russellville, Arkansas 72801 USA.
Benjamin J. Lubinski
Illinois Natural History Survey, Great Rivers Field Station, 8450
Montclair Avenue, Brighton, Illinois 62012 USA.
Modern-day floodplain rivers are subject to a variety of
environmental impacts mostly related to economic development.
These impacts are especially evident in floodplain habitats where
the effects of altered hydrology and associated nutrient exchange,
sedimentation, water withdrawal, and reduced connection between the
river and floodplain are most exacerbated. Our objective was
to examine relationships between floodplain lake fish assemblages
and environmental variables in a large river-floodplain ecosystem.
Additionally, a multiple-gear approach was used that included
high-pulse and low-pulse boat-mounted electrofishing, mini-fyke
nets, and experimental gill nets. Across all gear types,
multivariate direct gradient analyses indicated that lake size and
depth, and water clarity were the most important factors in the
structuring of lake fish assemblages. Fish assemblage
structure was not strongly related to river-floodplain connectivity,
though fish species richness in individual lakes was positively
correlated with a qualitative measure flooding magnitude in those
lakes. Procrustean analyses (Ho: Assemblages are different)
indicated that the multiple-gear approach was warranted as
lake-specific fish assemblages depicted by the different gear types
were different in all cases (P = 0.109-0.576) except between the two
electrofishing configurations (P < 0.001). Our assessment of
empirical fish-environment relationships in a large river-floodplain
system identified environmental factors important in the structuring
of riverine fish assemblages communities, and underscored the need
for multiple-gear assessments. Results can help guide future
river-floodplain management and aid resource managers in species
conservation efforts in these systems.
Patterns in Fish Community Structure and Diversity in Natural and
Artificially-created Wetlands in the White River, Arkansas
Mark C. Leao
U.S. Fish and Wildlife Service, Ecological Services Field Office,
176 Croghan Spur Road, Suite 200, Charleston, South Carolina 29407.
Edmund R. Buckner
Department of Agriculture, University of Arkansas at Pine Bluff,
1200 N. University, Box 4913, Pine Bluff, Arkansas 71601.
Michael A. Eggleton
Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff,
1200 N. University, Box 4912, Pine Bluff, Arkansas 71601.
Evaluations of fish community responses to wetlands restored by the
Wetland Reserve Program (WRP) are rare. Thus, this study
examined fish communities of WRP-created wetlands of various ages
and compared them to reference wetlands located in Arkansas’ White
River basin. Fish samples from pool and canal habitats of
wetlands were collected from March through June 2003 using modified
mini-fyke nets and experimental-mesh gill nets, with associated
water quality and habitat variables measured concurrently.
Sampling yielded a total of 8,988 fishes that comprised 49 species.
Multivariate direct gradient analyses generally indicated that fish
community structures differed among different-aged wetlands.
In pool habitats, analyses suggested that community compositions
exhibited a successional trend, whereby generalist-type species were
replaced by specialist-type species as wetlands aged.
Conversely, fish communities in canal habitats remained relatively
unchanged as wetlands aged. Repeated-measures analyses
comparing diversity, richness, and evenness between natural and
WRP-created wetlands suggested that created wetlands were capable of
supporting fish communities with levels of diversity and richness
comparable to reference wetlands within one year. Overall,
results suggested that WRP-created wetlands provide habitats and
environmental conditions that mimic natural wetlands in a relatively
short time period. Additional studies of similar scope would
help validate current findings and better define benchmarks of
future WRP projects.
Patterns of Macroinvertebrate Diversity and Community Structure
across a Gradient of River-Floodplain Connectivity
Bradley S. Williams and S. Reid Adams
Department of Biology
University of Central Arkansas
Conway, Arkansas 72035
501-605-7383
BradW0051@yahoo.com
Current Address for Bradley S. Williams:
Kansas Biological Survey
University of Kansas
Lawrence, Kansas 66047
501-605-7383
BradW0051@yahoo.com
A limited number of studies have examined the effects of
river-floodplain connectivity on macroinvertebrate diversity and
community structure, and even fewer have utilized a multi-spatial
scale approach. This study assessed these effects by sampling
macroinvertebrates within the vegetated shoreline of eighteen
riparian wetlands with different degrees of hydrologic connectivity
to the Arkansas River. Analysis included core samples and habitat
data taken from 6 backwaters contiguous with the main channel, 6
floodplain wetlands intermittently connected to the river by supra-bankfull
flooding, and 6 floodplain wetlands isolated from the river by
levees. A total of 93 taxa (28 non-insect and 65 insect taxa) were
collected (59 from backwaters, 73 from intermittent floodplain, and
66 from isolated floodplain wetlands). Though there was no
significant effect of connectivity on α diversity, overall β-1 and
β-2 diversity was higher in isolated and intermittent floodplain
wetlands than in backwaters. This indicated a greater degree of
compositional dissimilarity among the wetlands comprising these
regions, and that most of the diversity was maintained at the
regional scale. Non-metric multidimensional scaling ordination
combined with other analyses revealed a number of taxa with strong
associations with each wetland type and that macroinvertebrate
community structure was influenced by connectivity. The patterns of
macroinvertebrate diversity and community structure and the mosaic
of unique habitat types observed in the Arkansas River Floodplain
are a product of dynamic hydrologic processes such as
river-floodplain connectivity.
Fish Assemblages and Connectivity of Riparian Wetlands in the Lower
Arkansas River Floodplain Ecosystem
S. Reid Adams, Matt D. Schroeder, Robert L. Clark, and Bradley S.
Williams
Department of Biology
University of Central Arkansas
Conway, Arkansas 72035
501-450-5933
radams@uca.edu
Current Address for Bradley S. Williams:
Kansas Biological Survey
University of Kansas
Lawrence, Kansas 66047
501-605-7383
BradW0051@yahoo.com
We initiated this study to provide more complete information on
abundances and distributions of fishes in the Arkansas River
floodplain ecosystem and to better understand patterns of assemblage
composition and environmental gradients across wetland types.
Fish and environmental data were collected at 49 riparian wetlands
representing contiguous backwaters (perennially connected to the
main channel), intermittent floodplain wetlands (floodplain
waterbodies that are periodically flooded), and isolated floodplain
wetlands (floodplain waterbodies that no longer connect with the
main channel). A total of 220,116 individuals and 64 species
were collected. New information was obtained for numerous
species including four species of conservation concern: Notropis
maculatus, Erimyzon sucetta, Moxostoma pisolabrum, and Etheostoma
fusiforme. Ordination and associated analyses indicated
contiguous backwaters, intermittent floodplain wetlands, and
isolated floodplain wetlands had distinct fish assemblages.
Contiguous backwaters were relatively open-water habitats lacking
submerged vegetation taxa and inundated cypress trees. These
wetlands were characterized by pelagic fishes and generalist species
tolerant of reservoir-like conditions typical of the mainstem
Arkansas River. In contrast, isolated floodplain habitats were
heavily vegetated, cypress wetlands inhabited by fishes typical of
southern bottomland hardwood wetlands. Intermittent floodplain
wetlands contained elements of both assemblages. This study
indicates the Arkansas River floodplain ecosystem, despite
modification, continues to have a mosaic of wetland types supporting
a diversity of fishes. These data underscore the value of
cypress wetlands since they harbor a unique assemblage of fishes
that enhances diversity within the Arkansas River ecosystem.
Population Structure of Adult and Juvenile Paddlefish in Floodplain
Lakes along the Lower White River, Arkansas
Sandra J. Clark-Kolaks1, John R. Jackson1, and Steve E. Lochmann2
1Department of Biological Sciences, Arkansas Tech University,
Russellville, AR, USA
2Aquaculture and Fisheries Center, University of Arkansas at Pine
Bluff, Pine Bluff, AR USA
Paddlefish habitat use has been extensively studied for main channel
and backwater areas of large rivers. However, little research has
been done to address paddlefish use of natural floodplain lakes.
Sixteen floodplain lakes in the lower White River, Arkansas were
sampled using a boat electrofisher and gill nets during periods of
river connection (April-May) and disconnection (June-July). Fifteen
environmental variables were concurrently sampled in each lake that
included water quality, lake morphometrics, and quantitative
measures of connectivity. Of the 16 lakes sampled only seven lakes
contained paddlefish. One paddlefish was observed during connection
sampling. Forty-three paddlefish were observed during disconnection
sampling with eye-fork lengths ranging from 348 mm to 1040 mm. Fish
ranged in age from 1 to 11 years, suggesting that both adult and
juvenile paddlefish were using floodplain lake habitat. Using
stepwise linear regression, dissolved oxygen, variation in the start
date of connection, and surface area were significantly related to
catch per unit effort. Paddlefish catch per unit effort increased as
lake size and dissolved oxygen levels increased and variability in
the start date of connection decreased. Our research indicates that
juvenile and adult paddlefish are using floodplain lakes despite the
risk of being isolated in lakes for long periods of time, possibly
during spawning periods.
Pervasive Hydrologic Effects on Freshwater Mussels and Riparian
Trees in Southeastern Floodplain Ecosystems
Andrew L. Rypel1, Wendell R. Haag2, and Robert H. Findlay1
1Department of Biological Sciences, University of Alabama,
Tuscaloosa, AL 35487
2USDA Forest Service, Southern Research Station, Center for
Bottomland Hardwoods Research, 1000 Front Street,
Oxford, MS 38655-4915
We present long-term growth trends of 13 freshwater mussel species
from two unregulated rivers (St. Francis River, AR, Sipsey River,
AL) and one regulated river (Little Tallahatchie River, MS) in
southeastern USA. We also present long-term growth data for
baldcypress (Taxodium distichum) from five unregulated rivers in the
region (Cache River, IL, Choctawhatchee River, AL, Nottoway River,
VA, St. Francis River, AR, Sipsey River, AL). We developed
biochronologies for all taxa using standard dendrochronology
techniques and examined the relationships of annual growth of each
species to a suite of streamflow variables. Growth of 10
mussel species in unregulated rivers was negatively correlated with
mean annual streamflow, and minimum and maximum streamflow, but was
positively correlated with annual number of low flow pulses, and
annual number of hydrographic reversals. Baldcypress growth in
unregulated rivers was positively correlated to mean annual
streamflow, minimum and maximum streamflows, and annual number of
high flood pulses, but was negatively correlated to annual number of
low flow pulses, mean annual hydrographic fall rate, and annual
number of hydrographic reversals. Consistent trends across
ecosystems suggest that taxa-specific growth responses to hydrologic
variability are generalizable. Growth of the mussel, Quadrula
pustulosa from the Little Tallahatchie River was not correlated to
any streamflow variables suggesting that growth is decoupled from
hydrology in this regulated system. This study highlights how
interannual variability in streamflows benefits and maintains
diverse taxa in bottomland rivers over long periods and shows that
river regulation can disrupt these relationships.
The Degree of Co-occurrence between Zooplankton and Ichthyoplankton
Shape the Year-class Recruitment in Newly Inundated Bottomland
Hardwood Floodplains
B. T. Halloran, 120 Renewable Natural Resources Building, Louisiana
State University, Baton Rouge, Louisiana, 70803. email:
mahihmahi1@hotmail.com
D. A. Rutherford, 119 Renewable Natural Resources Building,
Louisiana State University, Baton Rouge, Louisiana, 70803.
email: druther@lsu.edu
M. D. Kaller, 224 Renewable Natural Resource Building, Louisiana
State University, Baton Rouge, Louisiana, 70803. email:
mkalle1@paws.lsu.edu
W. E. Kelso, 118 Renewable Natural resource Building, Louisiana
State University, Baton Rouge, Louisiana, 70803. email:
wkelso@lsu.edu
In temperate and sub-tropical floodplains, seasonal floodpulses
influence a broad range of important subsides within newly inundated
terrestrial systems (i.e., microbial, nutrient and invertebrate
cycles). As floodwaters rise and systems shift from dry to
lotic to lentic, access to newly flooded microhabitats is believed
to significantly enhance reproductive opportunities for fishes.
Yet post-flood conditions frequently offer sub-optimal
physicochemistry and/or foraging opportunities for young-of-the-year
fishes undergoing the ontogenetic shift from endogenous to exogenous
feeding. The degree of overlap between zooplankton (primarily
cladocerans and copepods) and ichthyoplankton should affect the
survivorship of newly hatched fishes, following the assumptions of
the match/mismatch hypothesis. However, few floodplain studies
have concurrently described the structure of both communities as
young fishes begin to actively search for food.
To better understand recruitment, we examined limnetic densities of
zooplankton and larval fishes in the Atchafalaya River Basin (ARB),
LA, over a 19-month period. Zooplankton abundance was
primarily associated with areas of the floodplain that had high
connectivity and stable water quality. The magnitude of the
floodpulse did not result in increasingly robust zooplankton
populations. Interestingly, both ichthyoplankton and
zooplankton often exhibited limited overlap suggesting a potential
food limitation following the onset of flooding. Therefore, it
appears that a potential fish recruitment bottleneck could occur
for: (1) species that reproduce discontinuously; (2) cohorts that
exhibit highly variably individual growth; and/or (3)
floodplain-dependent taxa that hedge on the arrival of a significant
annual floodpulse.
The Significant Nexus of Science to the Future Protection of the
Waters of the United States
Kim Diana Connolly
Associate Professor, University of South Carolina School of Law
Main & Greene Streets
Columbia, South Carolina 29208
803/777-6880
Connolly@law.sc.edu
Our nation has long recognized the value of floodplain ecosystems to
our economy and our way of life. Floodplains in many areas
have been properly deemed “waters of the United States,” which
provide various important “functions and values” or “ecosystem
services,” the most obvious of which is flood control but also often
includes some additional combination of water quality improvement,
habitat for endangered and other species, recreational and/or
educational activities and aesthetic values. Yet historical federal
authority to protect such waters through the Federal Water Pollution
Control Act (under which Congress sought to “restore and maintain
the chemical, physical and biological integrity of our nation’s
waters”) has come under attack in recent years. A 2006 U.S.
Supreme Court interpretation (Rapanos v. United States) came to no
majority opinion, with a resulting introduction of a new
jurisdictional test based on findings of a “significant nexus”
between a regulated area and a traditionally navigable water.
During the summer of 2007, federal agencies issued “guidance” to
interpret this decision (entitled Clean Water Act Jurisdiction
Following the U.S. Supreme Court’s Decision in Rapanos v. United
States & Carabell v. United States). Yet this long and
convoluted set of documents creates more questions than answers, and
mandates fact-specific analysis to assess detailed hydrologic and
ecologic factors. The role of scientists will thus be crucial
in future regulatory efforts under the Clean Water Act, as well as
attempts on a legislative or regulatory level to stabilize or
increase floodplain protections the matter by enacting new laws.
Integrating Economics in Floodplain Restoration: An Analysis of The
Nature Conservancy’s Emiquon Project on the Illinois River
Richard Sparks, Director of Research
National Great Rivers Research and Education Center
5800 Godfrey Road
Godfrey, IL 62035-2466
618-468-4826
rsparks@uiuc.edu
www.ngrrec.org
Restoring natural services provided by floodplains may not be as
simple as acquiring land from willing sellers and then simply
breaching levees or otherwise reintroducing floods. Conversion
of developed land to wetland reserves or wildlife refuges affects
local jobs and tax revenues. The Emiquon Floodplain
Restoration Project of The Nature Conservancy provides a good test
case. Emiquon was a 2,125-ha agricultural drainage and levee
district when it was purchased for $18.3 million in 2000 by the
Conservancy. Emiquon is situated along the Illinois River,
formerly one of the most biologically productive floodplain-river
ecosystems in the United States. However, between 1890 and
1924, 64% of the total floodplain area was leveed and drained for
farming. Although production of commodity crops increased,
natural goods and services plummeted. Today, restoration of
Emiquon would have reduced revenues to local taxing districts, but
The Nature Conservancy has agreed to continue payments in lieu of
taxes to local districts. In addition, some, but not all the
jobs and output value associated with the former farm have been
replaced by jobs and outputs related to management of Emiquon.
Restoration could result in a substantial economic gain, if
recreational development (compatible with restoration) were planned
and promoted. Other approaches to financing restoration and
compensating local taxing districts are being considered along the
Illinois River, including floodplain “nutrient farms” that would be
managed to remove nitrogen from river water. These new
approaches are part of a worldwide trend toward payments for natural
services, including services provided by restored floodplains.
Changes in Forest Management Practices Needed to Insure Timber
Quality of Bottomland Hardwood Stands
John D. Hodges
Although the United States Forest Industry is currently in a state
of flux, high quality hardwood veneer and sawtimber will always be
in demand. However, the change in forest ownership provides
both challenges and opportunities to insuring the production high
quality hardwood products. Past forest management practices
were originally limited as stands were typically high-graded and
left to naturally regenerate from lower quality material.
Information concerning natural stand management of bottomland
hardwoods in the 1960’s and 1970’s led to new techniques of stand
manipulation focused on production of quality material.
Through the years artificial regeneration within plantation culture
has been tried but results have been rather limited in the
production of quality material. This is the result of a lack
of knowledge of how to mimic natural stand progression in the
production of quality stems and the overall excessive cost of
plantation management.
(I would consider this paper to include some about older systems
used but have gone by the wayside and new or even possible systems
that would allow for improved timber quality)
Changing Landownership Patterns and the Hardwood Lumber Industry
Mark Barford, CAE
Executive Director
National Hardwood Lumber Association
The forest products industry is going through some dramatic changes
right now due directly to the effects of globalization. With
the influx of wood, paper, pulp and other products, the reliance on
domestic manufacturing has diminished, and domestic manufacturing
along with it. Like all stagnant or mature businesses, the
industry has to look at their model and make changes to stay
competitive, and one of the most dramatic changes made has been in
the area of forest land ownership.
When the forest products industry began their modern growth in the
early 1900’s, they determined that the only way to insure a steady
supply of raw material was to acquire relatively cheap timberlands
and manage them for long term benefits. The model worked well,
and these companies purchased millions of acres of low value land
that became quite productive through intensive management
techniques. This served the industry well, and made them good
neighbors as that steady ownership allowed communities to plan
knowing that certain ownerships would remain as productive forests.
As these lands have gained value for other uses, corporate boards
and accountants realized that the tremendous dollar investment in
the lands might have better returns in other areas of their
companies, and they began divesting of the land holdings. With
the gigantic exception of Weyerhaeuser, almost all major pulp and
paper companies have sold their properties, and some think it will
not be too long before Weyerhaeuser will follow suit.
Most sales of land have been going to some major forest land
investment groups also known as TIMOs – Timber Investment Management
Organizations. These are groups seemingly committed to the
same goals as the forest industry owners, those being forest health
and forest productivity. They seem committed to the
communities they are in, and in most cases have a staff of foresters
to guide them. But what is the long term goal of these TIMO’s,
and how long will their investments last? Many have a promise
with their investors that that the land ownership must turn over on
a regular basis, but to who and for what use.
This talk will review the changing ownership patterns of forest
industry lands, and what the long term prospects for use of that
land for other purposes will likely be. The forest industry
has been directly responsible for the management and use of forest
lands in the United States by adding value to the forests. As
that value is changed by the world markets, you will likely see some
shifts in how the forests are managed.
Managing Bottomland Forest for Wildlife
Randy Wilson, U.S. Fish and Wildlife Service, Migratory Bird Field
Office, Jackson, MS 39213, randy_wilson@fws.gov; 601.965.4903 ext 15
Kenny Ribbeck, Biologist Program Manager, Louisiana Department of
Wildlife, Wildlife Division, Forestry Section, P.O. Box 98000, Baton
Rouge, LA 70898-9000; (225) 765-2942;
kribbeck@wlf.louisiana.gov
The conservation objective in the Mississippi Alluvial Valley is to
provide forested habitat capable of supporting sustainable
populations of all forest dependant wildlife species. However,
forest loss, fragmentation, and hydrological change has markedly
altered habitat conditions within bottomland forests such that some
species of concern (e.g., ivory-billed woodpecker (Campephilus
principalis), Louisiana black bear (Ursus americanus luteolus), and
some migratory songbirds) have been severely impacted. To
provide habitat for these and other priority wildlife species, we
advocate forest conditions that are conducive to the continued
viability of this suite of priority wildlife species. Many
forest-dependent wildlife species are responsive to habitat
conditions at multiple spatial scales (e.g., landscape quality and
site quality). To address this issue, we define Desired Forest
Conditions as those forested landscapes that meet both Desired
Landscape Conditions and Desired Stand Conditions. Traditional
forest management has focused on production of forest products
(i.e., lumber or pulp) through silviculture that promotes optimal
growth and vigorous health of economically desirable tree species.
Often these traditional silvicultural methods are not optimal for
forest-dependent wildlife. Indeed, quality habitat for
priority wildlife species likely requires some sacrifice in timber
production and the retention of less healthy trees. Even so,
commercially viable, wildlife-oriented silviculture (i.e., Wildlife
Forestry) employing variable retention harvests can be used in
conjunction with forest restoration, regeneration, and natural
processes to achieve Desired Forest Conditions within bottomland
hardwood forests. The habitat conditions that result from
wildlife forestry silvicultural prescriptions will vary among sites
and forest types. For many forests, desired stand conditions
are: an average of 60‑70% overstory canopy cover which is
heterogeneously distributed, a basal area of 60‑70 ft2 per acre, and
60-70% stocking. Desired midstory and understory cover are
between 25‑40%, respectively. At least 2 dominant trees (emergents)
per acre should be retained. Some cavity trees (small and
large) as well as dead and/or stressed trees should be retained.
These stems will eventually contribute to coarse woody debris which
should average >200 ft3 per acre. To ensure future
merchantability of stands, shade-intolerant regeneration should be
present on 30-40% of the area. Implementation of these
recommendations will ensure that habitat is being provided for the
many priority wildlife species that inhabit bottomland forests.
SEQ CHAPTER \h \r 1The State of Knowledge Regarding Site Evaluation
for Bottomland Hardwood Management
Brian Roy Lockhart, Research Forester
U.S. Forest Service, Southern Research Station
Center for Bottomland Hardwoods Research
Stoneville, Mississippi
Site is defined as an area considered in terms of its environment,
particularly as this determines the type and quality of the
vegetation the area can carry. Site should also indicate the
quantity of desired products to meet explicit management objectives
(site quality); therefore, a site represents the sum of the
environmental factors, such as soils and climate, that affect the
quantity and quality of vegetative growth. Site quality is
important (1) to determine the suitability of a given site for
recommending specific woody and non-woody plant species for
afforestation or reforestation efforts, (2) to predict the quality
and quantity of wildlife habitat, including browse, hard mast, and
soft mast production, (3) to predict the quality and quantity of
timber products, and (4) to assess the impacts of land-use
activities on future production of desired products. In this
paper, I will provide descriptions of seven methods for evaluating a
bottomland site: (1) direct measurement, (2) species trials, (3)
indicator species, (4) experience and judgment, (5) soil-site
equations, (6) soil series, and (7) expert systems. Each
method has its advantages and disadvantages. These, along with
examples of use and the latest research results improving these
methods, will be discussed. Knowledge of site quality is the
necessary first step to management of the bottomland hardwood
resource. Evaluating site quality will also allow forest
resource managers to better manage forests to meet specific
landowner objectives in bottomland hardwood ecosystems.
A Decision Support Tool for the Landscape Scale Management of
Bottomland Hardwood Ecosystems of the Southeast
Aaron Hohl[6], Andrew Niccolai[7],
Chad Oliver[8]
Ecosystem management of bottomland hardwood forests requires
assessing the landscape scale effects of operational decisions made
at the stand or management group level. The expected condition
of individual stands and the landscape as a whole must be projected
at various points in the future. We developed a decision
support tool to facilitate the comparison of landscape scale
management alternatives for periods up to 50 years. The tool
facilitates the analysis of several ecosystem characteristics
including carbon sequestration, coarse filter biodiversity, tree
species diversity, standing and cut volume, and estimated economic
returns from timber management. The stand level effect of an
array of silvicultural pathways (e.g., no action, thinning, clear
cutting) were modeled using FVS-SE. Individual stands were
integrated into management groups and stand level results were
converted into a state transition model. The landscape level
effects of management can be tracked by specifying the proportion of
the landscape represented by each management group and allocating
each management group to one of the silvicultural pathways.
The tool offers a flexible way for managers to assess tradeoffs
between planned management alternatives.
Floodplain Forest Development Models: Do Examples from Old-growth
Forests Fit?
Bruce P. Allen, Charles P. Goebel, and Rebecca R. Sharitz
Bruce P. Allen
Savannah River Ecology Laboratory
Drawer E, Aiken, SC 29802
513 779-3306
allen.851@osu.edu
Models of large river floodplain forest development for the
southeastern United States have been based largely on historical
patterns observed in the lower Mississippi River floodplain.
The rate of sediment deposition is identified as the primary
mechanism that produces shifts in species composition. In the
absence of deposition, trade-offs between flood- and
shade-tolerance, as well as reproductive mechanisms, may play a
heightened role in determining species composition. With this
in mind, we asked the question - do the few examples of later
successional stage floodplain forests fit these models? To
answer this question, we present data from old-growth floodplain
forests across the Southeast including long-term data from the
Congaree National Park, one of the best remaining old-growth
floodplain forest on the Atlantic Coastal Plain. Historical
patterns of floodplain forests are used to address how forest
composition is changing through time and long-term data from the
Congaree document the impact of natural disturbance on forest
development patterns. Growing evidence suggests that lianas
are a more prominent component of late successional floodplain
forests than of younger forests.
Tree Survival and Growth Through 20 years of Green-Tree Reservoir
Management
Bobby Keeland and John McCoy
USGS, National Wetlands Research Center
700 Cajundome Blvd
Lafayette, LA 70506
Phone 337-266-8663
Keelandb@usgs.gov
Green-Tree Reservoirs, developed in Arkansas during the 1930s, are
bottomland hardwood forest stands that are flooded during the late
fall and winter to provide waterfowl habitat. Early reports
suggested that these impoundments provide moisture that improved
tree growth and mast production. More recent reports have
shown that green-tree reservoir (GTR) management results in reduced
vigor and tree growth. A 21,000 acre green-tree reservoir was
completed at the Felsenthal National Wildlife Refuge in 1985 and has
been flooded through management or heavy rainfall every year since
that time. Trees on 54 study plots, established prior to initial
flooding, were re-measured in 1990, 1995, 2001 and 2006 to follow
the fate of impacted forest stands. Annual mortality rates over the
21 year period varied by tree size, species and elevation. Overcup
oaks had the highest annual mortality at 4.6% while Nuttall and
willow oak mortality was lower at 2.8 and 2.9%, respectively. Across
species mortality rates were lowest at high elevation (2.3%) and
highest at low elevations (4.7%). Low numbers of seedlings and
saplings indicate that trees lost from the canopy are not being
replaced.
A Century of Disturbance Regime Changes in an Ohio River
FloodplainFforest: Implications for Wetland Conservation Area
Management
John L. Nelsona[9], John W. Groningera, Loretta
L. Battagliab, Charles M. Ruffnera
a Southern Illinois University Carbondale, Department of Forestry
b Southern Illinois University Carbondale, Department of Plant
Biology
Many bottomland conservation areas in the Midwestern and Midsouthern
United States share a similar land use and disturbance history of
drainage, conversion to agriculture, and abandonment prior to
inclusion in wetland conservation programs. This study
examines changes in forest vegetation associated with 20th century
land uses and the resulting variation in the disturbance regime at
Mermet Lake State Conservation Area in southern most Illinois.
These disturbances included clearing, drainage, and burning
associated with agriculture, followed by abandonment and inclusion
in a conservation area with partial restoration of hydrology and
fire excluded. A 2003 tornado and subsequent salvage
harvesting operation are recent occurrences shaping vegetation
composition.
This study employed historic land use records, dendrochronological
evidence, pre- and post-tornado vegetation, and post-salvage
logging soil data. Since settlement of the area, forest
vegetation at Mermet Lake has shifted from bald cypress to oak to
mixed bottomland hardwood dominance. Within the developing
forest, composition and diversity varies along a wind intensity
gradient with diversity increasing as a function of wind-induced
canopy failure. Species richness and community complexity
further increased within the salvaged area in response to exposure
of mineral soil and restoration of micro-topography by the salvage
operation.
Our results suggest that historic changes in site conditions have
been associated with complex changes in forest communities. These
relationships need to be considered to more effectively manage
wetlands conservation areas. Vegetation management
strategies that address these changes within a wetland conservation
context will be discussed.
Structure and Growth of Tidal Freshwater Forested Wetlands in
Relation to Salinity and Fertility
Ken W. Krauss1, Thomas W. Doyle1, William H. Conner2, Richard H.
Day1, and Jamie A. Duberstein2
1U.S. Geological Survey, National Wetlands Research Center,
Lafayette, LA, USA, 70506
2Baruch Institute of Coastal Ecology and Forest Science, Clemson
University, Georgetown, SC, 29940
Tidal freshwater forested wetlands comprise no less than 200,000 ha
within the southeastern United States. These are productive
ecosystems due in part to the quantity of nutrients received from
upstream and marine sources during inundation by the flood effect of
local tides. This study was designed to determine which
factors are most important in controlling growth (past and present)
and dictating the landscape position of tidal freshwater forested
wetlands relative to marsh. First, we inventoried forest
structure on several tidal freshwater forested wetland sites in
South Carolina, Georgia, and Louisiana to make linkages among
salinity, inundation, and site fertility. Second, we monitored
basal diameter increment of dominant trees on these sites monthly,
for over 4 years, to examine the inter-relationship with soil total
nitrogen (TN), total phosphorus (TP), porewater salinity, and
inundation (frequency, duration, and depth). Among all sites,
salinity ranged from 0.1 to 3.2 ppt and bulk density ranged from 0.1
to 0.7 g/cm3; bulk density was lowest at sites in Louisiana. The
ratio of soil TN to TP varied among sites dictating different tree
heights, basal areas, and growth rates. TN, for example,
ranged from 1.2 to 4.0 mg N/cm3 of soil volume. These data are
important for understanding the role of edaphic conditions in
setting growth limits in tidal freshwater forested wetlands and in
structuring current forest condition. Although historic growth
of these forests has been dictated by soil fertility, as salinity
prisms shift inland with sea-level rise, current growth becomes more
strongly linked to salinity.
Fire in Bottomland Forests: Insights from Disturbance Ecology of
Arundinaria
Paul R. Gagnon and William J. Platt
Louisiana State University, Department of Biological Sciences
Paul R. Gagnon
Louisiana State University
Department of Biological Sciences
202 Life Sciences Building
Baton Rouge LA 70803
office: (225) 578-7567
cell: (225) 278-6040
Multiple lines of evidence suggest that fire shaped bottomland
forests in the Southeast. Two studies of canebrake ecology,
and work by early USFS research foresters indicate that fire was a
recurrent disturbance in these riparian forests. We examine
the disturbance ecology of canebrakes as a case study of fire in
bottomlands. We also examine research from the Lower
Mississippi Alluvial Valley (LMAV) in the 1930s for insights about
fire. Canebrakes were once prominent in bottomlands of the
Southeast. Cane (Arundinaria sp.) is still common throughout
its historic range, but the expansive, monotypic canebrakes are now
exceedingly rare. Why have canebrakes not re-formed in the
increasingly numerous holdings managed for bottomland forest
restoration? Our own research with giant cane (A. gigantea) in
Tensas Parish, Louisiana suggests fire may be necessary for small
cane stands to amalgamate into dense and expansive canebrakes.
Our findings parallel those from the 1950s by Hughes, who studied
switch cane (A. tecta) in North Carolina. Both studies suggest
that without fire or some other recurrent space-opening disturbance,
small cane stands will never grow into canebrakes, but will instead
decline. Fire-scar analyses by research foresters in the 1930s
indicate that fires recurred in the LMAV during drought years every
5-15 years pre-dating the Civil War. We propose that in
particular areas of the LMAV, high ground was subject to recurrent
fires, and that canebrakes were dominant on these sites. Land
managers seeking to optimize existing cane stands as wildlife
habitat should consider fire as a tool.
Influence of Planting Stock, Planting Method, Fertilization, and
Competition Control on Survival of Oak Seedlings Planted in
Afforestation Areas – Second Year Results
A.W. Ezell, J.L. Moree, and J.D. Hodges
Department of Forestry
Mississippi State University
Thousands of acres in the Southeast have been planted with hardwoods
(primarily oaks) unsuccessfully in the recent past. Seedling
survival in these plantings has been unacceptably low and causes of
the mortality are often unidentified, but land managers have
recognized many factors as critical for survival. The relative
merits of seedling size and number of first order lateral roots
(FOLR) have long been discussed as relates to survival and early
growth of oak seedlings. Proper planting, including the choice
of method, has also been recognized as critical in seedling survival
and control of competing vegetation is essential for higher survival
and early growth in most afforestation. Large seedlings
planted with augers and provided with total competition control and
fertilization have been shown to achieve extremely high rates of
survival and rapid growth. The purpose of this study was to
evaluate the influence of the various planting/establishment
components (planting stock, planting method, fertilization, and
competition control regime) on the survival of Nuttall and white oak
seedlings during the first two growing seasons at two planting
sites. A total of 6,480 1-0,bareroot seedlings were planted
and evaluated during the study (3240 of each species).
One-half of these seedlings were grown under a special nursery
protocol to produce a large seedling with an extensive root system
and one-half were grown without any special protocol. Planting
methods included hand planting in augered holes, hand planting in
subsoil trenches, and hand planting in untreated areas (flat
planting). Half the seedlings received slow-release
fertilization at the time of planting. Herbaceous weed control
was completed in three regimes: first-year preemergent only, one
complete growing season, and total (two complete growing seasons).
All combinations of planting stock and treatments were
replicated at each site. Survival was evaluated monthly from May to
September. Results provide an excellent comparison of the
importance of each of the components in seedling survival for the
two years, and quantifies the extent of mortality occurring by time
during the growing season and by year. This information
can be of great use to land managers working in afforestation
efforts in the Southeast.
Conservation Practice Effects on Wetland Ecosystem Services in the
Mississippi Alluvial Valley
Stephen Faulkner, Wylie Barrow, Bob Keeland, Susan Walls
U.S. Geological Survey
National Wetlands Research Center
Lafayette, LA 70506
Tom Moorman
Ducks Unlimited, Inc.
Southern Regional Office
Ridgeland, MS 39157
Forest and wetland ecosystems that historically dominated the
Mississippi Alluvial Valley (MAV) provided an array of ecosystem
functions and services. The conversion of these natural areas to
row-crop agriculture has resulted in landscape-scale alteration of
hydrologic and biotic functions. The objective of conservation
programs, e.g., the Wetlands Reserve Program (WRP), Conservation
Reserve Program (CRP), is to restore and protect wetland functions
in agricultural landscapes. These programs have restored over
200,000 ha of wetlands in the MAV since their inception; however,
their effectiveness in achieving their objectives is not known. One
goal of the USDA Conservation Effects Assessment Program (CEAP) is
to assess the effects of conservation practices on ecosystem
services provided by wetlands. Forty-eight sites encompassing
WRP, native forest, and agricultural fields were randomly located in
AR and LA during April 2006. Site and landscape data were collected
to quantify sediment retention, migratory bird and amphibian species
richness, flooding extent, and waterfowl habitat. Significantly
higher amphibian and migratory bird species richness was measured on
WRP and CRP sites than adjacent agricultural fields. Approximately
70% to 77% of land enrolled in WRP in LA, AR, and MS was within the
0-24 month flood frequency. Based on flooding and food energy
values, the WRP conservation practices in these three states
increased migratory waterfowl foraging habitat by up to 54 million
duck-energy days, accounting for 14 percent of the total foraging
habitat target objectives for the tri-state area. Improvements in
design and management could increase the amount of ecosystem
services provided by conservation practices.
Hydrologic Controls on Swamp Forest Regeneration and Sustainability
Richard F. Keim, Louisiana State University Agricultural Center
Loretta L. Battaglia, Southern Illinois University
William H. Conner, Clemson University
Diane De Steven, USDA Forest Service Center for Bottomland Hardwood
Research
Coastal swamp forests occupy about 3000 km2 of the Mississippi River
Deltaic Plain, and are experiencing increased flooding and intrusion
of salt water caused by rapid subsidence of the geologically young
sediments and altered river flow patterns in the delta. These
changes increasingly jeopardize long-term sustainability of swamps
by reducing forest regeneration. Given their value for timber and
multiple nontimber values associated with their coastal location,
sustainability of forest management in swamps is an increasingly
important public policy issue. Regeneration success hinges on
hydrologic conditions, and any changes affect successional
trajectories. Deep flooding in the growing season prevents
regeneration from seed and favors shifts to marsh or open water,
even though standing trees may remain productive for decades.
Reduced flooding during the growing season favors regeneration of
less flood-tolerant bottomland hardwood species. Hydrological
variables that affect regeneration are depth, duration, frequency,
and timing of inundation; the ecological importance of some
variables is understood but interactions among variables combine to
control regeneration in complex ways. Sustainable timber management
in swamp forests requires site-specific knowledge of hydrologic
processes, but also must include some concept of risk in obtaining
natural regeneration because regeneration failures are common in
flood-prone sites. We present a conceptual framework of the
multivariate hydrologic control on regeneration, with applications
for management decisions based on likelihood of regeneration
success.
Floodplain Ecosystem Restoration: Commodity Markets, Environmental
Services, and the Farm Bill
Skip Hyberg, Economic Policy Analysis Staff, Farm Service Agency,
South Agricultural Building, stop 0519, Room 2745, Washington, DC
20250
Economic and cultural values, the same forces that have altered
floodplain ecosystems, will be the forces that determine the extent
of their restoration. Landowner investment in agricultural
production and forest and hydrologic restoration will reflect
perceived economic returns from investments, and personal
preferences
for ecosystem services each land use provides. If the 2007 Farm
legislation increases returns from bottomland hardwoods relative to
crop production, then more bottomland restoration will occur.
The crafting of the 2007 Farm Bill, particularly the language for
the Conservation (Title II), Forestry (Title VIII), and Energy
(Title IX) Titles, has been the primary focus for much of the
conservation community over the past year. Federal programs and
their effect on emerging bio-energy and environmental services
markets have received attention as drivers for restoring bottomland
ecosystems. Programs and emerging markets can encourage floodplain
restoration, but will be effective only if they improve economic
returns from bottomland management relative to other land uses.
The attention on the conservation, forestry, and energy titles has
led some to ignore the Commodity Title (Title I). This is a mistake.
Returns from bottomlands will be determined not only by Titles II,
III, and IX, but also by commodity markets and Title I, which sets
commodity price supports. Historically, Title I has had a far
greater role in driving changes in land use, and therefore
bottomland restoration, than other portions of the Farm Bill.
Past, Present and Future of Carbon as a Finance Tool for Bottomland
Hardwood Restoration in the Lower Mississippi Valley
David Shoch
Forester
The Nature Conservancy’s Climate Science Team
The Lower Mississippi Valley (LMV) is increasingly recognized by
investors and entrepreneurs as offering the most advantageous
conditions for sourcing forest carbon offsets in North America. The
presentation will relate experience to date with carbon as a forest
restoration finance tool in the LMV and discuss its future potential
in a changing economic landscape. Recent experience has been
predominately on state and federal lands where carbon has not had to
support substantial land acquisition costs. Continued access to
carbon finance for restoration work will depend on the political
certainty that carbon will have long-term value and investor
confidence that can be increased by better-informed growth and yield
projections. Proper project planning and implementation are also
essential to address expectations of additionality and permanence
that are peculiar to carbon offsets.
Early Successional Habitats in the Mississippi Alluvial Valley:
Their Role in Meeting Conservation Objectives
Leigh H. Fredrickson
Wetland Management and Educational Services, Inc.
Puxico MO 63960
Although the Mississippi Alluvial Valley (MAV) was extensively
forested at the time of European settlement, there were smaller
areas of herbaceous wetlands associated with abandoned channels,
beaver ponds, tree gaps, and native grasslands as well as sites that
were recently scoured or subjected to fires or sever wind storms.
Some of these sites such as Catahoula Lake were sizeable whereas
individual tree gaps were small but collectively from 3 to 5 percent
of the original forest may have been in this more open condition.
The reduced flooding during the growing season provided optimal
growing conditions for herbaceous plants on some sites annually
within the MAV but following the growing season these sites were
flooded at different times and for a variable duration during the
winter months. Thus, sites with adequate sun light and a seasonal
hydroperiod provided unique herbaceous resources as well as
conditions associated with reestablishment of the forest.
Foremost among the benefits was the provision of nutritionally
important food resources for a wide suite of species adapted to this
forested system. Among these were the extensive seed, browse,
and below-ground resources produced by annual and perennial
herbaceous plants that were essential for some species. Among
the animal groups adapted to these conditions were migrant dabbling
ducks that migrated from distant breeding sites to these wintering
areas where nutritionally valuable foods were in abundance and
essential for developing a physiological condition leading to
reproductive success at a distant location. The extensive use
by dabbling ducks is obvious and widespread but these sites also
provide important habitats for a vast array of less mobile and more
secretive resident species. Many of these sites have been lost to
other uses and extensive man-induced modifications compromise the
size, distribution, value, and function of the remaining sites.
To assure that the species associated with these sites continue to
have viable populations is an important conservation concern that is
complex, costly, and constantly changing. This paper discusses
the history and distribution of these sites, the factors that led to
their loss and modification, and some thoughts on conservation
strategies to assure that future generations continue to enjoy these
habitats and the species that are adapted to them.
Wildlife Use of Back Channels Associated with Islands on the Ohio
River
Andrew K. Zadnik, West Virginia University, Division of Forestry and
Natural Resources, P. O. Box 6125, Morgantown, WV 26506-6125, U.S.A.
James T. Anderson, West Virginia University, Division of Forestry
and Natural Resources, P. O. Box 6125, Morgantown, WV 26506-6125,
U.S.A.
Petra Bohall Wood, U.S. Geological Survey West Virginia Cooperative
Fish and Wildlife Research Unit, and West Virginia University
Division of Forestry and Natural Resources, P. O. Box 6125,
Morgantown, WV 26506-6125, U.S.A.
Kerry Bledsoe, West Virginia Division of Natural Resources, Wildlife
Resources Section, 110 Railroad Street, Farmington, WV 26571, U.S.A.
James T. Anderson
West Virginia University
Division of Forestry and Natural Resources
PO Box 6125
Morgantown, WV 26506-6125
(304) 293-2941 x 2445
wetland@wvu.edu
The back channels of islands on the Ohio River are assumed to
provide habitat critical for several wildlife species.
However, quantitative information on the wildlife value of back
channels is lacking but is needed to assist natural resource
managers in conserving these forested islands and embayments in the
face of increasing shoreline development and recreational boating.
We compared the relative abundance of waterbirds, turtles, anurans,
and riparian furbearing mammals during 2001 and 2002 between back
and main channels of the Ohio River in West Virginia. Wood
ducks (Aix sponsa), snapping turtles (Chelydra serpentina), beavers
(Castor canadensis), and muskrats (Ondatra zibethicus) were more
abundant on back than main channels (P<0.001). Anurans were
more abundant on back than main channels in early spring (P<0.05).
Conversely, belted kingfishers (Ceryle alcyon) and spiny softshell
turtles (Apalone spinifera) were more abundant on the main than back
channel during summer (P<0.001). These results provide
quantitative evidence that back channels are important for several
species of waterbirds, turtles, anurans, and furbearing mammals.
The narrowness of the back channels, the protection they provide
from the main current of the river, and their ability to support
vegetated shorelines and woody debris, are characteristics that
appear to benefit these species. We recommend conserving back
channel areas as important riparian wildlife habitat by limiting the
building of piers and development of the shoreline.
The Effects of Hydrologic Restoration on Birds Breeding in Forested
Wetlands.
Dr. Jeff Hoover, Illinois Natural History Survey
Channelization of rivers and streams threatens bottomland forest
bird communities because it can lead to the formation of lateral
gullies that connect streams to adjacent wetlands and drain the
wetlands when water levels in the stream drop below flood stage.
These adjacent forested wetlands may fill during spring floods and
be attractive breeding habitat for birds, but the unnaturally rapid
draining of the wetlands early in the breeding season may expose
some birds to high rates of nest predation. I studied how the
hydrologic restoration of off-channel wetlands (plugging gullies
that drain off-channel wetlands) affects the diversity, abundance,
and nesting success of birds breeding within forested wetlands
within the Cache River watershed in Illinois. I compared wetland
size and hydrology, bird diversity, bird densities, and nesting
success between treatment (gully plugs added) and control (gully
plugs not added) wetlands, and between pre-treatment and
post-treatment wetlands. Treatment wetlands showed larger increases
in size and retained water for longer durations compared to control
wetlands. The density and nesting success of Prothonotary Warblers
was higher in treatment wetlands than in control wetlands. Other
species dependent on forested wetlands (Wood Ducks and
Yellow-crowned Nightherons) also increased in density within the
treatment wetlands. Documenting changes in the bird community in
response to conservation actions provides a means to measure the
success of restoration activities in the Cache River watershed and
inform conservation plans and restoration efforts in other
bottomland forest ecosystems.
Response of Prothonotary Warblers to Flooding and Timber Harvest in
a Bottomland Hardwood Forest.
Larry A. Wood and Robert J. Cooper
Warnell School of Forestry and Natural Resources
University of Georgia
Athens, GA 30602
The prothonotary warbler (Protonotaria citrea) has been suggested as
an indicator of ecosystem integrity for bottomland hardwood forest
ecosystems. Many bottomland forests are actively managed for
timber and have undergone significant changes in natural
hydrological processes, and we suggest that prothonotary warbler
demographic parameters would make suitable response variables in
experiments involving those disturbances. Utilizing a
manipulative experiment over 5 years, we examined the effects of two
timber harvest techniques (single-tree selection, patch-cuts) on the
reproductive biology of prothonotary warblers at White River
National Wildlife Refuge, a managed, seasonally flooded, bottomland
hardwood forest in southeast Arkansas. Timber harvests reduced
the number of available nest cavities, reduced the density of
breeding males on the plots and male territories were significantly
larger on plots that were harvested. However, timber harvest
technique had no obvious effect on nest depredation or brood
parasitism frequencies. Productivity (number of fledglings per
plot and per hectare) remained similar within suitable habitat
regardless of treatment. Reproductive success was
strongly influenced by annual variation, principally the timing and
extent of annual flooding. Our findings indicate that hydrology had
the largest influence on prothonotary warbler reproductive success
and productivity and that continued anthropogenic alterations in
flooding patterns may have a greater influence than current timber
management on the future population levels of prothonotary warblers
in the Mississippi Alluvial Valley.
Vegetation Characteristics Associated with Habitat Occupied by
Swainson’s Warblers at the White River National Wildlife Refuge:
Implications for Management of Bottomland Systems
Jeremy Brown, Thomas J. Benson, and James C. Bednarz
Department of Biological Sciences
Arkansas State University
P.O. Box 599
Jonesboro, AR 72467
jeremyd.brown@smail.astate.edu
Widespread clearing of bottomland hardwood forests has restricted
Swainson’s Warblers (Limnothlypis swainsonii; SWWA), a species of
conservation concern, to seasonally-inundated zones in many
floodplains. Given the ground-foraging behavior of this
species, they likely are affected adversely by flooding.
However, little is known about patterns of habitat occupancy by
SWWAs at these wetland ecotones. We examined relationships
between SWWA occupancy and vegetation structure at relatively
high-elevation bottomlands at White River National Wildlife Refuge
(WRNWR). In 2004 and 2005, we systematically surveyed 1453
sites using song playbacks and collected vegetation data at all 70
occupied sites (4.8% occupancy) and 106 unoccupied sites.
Comparisons of occupied versus unoccupied sites revealed that mean
density of cane (Arundinaria gigantea), shrub, and total stems;
litter volume; understory density; and selected other measures of
habitat structure were significantly greater in occupied than
unoccupied sites. Based on 15 alternative a priori habitat
models for predicting SWWA occupancy, we found the model that best
fit the data contained the density of cane, vine, and shrub stems
and it accounted for 83% of the total AICc weight of all models
considered. However, cane stem density was the best single
predictor of SWWA occupancy with a sumed AICc weight of 0.99 for all
models including this variable. These results suggested that
cane, dense understory structure, and a well-developed layer of leaf
litter are key habitat components for SWWAs at WRNWR. Our
findings are especially relevant given that the canebrake ecosystem
is endangered and has declined substantially throughout the
Southeast.
Reproductive Success and Causes of Nest Failures for Mississippi
Kites in the White River National Wildlife Refuge: Response to
Altered Hydrology?
Troy J. Bader and James C. Bednarz
Department of Biological Sciences
Arkansas State University
Jonesboro, AR 72467
troybader@hotmail.com
During a 2-yr study on the Mississippi kite (Ictinia
mississippiensis), a species of conservation concern, in the lower
White River system we documented one of the lowest reproductive
success frequencies reported for this species. In 2004 and
2005, we located 39 Mississippi kite nests. We used infrared
time-lapsed recording systems to monitor 16 nests 24 hr a day.
The fates of the remaining nests were monitored periodically by
observation with a spotting scope. Eleven of the 39 nests
(28.2%) fledged one juvenile each. Two studies elsewhere in
the southeastern U.S. reported nest success for Mississippi kites of
42 and 61%. By any assessment, a nesting success of 28% was
not adequate to maintain the White River kite population.
Predation was the most common cause of nest failure (57%, N = 7),
with western rat snakes (Elaphe obsoleta) being the most common
predator (N = 3) of eggs and nestlings. We propose that the
modification of the hydrology of the White River system may be a key
factor in low nesting success of kites and possibly other birds.
Levees constructed along margins of the refuge in the mid 1960s to
control flooding on agricultural lands restricts the natural flood
regime during high flow periods, thereby increasing the depth and
duration of the flood waters and altering the timing of floods.
We offer several hypotheses how hydrological changes may have
disadvantaged nesting birds and provided advantages to predators
that may explain the high frequency of nest failures that we
observed.
Wood Duck Duckling Mortality and Survival in Mississippi and Alabama
Floodplain Ecosystems
J. Brian Davis, Ducks Unlimited, inc., 261 Newman Dr., North Little
Rock, AR 72117
Bruce D. Leopold, Department of Wildlife and Fisheries, Mississippi
State University, Box 9690, Mississippi State, MS, 39762, USA
Richard M. Kaminski, Department of Wildlife and Fisheries,
Mississippi State University, Box 9690, Mississippi State, MS,
39762, USA
Robert R. Cox, Jr., P.O. Box 712, Ipswich, SD 57451
tc \l1 "CHAPTER VFloodplain ecosystems in southeastern United States
provide critical habitats and resources for resident and migratory
populations of North American wood ducks (Aix sponsa) yet little is
known about mortality and survival of wood ducks in these systems.
We studied radiomarked hen and duckling wood ducks that used
palustrine and riverine wetlands in Noxubee National Wildlife Refuge
(NNWR) in Mississippi in 1996-1999 and the Tennessee-Tombigbee
Rivers and Waterway (TTRW) in Alabama in 1998-1999. We
estimated cause-specific mortality rates for 234 and 90 mortality
events of ducklings at NNWR and TTRW, respectively. Mortality
of radiomarked ducklings (n) was caused primarily by avian and
aquatic predators at NNWR in 1996-1999 and TTRW in 1998-1999.
Other agents of mortality at both areas included snakes, mammals,
exposure-related, and unknown causes. A composite estimate of
duckling mortality among years and areas was avian (0.459; n = 155),
aquatic (0.234; n = 79), snake (0.062; n = 21), mammalian (0.053; n
= 18), exposure-related (0.021; n = 7), and unknown causes (0.130; n
= 44). Our study was the first to quantify agents of mortality
and habitat-specific survival rates of wood duck ducklings (Davis et
al. 2007; Journal of Wildlife Management 71:507-517). Based on
this and other recent research, we recommend the following to
increase wood duck production and recruitment from nest boxes in the
Southeast:(1) monitoring of nest boxes during spring and removal of
down and unhatched eggs of completed nests, 2) erecting and
maintaining dispersed rather than clumped nest boxes, and 3)
promoting suitable brood habitats (i.e., scrub-shrub wetlands)
without aggregations of nest boxes that may attract predators and
dispersing nest boxes amid or adjacent to these habitats.
Habitat Factors Affecting Relative Abundance of Swamp Rabbits in a
Floodplain Forest Ecosystem
Paul D. Scharine, Clayton K. Nielsen, Eric M. Schauber, and Lyann
Rubert
Cooperative Wildlife Research Laboratory
Mailcode 6504
Southern Illinois University
Carbondale, IL 62901
phone: 453-6930
fax: 618-453-6944
e-mail: pscha119@siu.edu
Destruction and fragmentation of floodplain forest ecosystems has
resulted in population declines in swamp rabbits (Sylvilagus
aquaticus) throughout the northern fringe of their range in North
America. Furthermore, the patchy distribution of remaining
habitat increases risk of local extirpations of swamp rabbits due to
further habitat loss and stochastic events. Management of
swamp rabbits and their habitat requires knowledge of which habitat
factors, operating at multiple spatial scales, affect swamp rabbit
populations. However, there are few such studies for swamp
rabbits in floodplain forest ecosystems. During winter
(Dec-Mar) 2005-06 and 2006-07, we conducted fecal pellet surveys at
29 bottomland hardwood forest sites in southern Illinois to
determine relative abundance of swamp rabbits. We also
collected site-level habitat variables (e.g., stem density) and
calculated FRAGSTATS metrics (e.g., mean patch size) based on NWI
data. We used multiple regression to model the relationship
between habitat variables and relative abundance of swamp rabbits.
We interpreted 3 models (R2 = 0.63 - 0.66) based on AIC values.
In all models, the density of tree stumps >10-cm in diameter and
overall patch contiguity of sites and contiguity of upland cover
patches within sites were positively associated with relative
abundance of swamp rabbits. Larger sites and those containing
high woody stem density also supported more swamp rabbits.
Hence, for swamp rabbits, biologists should manage floodplain
forests for large, contiguous sites containing early-successional
characteristics and upland cover for use during flood events.
These management recommendations will also benefit other small
mammals in bottomland ecosystems.
Integrating Science Into the Restoration and Management of
Floodplain Ecosystems of the Southeast
Rebecca Sharitz
(No abstract)
[1] U.S. Army Engineer Research and
Development Center, Vicksburg, MS
[2] Arkansas Multi-Agency Wetland Planning
Team, Arkansas Game and Fish Commission, Little Rock, AR
[3] Arkansas Natural Heritage Commission,
Little Rock, AR
[4] Five Oaks Ecological Services,
Stuttgart, AR
[5] Arkansas State Highway and
Transportation Department, Little Rock, AR
[6] Corresponding Author: Aaron Hohl is a
Ph.D. candidate at the Yale School of Forestry and Environmental
Studies, 205 Prospect Street, New Haven, CT 06511, USA. Email
address: aaron.hohl@yale.edu.
[7] Andrew Niccolai is a Ph.D. candidate at
the Yale School of Forestry and Environmental Studies.
[8] Chad Oliver is Pinchot Professor of
Forestry and Environmental Studies and Director of the Global
Institute for Sustainable Forestry at the Yale University School of
Forestry and Environmental Studies
[9] Current affiliation US Forest Service,
Center for Bottomland Hardwood Research, Stoneville MS
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