classification of riparian wetlands ombrotrophic mixed rheotrophic mixed phreatotrophic flats...
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Classification of riparian wetlands
Ombrotrophic mixed Rheotrophic mixed Phreatotrophic
flats wetland overbank & co-flooding slope wetland
Asymmetric bi-directional Asymmetrical
small streams larger rivers small streams
Source/Chemistry
Typical System size
Riparian HGM class
Flow direction
Crenal wetlands Floodplains Crenal wetlands
Lateral/Valley structureRiparian zoneHyporheic zoneChannel zone
Alluvial vs erosional bench
Baker & Barnes 1998
ThalwegBankfullLeveeFloodprone
Floodplain Structure
Channel evolutionHydrographyValley geomorphology
Silver Maple>30%,Ash, Elm, Basswood
Ash, Silver Maple,Elm, SycamoreBlack Maple, Cottonwood
Silver Maple, Bitternut Hickory, Burr Oak, Ash, Elm
Ash, BasswoodSugar Maple, CottonwoodHop Hornbeam
Grn. Ash & Basswood > 60%White Cedar > 60%Canada Balsam
Cedar, Ash ElmHemlock, Cottonwood, Paper Birch
Dominants [order] & Indicators
Riparian Forest types in Lower Michigan
[adapted from Baker and Wiley 2004]
.96
silverm
.98
blackm
.99
sugarm 1.00
redash
1.00
nwcedr
sl
bl
su
as
wc
.15site
wetness
ave temp unit power
ss
p/pet gw sat
-.26
.22-.32
.09
.07
-.40
flood freq
-.40-.02
-.40
-.06
.32
floodpotential
ff
.42
lag area
-.60
.52
.08
.02
-.23
.18
.40flood
power
ed
.26-.66
unit shear
.82
-.43
.05
-.48
-.16
-.09
.40
x-sectslope
.51
.78
.16
-.05-.70
-.05
-.37
.56 -.37
.33-.41.21
.88
-.42 -.15
-.37 .53
.25
.19.53
-.50
.54
.61 -.22-.40
-.66
.41.36
-.62
MES BSM
SMS
MAS&GAB
CAF&CFB
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Fig. 5SILVERBLACKSUGARGREENCEDAR
A B
Ecological function of floodplains
Sediment offloading & storage
Hydraulic refuge
Nutrient processing/ enhanced productivity/ life-history adaptations
Basis for enhanced autochthonous and secondary production• the Flood-pulse concept• match-mismatch hypothesis
(1) The moving littoral in the ATTZ of a floodplain system in the central Amazon, withEstimates of annual production (P) and biomass (B). Estimates are as dry weight per hectare. The H2S zone has no O2
Junk, Bayley and Sparks: The Flood-Pulse concept
(2) Stage/Temperature couplingRelationship to enviromental predictability
Winemiller 2003
Types of stage/temperature coupling relevance to match-mismatch hypothesis for river fishes
Ecological consequences of floodplain fragmentation?
Sediment offloading & storageNutrient processingHydraulic refuge
Manage: (1) to to handle or direct with a degree of skill…(2) to alter by manipulation [Websters New Collegiate Dictionary]
•Management is unavoidable: doing nothing is an option
•Always two relevant aspects of a river: local and systemic
•River systems tend to local equilibriadeviations from equilibrium suggest ecosystem healthcaveats: equilibria are dynamic
multiple stable states
3 Principals of River Management
The concept of stream “Health”
Strengths:useful non-technical metaphorcaptures system complexityobjectifies process-response dynamics
Weaknesses:confuses homeostasis and dynamic equilibriumemphasizes single rather than multiple stable statesobjectifies subjective values
Technical issues:Biotic Integrity, IBI (s), regional references, and system expectations