Conceptual Ecological Model of San Acacia Reach of Middle Rio Grande River – 2/13/07 1 st Draft...
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Transcript of Conceptual Ecological Model of San Acacia Reach of Middle Rio Grande River – 2/13/07 1 st Draft...
Conceptual Ecological Model of San Acacia Reach of Middle Rio Grande River – 2/13/07 1 st DraftIbis Ecosystem Associates, Inc.
Diversion & Regulationof Stream Water
Structural Alteration &Development of Floodplain
Discharge of ContaminantsInto Stream System
Degraded Water Quality
Introduction and Spread ofNon-native Vegetation
River Channel Fragmentation
FloodplainLoss &
Fragmentation
High Temperature,High pH, Low DO
Barrier toUpstream
Movement ofSilveryMinnow
Severe FlowReductions
Loss of Natural VariabilityIn Annual & Seasonal
Discharge Pattern& Hydrograph
Hydrologic Degradation of River Channel Habitat:•Reduced Magnitude & Duration of Spring Peak Flows•Reduced Flowing Water With Low-Moderate Currents•Narrowing of River Channel•Reduced Over-bank Flooding in Spring•Dewatering of River Channel & Formation of Isolated Pools•Reduced Sand and Silt Substrates•Reduced Eddies From Debris Piles, Pools, & Backwaters
Saltcedar
Proliferation
Loss of PersistentMoisture Levels &Wetland HabitatsIn Riparian Areas
Increased FireFrequency &Intensity In
Riparian Areas
Loss of Dynamic CyclesOf
Riparian Habitat Succession
Loss ofConnectivity
BetweenFloodplain &Native Desert
Habitat
River Channel Habitat Quality:•Perennially Flowing River With Peak Spring Flows and Over-bank Flooding•Aggrading River With Shifting Sand Substrate•Sinuous, Braided River That Freely Migrates Across Floodplain, Producing Eddies From Debris Piles, Pools, & Backwaters
Floodplain Habitat Quality:•Persistent Moisture Levels & Wetland Habitats in Riparian Areas•Highly Variable Mosaic of Ephemeral Wetland Habitats, Supporting Willow & Cottonwood Stands Adjacent to Wetland Areas•Unfragmented Landscape of Wide Lateral Extent, With Riparian Habitat Connected to Native Desert Habitat
Rio GrandeSilveryMinnow
SouthwesternWillow
Flycatcher*
FloodplainLowered
Water Table
Drivers
Stressors
Effects
Attributes * Impact of cowbird on flycatcher nesting to be covered in text.
Conceptual Ecological Model of San Acacia Reach of Middle Rio Grande River – 10/07 Draft
Diversion & Regulationof Stream Water
Structural Alteration &Development of Floodplain
Introduction & Spread Non-Native Vegetation
RiverChannel
Fragmentation
FloodplainLoss &
Fragmentation
Barrier toUpstream
Movement ofSilveryMinnow
SevereFlow
Reductions
Loss of Natural VariabilityIn Annual & Seasonal
Discharge Pattern& Hydrograph
Hydrologic Degradation of River Channel:•Reduced Magnitude & Duration of Spring Peak Flows•Reduced Channel Avulsion During Spring Peak Flows•Reduced Over-bank Flooding During Spring Peak Flows•Reduced Flowing Water With Low-Moderate Currents•Narrowing of River Channel•Dewatering of River Channel & Formation of Isolated Pools•Reduced Sand and Silt Substrates•Reduced Eddies From Debris Piles, Pools, & Backwaters
Loss of PersistentMoisture Levels
& WetlandsIn Riparian Areas
Increased FireFrequency &Intensity In
Riparian Areas
Loss of Dynamic Cycles OfRiparian Plant Succession,
Producing Dense Even-agedStands, & Resulting In Loss
Of Habitat Mosaic
Loss ofConnectivity
BetweenFloodplain &Native Desert
River Channel Quality:•Natural Variability In River Flow Dynamics, With Peak Spring Flows, Avulsion, & Over-bank Flooding•Aggrading River With Shifting Sand Substrate•Sinuous, Braided River That Freely Migrates Across Floodplain, Producing Eddies From Debris Piles, Pools, & Backwaters
Floodplain Quality:•Persistent Moisture Levels in Wetlands & Riparian Areas•Highly Variable Mosaic of Ephemeral Floodplain Communities, Supporting Willow & Cottonwood Stands Adjacent to Wetland Areas•Non-fragmented Landscape of Wide Lateral Extent, With Floodplain Connected to Native Desert
Rio GrandeSilveryMinnow
SouthwesternWillow
Flycatcher
FloodplainLowered
Water Table
Drivers
Stressors
Effects
Attributes
Altered Physical &Chemical CharacteristicsOf River Water:•Reduced Sediment Load•Reduced Temperature•Increased Ammonia
Aquatic Communities:•Viable Populations of Key Indicator Groups of Aquatic Fauna•Aquatic Fauna Community Diversity
Marsh Communities:•Creation of New Marshes•Persistence of Established Marshes
Cottonwood – WillowCommunities:•Seedling Recruitment•Persistence of Established Communities
Conceptual Ecological Model of Working HypothesesAquatic Communities
San Acacia Reach of Middle Rio Grande River10/07 Draft
Recruitment-Level Flow Events•April-June3,000 – 4,000 cfs2-Week Duration3-Year Frequency
Hydrologic Connectivity•River Channel to Floodplain•Surface Water to Groundwater
Episodic Flow Events
Channel Avulsion & Scouring
BackwaterNursery Habitat
Viable Populations of Key IndicatorGroups of Aquatic Fauna
(Including Rio Grande Silvery Minnow)
Aquatic FaunaCommunity Diversity
Over-bankFlow
River & FloodplainManagement
Hydrologic &Geomorphic Effects
PerformanceMeasures
AquaticCommunityAttributes
Persistent PoolsAs Aquatic RefugiaDuring Dry Periods
Bank-full Flow&
Dynamic In-Channel Morphology
Recruitment To Adult StageSurvivorship By Age Class
Population Geometric Growth Curves
Diverse Sediment SizeDistribution &
Shifting Sand Substrate
Prevention of StrandingWith
Water Level Recession
Aquatic Habitat Heterogeneity:•Multi-Threaded Channel•Dynamic/Avulsive Channel•Channel Width/Depth Ratio•Backwaters•Woody Debris
Conceptual Ecological Model of Working HypothesesMarsh Communities
San Acacia Reach of Middle Rio Grande River10/07 Draft
Maintenance-Level Flow Events3-Year Frequency
Hydrologic Connectivity•River Channel to Floodplain•Surface Water to Groundwater
Episodic Flow Events•7,000 – 10,000 cfs•1-week Duration•10-Year Frequency
Channel Avulsion & Scouring
Bank-full Flow&
Dynamic In-Channel Morphology
Water Level Fluctuation•Minimum 3-Foot Fluctuation•< 3-Year Frequency
Marsh Community Maintenance:•Marshes Sustained by Surface Water & Groundwater•Marshes Sustained Entirely By Groundwater
Marsh Community Creation:•Active Channel Marsh Communities•Marshes Sustained by Surface Water & Groundwater•Marshes Sustained Entirely By Groundwater
Over-bankFlow
River & FloodplainManagement
Hydrologic &Geomorphic Effects
PerformanceMeasures
Marsh CommunityAttributes
Site Preparation & Management•Removal of Non-Native Vegetation•Fire Management•Other
GroundwaterLevel
Longevity and SuccessionOf Established Marshes
Marsh Community Maintenance:•Active Channel Marshes
Frequency, Location, & Spatial Coverageof Newly Created Marshes
Spatial Coverage ofEach Marsh Community Type
Conceptual Ecological Model of Working HypothesesCottonwood - Willow Communities
San Acacia Reach of Middle Rio Grande River10/07 Draft
Recruitment-Level Flow Events< 5-Year Frequency
Hydrologic Connectivity•River Channel to Floodplain•Surface Water to Groundwater
Episodic Flow Events
Channel Avulsion & Scouring
Water Level Fluctuation•Soil Wetting May-June•Maximum Groundwater Recession Rate of 2 – 4 cm/day
Persistence of EstablishedCottonwood & Willow
Communities
Successful RecruitmentOf Cottonwood &Willow Seedlings
Over-bankFlow
River & FloodplainManagement
Hydrologic &Geomorphic Effects
PerformanceMeasures
Cottonwood/WillowCommunityAttributes
Site Preparation & Management•Removal of Non-Native Vegetation•Fire Management•Other
Groundwater Level:Depth To Groundwater
Of 3 – 6 Feet
Frequency, Location, & Spatial CoverageOf Seedling Recruitment Of
Cottonwood and Willow
Location, Spatial Coverage, & LongevityOf Established Cottonwood & Willow
Communities
Creation of Scoured HabitatFor Seedling Recruitment,
Formation of Bars and IslandsFor Willow Establishment