Wetland Organisms
Wetland Definition Diagram
Stress Experienced In Wetlands
u Anoxia
u Salt
Concentrations
u Water
Fluctuation
1
Anoxic Conditions
u Soils
saturated/inundated
u Anaerobic Conditions
u May vary with season
Salt Concentrations
High salinity flux from
tides
Salinity gradient types
u Intermittent
(Seasonal) estuary :
in Mediterranean climates, estuary
forms during rainy season, dries or
cut off in dry season.
u Salinity varies across seasons.
2
Water Fluctuation
u
Tidal Systems
u
Non--Tidal Systems
Non
Protists
u
Anoxia (respiration)
– Ability to use internal organic compounds as
electron acceptors
– Ability to use inorganic ions in respiration
– Ability to use specific electron acceptors rather
than oxygen
u
u
sulfate
Salt (osmotic & toxicity)
– Complex potassium in cytoplasm
– Enzymes function normally
Vascular Plants
u
Anoxia
– Structural
– Nutrient absorption
– Metabolic
– Whole Plant Strategies
u
Salt
– Barriers
– Secretory organs
u
Water
– Photosynthesis
3
Structural Adaptations
u Aerenchyma
u Adventitious
Roots
u Lenticels
u Pneumatophores
u Pressurized
u Rhizosphere
Gas Flow
Oxygenation
Aerenchyma
Aerenchyma
4
Adventitious Roots
Prop Roots
Prop Roots
5
Lenticels
Pneumatophores
Pneumatophores
6
Knee Roots
“Knee” Roots
Root Adaptations
7
Plank Roots
Pressurized Gas Flow
u Air
moves into internal gas spaces of
aerial leaves
u Forced down to roots by gradient of
temperature and water vapor
pressure
Oxidized Rhizosphere
8
Physiological Adaptations
u Nutrient
Absorption
u Anaerobic Respiration
u Malate Production
Nutrient Absorption
u Normal
metabolism in roots
u Nitrogen – some wetland plants
absorb ammonium
u Iron/Manganese – oxidized
rhizospheres protect
u Sulfur – detoxification mechanisms
Rhizosphere Oxygenation
9
Anaerobic Respiration
Whole Plant Strategies
u Dormancy
during flooding
u Seed Production in nonnon-flooded
season
u Buoyant Seeds
u Vivipary
Whole Plant Strategies
10
Vivipary
Adaptations to salt - plant
Some: salt gland - eliminates excess salt, maintains
water balance. E.g., Spartina alterniflora
Vascular marsh plants either:
u Succulent : have high water concentration
To reduce water loss, have: few stomata,
reduced leaf area, photosynthetic stems.
Rid salts by shedding leaves
u Other halophytes (salt dwellers): rid salts by
a) saltsalt-secreting glands;
b) thin cuticles & many stomata → high
transpiration
Salt Adaptations
u
u
Barrier Cells in roots
Secretory Cells
11
Changes in Photosynthesis
u C3
Biochemical Pathway
– Phosphoglyceric Acid
– Much more common
u C4
Biochemical Pathway
– Oxaloacetic Acid
– Arid/wetter
– Use CO2 More Effectively
Animals
u Anoxia
– Specialized organs for gas exchange
– Mechanism to improve oxygen gradient
– Better circulation system
– Decrease activity during oxygen stress
– Shifts metabolic pathways
u Salt
– Move
– Control internal osmotic concentrations
Salinity adaptations - faunal
u Behavioral:
burrow, close up
12
Salinity adaptations - larvae
Many larvae cannot osmoregulate
Many estuarine inverts - pelagic larvae
u E.g., Callinectes sapidus
sapidus,, Eriocheir sinensis
are catadromous
u
u
Wetland Delineation
Purpose
– Jurisdictional
– Scientific
u
Definition
U.S. Army Corps of Engineers:
inundated or saturated by surface or ground
water at frequency /duration sufficient to
support vegetation adapted to saturated soil
conditions.
u
Diagnostic Characteristics
– Vegetation
– Soils
– Hydrology
Vegetation Indicator Status
Categories
Category
Symbol
Likelihood of
Occurring in Wetland
Obligate Wetland
OBL
>99%
Facultative Wetland FACW
>67% to 99%
Facultative
FAC
33% to 66%
Facultative Upland
FACU
1% to < 33%
Obligate Upland
UPL
<1%
13
Wetland Soil Indicators
u NRCS
u Field
Hydric Soil
Indicators
– Organic Soils
– Mineral Soils
uGleyed
uChroma
uChroma
1 with or without mottles
2 with mottles
– Sulfidic Material
– Sandy Soils
uHigh
organic content at surface
uStreaked
Hydrology Indicators
u Recorded
Data
– U.S. Corps of Engineers
– USGS
– State / Local Agencies
u Field
Data
– Soil Saturation
– Watermarks
– Drift Lines
– Sediment Deposits
Delineation Method
u
Preliminary Data
–
–
–
–
–
–
–
–
u
USGS Quadranlge Maps
NWI Maps
Soil Survey
Stream Gage
EISs
State Wetland Determinations
Local Wetland Inventories
Aerial Photographs
I nn-Field Data (transects)
– Visual Changes
– Chose Representative Points
– Characterize Each Change
u
u
u
Vegetation
Soils
Hydrology
14