Wetland Organisms
1
Wetland Definition Diagram
2
Stress Experienced In Wetlands
u Anoxia
u Salt
Concentrations
u Water
Fluctuation
3
Anoxic Conditions
u Soils
saturated/inundated
u Anaerobic Conditions
u May vary with season
4
Salt Concentrations
High salinity flux from
tides
5
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.
6
Water Fluctuation
u
Tidal Systems
u
Non-Tidal Systems
7
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
8
Vascular Plants
u
Anoxia
– Structural
– Nutrient absorption
– Metabolic
– Whole Plant Strategies
u
Salt
– Barriers
– Secretory organs
u
Water
– Photosynthesis
9
Structural Adaptations
u Aerenchyma
u Adventitious
Roots
u Lenticels
u Pneumatophores
u Pressurized
Gas Flow
u Rhizosphere Oxygenation
10
Aerenchyma
11
Aerenchyma
12
Adventitious Roots
13
Prop Roots
14
Prop Roots
15
Lenticels
16
Pneumatophores
17
Pneumatophores
18
Knee Roots
19
“Knee” Roots
20
Root Adaptations
21
Plank Roots
22
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
23
Oxidized Rhizosphere
24
Physiological Adaptations
u Nutrient
Absorption
u Anaerobic Respiration
u Malate Production
25
Nutrient Absorption
u Normal
metabolism in roots
u Nitrogen – some wetland plants
absorb ammonium
u Iron/Manganese – oxidized
rhizospheres protect
u Sulfur – detoxification mechanisms
26
Rhizosphere Oxygenation
27
Anaerobic Respiration
28
Whole Plant Strategies
u Dormancy
during flooding
u Seed Production in non -flooded
season
u Buoyant Seeds
u Vivipary
29
Whole Plant Strategies
30
Vivipary
31
Adaptations to salt - plant
Some: salt gland - eliminates excess salt, maintains
water balance. E.g., Spartina alterniflora
Vascular marsh plants either:
u Succulent
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
32
Salt Adaptations
Barrier Cells in roots
u Secretory Cells
u
33
Changes in Photosynthesis
u C3
Biochemical Pathway
– Phosphoglyceric Acid
– Much more common
u C4
Biochemical Pathway
– Oxaloacetic Acid
– Arid/wetter
– Use CO2 More Effectively
34
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
35
Salinity adaptations - faunal
u Behavioral:
burrow, close up
36
Salinity adaptations - larvae
Many larvae cannot osmoregulate
u Many estuarine inverts - pelagic larvae
u E.g., Callinectes sapidus , Eriocheir sinensis
are catadromous
u
37
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
38
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%
39
Wetland Soil Indicators
u NRCS
Hydric Soil
u Field Indicators
– Organic Soils
– Mineral Soils
u Gleyed
u Chroma
1 with or without mottles
u Chroma 2 with mottles
– Sulfidic Material
– Sandy Soils
u High
organic content at surface
u Streaked
40
Hydrology Indicators
u Recorded
Data
– U.S. Corps of Engineers
– USGS
– State / Local Agencies
u Field
Data
– Soil Saturation
– Watermarks
– Drift Lines
– Sediment Deposits
41
Delineation Method
u
Preliminary Data
–
–
–
–
–
–
–
–
u
USGS Quadranlge Maps
NWI Maps
Soil Survey
Stream Gage
EISs
State Wetland Determinations
Local Wetland Inventories
Aerial Photographs
In--Field Data (transects)
In
– Visual Changes
– Chose Representative Points
– Characterize Each Change
u
u
u
Vegetation
Soils
Hydrology
42