Stream Organisms - · PDF fileThe stream organisms are divided into three ... (euglenophyta)...
Transcript of Stream Organisms - · PDF fileThe stream organisms are divided into three ... (euglenophyta)...
Limnology
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Stream Organisms
Limnology
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The stream organisms are divided into three
sections:
Autotrophs
Invertebrates
Fish
Stream organisms
Limnology
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Autotrophs
Autotrophs
Autotrophs
Limnology
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Lotic phytoplankton :
Algae
Protozoans
Cyanobacteria
phytoflagellates
(euglenophyta)
Biodidac
Lotic phytoplankton
Limnology
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Benthic autotrophs
Benthic autotrophs
periphyton
benthic
autotrophs 3
(epilithon)
(epipelon)
(epiphyton)
Limnology
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Periphyton
Periphyton
(heterotrophic microbes)
Limnology
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Attached and benthic populations
blue-green algae
(epilithic forms),
(epiphytic forms)
(epipelic forms)
diatoms
green algae blue-greens
blue-green algae
(cyanobacteria)
Diatoms
Biodidac
green algae
(chlorophyta)
Limnology
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Seasonal succession in periphyton communities
Diatoms
winter, spring, and early
summer
Green algae cyanobacteria
Benthic autotrophs
www.urbanrivers.org/web_images/diatoms.gif
Limnology
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Distribution of autotrophs: Lakes vs rivers
phytoplankton
photic zone phytoplankton
Limnology
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Algal primary productivity
35-95 %
,
Limnology
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Macrophytes
Westlake (1975a) identified four primary growth forms:
1) Emergents
2) Floating-leaved species
3) Free-floating species
4) Submerged species
Limnology
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Macrophyte growth forms
Emergents:
Floating-leaved:
Free-floating:
(tropical)
Submerged: (
,
)
Emergent
Floating-leaved
Free-floating
Submerged
Limnology
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Aquatic macrophytes
( )
wetland
Macrophyte growth forms Limnology
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Basic macrophyte structure
,
,
(Hynes, 1970;
Westlake, 1975a).
Limnology
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Patchy distribution of macrophytes
( )
Limnology
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Macrophyte consumers
macrophyte
primary production herbivory,
dissolved organic
matter
Herbivory
, ,
carp, (Westlake,
1975b)
Limnology
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Stream invertebrates
benthic
macroinvertebrate
macroinvertebrate , crayfish,
Macroinvertebrates ,
5 microns (
, )
Limnology
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Insects
taxonomy
Limnology
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Morphological adaptations to running water
Limnology
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Morphological adaptations to running water
Limnology
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Classification of insects Limnology
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Aquatic insect orders
Limnology
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Aquatic insect orders Limnology
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Aquatic insect orders
Limnology
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Life cycles of aquatic Insects
Holometabolous
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Egg > > > Adult
caddisflies and
Holometabolous Hemimetabolous
Limnology
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Holometabolous life cycle
Complete metamorphosis in the caddisfly
Hydropsyche sp.
Larva
Pupa
Adult
Limnology
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Life cycles of aquatic Insects
Hemimetabolous
3
Egg > Immature (nymph) > Adult
stoneflies, mayflies
Limnology
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Hemimetabolous life cycle
Limnology
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Life cycle length
Multivoltine – several generations per year
Univoltine – one generation per year
Semivoltine – one generation every 2-3 years
Baetis
sp.,
univoltine
semivoltine
(Allan, 1995).
Limnology
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Ecological roles Macroinvertebrates food webs
Macroinvertebrate 4
Shredder POM > FPOM
Scraper diatoms > FPOM
Collector gatherer filterer FPOM
Predators
gatherer filterer
Scraper
Limnology
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General organic matter pathway Limnology
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Sources of organic matter Autochthonous – instream
diatoms; algae; submerged, floating, and emergent macrophytes
Allochthonous – out of stream
, , dissolved organic compounds, dead organisms
Limnology
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Types of organic matter
Dissolved organic matter
Particulate organic matter
Coarse particulate organic matter
> 1
mm
Fine particulate organic matter
, invertebrate
< 1 mm
Limnology
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Instream organic matter processing
, macroinvertebrates,
,
Limnology
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Shredders
Dominant food
Coarse particulate organic material (CPOM)
Feeding mechanisms
Herbivores –
Detritivores – CPOM
Representatives
Scathophagidae (dung flies)
Tipulidae (crane flies)
Macroinvertebrate functional roles in organic
matter processing
A caddisfly of the
family Limnephilidae
Limnology
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Collectors
Dominant food
Decompose fine particulate organic matter (FPOM)
Feeding mechanisms
Filterers - Detritivores
Gatherers - Detritivores
Representatives
Filterers
Hydropsychidae
Simulidae (black flies)
Gatherers
Elmidae (riffle beetles)
Chironomini
Baetis
Ephemerella
Hexagenia
Macroinvertebrate functional roles
A blackfly of the
family Simulidae
Elmidae
Hexagenia
Ephemerella
Limnology
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Scrapers
Dominant food
Periphyton (attached algae)
periphyton
Feeding mechanisms
Representatives
Helicopsychidae
Psephenidae (water pennies)
Thaumaleidae (solitary midges)
Glossosoma
Heptagenia
Macroinvertebrate functional roles
A dipteran of the
family Thaumaleidae
Helicopsychidae
Heptagenia
Limnology
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Predators
Dominant food
Feeding mechanisms
Engulfers –
Piercers –
Representatives
Engulfers
Anisoptera (dragonflies)
Acroneuria
Corydalus (hellgrammites)
Piercers
Veliidae (water striders)
Corixidae (water boatmen)
Tabanidae (deerflies & horseflies)
Macroinvertebrate functional roles
Anisoptera
Corixidae
Limnology
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Other macroinvertebrates Limnology
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Low concentrations in
winter and fall and at
high flow
High concentrations in
summer and at low flow
Seasonal variation in particulate organic carbon
Limnology
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( ):
(25%)
(50%)
CO2
(25%)
Fate of organic matter Limnology
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debris dams, beaver dams, floodplains,
Storage of organic matter
Limnology
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Net primary production versus litter fall
Stream Autotochthonous Allochthonous
Bear Brook, NH 0.6 g C/m2/year 251 g C/m2/year
Silver Springs, FL 981 g C/m2/year 54 g C/m2/year
Limnology
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Carbon fluxes in a stream ecosystem
autotochthonous allochthonous
macroinvertebrate
Limnology
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The River Continuum Concept
( )
( )
Limnology
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The River Continuum Concept
Limnology
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Stream order and the RCC
Low order streams
Coarse particulate
matter (CPOM)
Limnology
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Mid-order streams
CPOM
periphyton
CPOM
FPOM
Stream order and the RCC
Limnology
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High order streams
macrophytes
macrophytes
Stream order and the RCC Limnology
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