Aquatic Bryophytes
What is a bryophyte?
bryophyte?
I. Big picture
II. Biology
-Life Cycle
-Major Groups
-Adaptations
III. ‘Aquatic’
Aquatic’ Bryophyte Ecology
Heather Lintz
Botany and Plant Pathology
Oregon State University
Non-vascular:
Bryophytes
Bryophytes are here
• All land plants likely to
have freshwater algal
ancestor
Seedless vascular
Gymnosperms Angiosperms
• Algal ancestor had
floating eggs and
swimming sperm
• Bryophytes are the
first to meet the
challenge of land
• 4 Major Plant Groups
• 12 Plant Phyla
Gametophyte Reduction
Sporophyte
Sporophyte
Capsule
Sporophyte
Seta
Bryophytes
Angiosperms
• Dominant Gametophyte
• Reduced Gametophyte
Gametophyte
Leaf
Rhizoid
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Moss Life Cycle
Diversity in Bryo Sexuality
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Some species produce millions of spores
Sporophyte
meiosis
fertilization
Some species practice abstention
Gametophyte
Some species are transexual
Spores
Protonema
Antheridia
Archegonia
What is a bryophyte?
bryophyte?
3 Bryophyte Phyla:
Bryophyta
(Mosses)
I. Big picture
Hepatophyta
(Liverworts)
Anthocerophyta
(Hornworts)
II. Biology
Life Cycle
differences
Major Groups
Adaptations
similarities
thallus
III. ‘Aquatic’
Aquatic’ Bryophyte Ecology
(tends to be curly)
spiral leaf
arrangement
Distinguishing Features of Phyla
Mosses
Liverworts
Hornworts
dorsal-ventral leaf
arrangement or thallus
What do all bryophytes share?
•
•
Gametophyte dominance
Unbranched sporophyte
(although, it could be upside-down)
To Be Experienced In lab
In thalloid livers,
umbrella =
gametophyte
Thalloid liverwort sporophyte
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What else do all bryophytes share?
•
Biflagellate sperm
•
Form of sex organs
I. Big picture
II. Biology
-Life Cycle
-Major Groups
General
-Adaptations!
Aquatic Bryos
III. ‘Aquatic’
Aquatic’ Bryophyte Ecology
antheridium
-Aquatic bryo habitats
-Moss in bogs
archegonium
Bryophyte adaptations:
A. Obstacle - Dessication
Bryophyte adaptations:
B. Obstacle - Acquisition minerals
Unistratose
- Small size
- Direct absorption through cells
i. Plant : - poikilohydry
- growth form
- Primitive vasculature: endo vs. ectohydric
-size
-specialized traits
- Cation exchange capacity
leptoids
-asexual repro:
fragmentation; gemmae
ii. Spores : -waterproof sporopollenin
-spores are world travelers
hydroids
iii. Gametes : -some protection, but sperm still need film of water
Bryophyte adaptations
Aquatic Bryophyte Adaptations
C. Obstacle - gravity
Bryos fight gravity
- for light acquisition; spore and gamete dispersal
-Primary cell walls only, some turgor
support, not much
•
Generalizations are
hard to make
•
Submerged aquatic
bryos have: low
surface texture, open
growth from
•
Some aquatic bryos
are considered ‘xeric
hydrophytes’
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Some example questions in bryophyte ecology:
Bryophyte Ecology
The science of relationships
between organisms and their
environment
How do bryophyte communities vary with
environmental factors?
How (and why) do species co-exist?
Where are aquatic bryophytes found?
Oikos- home
Oekologie
Ecology
Ernst Häeckel
1834-1919
‘The study of home’
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What can bryophytes tell us aboutd Deli n
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rl
Wo day at
global climate change?
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Old
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How do bryophytes regulate the environment?
Where are ‘aquatic’ bryophytes commonly found?
Riparian and aquatic habitats in wadeable freshwater
channels = Bryophyte Heaven
Bryophytes are generally not abundant in
marshes
Lakes and Ponds = bryos can be found along shorelines
or in submerged habitats
MARSHES: Wetlands dominated by emergent plants
FENS: groundwater-driven peatlands
Bryos can abound!!!
Bryos are not in the ocean
FENS contain ‘brown mosses,’
A functional group of moss
genera known as ‘fen
indicators’:
Brachythecium
Amblystegium
Aulacomnium
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BOGS: Precipitation-driven peatlands dominated by
Sphagnum
Next eco question: How do bryophytes regulate the
environment (for example, in bogs)?
Sphagnum traits that influence the bog
environment:
• water holding capacity
• indeterminate growth
• cation exchange capacity
Sphagnum
Landscape
characteristics
Climate
The End
Bog characteristics:
• stagnant water (not flowing)
• anaerobic environment
• cations and nutrients are scarce
• very acidic
• no bacterial decomposition =
mummification
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