Lecture 5 - Wetands Flashcards
allogenic succesion is driven by the ..
environment
autogeneic succession is driven by conditions caused by .. vegetation
current
primary succession is on surfaces that .. supported vegetation
haven’t
-bedrock exposed by erosion
secondary succession is on surfaces that .. supported soil and vegetation
have
-recolonisation of set-aside farmland
aquatic wetlands are .. .. ecosystems
Shallow water ecosystems
telmatic wetlands are .. .. ecosystems
Wet terrestrial ecosystems
Marsh is a .. wetland
seasonal
Bogs are .. pH, Fen are .. pH and swamps are .. all three are examples of .. wetlands
Bogs are acidic, fens are alkaline and swamps are in between.
All permanent wetlnads.
Terrestrialisation occurs due to .. of lakes/pools with .. and ..
infilling
mud peat
Paludification is a process that once .. wetland becomes ..
Caused by impeded .. or increased ..
dry, wet
drainage, precipitation
-responsible for largest wetland in Britain
ombrotrophic bogs are dependant on .. for its ..
moisture, nutrients
-usually about 5m high in centre and its acidic
Rooting terrestrialisation ‘depressions’ are filled with ..
peat
Rafting terrestrialisation depressions are … filled, but the surface is covered by .. ..
not,
sphagnum moss
- often found in small, sheltered basins
autochtonous deposition is from the .. source
original
allochtonous infilling is from an .. source
external
-washed in
wetland succession via rooting begins with .. then …, then a .. and finally .. .. as the surface becomes .. ..
possibly leading to .. .. woodland
infilling, colonisation
fen, fen woodland
dry deciduous
-though little evidence deciduous woodland will form naturally
wetland succession via rafting differs from rooting as the .. and .. phases develop by direct colonisation of open water
swamp, fen
-often found in small, sheltered basins
substantial paludification in british uplands happened between ..-..ya
7500-5000
-caused by development of blanket bog
ombrogenous formation is .. ..
rain-fed
-requires 200+ days of rainfall per year and/or high humidity
blanket bog initiated by .. ..
forest clearance
-some developed over once cultivated land like dartmoor
O2 diffusion is … times slower in water than air
20000
O2 has ..% of solubility in water as it does air
3
Wetland decomposition is slowed by .. environment
Abundance of toxins such as .., .. and ..
… conditions
High concentrations of .. that inhibit .. activity
anoxic
Mn, Fe, S-
Acidic (often)
polyphenols microbrial
bog bodies have .. preservation as a consequence of low …
good, decomposition
- Tollund man
- Lindow Man
Lindow man had evidence of .. in stomach, .. around neck, massive .. injury and evidence of ..
mistletoe
rope
head
drowning
in low rooting oxygen, plants roots may undergo .. respiration
… oxygen to roots
release .. into rhizosphere
anaerobic
transport
oxygen
-rhizosphere is soil around roots
as a consequence of anaerobic respiration, wetland plants accumulate the .. toxic malic acid instead of ethanol
less
-also not necesarrily using anaerobic metabolism always
wetland roots have high root .., with .. and .. up to ..% of root volume rather than ..-..% like in dryland
porosity air space, channels 60, 2-7 -porosity provided by aerenchyma cavities and chanenls other oxygenating structures
oxygenation of the rhizosphere may occur by .. of oxygen out of root
.. oxidation on root surface
diffusion
enzymic
-can result in oxidisation of reduced phytotoxins in rhizosphere, reducing their toxicity/uptake
Dead stems of reed in winter may have an important function as ..
snorkels
-providing O2 to plants below
