-
diagnostic horizon
- podzolic Bh, Bhf, Bf
- all three are illuvial horizons, accumulation of amorphous products
-
morphological characteristics
- accumulation of amorphous material in B
- texture coarser than clay
- No Bt or Bf velow 50cm in the profile
- >/= 10cm and has moist, crushed color of BLACK or 7.5YR or redder
-
Bh horizon
- h for humus
- accumulation of colloidal humus
- must have at least 1% OC
- < 0.3% amorphous iron
- colour nearly black
-
Bf horizon
- accumulation of colloidal iron oxide
- at least 0.3% pyrosphosphate extractable Fe
- 0.5-5% OC
- high chroma, reddish colour
- single grain structure
-
Bhf horizon
- assoc with soils on the west coast
- > 5% OC
- has 0.3+% pyrophosphate extractable Fe
- usually single grain
-
podzol structure
none, single grained
-
horizon boundaries?
wavy, disturbed boundaries
-
climate
cool to cold perhumid climate
-
PGM?
- usually lacks carbonates
- is acid with coarse texture (low %BS)
-
type of vegetation
- conifers, mixed forests, heath
- plant groups that prefer acidic environments
-
distribution in canada
- boreal forest of the candian shield, appalachians, cordilleran
- eastern hardwoods of the appalachians
- coastal forest region of BC
- BC interior
-
soil forming factors: climate
- cool temperate regions
- net percolation (humid to perhumid)
-
soil forming factors: organisms
- forest (coniferous)
- herbaceous species decomposing (fungal) to acidic leachates
-
soil forming factors: relief
favors downward leaching and net percolation
-
soil forming factors: pgm
- sandy, carbonate free, low pH
- low buffering capacity
- iron containing primary materials
-
soil forming factors: time
>3000 yrs
-
________ of primary materials and translocation of ________ by formation of ____________
- chemical weathering
- Fe and Al
- organo-metallic complexes
-
biogeochemical weathering processes in L horizon
acidic litter
-
biogeochemical weathering processes in FH horizon
fungal decomposition
-
biogeochemical weathering processes in Ae horizon
intense biogeochemical activity
-
biogeochemical weathering processes in B horizon
- largely physical processes
- illuviation of products translocated from above
-
humic podzols
- Bh horizon of 10+cm
- occur on wettest sites
- peaty decompressions
- some degree of gleying (ex. Bhfgj)
-
ferro-humic podzol
- have Bhf of 10+cm
- LFH or O layers
- usually Ae
- colour changes with depth
-
humo-ferric podzol
- most common of the podzols
- has Bf horizon
- usually LFH and Ae
- strong red, fading gradually with depth
- strongly acid and low BS
-
how many orthic subgroups?
- one for each of the 3 GGs
- orthic humic podzol
- orthic humo-ferric podzol
- orthic ferro-humic podzol
-
subgroups besides orthic
- gleyed SG
- orstein SG
- placic SG
- duric SG
- fragic SG
- sombric SG
-
gleyed SG
gj in upper 100cm
-
orstein SG
- has an orstein layer 3cm thick
- Bfc
- assoc with perched water table?
-
placic subgroup
- Bhfc or Bfc < 5mm
- wet maritime climates
- thin single or multiple involute bands
- hard, vitreous, dark reddish brown
- Fe and Mn cement
-
duric SG
- in all 3 GGs
- during layer in lower B horizon
- strongly cemented with ubrupt upper boundary
- colour of pgm, massive structure
-
fragic SG
- in all 3 GGs
- Bx or BCx in lower solum
- high bulk density
- firm and brittle when moist
- had to extremely hard when dry
- clay cemented sand?
-
sombric SG
- mainly in humo-ferric GG
- has a mull Ah (earthworm activity)
- usually lacks Ae
- Bf horizon - in situ weathering and accumulation of iron oxide
-
nutrient removal through ________ have potential to affect the long term productivity of podzols
- forest harvesting
- more susceptible to nutrient leaching
- when whole tree is removed vs. stem harvest and leaving CWD
-
how are toxicity issues caused in podzols?
- acidification exacerbated by anthropogenic activities
- can mobilize Al in soil
- help fix by liming? to help pH increase
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