Boreal Forest: Soil-Vegetation Interactions

Question 1

___ trees are first to colonize an area, then ___ arrive

Answer 1

deciduous trees
conifers

Question 2

soil characteristics affect the soil ___ and ___ stores that determine the resulting floristic community

Answer 2

moisture
nutrients

Question 3

soil particles have a ___ charge, so ___ ions like __ become ‘affixed to the soil particle
Plants must __ or find a way to get these cations if they want them

Answer 3

negative
positively
calcium
exchange

Question 4

pedosphere=

Answer 4

soil conditions

Question 5

the pedosphere is affected by 4 other ‘spheres’:

These all change with location!

Answer 5

biosphere (organisms)
hydrosphere (water)
lithosphere (parent material/ earth)
atmosphere (air- energy/ gas exchange)

Question 6

**
4 main components of boreal forest

Answer 6

1. physical template
   - slope
   - elevation
2. Climate
   - clouds, sun, temp, precipitation
3. Biota
   - fire
   - insect outbreaks
   - forest structure
4. Soil
   - soil temp/ permafrost
   - soil moisture
   - nutrient availability
   - forest floor organic layer

Question 7

black spruce and tamarack will be found in areas with ___ soils (hydric), and ___ active layer and a ___ organic layer

Answer 7

gleysols (waterlogged)

thin
thick

Question 8

White spruce, birch, aspen, and firs will be found in ___ sites with ___ active and organic layers

Answer 8

mesic (flowing moisture)

medium

Question 9

Jack pine thrives in ___ sites with ____ soil where there’s a ___ active layer and ___ organic layer

Answer 9

xeric
podzols (dry and sandy)
thick (or no permafrost)
thin

Question 10

Which 4 factors drive the community segregation in the boreal forest

Answer 10

moisture
soil
active layer
organic layer

Question 11

why is there a thin active layer in podzols??

Answer 11

not much organic material stays at the surface because water goes through and take it with it (sandy particles allow water too flow through rapidly)

Question 12

Soil is composed of:
25% ___
25%___
45%___
5%____

Answer 12

25% air
25% water
45% mineral particles
5% organic matter

Question 13

What’s one way humans are directly changing the soils?

Answer 13

we compress soils with roads etc= changes the open spaces and makes it less permeable (less air and water can get in)

Question 14

List the following in order from largest to smallest particle size
silt
clay
sand
gravel

which one carries the least nutrient availability?
Which one has a negative charge & retention of cations?

Answer 14

gravel
sand
silt
clay

sand

clay

Question 15

____ hold the greatest volume of water b/c of ___ ratio. Is this water avail to plants?

Answer 15

clay
SA

not available to plants because clay holds it very strongly

Question 16

field capacity=

Answer 16

content of water remaining in soil a few days after being wetted and free drainage nearly ends

Question 17

at the ___ ___, water is still available, but it’s strongly attached to soil, so not very accessible to plants

Answer 17

wilting point

Question 18

the mosaic pattern of forests in boreal region is related to ___ patterns
- ___ in wet areas
- ___ in dry areas

Answer 18

drainage

spruce
poplars

Question 19

Why does soil have layers?

If there’s no ___ there’s no layers

Answer 19

the aging of the materials present on the surface (they leech downward)

leeching eg in tropical forests

Question 20

What are the 6 soil horizons?

Answer 20

• O horizon (humus)
• A horizon (topsoil)
• E Horizon (eluviation layer- movement of particles downward)
• B Horizon (subsoil)- illuviation layer ie movement into horizon
• C horizon (regolith)
• R horizon (bedrock)

Question 21

Podzolization=

Answer 21

downward transport of Fe and Al in conjunction with organic matter from the A and E horizons to the B horizon

Question 22

The __ horizon is lighter in color because the minerals have been leeched out, and the ___ horizon is darker because more minerals including oxidized iron (brown/red)

Answer 22

E
B

Question 23

Soil development and formation process:
1
2
3
4

Answer 23

1. additions (eg organic matter falling from trees)
2. losses (eg leeching or eluviation, or erosion)
3. translocations= eluviation or illuviation
4. transformations (chemical eg oxidations/ reduction)

Question 24

___ layer = taking away –>
___ –>
___ layer= bringing to

Answer 24

eluviation
translocation
illuviation

Question 25

What are the 6 main soil types of the boreal forest?

Answer 25

• Podzolic (found w Jack Pine)
• Brunisolic= young/ poorly developed soil
• Luvisolic= post-glacial retreat (lots f clay and silt)
• Cryosolic- permafrost soil
• Gleysolic= wetland soil
• Organic = wetland soil

Question 26

___ soil is dominant in boreal regions
It has __ parent materials and low ___ status because there’s lots of ___

Answer 26

podzolic

acidic
nutrient
leeching

Question 27

t/f
brunisolic soil always has horizons

Answer 27

false
young soils= less weathering so layers are less prominent
becomes more layered with age

Question 28

Lucisolic soils are __colored, __ horizons that develop in cool and ___ forested areas

They have __ soil due to ___ leaving behind silt and clay

Answer 28

light
eluvial
wet

loam
glaciation

Question 29

cryosolic soil has poor ___ because poor ___ through frozen soil

Answer 29

horizons
leeching

Question 30

As permafrost melts, ___ soils will become ___ soild

Answer 30

cryosolic
brunisolic

Question 31

Gleysolic soil is found in areas with modest ___ and high ___ ___
They have periodic __ conditions

Answer 31

drainage
water tables
anoxic

Question 32

what are the 2 types of bunisolic soils?

Answer 32

Eutric brunisols= dominate cooler high and mid-boreal regions

Malanic brunisols= in milder moist climates

Question 33

Organic order soils are common in ___ and have extremally __ parent material

They’re very vulnerable to ___ b/c they desiccate in dry years

Answer 33

wetlands
acidic

fire

Question 34

Soil and vegtation development is a function of
- ___ material
-
- ____ relief
- ____(biogeography)
-___

Answer 34

parent
climate
topographic relief
organisms
humans

Question 35

Why is the mosaic boreal forest reflective of soil conditions?

Answer 35

• soil was there first
• also b/c vegetation influences soil (eg open vs closed canopy)