SOILS

Question 1

Why is soil texturing key? 2 essential skills?

Answer 1

Key in determining potential hazards associated with different forest operations
2 skills: 1. be able to texture soils correctly
2. be able to define and apply hazard ratings

Question 2

high/med/low durability cast

Answer 2

high: clay
med: silty
low: sandy

Question 3

5 key soil assoc hazards

Answer 3

compaction/puddling
soil displacement
surface soil erosion
forest floor displacement
mass wasting

Question 4

compaction

Answer 4

greatest compaction hazards from clay
soil compaction=increased soil density
wet sites used improperly = puddling

Question 5

soil displacement

Answer 5

Mechanical movement of soil materials
-dependent on slope percent, presence of unfavorable substrates
-unfavorable substrates at depth 70% cf)
root restricting layers

Question 6

surface soil erosion

Answer 6

Wearing away of surface soil by water
-surface soil texture (0-15 cm) and subsoil texture (16-60cm) important in determining surface soil erosion hazard
variation of silts and sands produce highest sse hazard
more hazardous if combined with clay dominated subsoils
high precip factors and slope percent mean high hazard
long, uniform slpes less of a factor, still a hazard

Question 7

Forest floor displacement

Answer 7

Mechanical movement of upper organic matter
depth of LFH and Ah are critical
shallow organic layers means higher hazard
sandys are highest
significant factors:
shallow depth to underyling substrates
high CF contents
gullied terrain
high slope %

Question 8

Mass Wasting Hazard

Answer 8

Erosion by detachment and transportation due to gravity
highest hazards produced by:
sandy soils with high precip factors, moisture regimes and slope %s, particularly on gullied terrain

Question 9

continuous and discontinuous slope:

Answer 9

continuous:=150m slope length between slope segments which are at least 20m wide and less than 30% slope gradient at valley bottoms or between ridge crests
Discontinuous:< 150m slope length between slope segments at least 20m wide and <30% slope gradient at valley bottoms or between ridge crests

Question 10

slope length and uniformity: short, long, broken, uniform

Answer 10

short: 30% and occur relatively abruptly
uniform: gradually changing slope