Silvics and Silvicultural Systems

Question 1

what is thinning

Answer 1

overcrowding of young stands

Crown thinning is removal of larger trees

low thinning is thinning from below

Question 2

what is pruning

Answer 2

cutting lower branches for high grade logs (free of knots); higher densities at early stages may do the same job

Question 3

what is sanitation cutting

Answer 3

removal of infected or attacked trees from the stand and leave the healthy trees to grow

Question 4

what is silvics

Answer 4

• Involves understanding how trees grow, reproduce, and respond to environmental changes
• Study of the history of trees and forests

Question 5

what is the general procedure for wood production

Answer 5

o logging operation involves cutting trees down (felling)
o sawing trees up into proper lengths bucking)
o dragging it over the ground (skidding)
o dragging them to a road where it piled for loading into a truck (decked)

Question 6

what is whole tree harvesting (WTH)

Answer 6

drag whole tree to road and than construct bucking

Question 7

What is stem only harvesting (SOH)

Answer 7

conduct bucking then drag stem to road

Question 8

what are the differences between WTH and SOH

Answer 8

o Amount and size of materials (slash) left on the site
o Has implications for nutrients, habitat, and tree growth

Question 9

what is Silviculture

Answer 9

• Art and science of controlling the establishment, growth, composition, and quality of forest vegetation for the full range of forest resource objectives

Question 10

what is a silvicultural system

Answer 10

planned treatments during whole life of a stand designed to achieve specific stand structural objectives

specific harvesting regenerations, stand tending methods to get a predictable yield of benefits from the stand over time

Question 11

what are even aged stands

Answer 11

o One age class, some two aged classes ins open stands
o Well defined canopy with uniform height
o Bell shaped diameter distribution
o Regeneration period is <20% of rotation length

Question 12

what are uneven aged stands

Answer 12

o At least three age classes
o Differs in height age and diameter
o Uneven and highly broken/irregular canopy
o Inverted J form of diameter distribution
o Regeneration period occurs throughout entire rotation

Question 13

what are even aged systems

Answer 13

clear-cutting
patch cut
seed tree
shelter wood
coppice
retention

Question 14

what is clear cutting

Answer 14

 Stand removed in one harvest; new even aged stands are regenerated after harvest with previously cleared block

 Used to replace old stands with new vigorous stand ASAP

 Stand tending operations are easily incorporated into system

 Concerns: loss of old growth and environmental impacts

Question 15

what is a patch cut

Answer 15

small areas cut

selection cut

Question 16

what is seed tree

Answer 16

 Entire cutting unit managed as it is with clear-cut systems

 For designated time period those trees selected for supplying seed aren’t harvested

 Trees left just for supply seed for next crop

 Seed trees are harvested in removal cut once regeneration established

 Uniform and group seed system

Question 17

what is shelter wood

Answer 17

 Old stand removed in series of cuttings to promote even aged new stand under shelter of the old one

 central feature is that over storey leave-trees are left on site to protect regenerating understorey until understorey doesn’t need protection

Question 18

what is coppice

Answer 18

 Main regeneration method is vegetative sprouting of either suckers form the root system of trees or shoots from the cut stumps

Question 19

what is retention

Answer 19

 Aggregate retention
 Dispersed retention

Question 20

what is the uneven aged system called

Answer 20

selection

Question 21

what is selection

Answer 21

 mature timber is removed either as single scattered individuals or small groups at short intervals

 Repeated indefinitely where in even aged stand is maintained

Question 22

what is variable retention

Answer 22

Borrow aspects of both even and uneven aged regeneration cutting systems

• min 50% cut block or one tree length
• irregular retention boundary gives forest influence
  -regeneration in open area even aged from natural seed or planting

Question 23

what are fundamental management techniques for variable retention

Answer 23

reduce ecological impact of harvesting by retaining elements of stand and forest structure

Reduce aesthetic impact of harvesting to gain public acceptance