forestry 4 midterm
Terms
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- silviculture system
- =silviculture treatment throughout the life of a stand including regeneration treatments, protection, or cuttings
- insolation
- -heat, temperature, and light quality
- who eats seeds?
- squirrels, mice, voles, shrews, and insects.
- Minimum light requirements for survival
-
white spruce 12-15%
lodgepole pine 20%
balsam fir 8%
*growth rates differ by light levels - 2 regeneration methods
-
1. uneven aged
2. even aged - regeneration method
- =procedure by which a stand is replaced or renewed
- benefits of regeneration methods in uneven-aged stands
- used to maintain uneven-aged stands, maintain forest cover, provide a continuous flow of fiber
- What can be done to deal with temperature problems?
-
1. select species adapted to local climate
2. break up organic soil layers to increase soil warming
3. leave residual trees for protection - maximum sucker production
- soil is 20'C in summer, and is inhibited when soil is below 15'C
- regeneration method components
-
-removal of the old stand
-establishment of the new stand
-treatment of vegetation, slash, or soil for favorable reproduction conditions - silviculture
- =the art and practice of growing forests
- vegetative reproduction
-
1. sprouts
2. suckers
3. cutting
4. layering
5. coppice method - 2 types of clearcut
-
1. natural regeneration (seed, coppice)
2. artificial regeneration (aerial seedling, planting) - clearcutting
-
stand is removed with regeneration occuring after harvest
2 types:
natural regeneration
artificial regeneration - reenter stands
- =have to maintain access
- natural shelterwood method
- stands that already have established regeneration in the understory
- 3 steps in shelterwood method
-
1. prepatory cuttings
2. establishment of seedling cuttings
3. removal cutting - even-aged
-
(1 or 2 height or age classes of trees present)
-shelterwood
-seed tree
-clearcut - uneven aged
-
(3+ height or age classes of trees present)
-selection - problems of regeneration methods in uneven-aged stands
- -expensive, need to frequently reenter stands, operate over large areas, yeild reduced, not well suited for intolerant species
- regeneration methods in uneven-aged stands
- -single tree selection of group selection
- lethal temp. for growth
- 50'C is lethal
- why is clearcutting the method commonly used?
-
-simplicity
-cost
-yield
-preferred for intolerant species
-experience
-equipment - environment
-
factors include:
-insolation
-moisture and drought
-frost - coppice method
-
-"Low-forest system"
=short forests over short period of time - what is used to improve light availability for seedling growth?
-
-removal of overtopping vegetation
-vegetation management
-cleaning
-thinning - regeneration triangle
-
1. seed supply
2. seedbed
3. environment
*mandatory to have all 3 components - seed tree method
-
(similiar to clearcut systems)
- seedling growth and survival
- -mortality can occur during first year of germination, usually in winter b/c of freezing, frost...
- sexual reproduction
-
"High Forest System"
-by seed regeneration - seed supply
- = the amount and quality of seed that reaches seedbed conditions
- seed production variance
- =vairies with tree species, tree age, climate, and site conditions
- serotiny
- seed can remain viable inside of cones for several decades, and is released when cones are heated sufficiently high temp. by fire
- 2 sources of regeneration
-
1. vegetative reproduction
2. sexual reproduction - most favorable seedbed for germination
- -exposed mineral soil free of vegetation cover
- viability of seeds in the soil
- -lasts for 1 or 2 years
- dispersal of tree seed
-
-influenced by many factors:
1. height seed is released
2. distance from seed source
3. characteristics of seed
4. wind - seedbed
-
factors include:
-surface properties
-depth of organic matter
-vegetation cover
-elevated microsites