Exam 2: Forestry Flashcards
What is ecophysiology?
study of how the environment, both physical and biological, interacts with the physiology of an organism
Three basic components of ecophysiology
Tree biology
Site factors
Tolerance
factors related to plant distribution
temperature, moisture
what are three site factors?
climate, soil, topography
Three shade intolerant species
Aspen, paper birch, red pine
Two very shade tolerant species
Sugar maple, eastern hemlock
What is light compensation point?
point where photosynthesis equals respiration
Two soil properties that determine site suitability
soil pH, soil bulk density
How do mycorrhizal fungi benefit trees?
Increase surface area of roots which increases water and nutrient uptake
How is site quality measured?
Calculated as average height of dominant and co-dominant trees, within a given species, within a given site
Silviculture
Use of sustainable management to guide development of forest to fulfill natural resource objectives
Why are disturbance regimes a basis for silviculture?
disturbances fix genes
Dominant crown
sunlight at top and sides
Codominant crown
sunlight at top, little at sides
Intermediate crown
sunlight only at top
Suppressed crown
no direct sunlight
Seedling
1 -5 years, less than 3 ft tall
Sapling
5 - 15 years, greater than 3ft tall but less than 4 in DBH
Pole
15-60 years, in between 4 in and 8 in DBH
Mature
60-150 years, height and diameter growth slows
Old growth
over 150 years
Clearcut
most to all trees removed:
ideal with intolerant species, mimics severe disturbance
Seed tree
scattered trees left as seed source regen:
works well with southern pines and western larch
Seed crop and germination vary, competition, wind throw shallow root trees
Shelterwood
retain sufficient # of trees per unit area:
30 to 80% canopy
Visual quality is best
Coppice
cut trees down to ground level so they can stump sprout
Pro of natural regeneration
low cost
Con of natural regeneration
limited by seed dispersal, nature and probabilities
Pro of artificial regeneration
dependable and predictable
Con of artificial regeneration
higher costs, site prep
Why and when did silviculture start?
Timber shortages and 1664 in Germany
Advantages of mixed stands
More niches filled
Greater pest resistance
Diversity, flexibility and market prices
Social desires for aesthetics and recreation
Wildlife habitat diversity and refugia
Advantages of pure stands
Fit valuable species in stand
Easy to match site index
Ease with stand management
Reduced harvesting costs
Disadvantages of pure stands
Reduced aesthetics
Diversity decreased
Advantages of uneven stands
3 age classes or more
Reduced harvest residue
Steady income with small woodlots
Favorable odds with species regeneration
Disadvantages of uneven stands
Increased harvest costs because of frequent entry
Increased silviculture knowledge needed
Road maintenance greater
Increased admin
Advantages of even stands
Decreased residual damage
Growth rates more uniform
Wood quality and harvest volume greater
Less complicated to manage
Disadvantages of even stands
Decreased diversity
Increased susceptibility to pests
What is the purpose of intermediate treatments?
Improve:
Species composition and structure
Growth rate
Tree quality
What is stand evaluation used for?
determine if revenue is possible and if inputs are needed
Release treatment
free desirable species by removing competition
Improvement cuts
Remove low value trees (defective, deformed, diseased, insect infested)
Low thinning (below)
remove suppressed and intermediate crown classes
High thinning (above)
remove dominants and codominants
How does thinning affect forest growth?
total volume not increased but potential diameter is increased
Salvage cut
removes trees damaged by wind, fire, insects, disease, drought, flood ice storms
Metes and Bounds survey
based on simple descriptions of known features and measures distance between them
