BIOL 3447- Exam Flashcards
1
Q
what are the phases of silvicultural systems
A
- regeneration -> tending -> harvesting
- can be cyclical or as the interdependence of components
2
Q
types of management
A
- exploitation
- non declining even flow: continued access to resources
- balance structure: replenishment
- wise use: use in the present and continuous supply in the future
3
Q
exhaustible vs flow resources
A
exhaustible: resources of limited and finite amounts
flow: resources that are replenished to some degree
4
Q
single cohort system
A
- cohort establishment only at the beginning with replacement at rotation end
- single age class managed as one unit- homogenous stand conditions
- tending applied to promote development
- some harvest of immature trees to promote growth and generate revenue
5
Q
multi cohort system
A
- wide range of age classes- typically 3 cohorts at different stages of development
- tending and establishment of regeneration are concurrent
- return to stand at intervals to control structure and maintain cohorts
- periodic merchandising of logs to generate revenue
6
Q
describe the different levels of intensity of management
A
- wild: perfect alignment with ecological development, small amount of timber management if possible, may include protected areas or areas too remote for timber
- regulated: moderate alignment with ecological development, managed through ecological forestry, balance biological and commodity goals
- domesticated- managed through technological forestry, best conditions for growth, high levels of investment
7
Q
describe the factors affecting silvicultural decisions (5)
A
- accessibility (constructing roads)
- markets (is there a market to support the cost of growing timber)
- site quality (is the site of good enough quality to support growth)
- tree character and conditions (are the trees of good quality)
- ownership
8
Q
economic costs of silviculture
A
- access- can you get to and process the wood at a reasonable cost?
- interest- does anyone want the product and what price are they willing to pay?
- timing- how quickly can you get the product to market
9
Q
economic values of silviculture
A
- wood as a resource- easy to harvest, good insulating properties, strong and durable, can be harvested relatively endlessly
- stumpage- price on standing timber and the right to harvest it
- user fees- recreational opportunities, access to easement and conservation areas
10
Q
types of timber harvesting systems
A
- whole tree: removal of the entire tree (stem, branches, stump, roots) to the landing
- tree length: felling, topping, and delimbing trees in the forest, tree is bucked at the landing or mill
- cut-to-length: felling, topping, and delimbing the tree in the forest, tree is bucked in the forest
11
Q
describe some of the effects of silviculture on the ecosystem
A
- skid trails: temporary roads/trails used by logging equipment to remove logs
- machinery equipment may leave ruts or disturb soil
- increase in overland flow and mobility of debris and foreign chemicals
- removal of vegetation decreases shade and increases water temp
12
Q
best management practice
A
- optimal operating methods for preventing or reducing water pollution and protecting wetlands
- includes planning of transportation, appropriate retirement, planting landings, limiting how many roads can be in use at one time
13
Q
US clean water act (crown sustainability act)
A
- BMPs can be applied to landings, skid trails, truck roads, stream and wetland crossings, harvests by water
- includes installing water barres and culverts, leaving buffer strips, planning, seeding with stabilizing plants, controlling the season, controlling slash, periodic maintenance, retirement
14
Q
airborne laser scanning data
A
- digital surface model: elevation model that captures the environment’s natural and artificial features
- digital elevation model: representation of the bare ground (exclude surface objects)
- canopy height model: maps tree height as a continuous surface, DSM-DEM
15
Q
how can LiDAR be used to facilitate planning
A
- allows you to plan where best to do things:
- shut down skidding in saturated areas
- place landings on soft gradients
- prohibit machinery from stream side buffers
- make sure roads and trails are kept in good condition
- predict costs based on current surfaces
- detect ephemeral streams (important habitat features)
16
Q
how can water systems be protected
A
- riparian zone (interface between land and water) protection (maintain litter, reduce sedimentation, maintain shade)
- buffer strip: strips of vegetation that provide a physical barrier to slow the flow of water and reduce runoff
- filter strip: a narrow strip of vegetation that acts as a barrier to pollutants into the waterways
17
Q
describe the timeline of planning and implementing a harvest
A
- schedule operations to avoid critical times
- use machine operation strategies that minimize litter disturbance
- design trails/roads to keep the surface dry
- maintain landings to prevent erosion
- match equipment and practices to the needs and conditions
18
Q
fire triangle
A
- oxygen: fire is an oxidation reaction
- fuel: any combustible material, affected by moisture content and piece size
- heat: fire occurs when fuels are heated up beyond their ignition temperature, water is an effective fire suppressant because of its high heat capacity
19
Q
describe the different types of fires
A
- ground fire: burn below the surface, low frequency-high impact, long recovery, alters soil chemistry dramatically
- surface fire: burns lightweight fuels at the surface, moderate temperatures, high frequency- low impact, short recovery
- crown fire: high fuel loads with ladder fuels, low frequency- high impact, long recovery, resets the system for succession
20
Q
ignition
A
- requires activation energy to initiate the reaction
- most common forms of ignitions are lightning and humans
21
Q
what affects the spread of a fire (5)
A
fuel loads, landscape connectivity, topography, hydrology, wind
22
Q
general fire hypothesis
A
communities of plants have evolved with a fire regime and thus depend on fire
23
Q
what do forests require for fire to play a significant role (4)
A
- ignition sources
- appropriate fuel structures (type of fuel determines the type of fire)
- seasonality (at least one season with warm dry conditions)
- sufficient productivity
24
Q
describe the best fuels
A
- high SA:V (fine twigs)
- low moisture content
- high concentration of flammable compounds (terpenes)
- varied (encourages consistent fire)
25
Q
fire adaptations (5)
A
- thick bark
- high foliage/self pruning
- sprouting (persistence adaptation)
- stimulate germination
- serotiny
26
Q
describe the longleaf pine system
A
- seedlings germinate on mineral soil and have rapid growth
- grass stage- secondary needles and buds have protective resins, juvenile bank to survive fire
- mature trees have thick corky bark
- fire controls pests and competition
27
Q
describe the clearcutting system
A
- even age forest of shade intolerant species
- emulates large disturbances
- emphasis on light penetration to support regeneration
- applied as a mosaic over the landscape
- cost efficient and simple
28
Q
what does a successful clearcut require
A
- sufficient seed source
- receptive seed bed
- timely management of competition
29
Q
types of clearcuts
A
- conventional (complete removal of overstory)
- clearcut with standards (veteran trees are retained)
- seed tree (trees of seed bearing age are retained and dispersed throughout the stand, maintains structural diversity)
30
Q
clearcuts in Ontario
A
- retention of 10-36% of original stand
- minimum of 25 snags per ha
- variable sizes
- new clearcuts separated from older clearcuts
31
Q
modified clearcuts
A
- patch clearcut: patches are harvested in various shapes and sizes reflecting the underlying forest mosaic
- strip clearcut: adjacent strips cut sequentially, strip size and orientation regulated by ecological conditions, eventual coverage of entire stand
32
Q
describe the importance of seed sources
A
- harvest removes seed trees
- few species have a viable seed bank
- maximum widths are determined by the distance to adjacent seed sources
- site variation and advanced regeneration will influence regeneration sucesss
33
Q
environmental effects of clearcuts
A
- increases surface and soil temps
- increases evaporation and decreases humidity
- increases soil moisture (reduced interception of precipitation, increased infiltration and percolation)
- greater overland flow
- faster decomposition
- nutrient release
- leaching
34
Q
what microsite factors influence clearcuts
A
- slope- the steeper the slope the better draining the soil and more susceptible the site is to drought
- aspect- southern aspect is associated with a decline in regeneration
35
Q
describe the different types of retention
A
- provides habitat refuge, travel corridors, legacies, visual appeals
- dispersed: retained trees are spread throughout the area
- aggregate: retained trees are concentrated into habitat island- possibly more attractive to different species, provides operational value
36
Q
slash
A
provides temperature moderation, protection fro herbivores, more suitable microenvironment, slow release of nutrients
37
Q
describe the changing face of clearcuts
A
- historically, clearcuts had straight edges, square corners, and retained trees were isolated to thin strips along streams
- total, patches or bands of trees are retained throughout the site, there may be a mixture of aggregate and dispersed retention, greater visual appeal, diffuse boundaries
38
Q
free to grow status
A
stands that meet stocking, height, and/or height growth rate as specified in the ground rules and are judged to be healthy and essential free from competing vegetation
39
Q
silvicultural success
A
- all standards contained in the silviculture ground rule applied to that stand have been met
- e.g. standards for target species, acceptable species, future forest condition, wildlife habitat
40
Q
clearcut advantages
A
- high yields and low costs
- regeneration of shade intolerant species
- easy site prep and machine access
- pest control
41
Q
clearcut disadvantages
A
- dependence on seed rain/bank and risk of failed regeneration
- intense competition
- reduced transpiration effects and high evaporative demand
- soil disturbance and erosion
- increased fire risk
- loss of habitat
42
Q
shelterwood characteristics
A
- single cohort of mid-tolerant species
- emulates moderate disturbances
- primarily used with natural regeneration- new cohort develops under older trees
- sufficient canopy cover to mitigate change in microenvironment
43
Q
phases of a shelterwood
A
- remove: removing trees to modify the light environment and benefit regeneration
- retain: retaining adequate cover to create seed and a positive environment for seedlings
- maintain: producing the regeneration niche of the species you’re trying to regenerate
44
Q
cuts in a shelterwood
A
- prep cut: removing inferior trees, allow more room for good trees, gives time for seed to be produced
- seed cut: opening the canopy to 50%, hope that trees drop seed, allow for regeneration
- removal cut: most of the shelterwood is taken off, a few residual stems are left
45
Q
seed tree method
A
- appropriate number of individual trees are left across an open area to provide seed for production of the next crop of trees
- used for species that do well in open conditions but are limited by seed dispersal
46
Q
seed tree
A
residual stem that is a source of seed for the regenerating cohort
47
Q
characteristics of good seed trees
A
- upper canopy position (access to resources)
- thick stem relative to height
- well balanced symmetrical crown
- wind firm morphology
- large, medium dense crowns, tallness, and poor root anchorage makes trees more susceptible to wind
48
Q
forest regeneration success
A
- height and durability of seed trees
- frequency of seed crops
- seed production (related to crown size and stem thickness)
- seedbed suitability
- seed viability and germination rates
49
Q
shelterwood with reserves method
A
- individuals are selected and left to overtop the new cohort
- typically large diameter trees are retained at a low density
- rarely used in NA forestry
50
Q
advantages and disadvantages of shelterwood with reserves method
A
- D: increased variability in light environment, slower growth rate, trees may become flat topped
- A: more growth on retained, more aesthetic, maintains certain habitat features
51
Q
characteristics of reserve trees
A
- longevity (50-80 yrs)
- good form, no lean, dominant/codominant crown
- no dead/dying branches or epicormic branching
- species not prone to dieback
52
Q
strip shelterwood method
A
- parallel strips of 1 tree length in width are cut in successive entries
- creates progressive canopy openings until a majority of the stand has mature age class removed
- even aged stand
- initiates regeneration and ensures everywhere is close to viable seed
53
Q
group shelterwood method
A
- creates patches of regeneration dispersed throughout the site
patches are circular and approx 1 tree length in diameter - cuttings expand patches until they coalesce
54
Q
benefits of shelterwood
A
- vertical structure
- variation in environment/density
- legacy trees
- transition habitat
55
Q
objectives of selection silviculture
A
- sustained and regular yields
- stable structure and forest conditions
- full site utilization- optimal stocking and production of quality timber
- regular replacement of mature trees
- habitat availability
56
Q
characteristics of selection
A
- multiple cohorts
- high live crown ratios
- high vertical structure (foliage at all layers)
- wide range of diameters
- strong height:diamter relationship (based on vigour)
57
Q
working cycle
A
forest under a particular work plan- the area where one silvicultural system is specified
58
Q
balance
A
- each age/size class occupies the same amount of crown space (many small, few large)
- regulating densities in each cohort maximizes site occupancy
- negative correlation between crown size and density (lower density leads to larger crowns)
59
Q
q factor
A
- describes the slope of the exponential curve relative density to diameter classes
- q= # of trees in class (n)/ n+1
60
Q
problems with q type structure
A
- idealized ratio and not a realistic representation
- underestimation of ingrowth in spacing and pole size classes
- divergence of economic and biological effects
61
Q
steps in the selection system
A
- inventory of stand composition and structure
- identify the diameter classes for cohorts
- determine the appropriate residual density and cutting cycle
- compare actual diameter distribution to desired structure
- write a marking prescription to remove excess trees from overstocked size classes
- mark and cut the stand
62
Q
retention priorities
A
- target age class
- vigour, form, soundless, low risk
- species
- crow position
63
Q
rehabilitating a degraded stand
A
- retain an appropriate residual density even if high risk or low vigour trees are retained
- plan for 2-3 cuts to upgrade the stand over time
- choose a lower residual density and extend the cutting cycle
- lower the max diameter and retain some suboptimal trees
64
Q
regeneration in the selection system
A
- reduce the stocking of each diameter class
- removal of mature age class to release developing stand
- aim to propagate and promote the highest quality individuals int ehe and and allow them to replace inferior individuals
65
Q
effects of selection post harvest
A
- high residual stand density
- small increase in soil moisture and nutrients
- increase in diffuse light in the understory
- short term increase in temp and decomp
66
Q
variation in the light environment after selection harvesting
A
- increases depth of light penetration
- ground remains in partial shade
- saplings under gaps are stimulated
- germination and establishment of shade tolerant species is promoted
67
Q
foliage height diversity
A
- proportion of total foliage at different height s
- low score is associated with foliage concentrated in a few layers
68
Q
establishment
A
- important for revegetation a stand
- requires germination, shoot system penetration, and root system penetration
- requires net positive assimilation as soon as possible
69
Q
site preparation
A
- deals with changes of conditions that favour the species you’re trying to manage
- can be done before or after
- alters the physical environment or deals with competing vegetation
70
Q
goals of site prep
A
- vegetation control
- litter removal/mixing
- promotes decomposition
- alters nutrient balance
- modifies habitat and enhances conditions
- reduces fuel
- facilities operations
71
Q
passive site prep
A
- side effect of another activity- unpredictable
- often couple with natural regen
- skid trail mix soil, damage competing vegetation, and create a mineral seed bed
72
Q
active site prep
A
- intervention to enhance the regeneration process
- varied in intensity and extend depending on the application
- controlled and more expensive
73
Q
what are the types of site prep
A
- mechanical: altering the soil or litter, reducing competing vegetation, usually with machines
- chemical: application of fertilizer or herbicide
- fire: kill or reduce competition and reduce organic debris
74
Q
extent of site prep
A
- broadcast: affects the entire stand
- strip: applied in narrow alternating bands
- spot: focused exclusively on the development of seedlings
75
Q
types of mechanical site prep
A
- blading: bulldozers with blades that skim the surface
- bedding: elevating cultivated bed to promote drainage and aeration
- chopping/shearing: heavy rollers crush and separate debris (woody mulch)
- chaining: chain is dragged behind a bulldozer, promotes decomposition and aeration
76
Q
advantages and disadvantages of mechanical site prep
A
- A: slash management, mulching, vegetation management, improving drainage, scarification
- D: erosion, compaction, weeds, sprouting, nutrient loss, temperature variation
77
Q
chemical site prep applications
A
- individual stem
- broadcast: larger areas
- aerial: can treat hundreds of ha, only requires a few personnel, tightly restricted, must be applied at the correct time
- ground level: only practical with good access and practical quantity, more targeted, require more volume and people
78
Q
advantages and disadvantages of chemical site prep
A
- A: wide spread efficacy, sprout prevention, lack of forest floor disturbance, cost effective
- D: off target damage, variation in efficacy, timing requirements, increased fuel loads, restrictions
79
Q
prescribed burning
A
- controlled use of fire under conditions that permit its containment to a pre-determined area
- produces a specified intensity of heat and rate of spread to satisfy the planned objectives and provide the desired benefits with minimum damage at an acceptable cost
- a practical tool used in parks
- associated with the management of mid-tolerant species
80
Q
fire weather index
A
- based on temperature, relative humidity, wind speed, and rain
- varies from 0-23 (cooler, wetter conditions have lower scores)
81
Q
types of prescribed fire
A
- strip: light a protective back fire that consumes any fuel to prevent fire from burning past that point, then light a strip that slowly burns towards the back fire
- spot: similar to strip but uses patches
- ring: back fire is lit, perimeter of the burn area is lit and produces an updraft that causes rapid and intensive spread into the centre
82
Q
advantages and disadvantages of prescribed burn
A
- A: slash and debris removal, nutrient release, vegetation and pest control, fuel reduction
- D: release of toxins, narrow range of conditions, risk of escape, temporary, erosion, nutrient leeching
83
Q
12 points from the big meadow fire
A
- prescribed fires reduce hazardous fuel to restore forest structure and composition
- get fires back into the ecosystem
- reduces severity of future fires
- window of very specific conditions
- maintain fire resistant vegetation
- previous fire suppression
- fire knowledge has evolved
- limitation to when burns can occur, so burn whenever you can
- burn area is heterogenous
- regrowth involves different phases
- emergency response team investigates after
84
Q
choosing a site prep treatment
A
- vegetation present/desired
- distribution of species/debris
- topography and substrate
- planned management
- anticipated costs and benefits
85
Q
plantation
A
a forest community or stand established artificially by sowing or planting
86
Q
reasons for tree planting
A
- lack of seed source
- establish tree cover in an altered enviro (e.g. abandoned agriculture field)
- control composition, spacing, arrangement
- narrow window of conditions for establishment
- problematic natural regen
87
Q
objectives of tree planting
A
- products
- protective cover
- visual appeal
- animal food and cover
- windbreaks
- ecosystem restoration/rehabilitation
88
Q
urban forestry
A
- urban grove: a small closed tree community in undeveloped part of a city, unplanted
- urban savannahs: strips of street side trees widely dispersed or in isolated clusters of small trees in open groves or parks, planted
- paving trees: widely dispersed individual trees
89
Q
role of plantations in conservation
A
- mimics natural disturbance
- focus on native species
- conserves woody debris
- longer rotation
- early thinning
90
Q
selecting the right species for artificial regen
A
- must consider the goal of the plantation
- cover, landuse history, climate, aspect, soil
91
Q
translocation rules
A
- seed cannot be moved more than 161 km in distance or 150-300 m in elevation
- donor and recipient site should be similar
92
Q
biological potential
A
rate of germination
93
Q
cold stratification
A
the process of exposing seeds to cold and moist conditions to encourage germination
94
Q
scarification
A
the process of altering the seed coat to allow for quicker water absorption and improve germination rate
95
Q
sowing rate
A
the density of seed to spread in order to achieve a given stocking level (seeds/unit area)
96
Q
seed certification
A
verification of the source of the seed and an assessment of the relevant properties of the seed lot
97
Q
seed lot
A
- cohort of seed gathered from the same source during the same year
- seed may differ from year to year, so seed lot tell you about viability and germination rates
98
Q
types of seed
A
- unclassified seed: no info on where it comes from or its quality
- source-identified seed: from good natural stands or plantations where the location is registered, no additional attributes but tells you if its from the right seed zone
- selected: seed from a specific genotypes
- certified orchard seed: the highest level, proven by progeny test, highest quality with specific attributes from the best genetic line
99
Q
bareroot seedlings
A
- grown without pots or containers and shipped free of any medium around the roots
- must consider: temperature, soil moisture, and seedling activity
- spring is the best time to plant
100
Q
limitations of bareroot seedlings
A
- seedlings must be lifted at an appropriate time for planting
- seedlings deteriorate quickly after lifting and most be stored properly or planted immediately
- seedlings must be handled with care
- difficult to plant
101
Q
container stock
A
- grown in a receptacle filled with soil or other rooting medium and out planted with the rooting medium left undisturbed around the roots
- various containers and rooting media are used to maximize performance
102
Q
advantages of container stock
A
- control of growing conditions
- shorter nursery rotations and faster early growth
- uniform size and condition
- higher survivor ship
- much easier to plant
103
Q
limitations of container stock
A
- high production cost
- technical difficulties with production
- heavier than barefoot
- vulnerable to frost heave
104
Q
intermediate treatments
A
- deliberate cutting used to thin out a stand to provide more resources to the retained trees
- improves spacing, composition, and vigour
- includes release treatments (sapling) and thinning (post sapling- pre commercial/commercial)
105
Q
low thinning
A
- RC- lowest crown positions and overtopped trees
- R- upper canopy dominants, focusses growth on larger trees
- E- decreases vertical density, improves quality
106
Q
crown thinning
A
- RC- dominant and codominant crown positions, poor vigour and quality
- R- upper canopy dominants, favours best growing stock, fillers and trainers
- E- inform spacing, improves diameter growth, maintains some vertical diversity
107
Q
selection thinning
A
- RC- diameter limit, low quality/value species
- R- smaller trees, good growth form, promotes a certain species
- E- best genetic stock is removed, poor natural regeneration, decreased yield
108
Q
free thinning
A
- RC- spacing out crop trees
- R- uniform spacing or strips in natural stands, rows in plantations
- E- higher volumes from thinning, little changes in vertical structure, variety of trees retained
109
Q
how is a thinning method chosen
A
- present stand conditions
- species mixture
- stand age (time to rotation, self thinning)
- landowner objectives (product
- end use (market, non-timber values)
110
Q
A
