Lecture Midterm

Question 1

Describe as many indications of a healthy forest as you can

Answer 1

1. Soil erosion minimal & stream banks should be stable
2. Diverse & appropriate aquatic & wildlife species
3. Clean water should flow from streams except for extraordinary run-off conditions
4. Vigorous & healthy appearance of trees & understory plants
5. Growth & mortality consistent with ecosystem type & age of dominant trees
6. Vegetation diversity should be balanced between supply & demand of light, water + nutrients & growing space
7. Species age class distribution & stand densities should be within historical ranges for the site
8. Forests should be capable of tolerating & recovering from disturbances such as fire & wind
9. Should be free of non-native insects & vegetation
10. Insects, disease & fire frequencies should be within the normal range of the ecosystem

Question 2

What are the 12 noted negative impacts of diseases & pests in forests & provide an example of each

Answer 2

1. Tree mortality - defoliators, bark beetles, root disease
2. Destruction of solid wood - wood boring insects, decay
3. Growth reductions - decreased height and/or diamter growth = volume loss
4. Delayed regeneration - Lost time and increased costs of establishing a new crop
5. Stocking deficiencies - limits intensive stand treatment options, loss of growing space
6. Longer rotations - years added to reach a given size
7. Degeneration of species composition - mountain pine beetle disrupts harvesting of species profile
8. Loss of tree species - spruce weevil, white pine blister rust
9. Reduced tree or wood quality - deformity or decay @ entry wounds - terminal weevils, spruce budworm, stem decay, blue stain
10. Disruption of harvest scheduling and planning
11. Site degeneration - chronic growth loss, wildlife habitat loss aesthetics etc. - spruce weevil, mountain pine beetle
12. Limits silviculture system planning

Question 3

In brief, what are the main responsibilities of the Canadian Forest Service and the MFLNRO?

Answer 3

CFS:

research into: insect and disease mgmt

biological controls

biodiversity

biotechnology

genetic improvements

MFLNRO:

routine cruising/silviculture surveys

aerial surveys of outbreaks

ground surveys

Question 4

What are the general characteristics of fungi?

Answer 4

Heterotrophic
- Lack chlorophyll

Cell walls of chitin

Hyphae, mycelium

Have sexual or asexual spores or both

Parasites or saprophytes (or both)

Secrete enzymes and acids, digest outside the hypha then absorb them

Question 5

What are the distinguising characteristics of insects?

Answer 5

Body composed of 3 main divisions (head, thorax, abdomen)

Jointed legs

Antennae present

Wings USUALLY present

Question 6

5 adaptive features of insects

Answer 6

1. Flight - Disperse to colonize new habitat/leave unfavourable ones, escape predators
2. High reproductive potential - Keeps numbers high, evolve quickly
3. Small in size - tough to see, able to colonize small habitat
4. Physiology - specialized structures (mouth, antennae, wings, hard skeleton)
5. Exoskeleton - armouring, casing/attachments, low mas/weight, prevents moisture loss

Question 7

Describe the 2 types of insect life cycles

Answer 7

Complete metamorphasis - egg (resting stage), larvae (feeding stage), pupae (transformation), adult (sexual stage)

Incomplete metamorphasis - egg, various instars (stage in process where insect is immature), sexual adult

Note: Bark beetles go through 4 instar larval stages

Question 8

Give an example of each of these insect orders:

Lepidoptera

Coleoptera

Diptera

Hemiptera

Homoptera

Orthoptera

Hymenoptera

Answer 8

Lepidoptera - Butterflies, moths

Coleoptera - Beetles, weevils

Diptera - Flies, mosquitos, tabanids, midges

Hemiptera - True bugs (Stink bug)

Homoptera - Aphids, scale insects, cicadas

Orthoptera - Locust, preying mantis, cricket

Hymenoptera - Bees, wasps, ants

Question 9

Identify the type of life cycle associated with each order insect order

Answer 9

Lepidoptera - Complete

Coleoptera - Complete

Diptera - Complete

Hemiptera - Incomplete

Homoptera - Incomplete —>although it more closely resembles complete

Orthoptera - Incomplete

Hymenoptera - Complete

Question 10

What is the Phyllum and Class that insects belong to?

Answer 10

Phyllum - Arthropoda —> “jointed legs”

Class - Hexapoda —> “6 legs”

Question 11

Define abiotic injury

Answer 11

Damage caused by non-living or chemical factors in the environment

Question 12

Examples of things which might cause nutrient deficiencies in trees

Answer 12

• soil volume
• texture, permeability of soil
• soil alkalinity

Question 13

one possible symptom of nutrient deficiency

Answer 13

chlorotic needles (lack of chlorophyll)

Question 14

Examples of conditions that indicate symptoms of trees suffering from temperature extremes

Answer 14

• Birch dieback(water stress-higher temps, less moisture, increased dessication)
• Cedar Flagging(sunscald)
• Frost cracks/frost heaving
• Shoot/bud frost kill

Question 15

Examples of conditions that indicate symptoms of trees suffering from water extremes

Answer 15

• pole blight
• red belt (warm, dry winds in day, cold air drainage at night mean no water from frozen soils, needles dried out from wind and cant draw out water)
• winterkill : trees killed above where snowline was

Question 16

3 part definition of decline disease

Answer 16

• A slow, progressive deterioration in health and vigor
• Primarily affects a mature cohort of trees(group, similar age/ht/species) because they require the most nutrients and water
• Symptoms: initial symptoms are general, non specific, and non-diagnostic

Question 17

3 causal factors of decline diseases

Answer 17

1. Pre disposing factors: Long term(ie: climate, site, age, genetics)
   example: drought-prone
2. Inciting factors : Short term
   Example: drought conditions
3. Contributing factors: opportunistic fungi and insects like bark beetle. Finish off tree, but normally wouldn’t do so unless tree was declining
   Example: leptographium fungus on pole blight, Armillaria, Birch Die Back

Question 18

Decribe a decline disease on a specific tree species, briefly detail causal agents associated with tree’s evolution from healthy stem to mortality

Answer 18

Birch Die Back

Predisposing Factor: age and size class, problems most severe on drought-prone sites

Inciting factors: drought conditions

Contributing factors: birch die back combined with bronze birch borer(executioner) lead to stem death

Question 19

Factors that produce windthrow risk

Answer 19

Biophysical hazard + Treatment Risk = Windthrow Risk

Biophysical hazard: topo exposure, soil characteristics, stand characteristics

Treatment Risk: assessment of the wind loading on remaining edge trees in larger openings, or assessment of wind loading in retention harvesting areas

Question 20

Catastrophic winds

Answer 20

• infrequent
• unpredicatable
• local knowledge and historical perspective helpful with management
• tough to manage-volumes are significant
• salvaging these losses are important because: recovering economic losses, hard to clean up-need to allow for stand regen, fire, insects

Question 21

Endemic Winds

Answer 21

• peak winds expected to reoccur annually
• somewhat more predictable than catastrophic winds (possible to assess risk)
• management activities can reduce risk to a degree
• aerial wind throw patterns need to be assessed at both the stand and landscape levels (look at bigger picture)

Question 22

Characteristics of high hazard soils

Answer 22

• high coarse fragments
• shallow: watertable, root restricting layer, species rooting depth
• poor drainage
• finer textured soils

Question 23

Characteristics of high hazard stands

Answer 23

• windfirmness of species (want it to be high) ex-Py, Fd, Lw, Cw, Pl
• uniform structure
• good height/dbh ratio (high ratio more susceptible)
• root disease/stem decay

Question 24

Relative windfirmness of 13 tree species

Answer 24

HIGH: Py, Fd, Lw, Cw, Pl

MED: Bg, At, Ac, Ep

LOW: Sx, Bl

Question 25

Treatment risk for group selection, patch cuts, clearcuts

Answer 25

high risk occurs when: * downwind edge is perpendicular to damaging winds, equals susceptibility * open funneling * opening is greater than 5 tree lengths in windward direction * cut block edges project into an opening-more abrupt the angle, greater the risk

Question 26

Treatment risk for uniform retention cuts

Answer 26

* Greater than 50% stem removal(trees used to being protected) * vets and healthy dominants (high grading) * when the least windfirm species are left

Question 27

Resistance to mechanical injury for species: Lw, Cw, Bg, Pw, Fd, Cw, Bl, Sx, Pl, Hw

Answer 27

* VH: Lw, Py * H: Fd * M: Pw * L: Bg, Bl, Sx, Pl, Hw * VL: Cw

Question 28

4 Mechanical injury wound factors

Answer 28

1. **Relation of stand entry to occurrence of decay**( Greater the number of stand entries, high the probability of wound creation) 2. **Relation of wound height to percent stem removal** (Fewer trees harvested result in more damage due to more obstacles and difficulty of using designated skid trails) 3. **RElation of wound height to occurrence of decay** (frequency of infection decreases from ground up) 4. **Relation of wound size to occurrence of decay** (Small scars less likely to result in decay)

Question 29

Decay fungi and advanced regen

Answer 29

* Only when injured, younger trees generally susceptible to decay fungi (except for Cw with sweep in lower stem assoc with p.weirii) * Advanced regen is more suspect and should be checked for decay * Destructive sampling encouraged

Question 30

10 Guidelines for reducing wounds in partial cuts

Answer 30

1. Retention criteria should emphasize good form and vigour 2. Target species with good resistance to mechanical injury 3. Account for landing and processing needs with targeting residuals 4. Restric operating season. Avoid spring and early summer if possible (flowing sap, loose bark) 5. match the size and type of equipment to: topography, piece size, residual spacing 6. Plan for "rub trees" when skidding 7. Orient trails and skid directions to minimize sharp turns 8. Adapt falling techniques to the stand in question 9. Make objectives and priorities clear to operators 10. Be prepared to make adaptations to harvest methods if things arent going according to plan

Question 31

Explain why its important to avoid damage to residuals in partial cuts

Answer 31

* Scarring creates potential for decay entry in retained species * Time is decay's greatest ally so the younger the tree when it's injured, the greater the potential for decay to reduce stem value

Question 32

Describe nematodes

Answer 32

* worm-like, unsegmented animals * live on soil, feed on roots * Pinewood nematode-trees wilt and die

Question 33

Describe viruses

Answer 33

* Can live only in other organisms * disrupt cell functions * Alter DNA * symptom: yellowing, light green, or clear patches on leaves * Also used to control defoliators

Question 34

Describe bacteria

Answer 34

* simple one-celled organisms * with respect to trees, only a few disease causing agents known * Eg: fire blight on apple/pear trees or Defoliator controls (BTK)

Question 35

6 factors used to ID animal damage:

Answer 35

1. **Geographic Area**: many animals cause notable damage to trees within certain areas of the province but are not even present in others. (EG: hares only cause prolific damage in North and central interior of BC, but are all over BC) 2. **Season**: Some animals only cause significant damage at certain times of year (porcupines in the winter) 3. **Tree Species attacked**: many animals selective in type of tree, but not exclusionary. (EG: deer, elk and moose love Cw, but browsing can extend to all species) 4. **Age of tree this is damaged**: Some animals only cause damge to trees of certain ages (EG: bears dont damage young seedlings) 5. **Animal signs and symptoms**: droppings, tracks, trails, sheds, holes, quills, hair 6. **Type of Damage**: Most reliable indicator

Question 36

Types of damage by animal: deer/elk/moose

Answer 36

**DEER, ELK,MOOSE:** Seedling and sapling browse * Sapling, pole-sized andmature tree rubbing

Question 37

bear damage

Answer 37

usually only attacks pole size or larger all conifers susceptible (Fd,Lw preferred in interior) Large sections of bark stripped from trees Significant damage usually restricted to important habitat areas Number of trees attacked is low compared to other animals but consequences are high

Question 38

Porcupine damage

Answer 38

attacks all species and ages of conifers, but prefers saplings and larger damage almost entirely restricted to winter (feed on inner bark) bark is gnawed from trees rather than stripped can see evidence of both vertical and diagonal tooth marks cause scattered mortality over fairly extensive areas (treees die from lower stem being girdled) if mortality doesnt occur, top kill and deformity still can

Question 39

Vole damage

Answer 39

seedling damage most common fuzzy patches of gnawed bark around base of tree damage often extends below ground runway holes are key ID feature damage includes: mortality or reduced growth in young seedlings, scattered mortality in older seedlings if fully girdled, damage can be siginificant at height of 3-4 year population cycle

Question 40

squirrel damage

Answer 40

attacks concentrated in central and southern interior Pl most susceptible of conifers sapling to pole size preferred damage: cutting/pweeling of terminal shoots, removeal or hollowing out of buds damage id'd by gnawed surfaces rel. smooth with indistinct toothmarks reduced tree growth

Question 41

hare damage

Answer 41

snowshoe hare and cottontail rabbit damage only in north and central interior pl preferred of conifers, Pl not covered by snow in winter hit the hardest only trees less than 6cm dbh susceptible(distinguishes from squirrel damage) shear, knife like cuts bark gnawed in ragged patches around base of tree Damage: small seedlings die from root collar feeding, larger seedlings suffer growth stunting and deformity, damage extent mimics the 9-11 year population life cycle

Question 42

Main responsibilities of Canadian forest service and MFLNRO

Answer 42

CFS: * insect collections * research into: insects/disease management, biological controls, biodiversity, biotechnology, genetic improvement MFLNRO * cruising/silvicultural surveys * aerial surveys of outbreaks * ground surveys