FOR307 Final

What are examples of invasive alien forest insects

-asian longhorn beetle
-hemlock woolly adelgid
-emerald ash borer
-spongy moth

What organization creates the information sheets for the invasive insects

Ministry of National Resources and Forestry

What are the management strategies for EXOTIC (non-native) invasive species

-Prevention (legislation to prevent arrival)

-Eradication (prevent establishment, and elimination through quarantine and restricted movement)

-Regulation (=slow the spread; long term sustainable IPM approach to PREVENT SPREAD and manage pest insects)

-Management (prevention/biocontrol)

-Suppression (targeted remedial protection)

What does the Canadian Food Inspection Agency do?

-Legally responsible to implement IPPC (international plant protection convention) measures; ministerial orders for quarantine and eradication

1) Assessing risk and pathways (prevent arrival ; blacklists)

2) Permits for movement, import, destruction of infested material, eradication (prevent establishment)

3) Monitoring and control of spread (prevent spread)

What are the different ways for step 1: preventing arrival

-Early detection-risk assessment
--> world trade pathways and domestic movements (Asian longhorn beetle) ; b/c if they're in wood that's being transported, need to prevent them from arriving to other places

What are the different ways for step 2: preventing establishment

-QUARANTINE
--> custom inspection on-site, at harbours, public notices, etc

--> put up posters for asian longhorn beetle so people were aware
--> did inspections of cars, packaging material, etc

--> ERADICATION: all trees that are potential hosts had to be removed ; shredded down or incinerated so ALHB can't survive
-With EAB, started as quarantine, then eradication (80,000+ trees cut down), now SLOW-THE-SPREAD

What are the different ways for step 3: REGULATION

--> preventing the spread; containment and limit movement (slow the spread)
--> look at probably origin areas (like sawmills, firewood, etc) and contain the areas

What are the different ways for step 4: MANAGEMENT

-Management after eradication efforts

--> If previous steps don't work and insect not eradicated, then introduce things like biological control and prevention (classical biological control, conservation biological control, inundate biocontrol)

--> also ensure forest ecosystem diversity and forest resilience ; it provides long-term resilience against invasives (relative invasibility decreases with an increase in species diversity) --> forest diversity so we don't repeat dutch elm disease

What are the 6 strategies to stop pest invasion and maintain healthy resilient forests

1) Use diversity of native trees across a range of spaces and expected conditions = "hedge bets"

2) Keep genetic diversity (ex: extend tree lifespans, multiple seed sources, bring back native diversity)

3) Keep connectivity and protect old remaining vegetation and trees (heritage or legacy species and landscapes)

4) Plan diverse landscapes with minimal disturbance

5) Control non-native species (especially prevent entry)

6) Let NATURE be the guide with natural mortality (biocontrol = conserve, augment, and introduce)

What are the major factors contributing to deforestation in Canada (and how many HA were destroyed by fire in 2021, how many by insects in 2020?)

-Land clearing, fire, INSECTS

-2021 : 4.3 million HA by fire
-2020: 17.8 million HA by insects

What is a method of managing forest insect pests? What are the steps (6 steps)?

-By using integrated pest management (IPM)

1) Pest ID & Biology

2) Sampling / monitoring (forecasting, distribution)

3) Damage / impact values (may include economic / damage thresholds)

4) Management / control options AND PREVENTION

5) Integration / DSS (decision support systems)

6) Extension / Communication (partners / public)

What are the components of an IPM program

1) Pest identification
2) Monitoring
3) Injury levels and Action thresholds
4) Pest control tactics
4**) Prevention
5 + 6 ) IPM

What are different control methods for IPM and examples

-CULTURAL (remove diseased / sick and alternate host plants)

-PHYSICAL / MECHANICAL (remove/ kill pests by hand, cultivation, introducing pest traps)

-BIOLOGICAL (introduction of natural enemies to a new locale, augmentation)

-CHEMICAL (pesticide use)

What is the definition of IPM (what does it do)

-Uses all available science-based control options in a combined approach to implement the most environmentally sound and effective strategy to combat INVASIVE SPECIES

What is a fact about IPM steps?

IPM steps are not linear but they are cyclical and ongoing

Continually trying to improve IPM

IPM Case Study: Spruce Budworm
What would be the factors for Step 1?

Step 1: Pest ID and Biology

Spruce Budworm:
-Lepidoptera
-holometabolous
-has population cycles (every 30-40 yrs, lasts 10+ years)
-one lifecycle per year
-overwinter as larvae on host tree
-host mainly balsam fir and spruce trees and eats needles (defoliators) (feed on current and old foliage)
-parasitoids and lack of resources can decrease outbreak, as well as climatic factors

IPM Case Study: Spruce Budworm
What would be the factors for Step 2?

Step 2: Sampling/ Monitoring

At the tree level --> -look at ground branch densities (eggs/ larvae) and defoliation (can use pheromone trapping to predict populations)
-look at defoliation of current year and back-feeding on old foliage
-Or can use direct observation / passive or active trapping for insects (since they overwinter as second instar, can look for the hibernacula)

At stand level-->
-look for partial (top-kill) and whole tree mortality (especially mature stands)

Look at damage --> at stand level, do aerial assessment and mapping for landscape level populations (trees turn reddish)

IPM CASE STUDY: Spruce Budworm

What would the factors of Step 3 be?

Look at economic threshold or injury level--> for spruce budworm, it's based on damage and impact (ex: changes in defoliation, mortality, growth, use)

IPM CASE STUDY: Spruce Budworm

What would the factors of Step 4 be?

Step 4: Control Tactics (including natural mortality and prevention)

Natural mortality factors include

Weather --> cold, wet

Disease --> viruses, fungi

Predators --> birds, insects, mammals, etc

(spruce budworm has over 100 species of natural enemies)

Step 4: Prevention and Natural Resistance (reduce stress)

Forest level = silvicultural manipulations for diversity (like selection cutting and pruning, herbicides, resistance breeding, prescribed burning, prescribed insect outbreaks, etc)

Tree and stand level = cultural/ mechanical sanitation (like remove/reduce insects, sanitation (remove infested material), temperature (expose to high/low), moisture (submerge/mist), pheromones (attract and remove), regulation (quarantine)

What are the federal responsibilities for the regulatory framework

Pest control products act (PCPA) --> detailed health, environmental and value assessment; assign class designation and registers product

What are the provincial responsibilities for the regulatory framework

-Pesticides act and regulation --> classification system;

-Sale,
-Use, -Licenses/permits/ certifications,
-Transportation, storage, disposal, spills & clean up, etc

What are the purposes of insecticide used on crown (public) forests in canada?

1) Reduce pest numbers (population control)

2) Contain outbreak (geographically prevent spread)

3) Eradication (new pest/locations)

4) Protect foliage during an epidemic (reduce tree mortality)

Aerial vs ground application of insecticides?

Aerial: Biological (Btk - specific to Lepidoptera) --> no useable chemicals on crown forests
--> all applied with water

Ground: 17 compounds for 12 forest insect pests (3 are biological)
--> private land or fumigation

What are the reactions of different forest insects to microbial insecticides?

SPRUCE BUDWORM

--> VIRUS --> SUCCESS: slight-none

SPRUCE SAWFLY --> VIRUS --> SUCCESS: excellent

SPONGY MOTH --> VIRUS --> MODERATE. BACTREIA --> MODERATE.

FOREST TENT CATERPILLAR --> VIRUS = NONE. --> BACTERIA = GOOD

PINE SAWFLIES --> VIRUSES = EXCELLENT

so basically for Hymenoptera, viruses work great usually for killing them, not great for Lepidoptera

What are semiochemicals and what do they do to insects

Pheromones and/or host volatiles for suppression

--> natural or synthetic chemicals modify insect behaviour

--> operational for >13 spp. forest insects for detection

--> suppression (mating disruption) only for BARK BEETLES (like mountain pine beetle) and SPONGY MOTH

--> Very sensitive - no environmental impact (cheap and commercial but hard to quantify and hard in inaccessible stands)

What are the different ways for natural enemies for biological control

Classical introductions VS augmentation and conservation

Classical Introductions= balsam woolly adelgid, larch sawfly, spruce sawfly, winter moth, spongy moth, spruce budworm, EAB

Augmentation and Conservation = trichrogramma egg parasitoids (43 different species of trichrogramma), shrews for larch sawfly, European pine sawfly, spruce budworm, EAB

What are the 6 steps in an IPM PLAN

-Determine you have the correct species

-Determine where the insect is established

-Determine the course of action

-Implement the course of action

-Evaluate the action, modify, correct, adopt

-Document changes for improvement

-REPEAT

Insect Population Cycles

Most insects dont have population cycles

~17% of tree eating insects DO cycle

Study of population cycles in forests vs agriculture (why different?)

Study looking at pest population cycles in forest vs agricultural habitats

found that there were more agriculture pest cycles declining over time

BECAUSE of differences between habitats:
-intensity of management
-economic incentives
-host plants involved

What is the simple model of change in population density and what are the two types of growth (and equations)

Nt+1= Nt + B - D + I - E

Exponential vs Logistics Growth

Exponential:
dN/dt = rN

Logistic:
dN/dt = rN ((K-N)/K)

When happens to the per capita growth rate when the population exceeds carrying capacity

Per capita growth rate becomes negative (<1 female produced per female) --> population size decreases to K

What happens to the per capita growth rate when the population size is below carrying capacity

Per capita growth rate is positive (>1 female produced per female) --> population size increases to K

Why aren't populations always stable at K?

-Environmental variability
-multiple equilibrium points
-time lags
-allee effects

What are the types of forest insect population dynamics (3 types and example of insect)

Sustained Pulse: populations are relatively stable, carrying capacity is affected by the environment (ex: emerald ash borer)

Cyclical: populations go up and down in predictable ways, both influenced by and influencing regulating factors (ex: Forest tent caterpillar)

Eruptive: populations increase suddenly, escaping from natural enemies or overwhelming host (ex: mountain pine beetle)

What is an insect outbreak?

-When there is an increase from low to high population levels, -there is significant damage to host,
-economic and ecological impacts
-usually affects a large geographic area
-the species that have outbreaks are the ones we usually consider pests

What are the aspects of outbreak dynamics

-Amplitude (which is the severity of the outbreak - how high the peak is)
-Outbreak duration (how wide the peak is)
-outbreak frequency (period between peaks)
-increasing phase, peak, and decreasing phase (the highest peak of the outbreak)

POPULATION DENSITY OVER TIME

Outbreak duration factors (rapid vs slow environmental deterioration)

a) Rapid Environmental Deterioration
--> species with hosts that die quickly (conifers), produce defences quickly, or with natural enemies that respond quickly

b) Slow environmental deterioration
--> species with hosts that don't die right away (hardwoods), don't produce defences right away, or with natural enemies that respond slowly

Negative density dependence vs positive density dependence

Negative Density Dependence:

--> population growth rate declines as population density increases

-->For example, due to HIGHER PARASITISM (increased deaths), HOST CHEMICAL DEFENCES (increased deaths), SMALLER EGG MASSES (decreased births)

Positive Density Dependence:

-->population growth rate increases as population density increases

--> For example, due to OVERCOMING HOST DEFENCES (decreased deaths), EFFICIENT MATE FINDING (increased births)

Bottom-up VS Top-down regulation

Bottom Up:
--> plants regulate all trophic levels above them, providing the basis of all food webs

Top-Down:
--> natural enemies regulate all trophic levels below them, by keeping herbivores in check

What are the defence types for plant-insect interactions? and examples of each

Constitutive: always present in the plant

Inducible: produced in response to herbivory

Direct: affects herbivores negatively

Indirect: affects natural enemy positively

Direct Consistutive: trichomes

Indirect Constitutive: nectar

Direct Induced: traumatic resin ducts

Indirect Induced: plant volatiles

Why do populations of forest insects cycle?

For Lepidopterans:

Abiotic Effects

--> sunspots, climate effects (Moran effect)

Maternal Effects

--> crowding causes smaller females, reduces reproductive rate

Dispersal Between Populations

--> individuals disperse more often from dense populations

REGULATION BY NATURAL ENEMIES (top-down)

--> delayed density-dependence

RESOURCE LIMITATION (bottom-up)

--> starvation, induced plant defences reducing edibility of food

Examples of insect pests with population cycles? (4 of them)

Spruce Budworm, Forest tent caterpillar, Jack Pine Budworm, Spongy moth,

Spruce Budworm Population Cycle Factors

-Low frequency, long duration
-outbreaks happen every 30-40 yrs, and last for 10+ yrs
-variation across canada in amplitude and synchrony of outbreaks

What are the 3 hypotheses for the spruce budworm population dynamics?

SILVICULTURE HYPOTHESIS

--> Low Density: due to low availability and high vigour of preferred host (balsam fir) (bottom-up)

-->Rising: due to increased balsam fir availability, age-related decline in tree resistance, diminished predator community complexity / impact (top-down)

--> Declining: resource collapse

MULTIPLE EQUILIBRIA HYPOTHESIS

--> Low Density: due to natural enemy control (top-down)

--> Rising: due to favourable climate, resource pulse, moth invasion

-->Declining: due to resource collapse

OSCILLATORY HYPOTHESIS

-->Low Density: Natural enemy control

-->Rising: population escapes natural enemy control due to decline in enemy abundance/impact

-->Declining: mortality of older larvae and pupae with synergistic impacts of resource collapse

Forest Tent Caterpillar Population Cycle Factors (and top-down + outbreak duration affected by what?)

-High frequency, short duration
-Outbreaks happen every 9-14 yrs, lasts for 3-5 yrs
-OUTBREAKS DECLINE WHEN NATURAL ENEMIES INCREASE --> lagged density dependent regulation

-outbreak duration affected by forest fragmentation (most important regulating parasitoids and pathogens don't like edges)

What are the bottom-up host effects on dynamics of Forest Tent Caterpillar?

-outbreak cycle affected by stand composition

-outbreaks in stands dominated by trembling aspen happen more frequently (every 9 yrs) than those with maple (every 14 yrs)

Jack Pine Budworm Population Cycle Factors

-High frequency, short duration
-Outbreaks happen every 8-10 yrs, last for 3-5 yrs
-outbreaks decline when heavy defoliation reduces pollen cones: young larvae depend on pollen cones for refuge and food

Jack Pine Budworm top-down controls

-parasitoids are also a key component of outbreak declines
--> late instar and pupal parasitoids
--> both this and the factor of defoliation(pollen cone reduction) combine to produce observed cycles

Spongy Moth Population Cycle factors

-irregularly cyclic
-ONTARIO: 7-10 yrs
-NE U.S: 3-5 / 7-12 yrs
-Periods without cycles
-Large scale spatial synchrony of outbreaks in NE U.S

-amplitude of outbreaks can vary widely between populations
-forest composition can affect cycle length:
--> oak-pine: 4-5yrs
--> maple-beech: 9-10 yrs

What are low-density populations vs high density populations regulated by for Spongy Moth

Low-density populations regulated by small mammal predators on pupae
--> small mammals become less efficient at eating pupa at higher densities
-->small mammal populations affected by mast availability
--> mast availability affected by weather patterns

High-Density populations regulated by parasitoids and pathogens
--> especially necleopolyhedrosis virus (LdNPV)
--> density-dependent mortality from both parasitoids and pathogents
--> weather can also be a factor in NPV mortality (higher in wetter yrs)

How does climate change affect population cycles

-phenological mismatches
-range shifts
-lengthened growing seasons
-impacts of drought, floods, etc
-host quality (via co2, nitrogen)

CLIMATE CHANGE CAN:
--> cause collapse of cyclical dynamics
--> reduce outbreaks
--> increase severity of outbreaks

Why is it important to understand population cycles and the factors that lead to outbreaks

To help:
-predict if/when the outbreaks will occur
- decide if/when to manage
-predict how environmental changes may affect population dynamics

--> understanding that bottom-up and top-down factors are both significant in forest insect population dynamics helps broadly understand ecology

History of guild types over time with land plant diversity (what and when did these types come up) (5 of them)

Detrivory, Piercing-and-sucking feeding --> ~400 MYA (Devonian) ; occurred even before early vascular and non-vascular plants arose (arthropods develop mouthparts) (in paleozoic)

Leaf Eating and Galls --> ~350 MYA (Carboniferous); after early vascular and non-vascular plants (in paleozoic)

Leaf Mining --> ~250 MYA (Triassic); after primitive gymnosperms, before conifers (Mesozoic)

Pollen and Nectar Consumption --> ~150 MYA, during conifer appearance, right before angiosperms (Mesozoic)

Active Pollination --> ~100 MYA, during rise of angiosperms

What are the Tree Protection Strategies (2 categories) vs Insect Countermeasures (2 categories)

Tree Protection Strategies:

-ACTIVE DEFENCES

*physical defences, chemical defences, constitutive defences, inducible defences

-TOLERANCE

*high growth rate, increased photosynthetic rate, increased branching, carbon storage in roots

Insect Countermeasures:

-EXTERNAL

*avoidance behaviours (host selection, oviposition)

-INTERNAL

*tasting and avoidance, excretion (passive removal of ingested toxic substances), detoxification (chemical conversion of toxic substances), sequestration (using toxic substances for protection or pheromone production)

What does the plant side of defence do to prevent insect infiltration? (3 different things) (broad ideas)

-Disrupt insect feeding
-Disrupt mate-finding
-Disrupt egg-laying through chemicals (compounds, hormones & pheromones)

What is a hormone vs a pheromone?

HORMONE: internal communication with an organism

PHEROMONE: external communication between organisms of the same species

What are the plant defence traits within the context of plant-insect interactions (the 4 categories and their sub categories)

A) Mode of Action

--> Chemical (specific, targeted) VS Physical (barriers like thick bark, trichomes, etc that reduce feeding)

B) Temporal Sequence

--> Constitutive (always produced by plant) VS Inducible (induced as a respondse to attack)

C) Effective Dose

--> Quantitative (specialized, tannins, weak co-evolution) VS Qualitative (toxic, low dose, general alkaloids, good co-evolution)

D) Ecological Function

--> Indirect (affects the natural enemy positively) VS Direct (impacts the growth, survival of the herbivore negatively)

What are the physical methods of tree defence? (3 methods, and give example with insect species)

-Olioresins (conifers)

-Crystallization & mechanical effects

-Susceptible vs resistant varieties

EX: pitching out by pine species against MPB, Root weevils, etc (drowns them out when they're inside the bark/tree)

What are the phenological methods of tree defence? (2 methods and give example with insect species)

-Delay in bud burst following year (good for herbivores that need the bud cap to be off before they start eating; prevents it from being eaten)

-Leaf abscission

EX: delayed bud break in black spruce against spruce budworm (spruce budworm can't get into the expanding foliage until the bud cap is lifted - if this is delayed, they can't eat the food)

What are the biochemical methods of tree defence (2 of them)

-Constitutive defences (primary metabolism)

-Inducible defences (secondary metabolism)

--> nitrogenous (alkaloids, auxins) vs non-nitrogenous (phenolics/palatability, terpenoids, etc)

What are the hypersensitive reaction methods of tree defence (2 of them)

-increased oxidases & phenolics (phenolics reduce growth and penetration of microbial pathogens)

-local necrosis (sucking insects (especially adelgids), bark beetles, wood wasps)

What are the insect methods of coping with tree defence mechanisms with external leaf feeders, internal plant tissue or wood feeders, and symbiotic microorganisms?

1) External Leaf Feeders

-Behavioural Avoidance (including phenology) of toxicity (visual, olfactory)

-Feed on less desirable & poorly defended plants/parts

-Actively Cut Leaves (reduce turgor pressure)

2) Internal Plant Tissue or Wood Feeders

-Gall insects actively suppress host defence (insect preventing growth)

-Actively secrete, sequester, or detoxify chemicals

3) Symbiotic microorganisms

-Bark beetle & fungi/bacteria/nematodes

-Aphids and endosymbiotic bacteria (can inject the bacteria into the plant)

What's an example of where insects have evolved to feed on less desirable and poorly defended plants/parts (with cabbage root flies)

With the roots of the plants
-Cabbage root flies have adapted to eat the tap root (main root of plant)

What are insects constrained by with coping with plant defences?

-The properties of plant tissues they feed on
-The physical closeness/constancy of the relationship

What are the stages of Tree death spiral (with Douglas fir)

HEALTHY TREE --> COMPETITION (but then dominate) --> SUPRESSION (but then release) --> DEFOLIATION (but then they recover) --> BARK BEETLES (pitch defence) --> BLUE STAIN FUNGUS (blocks phloem transport and then tree dies) --> TREE DEATH

What is the damage done to trees by defoliators? (3 things)

-->Growth loss (radial and height)
--> New Structure damage (form and stability)
-->Mortality (whole and partial tree)

What is the damage done to trees by shoot, tip, bud, root feeders? (3 things)

-->Growth suppression (height)
--> Deformation (stunting, twisting)
-->Mortality (partial or whole tree)

What is the damage done to trees by Trunk feeders? (3 things)

-->Mortality (whole or partial tree)
-->Structural weakening
--> Disease vectoring

What is the damage done to trees by seed and cone feeders? (1 thing)

-->Loss of reproductive parts

What are the TREE LEVEL effects from leaf/needle damage by defoliators

Tree Level are physiological effects

REDUCED:
-photosynthesis
-carbohydrate production
-transpiration
-translocation

INCREASED:
-adventitious buds
-necrosis & lignification

What are the STAND LEVEL effects from leaf/needle damage by defoliators

Also whole tree mortality vs top kill insect species

They are ecological effects

INCREASED:
-tree mortality and stand growth loss
-light penetration
-water runoff/temperatures
-decomposition / leaching
-nutrient cycling
-fire and wind hazard

DECREASED:
-plant competition

WHOLE TREE MORTALITY by spruce budworm, spongy moth, forest tent caterpillar

TOP KILL by jack pine budworm

What are the TREE LEVEL effects from shoot/tip/bud/root damage

Tree level are meristematic effects

INCREASED
-adventitious buds
-deformities (curling, twisting, galls)
-hormone disruptions

EX: white pine weevil

REDUCED
-hormone (auxin) production (the leader of the tree produces the auxin which causes the tree to grow upright)

What are the STAND LEVEL effects from shoot/tip/bud/root damage

These are the ecological effects

REDUCED:
growth and competitive ability

INCREASED
-tree/part mortality
-structural diversity

What are the TREE AND STAND LEVEL effects from trunk damage FOR LIVING TREES

INCREASED
-whole and partial tree mortality
-disease and secondary pests
-structural defects
-fire and wind susceptibility

EX: Wood boring beetles

REDUCED
-timber quality

What are the TREE AND STAND LEVEL effects from trunk damage FOR DEAD TREES

INCREASED
-rot and decay
-stand structural diversity and habitat

REDUCED
-wood quality and quantity

Seed and cone damage effects

-Loss of seeds, cones & regeneration (up to 90% of crop lost)
-Similar effects as shoot and tip damage on branch growth
-Reduced overall tree growth (diameter and height) & competition
-Increased partial tree mortality and stand structural complexity

Insect feeding and tree response positive effects?

Increased tree fruiting and seed production, biomass accumulation, nutrient concentration, branch and tree growth

COMPENSATORY GROWTH w/ overall stand thinning and increased light, etc

What does tree damage depend on (5 things)?

TYPE OF INSECT

-chewing or sucking

-free living or sessile

TIME OF YEAR

-early, middle, or late season

TREE STRESS

-compaction, drought, pollution, disease

TYPE/PART OF TREE ATTACKED

-fast growing vs slow growing species

-conifer vs deciduous (conifers set buds the year before and if those are lost then they lose all the growth for the next year)

AGE OF TREE

-young, mature, old

What are the economic impacts of insect damage (4 things)

-lost timber value (volume, area, grade)
EXAMPLE:
--> insects that cause height loss and wood deformation (shoot-feeding guild) -- cause deformed trees, reduces timber volume and value

-shifts in harvest plans (delays, salvage/hazards)
--> EXAMPLES:
-salvage cut of dead trees (200,000 HA) in Nova Scotia following 15 yrs of spruce budworm defoliation
-delayed harvest schedule following spruce budworm outbreak in eastern canada

-poor site regeneration

-reduced seed production & seedling quality

What are the ecological impacts of insect damage (5 things) and some examples?

-accelerated forest succession

-shift in tree species composition
EXAMPLE:
--> with spongy moth defoliation, density greatly reduced

-changes in biodiversity and faunal communities

-increased susceptibility to other disturbances (insects, disease, fire,ice & windstorms)

-reduced ecosystem services (nutrients, erosion)
EXAMPLE:
--> changes in nutrient cycling and water runoff b/c of selective tree mortality in boreal forest stand after forest tent caterpillar defoliation of poplar (increased light, nutrients from FRASS, water penetration favours growth of conifers)

What are the social impacts of insect damage (3 things)

-increase in hazardous conditions and human risk
EXAMPLE:
--> wildfire risks increased

-quarantine and prevention

-aesthetics (urban values)

What is Present Net worth (PNW) for harvested 80yr old jack pine stands attacked by white pine weevil (and what happens when attacked)

When attacked, the leader is lost, which means there will be height loss and deformations

Undamaged stands = $6100/ha

Damaged stands= $4600/ha

What is the ranking of insect feeding guilds by potential impact on areas from least damage to most damage

-Gall formers (leaves, tips, shoots, buds)

-Cone and seed feeders (caterpillars and vertebrates)

-Trunk feeders (XYLEM - borers and vertebrates) (asian longhorn beetle white spotted pine Sawyer, etc)

-Defoliators (END OF SEASON (last yr's needles) OR EARLY SEASON (current year's leaves) (caterpillars, sawflies))

-Tips/Shoots/Buds/Roots (especially sucking insects (scales, aphids))

-Defoliators (MIDDLE SEASON (current and past year's leaves) (caterpillars and sawflies))

-Trunk Feeders (PHLOEM (bark beetles)) (like emerald ash borer)

What is a population

a group of individuals of the same species that occupy a given space at a given time

What is a community

an assemblage of species that occupy a given space at a given time

What do both a population and a community have

they both have emergent properties ; manifest characteristics that are more than the sum of the individual and population characteristics

both are subjective categorizations defined by humans

How do you measure and describe communities (3 terms)

Species Richness

Abundance

Diversity Index

What is Species Richness

it is the number of species in a community

What is abundance

it is the number of individuals of a species

What is diversity index

it is a measure of community diversity ; usually takes into account both richness and abundance of species

What is evenness a measure of?

it is a measure of relative abundance of species in a community

What are the 3 different types of diversity (with definitions)

alpha-diversity

-diversity of species within a community

beta-diversity

-change in diversity of species in communities along a gradient

gamma-diversity

-richness of species in a range of communities within an area

What do most communities have in terms of species abundance

most communities have many uncommon and rare species, and very few abundant species

What is "Rarefaction" and when would you use it?

RAREFACTION
-method to assess species richness while taking sampling differences into account

Would use it when trying to figure out what habitat has the highest species richness but also take into account the difference in habitats (like corn fields, old-fields, young forests, old forests)

What is an indicator species? What can they be used to assess?

it is a species whose presence, absence, or abundance is used to understand ecological conditions

--> it can be used to assess how an ecosystem is responding to stresses and changes

What are the pros and cons of using an insect as an indicator species

PROS:
-diverse
-abundant
-responsive to environment
-easily sampled
-in almost every habitat

CONS:
-time consuming to process
-expertise needed for ID
-responses vary by taxon

What can you assess with indicator species specifically?

-sustainable forest management practices
-success of forest restoration
-identify old growth or high quality stands for conservation

What is the intermediate disturbance hypothesis

habitats with intermediate amounts of disturbance have the highest diversity (ex: edges)

Whats the relationship with insect diversity and plant diversity at mid succession

insect diversity peaks with plant diversity at mid succession

but it doesn't decrease as much as plant diversity does

BECAUSE - for insect species diversity, increasing structural diversity of plants compensates for decreasing taxonomic diversity of plants

What forests have low, intermediate, and high productivity and how do they relate to species diversity?

LOW PRODUCTIVITY = boreal forest

INTERMEDIATE PRODUCTIVITY = temperate forest

HIGH PRODUCTIVITY= tropical forest

In the boreal forest, increase in disturbance causes a decrease in species diversity

In the temperate forest, as disturbance increases, species diversity increases (then it hits a peak and then decreases again - parabola shaped)

In the tropical forest, increased disturbance causes an increase in species diversity