Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest...
Transcript of Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest...
![Page 1: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/1.jpg)
How Will How Will ““PestsPests”” Change in Response to Change in Response to Extreme Climatic Conditions?Extreme Climatic Conditions?
• A population / species-interaction problem• Distributions are impacted at edge of range
because of climate and tolerance limits of species• Species interactions are not a clear response to
climate and exhibit many non-linear responses:impedes ability to predict
![Page 2: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/2.jpg)
GCTE Conclusions on PestsGCTE Conclusions on Pests
Agricultural pests and diseases will not be takeninto account unless the ecology of weeds, pestsand diseases under global change are explicitlyaddressed. It is an area of potentially majoragricultural and forestry impact; but unfortunatelyone which has not yet progressed very much.
Walker 1996
Global Change and Terrestrial Ecosystems
![Page 3: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/3.jpg)
What Is A Pest?What Is A Pest?
Organism:• living where it is not wanted• causing economic damage• capable of high densities - outbreaks
Mostly human centered factors
![Page 4: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/4.jpg)
What Is A Pest?What Is A Pest?
Forest insect pest species:• Most species are not outbreak species (i.e., not pests)• Population dynamics influenced by only one or a few factors
– Fortuitous result or outcome of adaptation to various mortality sources– At the mercy of a few, variable sources of mortality --”risk
concentrators”– Variation in host plant quality often critical
• Pests often recent, suggesting anthropogenic effect
Nothnagle & Schultz 1987 Insect Outbreaks
![Page 5: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/5.jpg)
Grasshopper Densities Vary in Space & Time
Different Year Effects?
![Page 6: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/6.jpg)
Environmental Change & Arthropod PopulationsEnvironmental Change & Arthropod Populations
What Will Happen to Arthropods?• Temperature will have big potential direct effects: on
both insects & food resources• CO2 will have little or no direct effects on insect pests• CO2 will affect food quality (increase C:N)• Unclear about direct affects of differences during
nighttime
![Page 7: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/7.jpg)
Environmental Change & ArthropodsEnvironmental Change & Arthropods
• Temperature Mediated Processes• Food-Quality Mediated Processes• Density-Dependent Responses• Influence on Dispersal• Regional Shifts
![Page 8: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/8.jpg)
Primary Mechanistic Linkages Primary Mechanistic Linkages
• Biophysical Constraints• Temperature-Dependent Energy-Mass
Budgets• Demographic (Population) Responses• Density Dependence• Food Webs• Integration and Scaling Up to Regional
Levels
![Page 9: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/9.jpg)
Life History & Climate: Forest InsectsLife History & Climate: Forest InsectsFor Outbreak Species:• Overwintering as egg provides superior synchrony between egg
hatch & budbreak• Exploiting early season foliage exposes larvae to risk of hatching
before food available and to cold temperatures• Mitigation by (a) ability to feed on less suitable foliage, (b) ability
to disperse as larvae, and (c) thermoregulation or thermalinsensitivity, (d) anti-predation patterns, (e) feed on shadeintolerant trees with wide window of availability, or (f)insensitivity to decline in food quality (i.e., older leaves)
![Page 10: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/10.jpg)
The Ecological Niche: Basic Framework The Ecological Niche: Basic Framework
• Performance Linked toNiche Position
• Niche Axes Reflect ExternalConditions
• Fitness Tracks PerformanceContours
• How Invariant Is A Species’Niche?
Niche Axis 1
Nic
he A
xis 2
Opti
mum
Unihabitable
![Page 11: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/11.jpg)
The Niche and Climate Change The Niche and Climate Change
Temperature
Food
Qua
lity,
[N
]
Opti
mum
Unihabitable
*
Current Conditions atTarget Site, *
New Environmental Conditions at Site
Temperature
Food
Qua
lity,
[N
] Unihabitable
**
![Page 12: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/12.jpg)
Niche Model Basis of Many Predictions Niche Model Basis of Many Predictions
Temperature
Food
Qua
lity,
[N
]
Unihabitable
**
Pest Population Increases?
Temperature
Food
Qua
lity,
[N
]
Unihabitable
**
Pest Population Decreases?
Effect of Change in Temperature
![Page 13: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/13.jpg)
Niche Model: Basis of Many Predictions Niche Model: Basis of Many Predictions
• Range Shifts• Population Dynamics Vary• Densities Change• Economic Thresholds Breached• Species Interactions Change
Response of system to new kinds & levels of environmental conditions can be predicted, if response surface known.
![Page 14: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/14.jpg)
Predicted Range Extensions Predicted Range Extensions
• 63% shifted north, 3% shifted south• Most (67%) had stable southern boundary - increase in distribution• Range shifts ca. 5-50x individual colonization distances - sequential
establishment of new species
Non-migratory butterflies• Data from 1900-1930 & recent
(Parmesan et al. 1999)Argynnis pahia Heodes tityrus
Green: expansionBlue: stableRed: absent in recent census
![Page 15: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/15.jpg)
Population Dynamics & the Niche Population Dynamics & the NicheStored Grain Beetles -- A Classic Study & Analysis
Calandra wins Rhizopertha wins
CompetitionThreshold
Temperature
Moi
sture
Such data are uncommon
Mcguire 1973Data from Birch 1953
![Page 16: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/16.jpg)
Temperature: Grasshopper Performance Temperature: Grasshopper Performance
Temperature Affects:• Metabolic Rate• Digestion• Survival• Reproduction• Activity• Flight Speed
![Page 17: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/17.jpg)
Temperature & Demographic Responses Temperature & Demographic Responses
![Page 18: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/18.jpg)
Temperature & Food Quality Interact Temperature & Food Quality Interact
• Nitrogen generally more important than carbohydrates to performance
• C:N ratios affected by N-availability and C- accumulation
• Water• CO2• Nitrates• Temperature
• Finite gut volume• Digestion rate is temperature dependent
![Page 19: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/19.jpg)
Biophysical Constraints Biophysical Constraints
• Thermal Constraints on Time & EnergyBudgets
• Operative Environmental & BodyTemperature Spectra– Spatial & Temporal Distributions
• Time & Activity Budgets• Habitat Suitability
![Page 20: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/20.jpg)
Insect Temperature ProfilesInsect Temperature Profiles
• Thermal buffering capabilities vary among days• Energy budgets vary accordingly • Constraint on population responses
![Page 21: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/21.jpg)
Available EnvironmentsAvailable Environments
Time of DayNum
ber o
f Poi
nts
5 August
Microclimatic Constraints
![Page 22: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/22.jpg)
Sites & Survival Sites & Survival
• Blocks 1 & 2 exhibit the longest periods available withmicroclimates in preferred ranges
![Page 23: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/23.jpg)
What Will Happen to Insect Pests?What Will Happen to Insect Pests?
Honest Answer:
We Don’t Know Because the Response Surface,Niche-Based Approach Is An InsufficientFramework!– Scaling– Nonlinear Responses– Modifying Effects of Species Interactions
![Page 24: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/24.jpg)
Context-Dependent Responses Common Context-Dependent Responses Common
Outcomes of interaction vary according to state ofsystem• Behavioral• Ecological• Evolutionary
Many mechanisms for buffering impact of extremeconditions
![Page 25: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/25.jpg)
Insects Have Some ControlInsects Have Some Control
Insects can significantly moderate the effectsof temperature shifts
• Thermoregulation• Activity Periods• Digestive Control in Response to Food
QualitySmall environmental changes may have noreal functional effect
![Page 26: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/26.jpg)
Thermoregulation Thermoregulation
Grasshopper body temperatures are regulated within anarrower window than ambient temperatures
Ageneotettix deorumBody
Tem
pera
ture
Air Temperature
![Page 27: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/27.jpg)
Thermoregulation Thermoregulation
Grasshopper body temperatures are greater than ambient airtemperature over large periods of the day when the sun is out &lower than highest temperatures
Time of Day
Tem
pera
ture
(oC)
Ambient Air Temperature
Body Temperature
Ageneotettix deorum
![Page 28: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/28.jpg)
Modified Species Interactions Modified Species Interactions
(Perring et al. 1984)(Toole et al. 1984)
Banks Grass Mites (Oligonychus pratensis)
![Page 29: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/29.jpg)
Modified Species Interactions: Mites Modified Species Interactions: Mites
• Interaction between spider mites & their predator mitestemperature driven
• Effective biological control if time lag between build-up& suppression not too great
• Boundary layers more important than macroclimate• Optimal temperatures may or may not be the same for
predator & prey species -- impact of interaction couldshift
![Page 30: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/30.jpg)
Phenological Phenological Shifts: Resource Match Shifts: Resource MatchPedunculate Oak, Winter Moth & Blue Tits
Product of Number and Mass of Caterpillars
+3oC TempsNormal Temps
Peak food availability to birds shifted earlier, for shorter duration
Brood sizes in Blue Tits expected to decrease since adults cannot lay early enough to coincide with narrower peak of food abundance
(Buse et al. 1999. Functional Ecology 13, Supp.)
![Page 31: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/31.jpg)
Compensatory Vs. Additive MortalityCompensatory Vs. Additive Mortality
• Additive Response: multiplefactors provide proportionateeffects on insect mortality
• Compensatory Response:multiple factors result in samefinal density when alone ortogether
Time
Num
ber o
f Ind
ivid
uals
Additive
Compensatory
![Page 32: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/32.jpg)
Grasshoppers, Food Quality & SpidersGrasshoppers, Food Quality & Spiders
Food quality and spider predation interact incontrolling grasshopper populations
Ambient Food Quality: Compensatory Mortality
Fertilized Grass: Additive Mortality
Combined with Spider Predation:
![Page 33: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/33.jpg)
Simple Ecological Model Predicts Complex ResponsesSimple Ecological Model Predicts Complex Responses
Nt Nt
N t+
1
N t+
1
*
*
*
O
Food Limitation No Predation
Food Limitation Predation
A B
![Page 34: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/34.jpg)
A Simple Ecological Model Predicts Complex A Simple Ecological Model Predicts Complex Responses by GrasshoppersResponses by Grasshoppers
Nt
Nt+
1
No Avian Predation Avian Predation
Nt
Pre
datio
n R
ate
(Pro
port
ion
/ wee
k)
*
Type lll Functional Response
Data of Belovsky & Slade: Montana Populations
![Page 35: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/35.jpg)
Complex Responses by Montana Grasshoppers Complex Responses by Montana Grasshoppers
• Both lower (predation) and upper (food-limitation)domains exist
• Different domains in different years
NtNt Nt
Nt+
1
Nt+
1
Nt+
1
1992 1993 1994
(Belovsky & Slade)
![Page 36: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/36.jpg)
Thresholds & Chaos Thresholds & Chaos
• Modeling exercise with good & bad environments• Get unpredictable responses from year to year• Chaotic dynamics in model adds to unpredictability
![Page 37: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/37.jpg)
Food Webs: Top-Down & Bottom-Up Food Webs: Top-Down & Bottom-Up
• Species interactions comefrom all directions
• Current debate on theaccounting of effects
• Uncommon species mayhave big effect!
• Role of temperature in theseinteractions not known, butsuspected
Food Web Above Soil Surface,Coachella Valley, CA
(Polis 1991)
![Page 38: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/38.jpg)
Final Points: Global Change & Pests Final Points: Global Change & Pests
• Climate important to pest population processes• Niche model has utility, up to a point• Food quality as important as temperature• Climate change will act directly & indirectly• Insects have many buffering mechanisms, behavior;
not an option for weeds or pathogens• Actual predictions will require incorporation of many
non-linear responses not yet understood
![Page 39: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/39.jpg)
Final Points: Global Change & Pests Final Points: Global Change & Pests
• While impacts of Global Climate Change on pests willrequire more study, much can be inferred from existingstudies
• “Pests” are not a different type of organism from non-pests in terms of basic responses
• Multiple species interactions must be incorporatedwhich makes problem more difficult
![Page 40: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/40.jpg)
Final Points: Global Change & PestsFinal Points: Global Change & Pests
• Species life history (evolutionary) adaptations may obscure ourability to detect species response to climate change --accordingly, species respond differently to changes in thermalenvironments (Hodkinson et al. 1999)
• For weeds (plants), competition can act as a powerfulamplifier of climate signal through changes in contribution ofspecies to primary production (population & ecosystem interactions)(Dunnet & Grime 1999)
![Page 41: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/41.jpg)
![Page 42: Powerpoint Presentation: How will 'pests' change in response ......Life History & Climate: Forest Insects For Outbreak Species: •Overwintering as egg provides superior synchrony](https://reader036.fdocuments.us/reader036/viewer/2022070221/613857cb0ad5d206764931e3/html5/thumbnails/42.jpg)
Thermal PerformanceThermal Performance