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Growth Form Response

Potential For Change After Mountain Pine Beetle (MPB) Attack: Ecosystem Dynamics During the Early Red Attack Phase

Drs. Anne C.S. McIntosh1 & S. Ellen Macdonald2, 1Alberta Biodiversity Monitoring Institute, 2University of Alberta, Edmonton, AB

• MPB, Dendroctonus ponderosae, is a native bark beetle of western North America pine forests

• However, MPB has expanded its range north & east into Alberta - changing the disturbance regimes for attacked lodgepole pine forests in Alberta

• We are studying relationships between the overstory, understory, & below-ground dynamics of western Alberta lodgepole pine stands (near Robb, AB) with different simulated MPB attack levels and/or forest management:

i. Control

ii. 50% MBP mortality

iii. 100% MPB mortality

iv. Clearcut salvage harvest after MPB attack

• MPB attack was simulated using glyphosate herbicide (applied summer 2009)

• We used a repeated measures randomized block design; overstory, understory, and below-ground data were collected each of 3 summers: pre-treatment (2008), treatment (2009), and post-treatment (2010)

II. RESULTS*

* Subset of results - error bars are SEs, Multivariate plots are non-metric multidimensional scaling ordinations.

5) ACKNOWLEDGEMENTS

For more information contact: anne.mcintosh@ualberta.ca

V. ACKNOWLEDGEMENTS

• There was short-term resistance to MPB for most understory & below-ground properties during red attack

• Dynamics in the salvage harvested stands followed patterns expected post-harvest and were not resistant

• Salvage logging will push these stands in a potentially very different direction than will the modified

natural disturbance regime that includes MPB

III. CONCLUSIONS

Forest Floor Microbial Community

Understory Plant Community

I. INTRODUCTION & METHODS

Understory

Below-ground

Overstory

Ecosystem Dynamics: Above- & Below- ground Linkages

50% Kill

Clearcut

100% Kill

Control

x 3 Replicate Blocks

Downed Wood

Treatment/Year

Control 50%kill 100%kill Salvage YearDo

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Treatment

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AB

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• McIntosh, A.C.S., Macdonald, S.E.. In press. Short-term

resistance of ecosystem properties and processes to simulated mountain pine beetle attack in a novel region. Ecosphere.

• McIntosh, A.C.S., Macdonald, S.E.. 2013. Potential for lodgepole pine regeneration after mountain pine beetle attack in newly invaded Alberta stands. Forest Ecology and Management, 295: 11-19.

IV. REFERENCES

MPB

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Overstory Basal Area

Community Response

Biomass

Respiration