24th congress for conservation biology, canada 2010

1Mixedwood Ecology and Management Program (UNBC) | Amalesh Dhar, Nicole Balliet, Chris Hawkins04/10/23

Amalesh Dhar, Nicole Balliet, Chris HawkinsMixedwood Ecology and Management Program

University of Northern British Columbia, BC

Regeneration and growth of Lodgepole Pine stands Following Mountain Pine Beetle Attack in

Central British Columbia


Introduction

The mountain pine beetle (Dendroctonus ponderosae Hopkins) (MPB) the most damaging biotic disturbance agent in mature lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) in BC.

The MPB typically attacks - larger trees with diameter at breast height > 20 cm and trees

above 60 years old- but younger tree (age even < 20 years) also attack if mature

trees are not available

The current infestation of lodgepole pine by the MPB in BC:

- over 9.0 million hectares - around 635 million m3 of mature pine killed in BC to the end of 2007

- predicted more than 800 million m3 mature pine will be killed bythe end of 2013


MPB infestation in BC : 2003-2013

Routledge 2004


Loss of mature pine in BC during the year of 1999 to 2013

Hawkins 2006

Mountain pine beetle infestation and projection (Hawkins 2010)

Projected: 80%/ 70% of mature pine killed by 2013/2017


Change in the landscape


Reasons for regeneration study

Regeneration and rates of growth (release) in MPB attacked stands are important because:

- forecasting the long-term prospects of these stands

- selecting stands for silvicultural treatments to improve yield

- forecasting impacts to hydrology, habitat, and vegetation types


Factors affecting regeneration

Factors affecting the growth and development of regeneration after MPB outbreak:

- overstory structure

- moisture content of the soil - availability of seedbed substrates

- dominancy of mosses on forest floor- proximity and abundance of parent seed trees

NB:further investigations on factors influencing the establishment of regeneration are required as different research findings found different results (Dhar and Hawkins , submitted)


Regenerative species composition in MPB attack stands

The most common shade tolerant species

The most common shade intolerant species

1) Lodgepole pine ((Pinus contorta Dougl. Ex Loud. var. latifolia Engelm.) 2) Trembling aspen (Populus tremuloides Michx.), or3) Paper birch (Betula papyrifera Marsh)

1) Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco), 2) Hybrid spruce (Picea glauca (Moench) Voss x P. englemanii Parry)3) Subalpine fir (Abies lasiocarpa [Hook.] Nutt.)


Regeneration density and distribution

Recent investigations on regeneration and their basic attributes for MPB attacked stands in BC

Geographic Area and BEC No. of Samples

Age sampled

Density Distribution Data holder

Northern Interior 35 - low patchy Coates 2008Flathead area, 22 70 low patchy

Pantage Creek (SBS dw2) 12 28 high wideStatland 2008

Takysie Lake (SBS dk) 15 79 high wide

SBSdw3, SBSmc3,SBSdk 50 - high - Delong et al. 2008

IDF, SBPS and SBS zone 56 - high - Zumrawi et.al. 2008

MSxk2, MSdm3, IDFdk1, IDFdk2 167 - moderate clumpy Vyse 2008

MS , Merritt 28 - high clumpy Nigh et al. 2006

Lakes TSA, SBSdk 302 100+ low sparse Rakochy 2005

SBS 6 subzones, 525 60-250 low variable Balliet et al. submitted

SBSdk, SBSmc, SBSdw, SBSmc 500 80 variable - Burton & Brooks 2008


Regeneration density in different investigations

St-1= Burton and Brooks (2007); St-2= Coates et al. (2006); St-3= Nigh et al. (2008); St-4= Balliet et al. (submitted); St-5= Vyse et al. (2009); St-6= Burton (2006)

Investigations

Abundance of regeneration reported in different investigation


Regeneration study Statland (2008)Regeneration study Hawkes (2008)Regeneration study Vyse(2008)

Regeneration study Hawkins (2006)Regeneration study Hawkins (2006)Regeneration study Vyse (2008)

Regeneration distribution in different investigations


Health of regeneration

The health of regeneration mostly influenced by:

Abiotic: • soil moisture content• falling branches and stems

Biotic: • browsing by animals • mistletoe infestation

Regeneration health in MPB attacked stands • Health of advanced regeneration in Pantage Creek and Takysie

Lake were of good to medium quality (Statland 2008) • 50 % of advanced regeneration was healthy following MPB attack

in the SBSdk (Rakochy 2005) • Regeneration in central British Columbia was healthy and vigorous

at the time of assessment (Balliet and Hawkins, submitted)


Change of MPB attacked forest in 25 years time

19832008

Hawkes 2008


Models

SORTIE-ND PrognosisBC Hybrid

Processed-based approach Empirically-based functions Combination of SORTIE-ND and PrognosisBC

Strength:1.It lies in ability to parameterize sub-models (growth, mortality, recruitment) using field data.2.A distinct strength of SORTIE-ND is the liberty with which new predictive equations can be added to the freely available source code

Strength:1). The extensive use of PSP data to calibrate the

growth equations to even and complex stands 2). The use of site and climate factors (e.g., slope

aspect, elevation) to adjust model predictions 3). The ability to accept a tree-lists from a variety

of inventory formats4) It lies in empirical growth Models calibrated

using permanent sample plots.

Strength:1.It combines the strengths of SORTIE-ND and PrognosisBC

Major Limitation: 1)Physiological approach to modeling growth tends to sacrifice precision2)Less clear, 3)and tree-lists in SORTIE-ND are not updated to match tree lists in PrognosisBC

Major Limitation:1.natural regeneration sub-model is required in PrognosisBC

2.There is no any well suited sub model and 3)PrognosisBC content longer list than SORTIE-ND

Major Limitation: 1) high variability between measured and observed regeneration 2)could not apply toa wider set of starting stand conditions,3) poor result


Knowledge gap

There are a number of important gaps in our knowledge relating to factors affecting advanced regeneration and residual trees of MPB attacked stands.

a) Secondary stand structure- Predict ecological degradation - Predict factors which directly influence the survival ability - Predict substrate and abiotic conditions favourable for germination- Compare the germination and growth amongst different biogeoclimatic subzones- Predict the release response of competing, non crop tree vegetation

b) Management- Set priorities for which stands to target for management activities- Determine the economic health of secondary stand structure - Develop the most cost efficient management activities- Determine the management strategy to reduce the risk of future MPB outbreaks


Knowledge gap

e) Knowledge management- Determine the effective processes of knowledge transfer from one region to another- Describe the influence of human intervention on the current MPB outbreak

c) Modeling- Incorporate forest health issues into stand level modeling- Identify limitations of models and modify them for more accurate prediction- Incorporate the impact of climate change into models for better prediction

d) Climate change- Forecast the impact of climate change on stand development- Determine the impact of climate change on current preferred and acceptable species- Establish permanent sample plots to track changes over of forest- Collect different climatic factors to predict MPB dispersal more accurately - Determine the impact of global warming on MPB survival, virulence, and distribution


Acknowledgements

For financial support: FSP project G095048

The authors would like to thanks all participants, who shared their presentations during the workshop, and the field tour discussion groups

Amalesh Dhar, Mixedwood Ecology and Management ProgramUniversity of Northern British Columbia3333 University WayPrince George, BC, Canada V2N 4Z9Email: [email protected]: +1-250-960-5778


Thank you

24th congress for conservation biology, canada 2010

Documents

nicole balliet

health of regeneration

regeneration density

regeneration factors

regeneration distribution

regeneration studyregeneration

establishment of regeneration

regeneration study hawkes