single year drought impacts on trees and forests

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Single year drought impacts on trees and forests

Steve D’Eon, R.P.F.

Program Forester

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Drought: From a tree perspective?

Impact on trees.Impact on forests.

What you should know about it.

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Drought: 1st How bad was it?Rain Gauge Data

Forest fires

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Station May JN JL May JN JL %

BROMLEY 36 38 13 91 95 66 34%

ROSS 34 46 25 94 83 60 44%

Hyndford 41 41 18 92 67 62 45%

HORTON 49 53 19 94 109 47 48%

ADMASTON 52 44 24 94 102 45 50%

WESTMEATH S. 41 45 36 94 79 58 53%

GRATTAN 43 52 42 94 77 78 55%

Haggerty 32 48 42 90 87 42 55%

Mcnab 58 62 29 94 108 55 58%

WESTMEATH N. 47 54 27 82 79 56 59%

ALICE & FRASER 48 64 33 90 93 52 62%

WILBERFORCE 38 50 47 94 54 57 66%

Raglan 51 72 51 88 86 66 73%

Lyndoch 46 95 41 83 84 44 86%

Griffith 49 86 51 94 87 32 87%

Brudenell 52 103 64 94 104 43 90%

Average 45 59 35 91 87 54 60%

2012 ------- 2011 -------

Month < 50 mm

Month < 25 mm

Source: http://www.agricorp.com/en-ca/Programs/ProductionInsurance/ForageRainfall/Pages/RainfallData.aspx

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Why I don’t like monthly rain gauge data. Daily data from Cormac

Monthly totals May 41 mm June 64 mmJuly 65 mm

August 75 mm

Daily data shows during the 34 day period June 20 to July 22

only 6 mm fell.

Data courtesy Frank Ahern, Cormac, Ontario

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30 days prior to July 16th

Red = 60 mm less than normal precip.

Source: http://www4.agr.gc.ca/DW-GS/historical-historiques.jspx?lang=eng&jsEnabled=true

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30 days prior to July 23rd

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Deviaton from average May-Aug precip 1939-2012

-300

-200

-100

0

100

200

300

year

mm

1939 1960’s 2012

Env. Canada, Ottawa airport data

9Photo courtesy OMNR fire

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Drought: 2012: 46 fires (2011 one fire)

11Photo courtesy OMNR fire

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Drought: From the perspective of a tree?

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Spring Freshette = soil moisture

2012

Normal year

2012: spring melt was early and not replaced by rain.

source www.wateroffice.ec.gc.ca

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Season when drought strikes is important

Figure courtesy Glen McLeod,

Trees Ontario

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Worst time to have a drought: Shoot and leaf/needle elongation

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Newly planted seedlings

Drought when they were elongating shoots….

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For a tree, Stress is Cumulative

2010 spring frost

Recent harvest

2012 acorn crop

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When drought pushes trees beyond their Tipping Point:

Aug. 20th looking sick but not dead.

19August 20th, 2012

20Same place, November 7th, 2012

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3. Drought Impacts on trees

• Stress into the future

• Growth loss, stem form

• Crown dieback

• Root dieback

• Death (especially newly planted)

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Stress into the future

Parts of a tree die.

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Stress into the future

Trees try to recover by epicormic buds. Left is early Sept. Above is Aug. 20th.

Photo: Linda Touzin OMNR

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Stress into the future

Excessive flowering or what is called a stress cone or seed crop.

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Drought impact: Growth loss Diameter, Height

2013?

2012

2011

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Drought impact: Stem Form

2011

2010

2009

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Crown/Root DiebackRoot dieback lies unseen but weakens the tree’s anchor, uptake.

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Crown/Root Dieback

Early leaf fall,

Dead and dying parts in the crown.

August 28th

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Drought caused Mortality

Germanicus Road, Eganville

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4. Drought Impacts on forests

• Forests are resilient.• Forests are more than just trees.• The resource is the site, trees are the crop.

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Drought Impacts on forestsStress continues into the future. (don’t add more stress!)Off-site species, thin soils, restricted rooting, sandy gravelly soils, poorly managed stands will all see greater impact from drought stress.

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Drought Impacts on forests

Photo curtsey of OMNR Pembroke fire

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Drought Impacts on forests

Taylor Scarr, OMNR

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South facing slopes Micksburg

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South facing slope

Goshen Road, Renfrew

Zion Line, Cobden

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Thin soiled knollsBehind Renfrew Toyota

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Thin soiled knollsZion line

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Recently planted

2009 (age 3)

2012 (age 6)

Lake Clear Road

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Recently planted

  Pr Spruce HW + Refill Total Proper Surv.

2004 33,350 0 0 0 33,350    

2005 186,150 0 0 22,900 209,050 89% 82%

2006 0 0 0 0 0    

2007 70,980 5,000 5,065 500 81,545    

2008 151,600 7,050 3,190 2,700 164,540 92% 93%

2009 48,550 10,300 650 500 60,000 88% 94%

2010 75,000 3,300 4,650 5,400 88,350 70% 73%

2011 69,640 18,350 5,450 4,450 97,890 95% 87%

2012 94,590 42,600 4,950 100k+ 142,140 95% 24%

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Recently planted

Kutschke Road

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Random patches

Goshen Road, Renfrew

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5. What you should know

• Monitor, don’t jump to conclusions.

• Seek qualified advice for things you don’t know.

• Best advice is to keep forests healthy and properly managed.

• Take a long-term perspective.

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What you should know

Confirm dead,

Refill plant,

Supplement nature.

DeadAlive

Watering maple, Zion Line, Cobden

Near Barry’s Bay

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Sanitize or let nature heal?

Hennen Road, Pembroke

Wood from browned out trees is marginally marketable up until dries out this spring.

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Monitor, advice

Monitor for secondary pests,

Sanitize, Let nature heal.

Ips pini CFB Petawawa

White spotted pine sawyer beetle

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What you should know:

• Don’t add more stress!!!

Green (live branches) pruning,

any activity that: compacts the soil, removes organic matter, removes nutrition, allows wind to blow through and dry out your stand…..

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What Should You Know?

• Don’t add more stress!!!

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Drought: From the perspective of a tree.

Impact on trees.Impact on forests.

What you should know.

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Thank You

Steve D’Eon, R.P.F.

613 732-5595

sdeon@sympatico.ca

steve.deon@ontario.ca