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The keys to successful natural regeneration of serotinous pine . Victor Lieffers Dept. of Renewable Resources

Soung-Ryoul Ryu, Hyejin Hwang, Maria Sharpe and Dave Schroeder


Lodgepole pine is adapted to regenerate after wildfire

Herman Stegehuis


Serotinous cones Fire breaks the resin bonds


Thick litter or feather mosses are poor seedbeds It is also quite dark for a shade intolerant tree


Fire removes organic matter thereby creating a seedbed


Drag scarification – exposes mineral soil or decomposed OM, positions cones near the ground


Cones landing on prepared seedbed


Seed banks post

MPB


Methods - Research sites


Research objectives • determine if canopy seed release after MPB. If so, the mechanisms responsible for seed release. • The second objective was to model the temporal changes in the canopy and forest floor seed banks after a MPB outbreak.


After MPB cones are left on the tree.

Feather mosses and litter is retained.


Methods - Cone openness

100%

Open

75%

50%

Partially open

25%

0%

Closed


Results – Canopy cone opening (Partial loss of serotiny)

Conclusion text‌


Red Phase

Flexible Stems and Brittle Twigs


Results – Forest floor-cone opening

Released cones via breakage, open and release seed due to soil-surface heating.


Results – Cone release

Cones are released onto the forest floor due to crown friction resulting in twig breakage.


Results – Forest floor cone opening

Conclusion text…


Seed predation Ground foraging rodents (forest floor seed) Deer mouse (Peromyscus maniculaturs)

Pine squirrel (Tamiasciurus hudsonicus)

Squirrels (Canopy and forest floor cones)


Squirrel predation


Methods - Buried cones Embedded in moss

Below moss


Embedded


Results – Cone burial


Seed banks post

MPB


ResultsSeed banks

After 6 years post MPB-outbreak, 45% of the canopy seed remains while 6% are still in cones buried in the forest floor.


27

Embedded


28


Conclusions • Nearly half of the canopy seed is on the ground by 6 years after MPB outbreak. • Cones open on the dead trees faster than living trees.

• Branch breakage, increased cone opening, and squirrel predation. • A small forest floor-seed bank develops due to cone burial of closed cones.


Yr. 3-4


Archer Lake, AB


Hyejin Wang


100 60 40 20 0

Cone opening (%)

80

Living Dead

0

2

4 Char height (m)

6

8


Hyejin Wang


What happens to the cones/seed

Closed

Partially open

Open


Cone opening • Dead trees had higher moisture content after a rainy period. • Cones high moisture content from dead trees opened earlier than cones from living trees. • Data suggests more resin breakdown on dead trees.


Surfaced


Intermittent


Continuous


6000

5000 Living

Seedling Density (seedling/hectare)

Girdled 4000

3000

2000

1000

Maria Sharpe

0 Control

Surface

Intermittent FBP Fire Type

Continuous


Conclusions • Fire promoted seedlings success. • Ground fires in girdled stands tended to open more cones, than fires in living stands. • In the red phase, duff moisture content was higher compared to living stands. • Fire in in the red phase, tend to consume less duff but this thicker duff appears to support seedlings.


Summary • Seed will rain down for a decade or more. • Forest floor disturbance is needed for pine seedlings to establish. • Fire or mechanical site preparation might prepare seedbeds.


Fire is unlikely to be applied in most years – Goldilocks effect.


What will happen if we do nothing? • Hawkins FEM 277: 107-115.


Beyond Beetle • Assess thinning, mechanical site preparation, planting and natural regeneration • Assess recovery of residual trees and diseases • Assess fuel loadings and fire risk


<50% light


After MPB some pine remain alive


Beyond Beetle â&#x20AC;˘ Examine how specific ecosites recover. â&#x20AC;˘ Assess fuel loadings.


Black spruce understory


Rich sites


Medium site


Poor ecosite


Thank You â&#x20AC;˘ Forrest Barrett, Kevin Quintilio, and Keith McLain

Government of Alberta Environment & Sustainable Resource Development


18viclieffersmpb%20regen%20fri%202014  

https://foothillsri.ca/sites/default/files/18VicLieffersMPB%20Regen%20FRI%202014.pdf

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