john l. willis, forestry, michigan state university, east lansing, michigan michael b. walters,...

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John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan Kurt W. Gottschalk, USDA Forest Service Research Station, Morgantown, West Virginia The Influence of Forest Substrate on Young Seedling Dynamics

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Page 1: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

John L. Willis, Forestry, Michigan State University, East Lansing, MichiganMichael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Kurt W. Gottschalk, USDA Forest Service Research Station, Morgantown, West Virginia

The Influence of Forest Substrate on Young Seedling Dynamics

Page 2: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Outline

Current seedling demographics

Management strategies and assumptions

Substrate case study 1: soil availability influence seedling establishment

within harvest gaps

Substrate case study 2: mechanisms of seedling

survival and development on different types of forest

substrate (preliminary)

Questions

Page 3: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Species Depauperate Seedling Layer

(Matonis et al. 2011)

Page 4: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Varying Harvest Gap Size

(Shields and Webster 2007; Bolton and D’Amato 2011; Kern et al. 2013)

Page 5: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Assumption #1

Desired species already are/will

become established in harvest gaps

Page 6: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan
Page 7: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Germination Substrate

Easily penetrated by roots

High moisture holding capacity (clays>silt>sand)

Majority of plant available nutrients

Page 8: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Harvesting Legacy #1 reduced bare mineral

soil/humus

-Removing mature, suppressed, diseased trees

-Harvesting in the winter

Page 9: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Assumption #2

Desired species will have access to light within harvest gaps

Page 10: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Density and height correlate positively with gap size

Loss of aboveground biomass

Competing non-tree vegetation Herbivory

Access to Light

Page 12: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan
Page 13: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Substrate Coverage(% cover)

% Light Availability (modified by overstory and

forest floor vegetation)

Non-Tree Vegetation(% cover and height)

Page 14: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Hemlock First Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Hem

lock

See

dlin

gs/2

m2

0

10

20

30

40

50

60

70

Hemlock Second Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Hem

lock

See

dlin

gs/2

m2

0

10

20

30

40

50

60

70

Eastern Hemlock (Tsuga canadensis)

Hemlock Germination

% Light Availability

0 10 20 30 40 50 60 70 80

Hem

lock

See

dlin

gs/2

m2

0

10

20

30

40

50

60

70

ST(<.1ac) GS (.1-.5) PS (.5-2)

Page 15: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Effect of Scarification on Germination

% Light Availability

0 10 20 30 40 50 60 70 80

Hem

lock

See

dlin

gs/ 2

m2

0

10

20

30

40

50

60R2=0.56

p<.0001

Effect of Light Availability on Survival (Year 1)

% Light Availability

10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100

R2=0.28p<.0001

Eastern Hemlock (Tsuga canadensis)

Effect of Light Availability on Survival Year (2)

% Light Availability

0 10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100

R2=0.20p<.0001

S

ST(<.1ac) GS (.1-.5) PS (.5-2)

Page 16: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Paper birch (Betula papyrifera)

Paper Birch Germination

% Light Availability

0 10 20 30 40 50 60 70 80

Pap

er B

irch

See

dlin

gs/2

m2

0

20

40

60

80

100

120

140

Paper Birch First Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Pap

er B

irch

See

dlin

gs/2

m2

0

20

40

60

80

100

120

140

Paper Birch Second Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Pap

er B

irch

See

dlin

gs/2

m2

0

20

40

60

80

100

120

140

ST(<.1ac)

GS (.1-.5)

PS (.5-2)

Page 17: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Effect of Scarification on Germination

% Light Availability

10 20 30 40 50 60 70 80

Pap

er B

irch

See

dlin

gs/2

m2

0

20

40

60

80

100

120

140

Effect of Light Availability on Survival (Year 1)

% Light Availability

10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100R2= .41

p <.0001

R2=.06p=.0289

S

The Effect of Light Availability on Survival (Year 2)

% Light Availability

0 10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100

R2= .15p=.0237

Paper birch (Betula papyrifera)

ST(<.1ac)

GS (.1-.5)

PS (.5-2)

Page 18: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Yellow Birch Germination

% Light Availability

0 10 20 30 40 50 60 70 80

Yel

low

Bir

ch S

eedl

ings

/2m

2

0

20

40

60

80

100

120

Yellow Birch First Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Yel

low

Bir

ch S

eedl

ings

/2m

2

0

20

40

60

80

100

120

Yellow Birch Second Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Yel

low

Bir

ch S

eedl

ings

/2m

2

0

20

40

60

80

100

120

Yellow Birch (Betula alleghaniensis)

ST(<.1ac) GS (.1-.5) PS (.5-2)

Page 19: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Yellow birch (Betula alleghaniensis)

Effect of Light Availability on Survival (Year 1)

% Light Availability

10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100

R2=.17

p=.0012

Effect of Scarification on Germination

% Light Availability

10 20 30 40 50 60 70 80

Yel

low

Bir

ch S

eedl

ings

/2m

2

0

20

40

60

80

100

120R2= .31

p<.0001

ST(<.1ac)

GS (.1-.5)

PS (.5-2)

Page 20: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

White Pine First Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Whi

te P

ine

See

dlin

gs/2

m2

0

2

4

6

8

10

12

14

White Pine Germination

% Light Availability

0 10 20 30 40 50 60 70 80

Whi

te P

ine

See

dlin

gs/2

m2

0

2

4

6

8

10

12

14

White Pine Second Year Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Whi

te P

ine

See

dlin

gs/2

m2

0

2

4

6

8

10

12

14

White Pine (Pinus strobus)

ST(<.1ac)

GS (.1-.5)

PS (.5-2)

Page 21: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Effect of Scarification on Germination

% Light Availability

10 20 30 40 50 60 70 80

Whi

te P

ine

Seed

ling

s/2m

2

0

2

4

6

8

10

12

14

White pine (Pinus strobus)

R2<.01p=.9054

R2=.11P =009

White Pine 1st Growing Season Survival

% Light Availability

10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100

R2=.11P =009

ST(<.1ac)

GS (.1-.5)

PS (.5-2)

Page 22: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Effect of Fencing on Survival (Year 3)

% Light Availability

0 10 20 30 40 50 60 70

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100

R2=0.19p=0007

F

Effect of Clipping on Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Pro

port

ion

Sur

vivi

ng

0

20

40

60

80

100R2=.36p=<.0001

Effect of Fencing on Survival

% Light Availability

0 10 20 30 40 50 60 70 80

Pro

port

ion

Surv

ivin

g

0

20

40

60

80

100

R2=.19p=<.0001

F

C

HemlockPaper Birch

ST(<.1ac)

GS (.1-.5)

PS (.5-2)

Page 23: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Conclusions

-Bare mineral soil/humus is CRITICAL for light seeded species germination, but not white pine.

-Low light availability is NOT a significant barrier to germination

-Increasing harvest gap size IMPROVES seedling survival for all species initially, but deer and non-tree vegetation are beginning to influence seedlings access to light(hemlock and paper birch)

-Group selection harvest gaps (.1-.5ac) may present the best opportunity to recruit this group of species….stay tuned

Page 24: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Case Study# 2:Seedling development

across substrates

Harvesting/thinning reduces interrupts the cycle of nurse log

creation by:

-Removing mature/diseased/suppressed trees

Page 25: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Decaying Coarse Woody Debris (Nurse Logs)

Drought stress

Competition from non-tree vegetation

Species specific pests/pathogens escape

Hardwood litter avoidance

(Harmon and Franklin 1989)

Page 26: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Nurse Log Seedling Demographics

2. Hemlock most capable of surviving on nurse logs

1.Sugar Maple provides poor substrate for all species of seedlings

4. Yellow Birch is better adapted for surviving on hemlock nurse logs

(Marx and Walters 2008)

3. Sugar maple least capable of surviving on nurse logs

Page 27: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Nutrient Limitation

(Marx and Walters 2006)

Substrate [N], µg/mlNmin µg.ml-

1.day-1 pHHemlock wood 1.5 0.115 3.7

Yellow birch wood 2.45 0.018 3.9Sugar maple wood 3.18 0.019 6.4

Soil 3.62 0.19 3.4

Page 28: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Nutrient ExtractionCarbohydrates

Nutrients

-Increased volume of soil explored

- Breaking down previously insoluble compounds

Page 29: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

All samples transported back to MSU Tree Research Center

Potted plant experiment: 12tree species X 7 substrates X 2 treatments

Tree species: PB,YB,WP,RP,SM, RM,RO,HEM,WS,BF,WA,NWC

Substrates: CWD of PB,SM,YB,HEM,BF,NWC and Soil

Sterilization Treatments: Gamma irradiated or not

Page 30: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Paper Birch Development

BF HEM PB SOIL YB NWC SM

Hei

gh

t G

row

th (

cm)

0

10

20

30

40Unsterilized Sterilized

Yellow Birch Development

BF HEM PB SOIL YB NWC SM

Hei

gh

t G

row

th (

cm)

0

5

10

15

20

25

30Unsterilized Sterilized

Page 31: John L. Willis, Forestry, Michigan State University, East Lansing, Michigan Michael B. Walters, Forestry, Michigan State University, East Lansing, Michigan

Acknowledgements