Impacts of Nitrogen Deposition on Microbial Community Carbon Dynamics in Forest Soils

Impacts of Nitrogen Deposition on Microbial Community Carbon Dynamics in Forest Soils

Daniel H. BuckleySchool of Integrative Plant Science

Christine GoodaleEcology and Evolutionary Biology

Friedlingstein et al (2006) Journal of Climate. 19:3337

The terrestrial C-cycle is difficult to predict

Lin Zhang et al., 2012, Atmos. Chem. Phys., 12, 4539-4554

NADP National Trends Network (NTN)

Rousk et al. 2010

Soil pH is a Driver of Microbial Diversity

Control

(NH4)2SO4

50 kg N57 kg S

NaNO350 kg N

Background Deposition - 6.6 kg N ha-1 yr-1

- 6.8 kg S ha-1 yr-1

Long Term N x S Enrichment Experiment

Sulfur57 kg S

Started 2011, 3 sites x 2 stand ages40 x 40 m plots + 10 m bufferAmendments (ha-1 yr-1)

Tree Growth Response

Pre-Treatment (2009-2010) Post-Treatment (2011-2014)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

Control NaNO3 (NH4)2SO4 Sulfur

Pre-

Trea

tmen

t On-

grow

th20

09-2

010

(t h

a-1yr

-1)

Other

WP

WA

SM

RO

RM

QA

EH

BC

BB

AB0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0


Post

-Tre

atm

ent O

n-gr

owth

2014

-201

1 (t

ha-1

yr-1

)

Other

WP

WA

SM

RO

RM

QA

EH

BC

BB

AB

Species

Soil pH at 5 years

3.5

4.0

4.5

5.0

5.5


0-10 cm Mineral

Treatment: p < 0.0001; NO3 > Control > AS, S

Stand: p < 0.0001; CC2, MP2 > CC1, MP1, BH2 > BH1

Treatment x Stand: p < 0.0001

0.2

0.3

0.4

0.5

0.6

0.7

Year 1 Year 2 Year 3 Year 4

Litt

er D

ecom

p. R

ate

(k y

r-1) Control

NaNO3(NH4)2SO4Sulfur

Litter Decomposition Rate

p = 0.01

p = 0.05

p = 0.001

Year of litter decomposition (t)

p = 0.02

a

b

abab

ab

b

aab

ab

b

aab

Site*** Treatment*** Site x Treatment*** Stand Age*** Site x Stand Age***

Bacterial Community Composition

Bacterial Community Composition

Site x Stand Age***

4.7 4.8 4.9 4.7 4.8 4.9

4.6 4.74.8 4.6 4.7 4.7

4.54.6

4.74.6 4.5

4.6

4.3

4.4

4.5

4.54.3

4.6

3.9

3.9

4.2

4.4

4.14.6

4.44.6

4.2

0

20

40

60

80

100

120

BH BH CC CC MP MP

1 2 1 2 1 2

C St

ocks

(t/h

a)

40-50 30-40 20-30 10-20 0-10 FF

Bald Hill Carter Creek Mt. Pleasant

Prim

ary

Fore

stSe

cond

ary

Fore

stBald Hill Carter Creek Mount Pleasant

Fungal Community Composition

2,724 Total Core OTUs

N + S372 OTU

S only169 OTU

N only164 OTU

94 OTU

118 O

TU

62 OTU

~470 Total Responsive OTUs

160-222 (NH4)2SO4 specific 118 N response 94 S/pH response 13-75 NaNO3 specific 0-46 S0 specific

Responsive Bacterial Taxa

13C-Cellulose

VerrucomicrobiaChloroflexi

Proteobacteria

BacteroidetesPlanctomycetes

Melainabacteria

Log

2 Fol

d C

hang

e

Impacts of Nitrogen Deposition on Microbial Community Carbon Dynamics in Forest Soils

School of Integrative Plant Science Daniel H Buckley Spencer Debenport

Ecology and Evolutionary Biology Christine Goodale Bhavya Sridhar Charlotte Levy Guin Fredriksen

Foliar Litterfall

Treatments start

Treatments start

Treatments start

No pre-treatment differences in soil properties by later treatment.*

0

20

40

60

80

100

120

Ctrl NO3 AS S

Soil

C St

ock

(t/h

a)

40-50 30-40 20-3010-20 0-10 FF

0.0

0.5

1.0

1.5

2.0

Ctrl NO3 AS S

Soil

S St

ock

(t/h

a)

40-50 30-40 20-3010-20 0-10 FF

-5

5

15

25

35

45

3.8 4.0 4.2 4.4 4.6 4.8 5.0pH

ControlNaNO3(NH4)2SO4Sulfur

-5

5

15

25

35

45

5 10 15 20 25C/N Ratio


*MP1 Control had higher pH than treatment plots. Other stands were better-matched.

4.7 4.8 4.9 4.7 4.8 4.9

4.6 4.74.8 4.6 4.7 4.7

4.54.6

4.74.6 4.5

4.6

4.3

4.4

4.5

4.54.3

4.6

3.9

3.9

4.2

4.4

4.14.6

4.44.6

4.2

0

20

40

60

80

100

120

BH BH CC CC MP MP

1 2 1 2 1 2

C St

ocks

(t/h

a)

40-50 30-40 20-30 10-20 0-10 FF

Pre-treatment: C stocks varied by site and stand age, and surface pH varied by site.

Four plots per stand,Four cores/plot.

Bars labeled with stand mean pH

Bald Hill Carter Creek Mt. Pleasant Primary or secondary (post-ag.) forest

0

50

100

150

200


CO2

Flux

(mg

C/m

2/hr

)P = 0.003P = 0.14P = 0.28

-80

-60

-40

-20

0


Aver

age

CH4

Flux

(ug

C/m

2/hr

)

P = 0.05P = 1.0P = 0.64

0

2

4

6

8

10

12


Med

ian

N2O

Flu

x (u

g N

/m2/

hr)

Gas Flux at 5 years

20%

40%

60%

80%

100%

0 1 2 3 4

Litt

er C

Rem

aini

ng (%

)


Year of litter decomp. 1 2 3 4 Year of N x S treatment

Litter Carbon Loss

5

P = 0.028S > AS

(NSD from ctrl)

P = 0.0008S, AS > Ctrl

(+NO3 NSD)P = 0.04S > Ctrl

(+N NSD)

Impacts of Nitrogen Deposition on Microbial Community Carbon Dynamics in Forest Soils

Environment

Transcript of Impacts of Nitrogen Deposition on Microbial Community Carbon Dynamics in Forest Soils