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Page 1: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and

Streamflow

Diane M. McKnight1, Erin Von Maytre1,John C. Priscu2,W. Berry Lyons3,

and Michael Gooseff1

1. Institute of Arctic and Alpine Research Boulder, CO2. Dept. of Biology, Montana State University, Bozeman, MT3. Byrd Polar Research Institute, Ohio State University,

Columbus, OH

Page 2: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.
Page 3: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Background – Ice Covered Lakes

Ice cover- 3-5 m thick, moat in summer Source- streamflow from glacial melt Loss- ablation of ice cover Water column- stable w/depth, some

lateral circulation Light penetration about 1% or less

Page 4: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.
Page 5: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Main Phytoplankton Species

Chlamydomonus intermedia Oscillatoria linenetica

Chlamydomonas subcaudata

Page 6: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Main Phytoplankton Species

Phormidium angustissimum

Chroomonas lacustris

Starburst protazoa

Page 7: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Dominant species occur in depth zones

Page 8: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Dry Valleys and Global Climate

Page 9: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Interannual variability in phytoplankton

Page 10: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Depth-wise ZonationTaxa Size(m3) Depths (m) % PAR1987-1991:Oscillatoria sp. 4 5-7 0.5-1.6

Oscillatoria limnetica 2 6-8.5 0.2-0.9

Cryptomonas sp. 276 7.5-9.5 0.1-0.4

Chroomonas lacustris

130 8.5-9 0.16-0.2

Pyramimonas sp. 583 9-10 0.16-0.2

Phormidium angustissimum

2 9.5-10.5 0.16-0.2

Chlamydomonas subcaudata

904 various 0.16-0.2

Page 11: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Depth-wise Zonation cont’

Taxa Size(m3) Depths (m) % PAROchromonas nannos*

170* 4.5-6.5 0.7-1.0**

Chlamydomonas sp. 6 4.5-8.5 0.4-1.0

Cryptomonas sp 308 4.5-8.5 0.4-1.0

Chroomonas lacustris

177 8.5-9.5 0.2-0.4

Pyramimonas sp. 335 8.5-9.5 0.2-0.4

* Vincent, 1981

** Vincent, 1988

Page 12: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Creek

Canada Glacier

Commonwealth

Glacier

Crescent GlacierHoward

Glacier

Green

Del

ta

Stre

am

Harnish

Stream

Von

Guerard

Stream

AikenCreek

Huey

Canada

Cre

ek

Stream

Stre amS eal

Lo

s t

McK

nigh

t

Creek

Cr e

sce n

tSt

rea

m

N

2 km

RelictChannel

Creek

Canada Glacier

Commonwealth

Glacier

Crescent GlacierHoward

Glacier

Green

Del

ta

Stre

am

Harnish

Stream

Von

Guerard

Stream

AikenCreek

Huey

Canada

Cre

ek

Stream

Stre amS eal

Lo

s t

McK

nigh

t

Creek

Cr e

sce n

tSt

rea

m

N

2 km

RelictChannel stream

gauge

algal transect

Page 13: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

0

5000

10000

15000

88-89 89-90 90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99

Vo

lum

e (

x 1

03 m

3 ) Onyx River(LWRT)

0

100

200

300

400

500

600

88-89 89-90 90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99

Vo

lum

e (

x 1

03 m

3 )

Lost Seal

Canada

Delta

NR NR NR

Page 14: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

100 150 200 250

0

5

10

15

20

25

30

35

Dep

th (

m)

Lake Hoare Cl (mg/L)

1993-94

1994-95

1995-96

1997-98

1996-97

1998-99

1999-00

Page 15: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

16-Nov

7-Jan Nov 4-Dec 30-Dec

Jan Nov Dec Oct Nov Jan Nov Dec Oct Nov Dec Oct Nov Dec

93/94 94/95 95/96 96/97 97/98 98/99 99/00

um

3 /ml

4.5m 5m 6m 8m 9m 10m

Chroomonas lacustris Biovolume

Page 16: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

4

5

6

7

8

9

10

0.E+00 5.E+06 1.E+07D

ep

th (

m)

4

5

6

7

8

9

10

0.E+00 5.E+06 1.E+07

Chlamydomonas intermedia Phormidium angustissimum Oscillatoria limnetica Chroomonas lacustris Cryptomonas sp.

Lake Fryxell 1997-98 Biovolume (m3/mL)

Nov. 18 Dec. 29

Page 17: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

4,500,000

5,000,000

Nov 18-Jan Nov 30-Dec

Jan Nov Dec Oct Nov Jan Nov Dec Oct Nov Dec Oct Nov Dec

93/94 94/95 95/96 96/97 97/98 98/99 99/00

um

^3/

ml

4.5m 5m 6m 8m 9m 10m

Chlamydomonas intermedia Biovolume

Page 18: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

Nov 7-Jan 18-Jan

Nov 7-Dec

30-Dec

Jan Nov Dec Oct Nov Jan Nov Dec Oct Nov Dec Oct Nov Dec

93/94 94/95 95/96 96/97 97/98 98/99 99/00

um

^3

/ml

4.5m 5m 6m 8m 9m 10m

Oscillatoria limnetica Biovolume

Page 19: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

0

20,000

40,000

60,000

80,000

100,000

120,000

Nov 7-Jan 18-Jan

Nov 4-Dec 30-Dec

Jan Nov Dec Oct Nov Jan Nov Dec Oct Nov Dec Oct Nov Dec

93/94 94/95 95/96 96/97 97/98 98/99 99/00

um

3 /ml

4.5m 5m 6m 8m 9m 10m

Phormidium angustisimum Biovolume

Page 20: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Phytoplankton species changesSpecies 1979-1981

Low flow

1989-1992

High flow

1993-99

Low flow

Chroomonas lacustris

dominant rare abundant

Cryptomonas sp.

present dominant present

Chlamydomonas subcaudata

present? abundant rare

Chlamydomonas intermedia

present? rare abundant

Phormidium angustisimum

rare? present present

Oscillatoria limnetica

rare? present >> present

Page 21: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Potential Factors Controlling Phytoplankton

Light regime in summer Nutrients (N)- diffusion from below

oxycline and input from streams Mixotrophy and overwinter persistence Microbial loop dynamics

Page 22: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Cyanobacterial mats in stream

Page 23: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Stream algal mat changes

Stream Habitat MatsChange from

1994-98

Canada pavement abundant none

Bowles pavement abundant none

Green pavement abundant new green mats

Delta (upper) pavement abundant new moss

Huey sandy sparse more orange, new black

Delta (lower) sandy sparse new orange

Von Guerard sandy sparse more mats

Lawson steep sparse more orange & moss

Page 24: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

0

200

400

600

90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99

Vo

lum

e (

x 1

03 m

3 )

Canada

00.20.4

0.60.8

1

90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99Co

nc

en

tra

tio

n (

M) SRP Nitrate

NR

NRND ND ND

Page 25: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

050

100150200250

90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99

Vo

lum

e (

x 1

03 m

3 )

Delta

00.20.40.60.8

1

90-91 91-92 92-93 93-94 94-95 95-96 96-97 97-98 98-99Co

nc

en

tra

tio

n (

M) SRP Nitrate

Q QNR

NR ND ND

Page 26: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Summarizing - trends 1987-99

Streamflow- high flow followed by sustained low flow

Major ions increased in upper water column

Stream mats-recovery followed by decrease

Stream nutrient fluxes- variable!!

Page 27: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

Conclusions

Phytoplankton response to changing climate occurs at the species level

Patterns for chlorophytes and cryptophytes related to flow regime

Increasing cyanobacterial abundance Potential factors include light regime,

nutrient fluxes, mixotrophy, and major ion chemistry

Page 28: Response of an Antarctic Lake Ecosystem to Climate Variation: Linkages between Phytoplankton Species Dynamics and Streamflow Diane M. McKnight 1, Erin.

A few words of Thanks:

National Science Foundation Project No. OPP-9211773, McMurdo Dry Valleys LTER.

MCMLTER colleagues Antarctic Support Associates staff


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