response of an antarctic lake ecosystem to climate variation: linkages between phytoplankton species...
TRANSCRIPT
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
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
Main Phytoplankton Species
Chlamydomonus intermedia Oscillatoria linenetica
Chlamydomonas subcaudata
Main Phytoplankton Species
Phormidium angustissimum
Chroomonas lacustris
Starburst protazoa
Dominant species occur in depth zones
Dry Valleys and Global Climate
Interannual variability in phytoplankton
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
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
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
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
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
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
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
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
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
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
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
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
Cyanobacterial mats in stream
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
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
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
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!!
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
A few words of Thanks:
National Science Foundation Project No. OPP-9211773, McMurdo Dry Valleys LTER.
MCMLTER colleagues Antarctic Support Associates staff