Response of the arctic wet meadow sedge,
Carex aquatilis, to changing temperature
Michael L. Lothschutz
IPCC (Intergovernmental Panel on Climate Change) 2007.
Carex aquatilis
(Water Sedge)
Hultén (1968)
Image Courtesy of Robert Slider
• Dominant sedge
• Occurs in most wet
meadows
• Shows variation in size
within its natural
habitat (Chapin, 1981)
www.area02alaska.org
ARM Climate Research (2005)
David Brannan (2005)
Barrow
Atqasuk
Research Design
• Two wet meadow
communities.
• Meter squared plots
• ITEX Passive Open-Top
Chambers
• Increase in 1-2 degrees
Celsius
– 24 controlled
MSU AEL (1999)
– 24 warmed
Barrow Wet Site (BW)
Atqasuk Wet Site (AW)
Research Design
Measurements during Summer
2007
Inflorescence Length
– Phenological Observations
– Inflorescence Counts
– Growth Measures
Leaf Length
•
Hultén (1968)
Phenological Observations
220
210
*
First Seed Visible
*
Flowering (Stigma or
Anthers
visible)Flower Withering
First
First Visible
Green
Inflorescence
Leaf
* Observed
*
170
www.mun.ca/biology/delta/arcticf/
*
180
www.mun.ca/biology/delta/arcticf/
190
www.mun.ca/biology/delta/arcticf/
Julian Day
200
AW warmed
AW
warmed
AW control
AW
control
BW warmed
BW
warmed
BW control
BW
control
160
150
Leaf
Inflorescence
Flowering
Phenological Observation
Withered
Seed
*
p<0.05
Number of Plants Flowering
4.0
Number Flowering / m²
3.5
3.0
warm ed
control
warm ed
control
Image Courtesy of Robert Slider
AW
AW
BW
BW
2.5
2.0
1.5
1.0
0.5
0.0
165
170
175
180
185
190
195
Julian D ay
200
205
210
215
220
Total Number of Inflorscences / m²
Total Number of Inflorescences
14
12
AW
AW
BW
BW
10
warm ed
control
warm ed
control
8
6
4
2
0
165
170
175
180
185
190
195
Julian D ay
200
205
210
215
220
Leaf Length
Inflorescence
Length
AW warmed
AW control
BW warmed
BW control
35
25
20
15
10
Inflorescence Length
30
Leaf Length
Leaf Length
(cm)(cm)
Inflorescence
Length
40
5
0
Hultén (1968)
185
190
195
200
205
Julian Day
210
215
Discussion
• Significant changes in Barrow
– Increase in Growth and Reproduction
– Phenological events occur earlier
• No significant changes in Atqasuk
Sources and Acknowledgements
•
Thanks to:
– National Science Foundation
– Grand Valley State University
– Robert Hollister, GVSU
– GVSU Arctic Ecology Program
• Robert Slider, Jeremy May,
Amanda Snyder
– Barrow Arctic Science Consortium
•
Sources
–
–
–
–
ACIA. 2004. Impacts of a Warming Arctic: Arctic
Climate Impact Assessment.
Chapin, F.S., III. 1981. Field measurements
of growth and phosphate absorption in Carex
aquatilis along a latitudinal gradient. Arctic and
Alpine Research 13:233-260.
Hollister R.D., P.J. Webber, C. Bay. 2005. Plant
Response to Temperature in
Northern Alaska: Implications for
Predicting Vegetation Change. Ecology.
86:1562-1570.
Hultén, E. 1968. Flora of Alaska and
Neighboring Territories. p.250
QUESTIONS?