Elevational And Temporal
Trends In Salix-feeding
Beetles And Associated Insects
Along Three Sierra Nevada,
California Drainages
John Smiley1, Elizabeth Dahlhoff2, and Nathan Rank3
1University
of California White Mountain Research
Station
2Santa
Clara University
3Sonoma
State University
John Smiley and Nathan Rank
at Upper Tyee Lake in Bishop
Creek drainage
“team beetle”
Work supported by: National Science
Foundation and our respective institutions
Elizabeth Dahlhoff
Elevation gradients are asymmetrical:
•
•
•
•
Most species will have an upper limit beyond which they cannot
physically survive (usually cold stress)
For many taxa, biodiversity decreases as elevation increases
Many species have a lower limit along the gradient, below which
natural enemies or heat-related stress prevents survival.
Between these limits is a zone in which a species can survive,
reproduce and send out dispersers to colonize new habitats.
drought or heat stress,
predators, pathogens and
competitors
1
mortality
rate
0
low
elevation
cold stress
zone of positive fitness
high
Q: how do plant and animal species respond to
changing climate along steep, montane elevation
gradients?
A: look at a multi-species food web inhabiting such a
gradient, and study it for a long period of time.
Centraleastern
Sierra
Nevada
University of California
White Mountain Research Station
Owens Valley Laboratories
Rock Creek
Bishop Creek
Big Pine
Creek
We have studied a willow-insect food chain since 1981.
Salix orestera Sierra Willow
For this presentation, we will examine:
•Insect Range Distribution since 1981
•Foliage Air Temperatures and trends
•Beetle Numbers since 1998
•Beetle Genetics and Physiology
changes along
elevation
gradients in 3
drainages
beetle: Chrysomela aeneicollis
Coleoptera: Chrysomelidae
wasp: Symmorphus cristatus
Hymenoptera: Vespidae
Ants: Formica sp.
Hymenoptera: Formicidae
fly larva: Parasyrphus melanderi
Diptera: Syrphidae
3750
3500
3250
3000
Y
2750
2500
2250
2000
1750
1500
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
year
Y
upper limit
lower limit
C. aeneicollis elevational range:
Long term record from Big Pine Creek
Are there decadal trends?: yes!
3750
3500
3250
3000
Y
2750
2500
2250
2000
1750
1500
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
year
Y
upper limit
lower limit
200
snow index
175
150
125
100
75
50
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
year
C. aeneicollis elevational range and winter snow % of normal:
Long term record from Big Pine Creek & Owens Valley region
Behavioral ecology of
wasp: Symmorphus
cristatus at Falls site,
2900m, Big Pine Creek
Lodgepole pine
borer
(Family
Carambycidae)
3750
3500
3250
3000
Y
2750
2500
2250
2000
1750
1500
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
year
Y
upper limit
lower limit
S. cristatus elevational range:
Long term record from Big Pine Creek
(note: prey most abundant along upper orange
band)
Quantitative C. aeneicollis counts begun in 1998,
Quantitative foliage air temperature recording begun in 2000.
3750
3500
3250
3000
Y
2750
2500
2250
2000
1750
1500
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
year
Y
upper limit
lower limit
White plastic cups were used as radiation shields, hung upside down from 12 cm diameter willow branch, with HOBO temp. logger suspended inside.
Shown: S. orestera above Green Lake, elev. 3410m (11,200’)
Big Pine drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Bishop Creek
drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Rock Creek drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Daniel Pritchett
30
20
Y
10
0
-10
date
Y
Mean(maxtemp)
Mean(mintemp)
Mean(avetemp)
Foliage air temperatures, averaged over 18 sites
(= daily “weather”). Note snow burial periods in spring.
01/01/2007
01/01/2006
01/01/2005
01/01/2004
01/01/2003
01/01/2002
01/01/2001
01/01/2000
-20
Q: Do foliage air temperatures lapse with
increasing elevation?
What is the lapse rate?
A: The answer depends on the
measurement (max or min) and the creek
drainage.
Foliage air temperature, all sites, all months:
20
15
Y
10
5
0
-5
-10
2600
2700
2800
2900
3000
3100
3200
3300
3400
Mean(m elev)
Y
maxtemp dev+13
avetemp dev + 3.74
mintemp dev -2
daily maximum lapse rate = 8.3 °C/km elev.
daily average lapse rate = 2.6 °C/km elev.
daily minimum lapse rate = n.s.
Foliage air temperature, all sites, summer only:
30
25
Y
20
15
10
5
0
2600
2700
2800
2900
3000
3100
3200
3300
3400
Mean(m elev)
Y
maxtemp+25.5
avetemp+12.3
mintemp+3.5
daily maximum lapse rate = 5.8 °C/km elev.
daily average lapse rate = 2.8 °C/km elev.
daily minimum lapse rate = n.s.
Big Pine Creek foliage air temperatures, summer only
30
25
Y
20
15
10
5
0
2700
2800
2900
3000
3100
3200
3300
3400
Mean(m elev)
Y
maxtemp+25.5
avetemp+12.3
mintemp+3.5
daily maximum lapse rate = (12°C/km elev.)
daily average lapse rate = (4.6°C/km)
daily minimum lapse rate n.s.
Bishop Creek foliage air temperatures, summer only
30
25
Y
20
15
10
5
0
2700
2800
2900
3000
3100
3200
Mean(m elev)
Y
maxtemp+25.5
avetemp+12.3
mintemp+3.5
daily maximum lapse rate = n.s.
daily average lapse rate n.s.
daily minimum lapse rate n.s.
3300
Rock Creek foliage air temperatures, summer only
30
25
Y
20
15
10
5
0
2600
2700
2800
2900
3000
3100
3200
3300
Mean(m elev)
Y
maxtemp+25.5
avetemp+12.3
mintemp+3.5
daily maximum lapse rate n.s.
daily average lapse rate = 2.1 °C/km
daily minimum lapse rate n.s.
3400
Q: are there long term trends in foliage air
temperatures?
A: maybe not in our data, nor in a longer
data set from Big Pine Creek. Yet
warming trends are seen in other local
data sets….
Barcroft Field Station July Average (Daily Max, Min Air Temperatures)
65
60
55
Y
50
45
40
35
30
1950
1960
1970
1980
1990
2000
2010
year
July max
Y
July min
Bishop Airport July Average
110
100
Y
90
80
70
60
50
1940
1950
1960
1970
1980
year
Y
average max
average min
1990
2000
2010
Barcroft Field Station July Average
65
60
55
Y
50
45
40
35
30
1950
1960
1970
1980
1990
2000
2010
year
July max
Y
July min
Big Pine Creek snow station, July Average
70
65
60
Y
55
50
45
40
35
30
25
50
55
60
65
70
75
80
July
Y
Column 3
Column 4
85
90
95
100
105
110
July Averages
65
60
55
50
Y
Barcroft
45
40
35
30
2010
2000
1990
1980
1970
1960
1950
year
July min
July max
Y
70
65
60
Y
55
Big Pine Creek snow station
50
45
40
35
30
25
50
55
60
65
70
75
80
85
90
95
100
105
110
1985
1990
1995
2000
2005
2010
July
Y
Column 3
Column 4
30
25
Y
20
Foliage – all sites mean
15
10
5
0
1950
1955
1960
1965
1970
1975
1980
year
Y
Mean(maxtemp)
Mean(mintemp)
1984
North Palisades Glacier
2006
Q: are there
trends in
number of
beetles over
time? Over
elevation?
A: it depends
on the
drainage…and
something
abrupt
happened in
2006
C. aeneicollis numbers were estimated by
counting as many beetles as possible during a 10
minute period, at each of about 40 sites,
including all of the temperature logger sites.
elevation of peak beetle abundance
3400
3300
elevation (m)
3200
BP
3100
BC
3000
RC
2900
2800
2700
1998
2000
2001
2002
2003
2004
2005
2006
late
2006
numbers of beetles at 6 sites in Big Pine Creek
6
5
4
3
2
3385
3246
3126
2997
0
2926
1
2800
beetle abundance score
7
elevation (m)
1998
2000
2001
2002
2003
2004
2005
2006
elevation of peak beetle abundance
3400
3300
elevation (m)
3200
BP
3100
BC
3000
RC
2900
2800
2700
1998
2000
2001
2002
2003
2004
2005
2006
late
2006
5
score
4
3
2
1
0
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
year
Green Lake beetle abundance 1998-2006
20
20
20
Y
30
Y
30
Y
30
10
10
10
0
0
0
150 160 170 180 190 200 210 220 230 240 250
150 160 170 180 190 200 210 220 230 240 250
150 160 170 180 190 200 210 220 230 240 250
day
day
day
Plot for year=2000
Plot for year=2001
Plot for year=2002
20
20
20
Y
30
Y
30
Y
30
10
10
10
0
0
0
150 160 170 180 190 200 210 220 230 240 250
150 160 170 180 190 200 210 220 230 240 250
150 160 170 180 190 200 210 220 230 240 250
day
day
day
Plot for year=2003
Plot for year=2004
Plot for year=2005
30
Y
20
10
0
150 160 170 180 190 200 210 220 230 240 250
day
Plot for year=2006
Nothing unusual about summer 2006?
Heavy rain/hail in early July.
Q: can genetics, physiology, and/or behavior help explain
what might be happening?
A: look at PGI, heat shock proteins and running
performance after different types of temperature stress.
PGI
•Phosphoglucose Isomerase (PGI) is an important metabolic
enzyme involving cellular energy supplies including glycolysis
and glucogenesis.
•PGI is often observed to limit aerobic performance.
•Studies on a variety of ectothermic species including sea
anemones, butterflies and beetles (our study) suggest that alleles
of PGI exhibit a tradeoff between enzymatic efficiency and
thermo-stability: the more active, efficient isozymes seem to be
more sensitive to temperature extremes.
•In our system the PGI-1 enzyme is the more efficient but less
stable form when compared with PGI-4.
Rock Creek; Mt. Dana; Oregon; Montana; Colorado
1
▲
▲▼
●▼
▲
▲
◆▲ ▲
▼ ▼
▲▼ ●
◆▼
▼
PGI-1 FREQUENCY
0.9
0.8
0.7
▼
◆
●
0.6
◆
0.5
●
● ◆
◆◆
◆
◆
●
●
●
● ●◆
◆
North Lake
George Lake
Green Lake
Chocolate
Lakes
0.4
0.3
Big Pine Creek; Taboose Creek
0.2
0.1
2500
2700
2900
3100
ELEVATION
north
3300
Bishop
Creek
south
PGI, HSP’s and running performance
•Temperature stress in ectotherms such as the willow leaf
beetle induces heat shock proteins (HSP’s) which quickly
build up in the tissues and protect enzymes such as PGI from
degrading and losing efficiency.
•The induction of HSP’s permit better enzyme performance
after stressful conditions, and thus faster running speed.
•Our findings suggest that PGI-1 individuals seem to be more
fit during milder weather with infrequent temperature
extremes, while PGI-4 individuals are better in more extreme
environments.
•Cold temperature extremes are much more common in the
early and late season, but the timing of snowmelt determines
whether or not beetles experience this severity of cold.
#Days logger is buried under snow, as function of elevation
200
days
150
100
50
0
2800
2900
3000
3100
3200
3300
elev
X=Rock Creek; O=Big Pine Creek; =Bishop Creek
Findings:
Foliage air temperatures:
• Lapse with elevation as predicted for afternoon highs.
• Lapse rate reduced for nighttime lows. Nighttime lapse rate
“anomaly” seen most strongly in north-south oriented Rock
Creek and Bishop Creek drainages
• Minimal warming seen over past 10-20 years
Yet:
Beetle distribution change:
• 25 year inter-decadal upward trend in Big Pine Creek for beetles
and predators.
• 8-year upward trend in Big Pine Creek but not Bishop Creek or
Rock Creek. Temperature regime? Wasp predation?
• Upward shift in summer 2006 – will it persist?
• Genetics and physiology: no clear pattern with elevation, but
with latitude, yes.
Questions
Why are beetles moving up? Why shift in 2006?
Temperature shifts not recorded/analyzed in data? Timing of
snow melt? Earlier snow melt probably favors higher elevation
beetles where the snow melts later.
Changing plant quality as food for beetles? Does altering
ambient CO2 concentration affect Salix orestera foliage?
Published literature would suggest not, but we should measure
this if possible.
Need longer-term data set. We are trying to secure long-term
funding from NSF.
North Palisade Glacier: how long before the willows get here?
Present glaciers
END SLIDE
2001
Falls site, Big Pine Creek
2006
Lodgepole pine borer
(Family Carambycidae)
Big Pine drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Big Pine drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Bishop Creek
drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Rock Creek drainage
Elevation color bands:
4000-4250m light gray
3750-4000m light blue
3500-3750m blue
3250-3500m blue-green
3000-3250m green
2750-3000m yellow-green
2500-2750m tan
2250-2500m light tan
2000-2250m yellow
Daniel Pritchett
Big Pine Creek foliage air temperatures, all months
15
Y
10
5
0
-5
2700
2800
2900
3000
3100
3200
3300
3400
Mean(m elev)
Y
maxtemp dev+13
avetemp dev + 3.74
mintemp dev -2
daily maximum lapse rate = (9°C/km elev.)
daily average lapse rate = (3°C/km)
daily minimum lapse rate n.s.
Bishop Creek foliage air temperatures all months
20
15
Y
10
5
0
-5
2700
2800
2900
3000
3100
3200
3300
Mean(m elev)
Y
maxtemp dev+13
avetemp dev + 3.74
mintemp dev -2
daily maximum lapse rate = (11°C/km)
daily average lapse rate =(4°C/km)
daily minimum lapse rate n.s.
Rock Creek foliage air temperatures, all months
15
10
Y
5
0
-5
-10
2600
2700
2800
2900
3000
3100
3200
3300
3400
Mean(m elev)
Y
maxtemp dev+13
avetemp dev + 3.74
mintemp dev -2
daily maximum lapse rate = (5.5°C/km)
daily average lapse rate n.s.
daily minimum lapse rate n.s. (+4°C/km!)
Barcroft Field Station July Max, Min Air Temperatures
65
60
55
Y
50
45
40
35
30
1950
1960
1970
1980
1990
2000
2010
year
Y
July max
July min
Bishop Airport
110
100
Y
90
80
70
60
50
1940
1950
1960
1970
1980
year
Y
average max
average min
1990
2000
2010
Barcroft Field Station July Max, Min Air Temperatures
65
60
55
Y
50
45
40
35
30
1950
1960
1970
1980
1990
2000
2010
year
Y
July max
July min
Falls Site, Big Pine Creek July Max, Min Air Temperatures
70
65
60
Y
55
50
45
40
35
30
25
50
55
60
65
70
75
80
July
Y
Column 3
Column 4
85
90
95
100
105
110
North Palisade Glacier: how long before the willows get here?
Present glaciers
PGI, HSP’s and running performance
Temperature stress in ectotherms induces heat shock proteins
(HSP’s) which quickly build up in the tissues and protect
enzymes such as PGI from degrading and losing efficiency.
Our findings suggest that PGI-1 , the more sensitive form,
immediately induces HSP production in response to only 4h of
extreme heat (36 C.) or cold (-4 C.), but that this is not enough
stimulus to induce drastic HSP production in beetles with
PGI-4. As a result, PGI-1 beetles outperform (outrun) PGI-4
beetles after either stimulus. However, after a second bout of
heat or cold on the second day, the PGI-4 beetles induce
HSP’s and generally outperform the PGI-1 beetles thereafter.
Thus PGI-1 seems to be superior during mild weather with
infrequent temperature extremes, while PGI-4 is best in more
extreme environments.
Genetics
•Beetles are collected in the field, frozen and analyzed in the lab
•Principal alleles (forms) of the enzyme are determined,
including PGI-1 and PGI-4
•Predict that PGI-1 would be more common at lower elevations?