Transcript Climate Change & Human Impact Through Fossil Insects

Climate Change & Human Impact
Through Fossil Insects
Phil Buckland
George...
seaofdefence
walltoday?”
taller today?”
”Say, Thag...
wall
ice closer
Contents
PhD Aims
Why Insects (mainly beetles)
Bugs - Coleopteran Ecology Package
Insects & Climate
Insects & Human Impact/Environmental Change
Sites
Aims
Compare Early Holocene climate and environmental signals
from fossil insects for:
- remote/undisturbed sites.
- sites with known human activity.
Create an Early Holocene climate change curve for Northern
Sweden from fossil insects.
Enhance the capabilities of the Bugs Coleopteran Ecology
Package - with respect to climate, environmental &
archaeological interpretations.
NOTE: These are intrinsically related.
Why insects?
Fig.
Diversity - ~99% of all species of animal, found in all
terrestrial and freshwater-brackish environments.
75%
arespecific,
beetles (skalbaggar)
Habitat
depend on a range of environmental
factors e.g. temperature, humidity, food source...
Environmental dependency can be determined from
collection of modern specimens
Species constancy – migrate rather than evolve
(Exceptions in isolated islands/mountains)
Fig.
Respond rapidly – annual reproductive cycles
Species not dependent on higher vegetation/other species
Fig.
Fig.
Fig.
Species transported with host
Preserve well in waterlogged (or dry) sediments
Often identifiable to species on fossil parts
BUGS
Database of Coleopteran Ecology & Distribution
5400+ taxa
includes:
- 19300+ habitat entries
- 16500+ distribution entries
- approx. 23000+ fossil record entries
2200+ references
420+ sites with abundance/collection data
(mainly archaeological & geological)
BUGS - Fossil Record
Diacheila arctica
Sortable on any field.
All fields hotlinked…
BUGS - Fossil Record
Diacheila arctica
Modern
Late Glacial UK distribution
BUGS - Query features
Complex questions, such as:
list all species found at English Late Glacial sites
list all sites where selected species are found
list species with similar ecology that are equally threatened
summarise ecology codes for a site (basic diversity stat’s)
statistically compare sites and species lists
show sites with similar faunas
Climate Change
Early Holocene Climate Change
Bølling/Allerød
8200 Cold
Younger
Event...
Last
Dryas
Ice stadial
Age
Interstadial
GISP2 Dataset
Rapid Climate Change Events
(Oxygen Isotopes)
A widespread, ~200 year abrupt cold event 8200 years ago
Insect responses to change (2)
Example: Diachila arctica
Younger Dryas?
Present distribution
Mutual
Climatic
RangeChange
(MCR)
Insects
and Climate
Overlays modern temperature data on fossil assemblages
1. Collect modern temperature dependency data for species...
Thermal envelope for species
- T Max +
Species 1
+
- T Range +
TMAX = mean temperature of warmest month
Beetle finds
Weather station
data
TRANGE = difference between TMAX
and mean of coldest month
Mutual Climatic Range (MCR)
Overlays modern temperature data on fossil assemblages
2. Calculate temperature overlaps for species in each sample...
- T Max +
Species 1
Species 2
Species 3
...Species n
- T Range +
Mutual Climatic Range (MCR)
Data from Alley et al. (1993), Nature 362 and
Walker et al. (1993), Quaternary Newsletter 69
15000
Oldest Dryas
14000
13000
Bøllinger/Allerød
12000
11000
10000
Preboreal
Younger
Dryas
0.2
0.1
25-year
smoothed data
0.0
o
T.Min oC
MCR
data
UK
0.3
T.Max C
3. Construct time series
(if sequential sampling)
and C14 calibrate...
Accumulation (m ice per yr)
Calender years before present
16000
30
25
20
15
10
5
0
10
5
0
-5
-10
-15
-20
-25
-30
St.Bees
Glanllynnau
15000
14000
13000
12000
11000
Radiocarbon years BP
10000
Mutual Climatic Range (MCR)
4. Compare with other datasets
Data from Alley et al. (1993), Nature 362 and
Walker et al. (1993), Quaternary Newsletter 69
14000
13000
Bøllinger/Allerød
12000
11000
10000
Preboreal
Younger
Dryas
0.2
0.1
25-year
smoothed data
0.0
o
MCR
data
UK
15000
Oldest Dryas
T.Max C
GISP2
0.3
T.Min oC
3. Construct time series
(if sequential sampling)
and C14 calibrate...
Accumulation (m ice per yr)
Calender years before present
16000
30
25
20
15
10
5
0
10
5
0
-5
-10
-15
-20
-25
-30
St.Bees
Glanllynnau
15000
14000
13000
12000
11000
Radiocarbon years BP
10000
Integrating MCR & BUGS
1. Convert existing MCR data to a more useable form.
2. Create user interface for MCR analyses.
3. Program new system for MCR envelope calculation from
historical weather station data and historical beetle finds.
a) Nearest geographical neighbour
b) Lapse rate interpolation
Extracting the signals...
Compare background signals (climate?) with disturbed signals
Total signal
Components
eg. PCA axis 1
Resolved through semiquantitative or statistics...
Sum m er
Tem p.
W in te r
Tem p.
P re c ip ita tio n
etc...
Extracting the signals...
Compare background signals (climate?) with disturbed signals
signal
Components
A axis 1
Resolved through semiquantitative or statistics...
Sum m er
Tem p.
W in te r
Tem p.
P re c ip ita tio n
F o rest
S ig n a l
D o m e s tic
a n im a ls
A g r ic .
S ig n a l
Post Settlement
Plant
Soil
14
Landscape
Change
Geology
Pollen
Insects
Tephra
C
Macro.
Properties
in
Iceland
Disturbed signals
Background signals
Farm
Deserted farm
Woodland
Bare ground
Sites - Njulla, Abisko
background signals
~9500BP →
Sites - Njulla, Abisko
Sites - Hemavan
background signals
~8500BP →
Sites - Hemavan
background signals
Sites - David’s Bog (Fagerviksjön)
disturbed signals
...others under consideration...
~6000BP → & ~9000BP →
Bugs in the web...
[email protected]
www.bugs2000.org
www.umu.se/envarchlab
www.umu.se/archaeology
Figures
Modern distributional data
Diachila arctica
Insect responses to change (1)
Rhyzopertha dominica
Kapucinerbagge
Transported with hosts...
Sheep lice - Damalinia ovis
Grain mites
Sitophilus granarius
Kornvivel
Oryzaephilus surinamensis
Sågtandad plattbagge
Preserve well...
Heleomyza borealis - puparia
Greenland ~1350AD
Dung beetles (Aphodius sp.)
Armana, Egypt ~1350BC
Alphitobius diaperinus
lesser mealworm beetle
Fossils identifiable to species
Notiophilus bigutatus
Responding to Climate Change
Example: Diachila arctica
Younger Dryas?
Present distribution