Lecture 8 (Paleoecology)

Paleoecology
Useful materials
1. Written archives; archives from long-lived
species
2. Remains left by aboriginal peoples
3. The geological record
Historical Ecology from near time—records of
European peoples
Example
Large predators, ungulates, and
forests in North America
Historical data?
Tree rings
Park visitation records
Deer harvest records
Deer Irruptions Following Predator
Removal
Leopold et al. 1947
Gallatin Range
Gallatin Range
High
Risk
Sites
Halofsky and Ripple in press
Zion Canyon
Turtles and sea grasses
Loren McClenachan
Jeremy Jackson
HUMANS
TURTLES
TURTLEGRASS EPIPHYTES (McClenachan et al. 2006)
Green Turtle Nesting Beaches
Historic
population
91 million
Modern
population
<300,000
=modern nesting beach (major)
=modern nesting beach
McClenachan et al. 2006.
Frontiers in Ecology 4:290.
What were the ecological consequences?
Historic population= 91 million
§  consumed 45% of annual seagrass
growth
§  transmit nutrients to animal food chain
Modern population= <300,000
§  consumes <0.1% of annual seagrass
growth
§  uneaten seagrass buried in sediment
§  seagrass wasting disease
So more turtles=more productivity, less disease
Paleoecological inferences from
older materials
l 
Prehistoric middens
l 
The fossil record
l 
Geochemistry
Cod
Coral
Oyster
Northern fur seal
Seth Newsome
Historical data
Midden faunal remains
Isotopic analyses
Mean bone collagen isotope values of ancient pinnipeds as well as abundance estimates from
selected archaeological sites.
Newsome S D et al. PNAS 2007;104:9709-9714
©2007 by National Academy of Sciences
NFS YOY harvest profiles for selected archaeological assemblages, representing the percentage
of identifiable specimens (where NISP is number of identifiable specimens) versus age (in
months).
Newsome S D et al. PNAS 2007;104:9709-9714
©2007 by National Academy of Sciences
Bone collagen δ15N values for one modern and two Holocene NFS ontogenetic series (2–30
months of age): ×, modern Pribilof Islands (Bering Sea); ○, prehistoric Umnak Island (eastern
Aleutians, Alaska); ●, prehistoric Ozette (Olympic Peninsula, Washington).
Newsome S D et al. PNAS 2007;104:9709-9714
©2007 by National Academy of Sciences
Aleuts, sea otters and kelp forests
Historical data
Aleut kitchen middens
Modern ecological data
Max diameter ≈ 35mm
Max diameter ≈ 100mm
Influences on ocean systems:
i.  As consumers;
ii.  As prey;
iii.  As detritus
Whales, penguins and
krill in the southern
Ocean
Perturbation--overexploitation
Laws, Phil. Trans. Roy. Soc. 1971
Historical data
• Whale landing records
• Egg shells from Adele penguin
rookery
• Isotopic data from modern system
and from the penguin egg shells
through time
Southern Ocean Whales
15
Humpback
0
25
Blue
Catch
(thousands)
Catches
(thousands)
0
25
Fin
0
Sperm
15
0
Sei
15
0
7
Minke
0
1905
1905
1925
1925
1945
1945
Year
1965
1965
1985
1985
Penguin Colonies Leave Footprint
An ~8,000 year record of δ15N values of
Adélie penguin eggshell from Antarctica
Holocene Fish
1911-1917
Krill & Fish
Modern
W
P
K
Emslie and Patterson, PNAS, 2007
Sardine
Anchovy
Historical data
• Fisheries landings
• Ocean temperature data
• Fish scales in varved sediment cores
Baumgartner et al., CALCOFI Report, 1982
Paul Martin
“Twilight of the Mammoths”
Historical Data
The fossil record
The climate record
Greenland ice cores
Wood rat nests—plants
Ancient dung
How much did we lose?
58
32
10
66
Felisa Smith et al. Am. Nat. 2004
An optimistic vision for 21st
Century conservation
What does it mean
Two explanations
Human Overkill
Climate change
Indirect effects?
•  Vegetation and fire
Chaparral fire
Indirect effects?
•  Climate change
Felisa Smith
Smith et al. Nature Geology 2010
Who went extinct?
NA: 78 species, 53 herbivores of
mostly large size
SA: 76 species, 61 herbivores of
mostly large size
GISP2 core: Brook et al. 1996 Science Historical Data
• The fossil record
• Geochemistry—iridium
concentrations