frank k. lake ph.d. 2007, osu usfs psw research ecologist tribal ethno-ecology
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Archaeological evidence for climate change impacts on people and natural
resources of the PNW [and Calif.!]• Frank K. Lake
– Ph.D. 2007, OSU– USFS PSW Research
Ecologist– Tribal Ethno-ecology– Fuels, Fire, and Fisheries
Management*Program on Climate Change: University of Washington/Friday Harbor Laboratory- Thanks!
Evidence: Sources of data used• Archaeological
– Lithic: Hunting and food processing artifacts
– Human, animal, and plant remains: AMS 14 C ages
– Establishment and occupation site chronologies
– Climate and natural resources conditions
Prentiss et al. 2006: Archaeology of NW North America
Climatic Processes and Pattern Impacts on Tribal Cultures of the PNW
• Historical Reconstruction– Marine Fossil/Isotopic
Record– Tree Rings, Climate
and Fire Regimes– Neotoma (Pack Rat)
Nests– Pollen and Microfossil
Records
• Tribal Culture Reconstruction– Archaeological data
sources– Linguistic divergence– DNA/genetic traits– Cultural traits,
technologies, and socio-economic systems
Subsistence Intensification: • A process of change in subsistence behavior
whereby and increase in energetic return to land area or labor input required to acquire resources to meet socio-economic [survival] needs– Intensification can be adaptive or maladaptive– Labor correlated with technological
innovations or socio-economic organization• TI: Methods to extend intra-annual utility of
subsistence resources- “Get more per time of year or season” with labor available
Tribal Cultures, Natural Resources and Climate
• Cultural Complexity– Resource
specialization
• Bio-physical Productivity– Climate influenced
resource availability
Scale of Major Climate Change Periods Affecting Tribal Cultures• Last Glacial Maximum• Younger Dryas• (Middle) Holocene
Maximum• Medieval Climatic
Anomaly• Little Ice Age• PNA/PDO, La Nina/El
NinoWest et al. 2007 of Woolfenden 1996
PNW-Calif. Climate Change and Tribal Cultural Adaptive Responses
• Demographic shifts/migrations to more productive environments
• Changes in cultural technologies and socio-economic systems
• Cross-cultural conflicts and/or diversification
• Environmental changes and subsequent human responses
“…it was not climate that prehistoric populations were interacting with per se, but the effects of climate on the biophysical environment” (West et. a. 2007).
Factors limiting the evidence of first peoples and development of tribal cultures in the
PNW and Calif. • Glaciation [Open coast?]• Sea level [When and where?]• Marine and precipitation
erosional forces • Landscape/Vegetation change• Site/area conditions at time of
settlement and occupation• Site preservation (acidic soils
and organic material decomposition)
Palaeocoastal Settlement:
13,00-11,500 cal BP• Evidence for
each major region of the Pacific coast– Northwest
Coast– Alta California – Baja California
Erlandson et al. 2008: Life on the edge…
Mid-Holocene: 5800 cal yr BP• Major changes in PNW
cultures observed• Sea level stabilization
– Southern PNW/Calif.• Increased subsistence
specialization and technologies
• Increased abundance of “critical” natural resources: Fisheries
• Cultural transition circa 4850 cal yr BP Moss et al. 2008: Mid Holocene Culture and Climate
on the Northwest Coast of North America
Mid-Holocene Adaptive Responses and Specialization:
Southern Calif-Channel Islands: Increased resource utilization, cultural technologies, and intensive resources exploitation
Kennett et al. 2007
Mid-Holocene Adaptive Responses and
Specialization: Southern Calif. (continued).
• Sea temperatures affected ocean and coastal vegetation productivity
• Different species of shellfish exploited [or affected by SST??]
• Nitrogen and carbon isotopic composition of human bones support diversified marine and terrestrial adaptation and resource utilization
• Data allow for a comparison of prehistoric human island and mainland adaptive strategies
• DNA-human genetics distinguish two cultural/linguistic groups for northern, southern islands, and main land
Kennett et al. 2007
Late Holocene: PNW Plateau [to/from Coast]
Prentiss et al. 2006: Archaeology of NW North America
Bow/Arrows
Medieval C.A.
Glacial advance, expanded forest cover, greater salmon
To Calif.?
Mid to Late Holocene Climate change impacts to southern PNW hydrology and fisheries resources
• Sea level stabilization– Estuaries and river access– Precipitation regimes and basin
hydrology– Changes in sea surface
temperatures and productivity– Salmonid, other fish species
distribution and run times• Tribal harvest technologies
– Tidal and in-river weirs– Specialization of capture/harvest
techniquesByram 2002: Oregon Coast Fish Weirs
Columbia River: Paleo-hydrology and Salmon Resource Availability [Specialization or Climate?]
Fluctuations of salmon abundance correlate with regional precipitation and hydrology phases.
Medieval Climatic Anomaly: AD 800-1350 • Drought conditions in the
Pacific West/Great Basin• Abrupt declines in
productivity caused by repeated and prolonged droughts
• Shortages of food and water-reduced productivity
• Increased warfare/stress among groups
• Forced migration to more productive habitats by small groups Jones et al. 199: Settlement disruption-Big
Sur Cal coastal village/sites
Central Calif.: Late Holocene with Medieval Climatic Anomaly
Droughts with periods of cool/wet: Cool ocean temperatures and arid inland environments AD 450-1350 [Jones and Schwitall 2008]
Linguistic Prehistory and Evidence: Cultural Demographic Shifts in Response to Climate
Change• Penutian language family and
related tribal groups the most widely established in the PNW and Calif. circa 1850 AD.
• Penutian dialects on the Columbia Plateau/Northern Great Basin having a series of coastward migrations west of the Cascades and Sierra Nevada mountains
• Medieval Climatic Anomaly– Interior warming and drying– Loss of productive wetlands– Forced movement westward to more
productive maritime influenced resources.
Golla 2007
Linguistic and Archeological of PNW-Calif. Culture Migrations
• Circa 1,300 BP Algic groups moving from Columbia Plateau west to Puget Sound and NW Calif. (A.D. 100 and 700)
• Athabaskans soon followed from SW Alaska south in to PNW/NW Calif. (A.D. 800-900)
• North Cal. Penutian migration and establishment A.D. 500-600 (beginning circa 1,200 BP) Whitaker et. al. 2000: Obsidian
sources and trade
Human DNA: Evidence of Cultural Migrations and Settlement Patterns in Response to Climate
• Genetic data indicates similarities and differences among tribes which appeared otherwise similar based on cultural traits at the Late Holocene/Little Ice Age
• DNA is compared with linguistic data provide insights to migration and establishment chronologies
Consensus tree of western NA populations based on genetic
distances constructed with mtDNA haplogroup frequencies
AD 1400-1700-Little Ice Age: Cultural Establishment and
Specialization• Similar cultural
subsistence practices and socio-economies
• Diversification of labor based on classes or status
• Shared (formerly borrowed) cultural traits, but different languages and genetic origins
PNW Coast
Plateau
California
Overview of Evidence• Climate influences bio-
physical processes at various scales– Productivity, Hydrology
and Fire Regimes– Humans adapted to and
were influenced by climate’s influence on natural resources
• Archaeological evidence integrated with paleo-science data provides spatial and temporal phases in which to understand human-environment relationships
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