Anthro C12AC

Mon, 01 Jan 0001 00:00:00 +0000

Anthropocene #

The time when human activity began to have an influence on (global) landscape due to our use of fire
Large subject used in a range of fields – no single definition
Defining feature: combustion of carbon and greenhouse gases
Ice core measurement technique
- As ice forms, methane and CO2 get trapped along with ash/dust/pollen which scientists can measure by coring
- Ice can be dated so we can compare these variables so we can see change in greenhouse gases over time
Beginning is disputed
- Industrial revolution (1780s)
  - Most popular among scholars
- Atomic Testing (1940s)
  - The isotopic by-products of bomb testing provide a distinctive marker horizon in ice cores, ocean and lake sediments, and soils
- Stages idea:
  - Includes vital events such as forest cutting and grassland conversion: the two largest spatial transformations of Earth’s surface in human history
  1. 1.8 million years ago: When fire was discovered
  2. 6000-4000s years ago: With neolithic agriculture
  3. 1780s: Industrial revolution
Identifying fire requirements:
1. Evidence of temporal or spatial changes in fire activity and vegetation
2. Demonstration that these changes are not predicted by climate parameters alone
3. Temporal/spatial coincidence between fire regime changes and changes in the human record

Pyrogeography #

History of the variation of fire activity over space and time at the landscape scale in different regions of the world
Pyrogeography started in Silurian period when plant life began
Fire requirements: 13% Oxygen in a normal environment and 30% Oxygen in damp vegetation.
Fires are a selection force in the evolution of plants

Four phases for Pyrogeography #

1. Natural Biospheric Fire – Natural Fire Regime #

(Potential) start date for pyrogeography
During Silurian and Devonian Periods (440-400 HYA)
Natural fire regime started during this period because it was the first time that the fire triangle came together
Fire triangle:
- Ignition Source: (Since beginning) Natural ignition from lightening (most common), volcanoes, (rarely) falling rock sparks
  - These natural sources tend to only begin fires in the dry season
  - Lightening is most common in mountain regions (over a costal region)
- Oxygen Source: (Cambrian period) Atmospheric Oxygen (from photosynthetic plants) leads to appearance of photosynthetic organisms
- Fuel Source: (Silurian and Devonian Periods) Enough terrestrial plants in ecosystems to acts as fuel
During this time, natural fire regimes evolved
- As coal became more common (Carboniferous period), fires did too
Started long time ago, before humans and dinosaurs

2. Wildland Anthropogenic Fire – Hunter/Gatherer Fire Regime #

When people began acting as the ignition source
Primarily used fire for domestic cases
- Heating, cooking, warmth, etc.
When people move to a new land
- Major changes in fauna, vegetation, and fires (charcoal)
- People seem to bring fire with them as they migrate
Start dates
- 40 ka for Australia
  - 90% of fauna went extinct
  - Lots of evidence of fire
- 45 ka for Highland New Guinea
- 50 ka for lowland Borneo
- 20 ka for the Americas
  - Extinctions of many animals and vegetation
    - Debate: are these because of natural process like climate change (ice age -> post ice age?) or do people play a large role
  - Native Perspective – Indigenous people have been here since time began

When did humans actually discover fire? #

Defining the bridge between phase one and two is difficult
Definition problems
- Do we ask when did (modern humans / hominin ancestors) develop the ability to control and utilize fire?
- We also need to distinguish between (1) controlling / utilizing fire and (2) being able to start a fire on a whim
Archeological problems
- Fire exists naturally, so we can’t assume all fire evidence is from human action
- Other natural processes can look like fire (e.g. staining by minerals in soil, oxidation causing reddish patches)
- Combustion of natural objects (e.g. bushes) can leave charcoal which looks like a human hearth
  - Additionally, evidence of a hearth doesn’t mean that humans started/controlled fire
- Provides a single snapshot, has little temporal depth
Archaeological Record Analysis
- In the field:
  - Observation and collection of materials
  - Study the geology of the site
- In the lab:
  - Microscopic analysis to see if there was burning
  - If so, could the location of the sample been transported after combustion?
  - Further, how does the history of the burned object associate with cultural items

How long has fire been controlled? #

Europe: Strong evidence of 400,000 - 300,000 years ago
Western Asia: One established case from 780,000 years ago. Other sites are similar to Europe
Africa: Claims have been made for a cave site that shows fire around 1.5-1.6 million years ago
Note that opportunistic use of fire could have happened much earlier
- Eg. lighting a torch from a natural-starting forest fire

3. Agriculture Anthropogenic Fire – Agricultural Fire Regime #

Required fire to alter the natural vegetation from perennial-dominated to annual-dominated landscapes.
People preferred to live in fire-prone places because the burning provides advantages for hunting, foraging, cultivating, and livestock herding

4. Industrial and Domestic Anthropogenic Fire – Industrial Fire Regime #

Low-severity surface fire regimes are being replaced with low-frequency, high-intensity crown fires that are outside the historical range of variability for these ecosystems
Western US: forests have also experienced an increase in hazardous fuels due to highly effective fire suppression policy that excluded fires for much of the 20th century
Eastern US: Fire suppression has shifted oak and pine woodlands to mesophytic hardwoods consequently reducing flammability and fire activity
Globally: urban areas have steadily expanded into wildland areas
- Producing more ignition sources (arson and accidental)
- Exposing more people to wildfire

Key Factors in Fire Regimes (Discussion 8-30) #

Frequency
- The interval of fire occurrences
- E.x. every four years
Area
- Size, distribution, location
- Ground fires (primarily dead plants) vs crown (burning upper canopy of living trees)
  - Crown fires areas are more difficult to manage because controlled burns still damage natural resources
Severity
- How destructive a fire is (high mortality = high severity)
- Change in dominant species / change in ecosystem
- Quantifiable by how much soil on the ground is visible
Seasonality
- How the season affects fires
- May or may not be annual
- May arise due to weather conditions
- Ex. Annual to decadal cycles of drying conditions
Interactions
- General activity on the landscape leading to different fire outcomes
- Droughts leading to stress on fuels
- Beatles eating bark, making trees more vulnerable
- Fire suppression leading to less severe fires
- Climate change making fires more severe

Biodiversity and Fire as a Selective Variable in Evolution #

C4 grass
- Spread during seasonal climate in the tertiary period (when fires became more common)
- Fires lead to woodlands and created environments favorable to C4 grasslands
- Since C4 is high flammability, it would have produced a feedback process that further increased fire activity,
  - Thus maintaining the grassland-dominated landscape
  - This process is similar to the one currently maintaining many of our savannas
Plant attributes
- Heat shock
  - Certain species have seeds that will open with heat
  - Not exclusive to fire; correlated with soil heat too
- Smoke
  - Highly selective and specific to fire
  - Smoke is a mixture of specific chemicals unique to itself
- Note that plants become resistant to certain fire regimes, not necessarily all
  - Changes in fire regime can kill off fire resistant plants
Even small differences in the deployment of fire outside of natural lightning strikes can alter patterns of forest succession, fuel availability, and seasonality of ignitions

Fires Relating to Evolution #

Beneficial Attributes
- Cooking hypothesis
  - Key claim: Fire + cooking started with the Homo erectus. As such, humans have evolved around a cooked diet that they can’t live without
  - Led to fitness advantage
  - More energy + nutrient from food, enabling body and brain size increase
  - Detoxing effect
  - Increase digestibility of all food
  - Cooking takes time, leading to social development
    - Distribution of tasks among group: (collection, preparation, even stealing)
  - Cooking accounts for reduction in jaw, tooth size (due to softer food), stomach, and digestive system size
  - There is no evidence of modern human societies existing without cooked food
  - Counterpoints:
    - It’s still unclear that Homo erectus controlled fire
    - There are some sites that show no example of cooking: e.g. Neanderthal sites in cold climates
    - Energetic effects aren’t well quantified
    - Digestive evolution may not have been linear; other adaptations related to fire occurred after Homo erectus
- Protection benefits at night (especially versus the alternative: sleeping in trees)
- Allowed much better vision in caves
  - Enables cave art
- Evidence that some hominids could use fire to morph certain woods into tools (e.g. digging sticks, hafted spears)
- Allowed humans to colonize colder environments
- Increase prey abundances, maintain mosaic landscapes, and increase pyrodiversity and succession stage heterogeneity
Social bonding
- Led to camp fires
- Allows people to stay up later
- Fire could be used as a story telling enhancer, means to pass on history, culture, etc.
- Provides a sense of intimacy and openness
- Opportunity for music
Fire-stick farming
- clearing ground for human habitats
- facilitating travel
- killing vermin, hunting
- regenerating plant food sources for both humans and livestock
- warfare among tribes
Woody, closed-canopy shrublands were opened up or entirely displaced
- Led to spread of fast-growing annual species that provided greater seed resources, travel, and hunting and planting opportunities
- Ex. CA land was only used for agriculture after burnings, which led to many other alien plants spreading too
- Reductions in arboreal cover and woody understory have the most potential to enhance erosion
- Reshaping of landscapes has posed problems for ecologists trying to understand contemporary landscape patterns

Overview of Fires in California #

Conflagrating California

EECS 126

Mon, 01 Jan 0001 00:00:00 +0000

I did not take digital notes, but can vouch for these below.

CogSci C100

Mon, 01 Jan 0001 00:00:00 +0000

CS194

Mon, 01 Jan 0001 00:00:00 +0000

Redirecting to cs194.mehvix.com… #

Frank's ASAMST 20A

Mon, 01 Jan 0001 00:00:00 +0000

Week 1 (January 18 & 20): Introduction to the course. History, Memory, and Racialization #

Reading: Tataki, Strangers from a Different Shore, Preface and Ch. 1: “From a Different Shore.”

What is Asian American Studies?

Panethnicity
- “pan” - a conglomeration
- “ethnicity” - belonging to a social group
- Panethnic identity example: Asian American
Panethnicity Cultural Literacy
- One’s competency about their implicit biases

Reading:

Angel Island versus Ellis Island
- Angel Island was the west coast immigration entry point for people coming from the west (mainly Asian migration)
- Ellis Island was the entry point for many immigrrants from the east (mainly European)
“Multiculuralism was a find of fear and optimism around how we are a very mixed country and what binds us together is this appreciation of different ethnic backgrounds, but we also assimilate under some cultural practice/viewpoint” - Michael Chang

Docs on notes.mehvix.com

Anthro C12AC

Anthropocene #

Pyrogeography #

Four phases for Pyrogeography #

1. Natural Biospheric Fire – Natural Fire Regime #

2. Wildland Anthropogenic Fire – Hunter/Gatherer Fire Regime #

When did humans actually discover fire? #

How long has fire been controlled? #

3. Agriculture Anthropogenic Fire – Agricultural Fire Regime #

4. Industrial and Domestic Anthropogenic Fire – Industrial Fire Regime #

Key Factors in Fire Regimes (Discussion 8-30) #

Biodiversity and Fire as a Selective Variable in Evolution #

Fires Relating to Evolution #

Overview of Fires in California #

EECS 126

CogSci C100

CS194

Redirecting to cs194.mehvix.com… #

Frank's ASAMST 20A

Week 1 (January 18 & 20): Introduction to the course. History, Memory, and Racialization #