Intro

• Wood → central but oft overlooked role in history, from human evolution through the American Revolution and on to today
• Goal = reframe conventional wisdom of history being dominated by stone, bronze, and iron → most of our time has actually been dominated by wood
  • It is crucial for our physical, psychological, and envt health to return to the “Age of Wood”

Part I: Wood and Human Evolution

Our Arboreal Inheritance

• Western cultures → emphasize sepAration of man and nature, while Eastern cultures (where people lived near other primates) → continuity with nature
• Divide between primates and other mammals mostly from our adaptations to living in trees: softness and structure of our hands/grip, etc.
• Increase in body size, neocortical size, and intelligence occurred in response to changes in diet from arboreal lifestyle
  • Fruit is much more energy-rich than insects or vegetation, but requires memory of where/when to find it
  • Explains why fruit-eating monkeys are more intelligent than leaf-eaters
• What about difference between monkeys and apes?
  • Larger body size → falling from height has more severe consequences → more intelligence needed to understand and consider mechanics of tree branches
  • Ex. how well and carefully orangutans navigate, ability of many apes to make wooden tools
• Apes → humans: evolution of bipedalism... but hypothesis now = walking on two feet first evolved bc benefits for moving in the canopy!

Coming Down from the Trees

• Why did early humans continue semiarboreal lifestyles even after they had the ability to live on the ground?
• Fortuitous proprieties of wood:
  • Hardens after it dies → very useful for tools
  • Becomes flammable → fires became means of protection when living on the ground
    • Fires also → more time for social interaction, exchanging information
    • Cooking food → much more easy to mechanically digest, much higher energy yield

Losing Our Hair

• Likely more to reduce ectoparasite load than temperature regulation
• Did lead to new methods to keep warm at night— namely, wooden shelters, which have been shown to feel 2-8 deg warmer than surroundings!
  • Enabled expansion to colder climates, more strategies to stay warm— but by using intelligence rather than adaptation

Tooling Up

• First large tools likely wood, despite common narrative
  • Strength in both compression and tension (even more so when dried), vs brittleness of stone
  • Increasing success of humans ← development of wooden tools, esp weapons
    • First advance = using stone tools (usually smaller, like axes and saws) to construct wooden ones— woodworking! Whole act of making a tool for future use indicates large increase in complexity and thus intelligence
    • Composite weapons with stone and wood, new techniques of throwing spreads, ultimately development of the very complex wooden bow & arrow

Part II: Building Civilization

Clearing the Forest

• 15k ya, warming climate → advancing forests → adaptations in hunting techniques to smaller animals, development of tools to cut through trees
  • Ability to fell a tree → many new uses of material: whole logs and planks for construction/pathways, building watercrafts
• Spread of agriculture → more motivation to clear forests— by cutting them down if necessary, or fire (hard in wetter climates with large trees)
  • Development of axes, adze with stone, and all utilizing properties of wood very intentionally
• Coppicing = method of managing woodlands— some trees don’t die when cut down, but sprout new shoots that can be repeatedly harvested
  • Coppices grow more rapidly than a new tree bc have established root system, less distance to transport water, and produce straighter and stronger wood than branches
• Overall, use of stone tools to manage forests affected development of farming around the world, in diverse ways
  • In Europe, helped farmers clear the land; in New England, development of forest gardens, etc.

Melting and Smelting

• Ability to smelt and shape metals enabled by wood and often for the purpose of harvesting and shaping wood
• Long before use of metals, people developed charcoal-fired kilns for working with ceramics, glass— very difficult to get wood to burn at high enough temps, first converting wood to charcoal by limiting air supply
  • Charcoal also used to obtain pure metals from ores, bc reactive carbon pulled out oxides (or something like that)
• Copper and bronze tools → invention of plank ships (wider than just a log) and the wheel → revolutionized transportation
  • To see impact of metal tools, compare Old World & New World tech— not that people in the Americas didn’t invent plank ships and wheels themselves (small clay versions and isolated other examples exist), but never became widespread bc didn’t have the metal tools to do so

Carving Our Communities

• Use of iron: more difficult than copper/bronze bc can’t melt it down, but have to heat it up and hammer into shape, but material had several advantages
  • Better mechanical properties → finer and harder edges; could make “bad iron” which corroded less
  • Much more prevalent in Earth’s crust → could be mined and smelted locally, more cheaply
• Iron tools → continued tradition of green woodworking— using freshly-cut logs
  • One challenge = problems with “springing” for certain trees once cut down due to changes in prestressing
  • Advances in wooden architecture = using stone foundations to slow rotting, use of the roof truss
  • Viking longship
• Carpentry → used seasoned wood, more precise and better for smaller objects, used new set of iron tools
  • Saws, the plane
  • Could make things like doors, rectangular furniture
• Making rounded objects: technique of turning, relied on tools like the lathe → cups and dishes; steam-bending → things like barrels; all three techniques → better wheels

Supplying Life’s Luxuries

• Differences between density, color, etc. of different tree species → some used for decoration, luxury items
• Grain qualities of timber especially important in building musical instruments— transmitting vibrations, resonance; eventually replaced by iron, ivory, etc.
• Overall, the rich lived in a world with far less wood than the poor, but lifestyle would have required much more wood to power by means of charcoal needed to make the metals, porcelain, glass, etc. that they treasured

Supporting Our Pretensions

• History of architecture → development of better and better techniques to use timber stabilize and shorter stone buildings
  • Even in completely stone structures, wood used to build, chip off usable pieces
  • Possible that Stonehenge could have actually been covered in a ring-shaped wooden structure
• First stone structures = replicas of wooden ones, like the Parthenon, ancient Egyptian temples, but often had to rely on wooden supports for roofs, etc
• Romans → first ones to build large roofs, by invention of wooden roof trusses (ex. the Pantheon)
  • Gothic cathedrals made to look like entirely stone, but still had roofs supported by wooden trusses (why Notre Dame burned so easily)
• Stone castles often used wood paneling and shutters for insulation, as much better (10x!) at stoping heat loss
• Building styles in China seem less complex, but allow for flexibility that gives structures resilience to earthquakes

Limiting Our Outlook

• Reliance on wood imposed limits on “progress” during Middle Ages— stifled economic and population growth, development of new tech, helped impose conservative worldview
• Not just because trees didn’t grow fast enough to provide lumber and firewood
  • Bigger issue = harvesting and transporting large quantities of wood to where it needed to go → why medieval Eur cities are all by large rivers
  • Iron production especially limited by access to wood
• Production of wood items also time-consuming bc reliance on hand tools
• Scattered and decentralized nature of woodcrafts → innovations did not spread easily, long apprenticeships— conservative approach that leads to less mistakes but also less progress
  • Separation of intellectual life and crafts also studied progress

Part III: Wood in the Industrial Era

Replacing Firewood and Charcoal

• Brief Golden Age of the Dutch, fueled by their limited supply and use of peat as a fuel
• Use of coal in England (lots of mines) → expansion of London, mingling of lots of intellectuals and inventors → Royal Society, etc., spread of information → Scientific Revolution
  • Cheaper energy source → manufacturing of pottery and glass replaced wood, broke down power of craft guilds
  • Before coal could replace charcoal in iron smelting, new method of first converting coal to coke needed; led to cast iron which was great
  • Cast iron used for cannons, guns, steam engine
• Continental Europe didn’t switch to coal as fast, so still dealing with supply and transport issues of wood
• America improved charcoal method to smelting iron instead of using coke → still reliant on wood

Wood in the Nineteenth Century

• Despite all the aforementioned change, little affect on infrastructure— people still lived in relatively small wooden structure
• Invention of wrought iron → superior mechanical properties to wood and cast iron → used for new and bigger bridges, railways, in much bigger structures (like Crystal Palace), and esp. in building warships
  • Frames of Eiffel Tower, Statue of Liberty both designed by same guy out of wrought iron
• Wrought iron also employed to enhance how people could use wood
  • Ex. first machine tools/production line to make ship’s blocks (part of pulley system)
  • Combined iron and wood to get the best of both materials (led by North Americans and Scandinavians, who were still using a lot of timber): railways, nails, machine-made screws
• Production of wood pulp and methods to break down lignin to make paper from wood → more widespread media (newspaper, books)
• All the while, US relying most on wood for building/infrastructure

Wood in the Modern World

• End of 19th c → more widespread use of steel and concrete— and combined, in reinforced and prestressed concrete
  • Steel bridges, skyscrapers
• Age of polymers— thermoplastics, carbon fiber and other composites
• New wood materials: plywood (thin layers at different angles to get rid of anisotropic), cheaper forms like chipboard, wood laminates

Part IV: Facing the Consequences

Assessing Our Impact

• Deforestation myths— over exploitation of forests → environmental catastrophe → collapse of civilization
  • Based on false assumptions from our experience with modern industrial forestry
  • Little evidence that deforestation historically actually led to rapid soil erosion— usually happened very slowly, and was counteracted by farming practices
  • Amazonians managed forests pretty intensively (Dark Earths); that we only now are learning this shows that it was not inherently destructive
• Actual patterns: clearing of broad-leaf forests in preference of coniferous, bc sign of good soil
  • Initially cut down trees to clear land, not for timber; as demand for wood rose, most civilizations could meet it by managing small nearby forested areas
  • Only since industrialization has deforestation (esp. of coniferous forests, old growth regions) happened so rapidly as to threaten collapse
  • Also evidence for shifting composition of forests from centuries of selective logging
  • Age of Discovery after 1492 actually led to period of reforestation, as indigenous people were killed off by disease and their lands returned to forest
    • So extensive it may have contributed to Little Ice Age
• Plantation forestry → disastrous for many reasons
  • Assumes timber is only valuable resource → no diversity in species (only fast-growing, straight-trunks)
  • Outcompete native species and vegetation → forest fires
  • Monoculture very vulnerable to pests and disease which can spread to surrounding ecosystem
  • Doesn’t fit with time scale of supply and demand

Mending Our Strained Relationship

• Role of science and tech: creating new materials derived from wood (polymers to replace plastic, replacements for concrete and steel)
  • However, still very energy intensive, doesn’t connect us with trees directly
• Urban forestry → planting trees in cities
  • Benefits of temp control, air quality, but still level of disconnect between value of the trees and people
• Implementing more sustainable/low-impact logging methods
• Overall, integrating our society more with the outdoors, woodcraft, etc.