Timber

Timber production refers specifically to commerce oriented to the building industry—especially the ship-building industry—but also timber as fuel.
UI description:

Timber represents wood of enough quality available in the Holding for construction, from either local sources or trade.
Rich wood sources are found in Forest or Taiga terrain, and is usually unavailable in Desert or Drylands, but also in Farmlands. Forestry Buildings improve available timber in a holding.
County Development with its increased Population and land use decreases the amount of quality wood available.
Timber is essential for:

• The construction of Buildings.
• Ship-building, for the costs involved when an army attempts to move through the sea.
• As a source of fuel, such as in metalworking.
• For the creation of quality wooden artifacts.

CK3 game images used in this article are hyperlinks to navigate through the Crusader Kings III Wiki for appropriate explanations of game concepts.

Timber Base Value

Timber Base Value of a holding depends on:

1. (+) Traded Timber Value, from Timber Industry (see below).
2. (×) Forestry Building (multiplying all Buildings in a County):
   1. Logging Camps: +10%
   2. Resin Collectors: +15%
   3. Charcoal Burners: +20%
   4. Wood Pastures: +25%
   5. Tilled Fields: +30%
   6. Honey Pastures: +35%
   7. Forest Glassworks: +40%
   8. Sawmills: +45%
3. (×) Forest Cover Terrain (multiplying all Holdings in a County):
   •  Farmlands: 15%
   •  Floodplains: 10%
   •  Desert: 0%
   •  Desert Mountains: 0%
   •  Drylands: 10%
   •  Forest: 250% (slash-and-burn)
   •  Hills: 135%
   •  Jungle: 250%
   •  Mountains: 150%
   •  Oasis: 70%
   •  Plains: 100%
   •  Steppe: 50% (for steppe-forest areas)
   •  Taiga: 250%
   •  Wetlands: 90%
4. (+) A few county holders have traditionally a better access to timber sources (adding an extra Forest Cover Terrain modifier value to each held county):
   • King of Venice: from local production to Terraferma polities to legal management [Beaudoin 2014]
   • Emperor of Byzantium: local production around the Sea of Marmara was constant, so the emperor had usually access to timber, but—unlike the west—the empire didn’t regulate the use of forests, leaving it to particulars through taxes [Dunn 1994].
5. (×) Province Development modifier.
6. (÷) County Trade Deal Modifier:
   • Trading Post (Permanent): -15%
   • Trading House (5 years): -40%
7. (×) Province Trade Product modifier.

Trade Timber Value

Timber Trade Value adds up:

• (+) Timber Base Value (see above).
• (×) Banned Strategic Exports: +100%
• (÷) Increased Consumption from Development: (– –).
• (–) Holding timber Maintenance cost:
  •  Castle maintenance cost: -20% x Level
  •  Temple maintenance cost: -15% x Level
  •  City maintenance cost: -25% x Level
• (–) Active Construction cost:
  • Building construction cost: -75%
  •  Castle upgrade cost: -50%
  •  Temple upgrade cost: -100%
  •  City upgrade cost: -150%
• (–) Current Consumption from MAA:
  •   Skirmishers -40% (shield, lance)
  •   Archers -100% (bow/crossbow, arrows)
  •   Pikemen -100% (pike, shield)
  • Light Cavalry: -25% (lance; shield?)
  • Heavy Cavalry: -25% (lance; shield?)
  •   Horse Archer: -75% (bow, arrows)
  •   Camel Cavalry: -25% (lance)
  • Elephant Cavalry: -50% (lances; mounts..)

*Each unit of 100 consumes 25% of this value.

Timber Industry

Probably the most relevant aspect for historicity is that certain regions had a conspicuous lack of wood sources. So, for example, Muslims relied heavily on external sources—Iberia (NW Africa), Syria/SW Anatolia (Egypt, Middle East) and India (Persia, Arabia)—to maintain a usually poorly built and expensive fleet.

Europe

Data from 1512 Tagfahrt source of German Hanse.

Russian and Norwegian timber are the preferred sources, but trade connections are rather traditionally heavily reliant on Baltic sources (Gdansk, Königsberg, Riga). In fact, dendrochronology shows that shipbuilding from Scandinavia increased reliance on Baltic sources with time, which means that export potential weighed more than their estimated quality. Wood from the Baltic could be found up to Iberia.

Scandinavia

Norway, best quality. Selected Bergen due to Vanilla terrain and its direct trade with Iceland, Shetland, Orkney,… [Vandenabeele 2016]. Factor compensates for terrain worse than Novgorod
Bjorgvin · Scandinavia · Catholic · 35%.

Northern Europe

for Hanseatic Bremen and Oldenburg; not very good quality, but (much needed) crooked wood in Hansa [Vandenabeele 2016]
Oldenburg · Germania · Catholic · 10%.

Baltic

The selected Region corresponds to the orientation of each specific group.

Forests from Pomerania (near Stettin) [Vandenabeele 2016], probably through Wolin first, then Gdansk. Factor accounts for early trade
Landsberg · Germania · Catholic · 35%.

for Prussian timber and LMA Osterode/Ostroda planks [Vandenabeele 2016], probably through Königsberg
Allenstein · Central-East Europe · Catholic · 25%.

Forests from Livland and Courland (traded through Riga from its hinterland) [Vandenabeele 2016]. Factor accounts for late trade
Jersica · Scandinavia · Catholic · 15%.

Eastern Europe

Russian, best quality. Selected Scandinavia-Catholic for its trade with England and Hansa rather than Byzantium [Smith 2009]. 5 counties of Taiga mean a huge potential for export
Novgorod · Scandinavia · Catholic · 25%.

Byzantium

For Athos peninsula and other parts of the Khalkhidike, noted as exports forbidden by John I in 972, and still exported by Latins in 1278 [Dunn 1992]
Ierrisos · Byzantium · Orthodox · 50%.

Italy

Timber from Apulia shipped through Amalfi [Graham-Campbell 2007]. Historical aridity in Salerno [Beaudoin 2014]
Lucera · Italy · Catholic · 25%.

“Syrian” sources

Forests from Lebanon [Kedar & Wiesner-Hanks 2015]
Beirut · Jerusalem · Ashari · 25%.

Forests from the mounts near Lebanon [Kedar & Wiesner-Hanks 2015]
Baalbak · Jerusalem · Ashari · 10%.

“Western” Muslim sources

These here are just the sites organized mainly to provide the Muslim world that lacked them.

Alcácer do Sal (also Silves) covered in pines. Important for the Muslim world [cf. Constable 1994]
Montemor · Iberia (Muslim) · Muwalladi · 25%.

for Cuenca (due to forested areas in Vanilla). Important for the Muslim world [cf. Constable 1994]
Segura · Iberia (Muslim) · Muwalladi · 25%.

Levant coast and Tortosa (due to forested areas in Vanilla). Important for the Muslim world [cf. Constable 1994]
Fraga · Iberia (Muslim) · Muwalladi · 25%.

“Eastern” Muslim sources

Probably the most used source in Persia and Arabia were teak-wood from India’s western coast [Raychaudhuri & Habib 1982]:

for Surat teak-wood ship-building and exports [Raychaudhuri & Habib 1982]
Navasarika · India (North) · Digambara · 50%.

for western coastal teak-wood (unclear how much was exported/used)
Daman · India (North) · zurvanism · 25%.

for western coastal teak-wood (unclear how much was exported/used)
Thana · India (South) · Digambara · 25%.

for western coastal teak-wood (unclear how much was exported/used)
Panaji · India (South) · Yapaniya · 25%.

for western coastal teak-wood (unclear how much was exported/used)
Honnore · India (South) · Yapaniya · 25%.

for Malabar teak-wood ship-building and exports [Raychaudhuri & Habib 1982]
Calicut · India (South) · Vaishnavism · 50%.

for Malabar teak-wood [Raychaudhuri & Habib 1982]
Mahoyadapuram · India (South) · Vaishnavism · 25%.

for Malabar teak-wood [Raychaudhuri & Habib 1982]
Kollam · India (South) · Vaishnavism · 25%.

for Bengal teak-wood ship-building and exports [Raychaudhuri & Habib 1982]
Candradvipa · India (South) · Theravada · 25%.

for Sri Lankan ebony [Raychaudhuri & Habib 1982]
Kotte · India (South) · Theravada · 15%.