Forest simulation models in Norway:

1

COST ACTION FP0603 Forest models for research
and decision support in sustainable forest
management

• Forest simulation models in Norway
• main developments and challenges
• Kjell Andreassen and Tron Eid

1st Workshop and Management Committee
Meeting.Institute of Silviculture, BOKU.8-9 of
May 2008Vienna, Austria
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Main features of Norwegian forests

• Forest cover (total/share)
• 8 mil. ha / 28 of land productive forest
• 2 mil. ha / 6 Non-productive forest
• 13 mil. ha / 46 Higher altitude than
  coniferous forest boundary line
• Growing stock, annual growth and cuts
• 680 mil. m3, 25 mil m3 y-1, ca 35 of the
  annual growth is cut
• Main species
• Picae abies (46), Pinus sylvestris (32), Betule
  pendula/pubescens (14), others (8)
• Main non-wood products and services
• Berries, hunting (35.ooo moose hunted/yr),
• Climate restrictions/protection, biodiversity,
• Recreation, cabins
• Main risks
• Droughts
• Windthrows
• Fungi insect attacks
• Water floods
• Effects of climate change
• Few forest fires (0.004 of area/yr gt 23500 yr
  rotation of fires)

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Forest modelling approaches and trends

• Empirical models
• Stand models (mean tree method) are widely
  used (i)
• The trend has been towards individual tree-level
  (ii)
• Models exist for the main coniferous trees, birch
  and other broadleaves
• Diameter distribution models for the main species
• Recent research has been concentrated to
• New growth models has been developed
• Modelling regeneration
• Modelling uneven-aged management
• Modelling non-timber products and services

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Forest simulator
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Forest modeling approaches and trends in Norway
System Biology Economy Multi-functional aspects User flexibility
S50-software (Gotaas 1967) Volume directly - No None
Avvirk1 (Hobbelstad 1979) Volume directly - No A little
Avvirk2 (Hobbelstad 1981) Volume Directly - No Some
Avvirk3 (Hobbelstad 1988) Average Tree yes No Good
Gaya-JLP (Hoen Eid 1990) Average Tree yes No High
Bestprog (Blingsmo Veidahl 1991) Average Tree yes No Good
Avvirk-2000 (Eid Hobbelstad 1999 ? Average Tree yes Some Good
Gaya/Sgis (Hoen Gobakken 1997? Average tree yes Yes High
T (Gobakken, Lexerød Eid 2007 ? Individual tree
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Advantage of Individual-tree models vs Stand
level based models

• May describe forest dynamics according to
• - selective cutting in un-even-aged forest
• - different thinning methods, seed trees and
  shelter wood in even-
• aged forest
• - traditional treatments in even-aged forest
• Timber quality (tree size and wood properties)
• Forest structure (within-stand diversity)
• Multi-functional aspects (e.g. lichen,
  biomass/carbon)
• Permanent country representative sample plots
  from NFI
• Laser-scanning -gt diameter distribution -gt
  individual trees

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Sub-models used in the T-simulator
Task Dep. var. Independent variables Independent variables Independent variables
Tree Stand Site
Recruitment young even- aged forest (Lexerød Eid 2005) iN A, N, PNsp ALT, LAT, SI
Height growth young even- aged forest (Tveite 1977) h A SI
Recruitment old even-aged and uneven-aged forest (Lexerød 2005) iN BA, PBAsp, N, HD, LAY ALT, LAT, SI, VT
Diameter growth old even-aged and uneven-aged forest (Bollandsås 2008) id d, bal BA, PBAsp SI, LAT, R
Height relationship old even-aged and uneven-aged forest Bollandsås (2008) h d ALT, LAT, SI
Mortality old even-aged and uneven-aged forest (Eid Tuhus 2001) Ps d, bal PBAsp SI
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Economical sub-models

• Cost functions for harvesting/forwarding
• f(dbh, volume ha-1, harvesting method)

• Timber price f (dbh, h)

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Modelling non-timber products and services

• Moose hunting (meat and recreation) vs timber
  production. Important in Norway
• Recreation in forest areas
• Water yield, water quality, trade-offs of water
  and forest

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Models for predicting risk of hazards

• Windthrows (some simple models is developed)
• Fire ecolocical effects
• Fire probability and damage Ecological
  important for many species. Effects on
  vegetation, mosses

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Simulators and information systems

• Inventory
• NFI
• Forest owners assosiation
• Stand level simulators
• Bestprog
• Gaya/Sgis
• Avvirk 2000
• T - simulator
• Forest level decision support systems
• Avvirk 2000
• Gaya
• Process based simulators
• No process based simulators are still developed
  in Norway

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Future challenges

• How to simulate mixed forests and mixed treatment
  
• Process based models - conversion from
  international models
• Non-timber products and services
• Model risk and succession (after hazards)
• Distance dependent individual tree growth models
• A more flexible stumpage value calculation system
• Models describing wood properties
• Multiple use and environmental aspects
• Other production functions (berries, forest
  structure)
• 3-D GIS interface
• Carbon budget
• Integrate and demonstrate the potential of models
  and simulators for both scientists and other
  users. Further development/calibration of basic
  biological models.

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Some references

• Eid, T. Hobbelstad, K. 2000. AVVIRK-2000 - a
  large scale forestry scenario model for long-term
  investment, income and harvest analyses. Scand.
  J. For. Res. 15 472-482.
• Eid, T. 2004. Testing a large-scale forestry
  scenario model by means of successive inventories
  on a forest property. Silva Fenn. 3 305-317.
• Lexerød, N. Eid, T. 2006. Assessing suitability
  for selective cutting using a stand level index.
  Forest Ecology and Management 237503-512.
• Gobakken, T., Lexerød, N. Eid, T. 2008. T a
  forest simulator for bio-economic analyses based
  on models for individual trees. In press.
  Scandinavian J. of Forest Research.
• Andreassen, K. Tomter, S. 2003. Basal area
  growth models for individual trees of Norway
  spruce, Scots pine, birch and other broadleaves
  in Norway. Forest Ecology and Management
  18011-24.