PREFACE ........................................................ xi
LIST OF CONTRIBUTORS ......................................... xiii
1. INTRODUCTION TO SUSTAINABLE UTILISATION OF FOREST ENERGY ..... 1
Anders Lunnan, Inge Stupak, Antti Asikainen, Karsten
Raulund-Rasmussen
1.1. Introduction ............................................ 1
1.2. Energy policy ........................................... 2
1.3. Sustainable development and forest policy ............... 4
1.4. The WOOD-EN-MAN project ................................. 6
1.5. References .............................................. 7
2. FOREST ENERGY RESOURCES AND POTENTIALS ....................... 9
Dominik Röser, Antti Asikainen, Inge Stupak, Karri
Pasanen
2.1. Introduction ............................................ 9
2.2. Natural conditions ..................................... 11
2.3. Types of forest bioenergy .............................. 12
2.3.1. Forest types .................................... 15
2.3.2. Differences among tree species .................. 16
2.3.3. Physical properties ............................. 17
2.4. Present use of forest biomass for energy ............... 18
2.4.1. Firewood ........................................ 18
2.4.2. Primary residues ................................ 19
2.4.3. Secondary residues .............................. 20
2.5. Estimation of woodfuel potential ....................... 21
2.5.1. Net annual increment, fellings, and roundwood
balance ......................................... 21
2.5.2. Residues from fellings and roundwood balance .... 23
2.6. References ............................................. 26
3. EFFECTS OF VERY INTENSIVE FOREST BIOMASS HARVESTING
ON SHORT AND LONG TERM SITE PRODUCTIVITY .................... 29
Karsten Raulund-Rasmussen, Inge Stupak, Nicholas Clarke,
Ingeborg Callesen, Heljä-Sisko Helmisaari, Erik
Karltun, Iveta Varnagiryte-Kabasinskiene
3.1. Introduction ........................................... 29
3.2. Nutrient fluxes to and from forest ecosystems .......... 32
3.2.1. Deposition ...................................... 33
3.2.2. Leaching ........................................ 38
3.2.3. Nutrient removals in forest biomass
harvesting ...................................... 40
3.2.4. The soil as a source and a store of nutrients ... 47
3.3. Assessment of long term productivity consequences
of very intensive harvesting ........................... 53
3.4. Case studies - examples of assessments of
vulnerability and compensation recommendations ......... 57
3.5. Synthesis and nutrient compensation recommendations .... 65
3.6. References ............................................. 70
4. WOOD ASH RECYCLING - POSSIBILITIES AND RISKS ................ 79
Erik Karltun, Anna Saarsalmi, Morten Ingerslev, Malle
Mandre, Stefan Andersson, Talis Gaitnieks, Remigijus
Ozolinčius, Iveta Varnagiryte-Kabasinskiene
4.1. Introduction ........................................... 79
4.2. Wood ash properties .................................... 80
4.2.1. Wood ash composition and quality ................ 80
4.2.2. Contamination risks ............................. 83
4.2.3. Pre-conditioning before recycling ............... 85
4.3. Effects of wood ash application on soils ............... 86
4.3.1. Soil acidity changes ............................ 86
4.3.2. Effects on microbiological processes
in the soil ..................................... 88
4.4. Effects of wood ash application on trees ............... 91
4.4.1. Mineral soils ................................... 91
4.4.2. Peat soils ...................................... 92
4.4.3. Tree physiology, morphology and biochemical
status .......................................... 93
4.4.4. Effects on fine root growth, mycorrhiza and
vitality ........................................ 94
4.5. Effects of wood ash application on ground and
understorey vegetation ................................. 95
4.5.1 Species composition .............................. 95
4.6. History, current use and regulation of ash recycling ... 97
4.7. Recommended doses and regulations ..................... 100
4.8. References ............................................ 101
5. INSECT PESTS AND FOREST BIOMASS FOR ENERGY ................. 109
Leif Martin Schroeder
5.1. Introduction .......................................... 109
5.2. Pest species .......................................... 110
5.2.1. The spruce bark beetle ......................... 111
5.2.2. Pityogenes chalcographus ....................... 112
5.2.3. The pine shoot beetles ......................... 112
5.2.4. The pine weevil ................................ 114
5.3. Risk for tree mortality in relation to insect
density and tree vigour ............................... 114
5.4. Insect reproduction in forest fuel .................... 116
5.5. Influence on regional population densities ............ 118
5.6. Risk for damage close to forest fuel piles ............ 119
5.7. Legislation ........................................... 121
5.8. Conclusions ........................................... 122
5.9. Management recommendations from an insect pest
perspective ........................................... 123
5.10.References ............................................ 124
6. THE EFFECTS OF FOREST BIOMASS HARVESTING ON BIODIVERSITY ... 129
Mats Jonsell
6.1. Introduction .......................................... 129
6.2. Potential problems for biodiversity due to forest
biomass harvesting .................................... 130
6.3. Organisms that may be affected by bioenergy use ....... 131
6.3.1. Wood living organisms .......................... 131
6.3.2. Organisms dependent on piles of logging
residue ........................................ 132
6.4. Associations with different types of wood ............. 133
6.4.1. Tree species ................................... 133
6.4.2. Sun exposure ................................... 134
6.4.3. Diameters ...................................... 135
6.4.4. Decay stages ................................... 137
6.4.5. Tree part ...................................... 137
6.5. Dispersal of saproxylic organisms ..................... 138
6.6. Risks for species loss ................................ 140
6.6.1. Processes that create dead wood in natural
and managed forests ............................ 141
6.6.2. Risks of species loss due to degree of
sun exposure ................................... 143
6.6.3. Risk of species loss due to tree species
associations ................................... 145
6.7. Trapping of insects in piles of logging residues ...... 145
6.8. Management recommendations ............................ 147
6.8.1. Extraction of logging residues ................. 147
6.8.2. Storage of logging residues in the forest ...... 148
6.9. References ............................................ 148
7. REVIEW OF RECOMMENDATIONS FOR FOREST ENERGY HARVESTING
AND WOOD ASH RECYCLING ..................................... 155
Inge Stupak, Antti Asikainen, Dominik Röser,
Karri Pasanen
7.1. Introduction .......................................... 155
7.2. Environmental aspects ................................. 157
7.2.1. Soil nutrient fertility ........................ 157
7.2.2. Soil organic matter and carbon storage ......... 164
7.2.3. Wood ash recycling and other nutrient
compensation ................................... 165
7.2.4. Hydrology and water ............................ 171
7.2.5. Biodiversity ................................... 171
7.2.6. Insect pests and fungal diseases ............... 174
7.2.7. Harvesting damages ............................. 176
7.3. Silvicultural aspects ................................. 178
7.3.1. Woodfuel from early thinnings .................. 178
7.3.2. Logging residues from forest regeneration ...... 179
7.3.3. Stump harvesting ............................... 180
7.3.4. Storage ........................................ 181
7.4. Costs, technical, and logistic aspects ................ 181
7.4.1. Existing recommendations and guidelines ........ 182
7.4.2. Harvesting of forest fuel - overview of cost
factors ........................................ 183
7.4.3. Accessibility .................................. 183
7.4.4. Density, amount of harvestable fuel, and
forwarding distance ............................ 183
7.4.5. Quality of chips ............................... 185
7.4.6. Storage of harvested material to buffer
demand ......................................... 185
7.4.7. Harvesting methods ............................. 186
7.5. Economic aspects ...................................... 186
7.6. Social and health aspects ............................. 188
7.7. Landscape, archaeology, culture, non-wood goods ....... 188
7.8. Benefit and drawback trade-offs ....................... 189
7.9. Conclusions ........................................... 191
7.10.References ............................................ 191
8. POLICY AND ECONOMIC ASPECTS OF FOREST ENERGY UTILISATION ... 197
Anders Lunnan, Lelde Vilkriste, Gunnar Wilhelmsen,
Diana Mizaraite, Antti Asikainen, Dominik Röser
8.1. Introduction .......................................... 197
8.2. Sustainability from an economic point of view ......... 199
8.2.1. Sustainable production of woody biomass ........ 200
8.2.2. Sustainable use of woody biomass ............... 203
8.3. Constraints and measures of bioenergy utilisation ..... 205
8.4. Supply of wood-based biomass for energy ............... 209
8.5. The market for wood for energy ........................ 218
8.6. Regional co-operation and impacts ..................... 225
8.7. External effects - economic and regulatory aspects .... 228
8.7.1. Investment programmes .......................... 228
8.7.2. Joint implementation ........................... 229
8.7.3. Green electricity - Green Certificates ......... 230
8.7.4. Bioenergy-based thermal production ............. 231
8.7.5. Promotion and use of biofuel for transport ..... 231
8.8. Conclusions ........................................... 231
8.9. References ............................................ 232
9. ENERTREE - DECISION SUPPORT TOOL TO ANALYSE FOREST
BIOMASS EXTRACTION SCENARIOS ............................... 235
Karri Pasanen, Inge Stupak, Dominik Röser, Antti
Asikainen, Karsten Raulund-Rasmussen
9.1. Introduction .......................................... 235
9.2. Decision making on forest energy by forest owners ..... 237
9.3. EnerTree .............................................. 239
9.3.1. Model structure ................................ 240
9.3.2. Decision environment ........................... 240
9.3.3. Input variables ................................ 243
9.3.4. Stand characteristics .......................... 245
9.3.5. Growth and harvesting simulations .............. 245
9.3.6. Decision criteria and alternative scenarios .... 246
9.4. EnerTree example calculation .......................... 250
9.5. Evaluation and future developments .................... 252
9.6. References ............................................ 254
INDEX ......................................................... 257
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