Deliverable 6: List of ongoing experiments - Ctba

List of ongoing experiments 

Deliverable D6 

STODAFOR – Storm Damaged Forests : efficient and safe 

harvesting and log conservation methods 

May 2003 

Didier Pischedda, CTBA, France 

Emmanuel Bastet, CTBA, France 

Project Coordinator : CTBA, 10 avenue de Saint Mandé 75012 Paris, www.ctba.fr/stodafor/index.htm 

Project partners : FVA (D), KVL (DK), EMPA (CH), CBE (P), BFH (D), UPM (E), DLFRI ( DK), TTI (I), Afocel (F), TUD (D), BRE (UK), 

FMRE (A), ICSTM ( UK), UOP (UK), NISK (N)

Participants: 

This European project is currently carried out by the following 16 partners under the global 

coordination of CTBA. 

CTBA, Technical Institute for Wood Technology and Furniture Manufacture (France): 

Didier Pischedda – Coordinator 

Emmanuel Bastet 

FVA, Forest Research Institute of Baden-Wuerttemberg (Germany): Gerold Mahler 

Manuela Bacher 

Christian Pfeil 

KVL, Royal Veterinary and Agricultural University (Denmark): Andreas Bergstedt 

EMPA, Swiss Federal Laboratories for Materials Testing and Research (Switzerland): Martin Arnold 

CBE, Biomass Centre for Energy (Portugal): Joana Carinhas 

BFH, Bundesforschungsanstalt für Forst- und Holzwirtschaft (Germany) : Rolf-Dieter Peek 

UPM, Universidad Politecnica de Madrid (Spain): Eduardo Tolosona 

DLFRI, Danish Forest and Landscape Research Institute (Denmark): Ebbe Boellehuus 

TTI, Trees and Timber Institute (Italy): Claudio Pollini 

Claudia Nati 

Lorenzo Valenti 

AFOCEL, Association Forêt Cellulose (France): Maryse Bigot 

Jérôme Moreau 

TUD, Technical University Dresden (Germany): Claus-Thomas Bues 

BRE, Building Research Establishment (UK): Keith Maun 

FMRE, Institute of Forest and Mountain Risk Engineering (Austria): Ewald Pertlik 

ICSTM, The Imperial College of Science Technology and Medicine (UK): David Dickinson 

UOP, University of Portsmouth Higher Education Corporation (UK): Rodney Eaton 

NISK, Norsk Institutt for Skogforskning (Norway): Jan Bjerketvedt 


Project partners : FVA (D), KVL (DK), EMPA (CH), CBE (P), BFH (D), UPM (E), DLFRI ( DK), TTI (I), AFOCEL (F), TUD (D), BRE 

(UK), FMRE (A), ICSTM ( UK), UOP (UK), NISK (N) 

2

Contents 

Participants: 2 

1. Objectives 4 

2. General comments 4 

3. List of ongoing experiments 4 

3.1. France 4 

3.2. Germany 5 

3.3. Switzerland 6 

3.4. United kingdom 6 

4. Patents 6 

5. Conclusion 7 

Annexes 8 




3

1. Objectives 

The main objective of Workpackage 4 was to make out a list of the ongoing research and 

experiments started after December 1999. 

2. General comments 

All the partners were involved in this work. Nevertheless, only 4 countries launched some 

research following this event since many of them such as the UK, Spain, Portugal, Norway 

and the Netherlands were not affected by the storm. The numbers of ongoing research is the 

following: 

• France : 10 

• Germany : 5 

• Switzerland : 2 

• Great Britain : 1 

Due to the rather late date of the project’s “kick-off” (November 2001), most of the ongoing 

research were launched before any common harmonised procedures were ready for use, 

especially with regard to log conservation. But the fact remains that the work out of these 

common procedures will greatly improved the exchange between countries in the future. 

3. List of ongoing experiments 

3.1. France 

Institute Title Description / remarks Annexe 

CTBA 

CTBA, 

ONF, 

DERF 

CTBA, 

INRA, 

LRBB 

Assessment of the beech (Fagus 

sylvatica) properties and more 

precisely its coloration following a 

period of immersion and water 

spraying 

Comparison between logs conserved 

under water spraying conditions and 

green timbers in terms of sawing, 

drying, and planing processes, and in 

terms of environmental and trade 

issues 

Assessment and improvement of live 

conservation method of blown trees 

for beech (Fagus sylvatica) 

Experimental site for maritime 

pine’s log conservation (Pinus 

Pinaster) using three different 

methods 

Objectives:⇒ Colour assessment 

⇒ Assessment of the ‘steaming’ process 

⇒ Assessment of rotary cutting of veneer 

⇒ Environmental impacts (PH, COD, 

Nitrogen, BOD) 

Objectives: Comparison between green and ‘water 

sprayed’ logs in terms of : 

⇒ sawing/planing process 

⇒ Kiln drying process 

⇒ Environmental impacts 

Objectives: 

⇒ Assessment of the wood quality of live conserved 

trees (according to the CTBA’s protocol and in term 

of economical loss) 

⇒ Assessment of the wax application method on the 

faces 

Goals: ⇒ Assessment of the mechanical properties 

(MOE, MOR) using non destructive methods 

⇒ Environmental impacts (PH, COD, 

Nitrogen, BOD, toxicity) 

⇒ Assessment of the industrial site 




4 

1 

2 

3 

4

AFOCEL 

CTBA 

LEF 

(Economic 

Laboratory 

of Forestry 

of 

ENGREF) 

Storage of logs under water 

sprinklers: Regulations, technical 

and economical aspects 

Blue staining in maritime pine 

(Pinus Pinaster) windthrown stored 

on site 

Fibres quality of maritime pine 

windthrowns stored on site and 

under water sprinkling 

Assessment of beech (Fagus 

sylvatica) storage under humid 

conditions: compact piles covered 

with plastic sheets (PVC) and 

polyethylene sheets 

Assessment of storage under drying 

conditions (compact pile/ log 

debarked) of spruce (Picea abies) 

and fir (abies alba) 

Log conservation in France by water 

spraying/ economic issues 

3.2. Germany 

Description of the French regulations, the equipment 

and the economical aspects that need to be taken into 

account to implement a water sprayed site 

Monitoring of the evolution of blue staining in 

windthrown maritime pine stored on site for 10 

months 

Moisture content, pulping yield and kraft parper 

properties were assessed every month for 3 different 

type of conservation: on site; wet storage and dry 

storage 

Thanks to a special device, the logs were regularly and 

visually monitored as well as the moisture content in 

each batch within a 2 years period. 

After a 6 months period of storage, 2% loss in yield 

and 18.5% economic loss due to downgrading of the 

raw material 

Goals: ⇒ Economic assessment of log conserved 

under water spraying 

⇒ Assessment of the industrial site 

Institute Title Description / remarks Annexe 

FVA 

Log conservation under oxygen 

exclusion / Oxygen exclusion 

method: 2000-2001 

Storm damaged forest: Efficient and 

safe harvesting and log conservation 

methods - 1 

Storm damaged forest: Efficient and 

safe harvesting and log conservation 

methods - 2 

Beech conservation under oxygen 

exclusion 

Root rot in water stored piles 

Goals: improvement of the method for fir, larch, 

Norway spruce, beech, Douglas fir (assessment for 

sawmill and veneer mill quality) 

Objective: conservation of logs wrapped with plastic 

film under realistic conditions (e.g. 2500 m3 beech 

roundwood for production of veneer were packed up 

for industries in plastic film) 

Objective: storage under plastic films: estimation of 

the surviving rate of wood damaging insects and fungi 

at conifer logs, that were stored without oxygen for 

different long times. 

Assessment of beech conservation under oxygen 

exclusion during a 16 months period in terms of 

discoloration, cracks and exterior and interior wood 

quality 

Assessment of root rot evolution under water 

sprinkling conservation on Spruce and Fir 




5 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15

3.3. Switzerland 

Institute Title Description / Remarks Annexe 

EMPA 

Study of extent, detection, cause and 

consequences of compression 

failures 

Collection and analysis of current 

experiences with different methods 

3.4. United kingdom 

Wood utilisation: wood properties, grading, early 

detection, modelling of damage mechanisms 

Log conservation, entomology, wood quality 

monitoring by ultrasonic 

Institute Title Description / Remarks Annexe 

UOP 

4. Patents 

Susceptibility of harvested 

softwoods to infection by sapstaining 

fungi 

Susceptibility of 5 softwood species to blue stain 17 

With regard to the patents, 2 patent applications were filed concerning logs conserved under 

oxygen exclusion (log piles wrapped in plastic sheets). One is French and the other is 

German. 

The German patent has been filed by the Forest Research Institute of Baden-Württemberg 

(FVA) and the Technical University of Dresden (TUD). It is an European Patent under the 

Publication-Number: 0946340. This latter was published in the paper 'Patentblatt', 

14.11.2001. 

The inventors are the following: Dr. Gerold Mahler, Kirchzarten 

Christoph Richter, Tharandt 

Dr. Martin Groß, Freiburg 

Andreas Weber, Tharandt 

Thomas Maier, Gundelfingen 

Jürgen, König, Tharandt 

Concerning the French pattern, the name of the French owner company, is STEP. 




16 

6

5. Conclusion 

Although only 4 countries launched some experiments following the storm in December 

1999, no doubt that the works described throughout this deliverable, will greatly improved the 

understanding and the efficiency in terms of global management when undergoing such 

storm. With regard to France, the greater number of experiments is probably due to the fact 

that France was poorly involved in the big storm in 1990 whereas Germany had to stand up to 

millions of destroyed hectares. Concerning the other countries, the low number of launched 

experiments is simply due to the fact that these latter suffered only slightly from this storm. 

Following this bibliographical work, a more active phase becomes possible i.e. figuring out 

the remaining unsolved questions (D5) and the relevant additional experiments which 

deserved to be launched in the future (D7). This deliverable is also an important step towards 

a better cooperation between the European countries where many research remained unknown 

from a country to another. 




7

Annexes 




8

Annexe 1 : Assessment of the beech (Fagus sylvatica) properties and 

more precisely its coloration following a period of immersion and water 

spraying 

Intermediary report 

ABSTRACT CONCERNING : Ongoing research project 

TYPE OF DOCUMENT : Ongoing experiment/ research project 

THEME : Conservation 3.2.1. Water storage, compact pile with water sprinkling/spraying (logs with 

bark) 

Conservation 3.2.2. Water storage. Ponding/Immersion (log with bark) 

ORIGINAL TITLE : Evolution des propriétés du bois de hêtre et plus particulièrement sa coloration lors de 

conservation par immersion et aspersion. 

AUTHORS : J.L. Bonnet, J. Mirjolet 

PUBLICATION DATE: ongoing 

ORGANISATION : CTBA, ONF 

COUNTRY: France 

ABSTRACT CONTENT: 

This project deals with the conservation of beech (Fagus sylvatica) under water storage (water spraying and 

immersion). It is expected to last 2 years and it consists in an examination of the planks sawn from the conserved 

logs. Some planks were steamed. Some veneers were also cut and examined. 

The first results are the following: 

• The immersed logs are darker in colour than the water sprayed ones. 

• After 13 months, immersed logs are heterogeneous in colour. During the kiln drying, 

some wide stains appeared under the sticks. These defects do not occur after a 6 

months period of water spraying. 

• In terms of colour, the water sprayed logs are better conserved than the immersed logs. 

In the case of immersed wood, the discoloration starts from 1 month after the 

beginning of the storage. Concerning water sprayed logs, discoloration occurs from 

the 6 th month of conservation 

• The steamed planks present homogeneous colour and are barely distinguishable from 

the planks coming from green logs. The steaming process seems to be achieved more 

quickly than for green wood (the necessary time for the steaming process decreases by 

15 to 20% for water sprayed logs and by 20 to 25% for the immersed logs) 

• The veneer manufacture occurred without particular problems apart from a small 

percentage attacked by fungi. 

The following first conclusions may be drawn from these results: 

• It does not seem possible to obtain planks clear in colour with water storage methods 

as far as beech is concerned. 

• Steaming process is an appropriate method to make planks homogeneous in colour. 




9

• With regard to the environment, PH, COD value (Chemical oxygen demand), nitrogen 

value and O2 content were measured. No pollution was obvious. On the contrary, 

water quality seemed to be enhanced in the case of immersion. 

10 



(UK), FMRE (A), ICSTM ( UK), UOP (UK), NISK (N)

Annexe2 : Comparison between logs conserved under water spraying 

conditions and green timbers in terms of sawing, drying, and planing 

processes, and in terms of environmental and trade issues 



THEME : Conservation 3.2.1. Water storage, compact pile with water sprinkling/spraying (logs with bark) 

ORIGINAL TITLE : Comparaison entre la transformation des bois conservés sous aspersion et celle des bois 

frais (Sciage, séchage, rabottage, intérêt environnemental, aspect commercial) 

AUTHORS : Vautherin P., Snieg O., Bastet E. 


ORGANISATION : CTBA 



The aim of this study is to determine the differences between green timbers and logs conserved under water 

spraying in terms of environmental and economical issues and in terms of management throughout the sawing, 

planing and drying processes. 

The work is currently carried out within French companies. Three species are examined, namely oak (Quercus 

Spp) for hardwoods and fir (Abies Spp) and spruce (Picea Abies) for softwoods. The study is expected to last 2 

years from 2002 to 2004. 

At that moment, oak has been the only species studied with regard to the sawing process. This work was 

performed in the sawmills at an industrial rate. The following data were measured: moisture content, energy 

consumption, blade wear, cutting speed, cutting height , nodosity. At that point, 4 main conclusions may be 

drawn from the study: 

1. Whatever the wood type (water sprayed or green timbers) and the cutting height, the energy consumption 

remains more or less the same. This phenomenon may be explained by the fact that the sawyer always tends 

to have the same cutting resistance. In other words, for a same type of timber, the thicker is the sawn board, 

the slower it is sawn, but the energy consumption remains the same. The difference in energy consumption 

between fresh and water sprayed logs ranges from 1% to 6% depending on the sawmills. 

2. The influence of the nodosity is negligible compared to the thickness of the board (100 times smaller) 

3. In the same way, the influence of the blade wear is negligible compared to the thickness of the board. 

Nevertheless, a significant decrease in speed of the sawing process occurs while the wear blade increases. 

4. At an equal energy consumption level and for the same log diameter, the speed of the sawing process seems 

to be 10% to 20% higher for the water sprayed logs than for the green logs. However, it should be noticed 

that the time spent by the blade into the wood (which is the time measured in the study) represents 25% of 

the total sawing process (sawing + movement of the bogie carriage for log saw + log turning) 

Some general observations have also been made: 

• Debarking: easier but the size of the bark pieces is also bigger and they can obstruct or clog up the debarker. 

11 




• Immediately after the sawing process, the boards issued from the water sprayed logs seem to be slightly 

darker. Besides, this difference tends to disappear following the drying process. 

• On a logistic point of view, it seems that the benefits involved by this conservation method are significant. 

Actually, this latter prevents the wood from deteriorating during spring time (dote, mould, brown striped, 

etc.) and being downgraded. 

12 




Annexe 3 : Assessment and improvement of live conservation method of 

blown trees for beech (Fagus sylvatica) 


TYPE OF DOCUMENT : Project report 

THEME : 3. Conservation methods; 3.1. On site conservation ; 3.1.1. live conservation of blown trees 

3.6. Chemical wood protection 

ORIGINAL TITLE : Suivi et amélioration de deux techniques de conservation du bois de hêtre en Meurthe et 

Moselle et en Haute Marne 

AUTHOR : I. Vinkler 

PUBLICATION DATE: August 2002 

ORGANISATION : CTBA, ONF, DERF 



This project deals with beech (fagus sylvatica) live conservation over a 2 years period. 704 blown trees were 

examined, scattered in two French regions (‘Meurthe et Moselle’ and ‘Haute Marne’). Just after the storm, these 

trees were still living since their roots were partly damaged or even not damaged at all. 

Concerning harvested logs, in order to slow down the drying speed of the logs, a method using wax on the faces, 

was also assessed. 

If the method involving wax is still used in France for oak in some cases, this technique seems totally inefficient 

for beech: the attacked log percentages remain exactly the same compared to the logs without wax on their faces. 

As far as live conservation is concerned, the general results are rather encouraging: after one year, the percentage 

of attacked logs by fungi (involving an economical loss) ranges from 7% to 16% for scattered blown trees and 

around 30% for blown trees located in totally damaged area (i.e. exposed to 100% of the sunlight). After 2 years, 

the percentage of wood deterioration increases widely with regard to scattered blown trees, ranging from 27% to 

35% (average made for every sample area). 

With regard to paper pulp properties, these latter are strongly correlated with the moisture content. Therefore, an 

important decrease in pulp yield occurred during the second year following the December 1999 storm. This pulp 

yield decreased by 5% within the second spring/summer period. Nevertheless, the pulp properties following the 

first live conservation year remained good and steady. 

Among the factors likely to influence wood deterioration, the far most important is the sample area’s light level. 

The more the blown trees are exposed to the sunlight, the higher is the deterioration rate since the quicker 

decreases the moisture content. Other factors, such as the site type, the ground contact, the crown damages or the 

log diameter are negligible compared to the light level. However, the following observations were noticed: 

1. The effect of the log’s ground contact seems to influence the wood quality only the second year but 

remains negligible. 

2. The more the crown is damaged, the higher the deterioration rate. 

3. The bigger is the living tree’s diameter, the higher the deterioration rate. This trend is only obvious 

the second year of live conservation. 

4. When the tree falls down, the more its roots’ network is displaced, the higher the deterioration rate 

13 




Conclusion: 

As far as beech is concerned and despite the fact that this species is likely to colour quickly, live conservation is 

a rather efficient and inexpensive method within the first year following the storm. It could even be worth using 

it during the second year provided that the blown trees are scattered in the forest (trees not or partly exposed to 

the sunlight). 

14 




Annexe 4 : Experimental site for maritime pine’s log conservation (Pinus 

Pinaster) using three different methods 

Intermediary report 



THEME : Conservation 3.2.1. Water storage, compact pile with water sprinkling/spraying (logs with 

bark) 

Conservation 3.6. Chemical wood protection 

Conservation 3.2.2. Water storage. Ponding/Immersion (log with bark) 

ORIGINAL TITLE : Site atelier de conservation longue durée du pin maritime / Rapport intermédiaire 

AUTHORS : Anonymous. 


ORGANISATION : CTBA, INRA, Pine Institute, ONF, CEMAGREF, LRBB, AFOCEL, Xylomeca 



An experimental platform has been implemented in the South West of France (Aquitaine) to assess within a 3 

years period, the wood quality and the impact on the environment of the 3 different log conservation methods 

(water spraying, immersion, chemical treatment). 

The species involved is maritime pine (Pinus Pinaster). Slightly more than 2000m 3 are monitored, of which 15% 

of paper wood, 15% of blowndown timbers already deteriorated by fungi and 70% of fresh industrial wood. 

The following table summarises the timber volume involved depending on the wood type (paper wood, industrial 

wood, deteriorated wood) and the conservation methods used. 

Conservation methods Wood type Volume (m 3 ) 

Water spraying 

Industrial wood 400 

Paper wood 325 

Attacked wood 150 

Immersion Industrial wood 125 

Chemical treatment Industrial wood 375 

Water spraying with recycling water 

system 

Witness 



Attacked wood 150 

With regard to the environment, the following data are measured: PH, conductivity, COD value (Chemical 

oxygen demand), BOD value (biological oxygen demand), nitrogen value, toxicity on luminescent bacteria 

called Vibrio Fisheri. 

15 




As far as wood quality is concerned, 3 non destructive methods were tested and correlated to the results obtained 

with the usual destructive methods: ultrasound analysis (Sylvatest/ CTBA), vibrator analysis and resistance 

analysis. This latter is achieved thanks to a machine called ‘resistograph’ which measure the rate of penetrability 

of a screw into the wood in a diametrical direction. 

CTBA and AFOCEL have also carried out a survey among the south west industrial sites to gather information 

on equipment, costs and to assess the defects and the advantages of their wood conservation. 

Intermediary results: 

By a period of 2 years, the toxicity involved by the 3 different types of log conservation seems to remain low but 

fluctuates within the very first months. 

Concerning the wood quality, the association of the non destructive methods appears to be an efficient system to 

measure MOE and MOR since their results are well correlated with the ones obtained with destructive methods. 

Furthermore, it seems that the mechanical features do not degrade even after a 2 years conservation period of 

time. 

The first results after 8 months showed that whereas most of the untreated logs were bluestained, 73 % to 100 % 

of water-immersed logs and 94 % to 100 % of water-sprayed logs were preserved with less than 6 % of 

bluestained area. Moreover, neither preservation method led to a loss of modulus of elasticity or of rupture. 

16 




Annexe 5 : Storage of logs under water sprinklers: Regulations, technical 

and economic aspects 

ABSTRACT CONCERNING : Common practice 

TYPE OF DOCUMENT : Technical publication 

THEME : Conservation 3.2.1. Water storage, compact pile with water sprinkling/spraying (logs with bark) 

ORIGINAL TITLE : Stockage des bois par aspersion. Aspects réglementaires, tecniques et économiques 

AUTHORS : J. Moreau (Afocel) 

PUBLICATION DATE: 2000 

ORGANISATION : Afocel, ENGREF-INRA, CEMAGREF 



After the storms that occurred in France in December 99, the amount of windthrown wood was estimated 

at 138 millions of m3 (accounting for 3 harvesting years in France). 

Various means were used in order to face with this huge incoming wood amounts before wood gets 

degrade. Harvesting means and rate of sawmills productions were increased, sawings were stored, round 

logs were exported and logs were stored under water sprinklers. 

The aim of this document is to describe in concrete terms the storage of logs under water sprinklers. 

The first part screens the different storage methods (on site conservation, storage, at road side, under low oxygen 

atmosphere, underwater laying, under water sprinklers) and take stock for each method of the expected 

wood quality. 

In the second part, the storage under water sprinklers is then specifically approached and developed 

through technical and regulations aspects whose knowledge is essential to set up a storage place. 

The technical study of the storage (size of the water sprinkler system, ducts kinds, logs layout) is also 

approached through four concrete examples. 

In the end, a calculation methods of the storage costs and profitability analysis is 

presented. Spreadsheets files are available on the enclosed floppy disk. 

17 




Annexe 6 : Blue staining in maritime pine wind-thrown (Pinus Pinaster) 

stored on site 


TYPE OF DOCUMENT : Ongoing experiment 

THEME : Conservation 3.1.1. : In situ storage, live conservation of wind-thrown trees 

ORIGINAL TITLE : Evolution du bleuissement des chablis de Pin maritime dans le massif Landais 

AUTHORS : J. Moreau (AFOCEL), J.R. Liarçou (CRPF Aquitaine) 

PUBLICATION DATE: 02/2001 

ORGANISATION : AFOCEL, CRPF 



After the hurricane that occurred in France in December 1999, the huge amount of wind-thrown wood involved phytosanitary 

hazards. In the short run, the most formidable threat of depreciation for saw-logs was the development of bluestain. 

Hence AFOCEL lead with CRPF a study in order to monitor the evolution of bluestain contamination in maritime pine windthrown 

stored on site in South West of France. Each month, from March to December 2000, the degree of bluestain 

development in wood was assessed on 600 fresh saw-logs selected just after felling on 20 damaged stands. 

The contamination of the wind-thrown trees remains limited. One year after the storm, 40% of saw logs observed were not 

contaminated by bluestain. Before the insects attacks occurred no bluestain damage was notice on logs on dry site but there 

were several logs contaminated on wet site. On such land trees contamination could have happen through broken roots. After 

insects attacks the contamination of the logs rapidly reach 60% on both type of site. 

If a storm occurred in winter season, we could make this simple recommendation: to harvest first wind thrown 

trees on wet sites and quickly before insects attacks. 

18 




Annexe 7 : Conservation of maritime pine windthrown in the South 

West of France 


TYPE OF DOCUMENT : Ongoing experiment 

THEME : Conservation 3.2.1 : Water storage, compact pile with water sprinkling / spraying (logs with 

bark) 

Conservation 3.1.1 : In situ storage, live conservation of wind-thrown trees 

ORIGINAL TITLE : Qualité des fibres issues des bois de chablis de pin maritime 

AUTHORS : J. Moreau, P. Nougier, G. Chantre (AFOCEL) 

PUBLICATION DATE: mars 2002 

ORGANISATION : AFOCEL 



After the hurricane of December 99, 25 millions of m 3 of maritime pine windthrown wood were stored on-site in 

South West of France (accounting for three harvesting years). Various means were used to face this huge 

incoming wood amounts before wood gets degrade, like the increase of harvesting means and rate of sawmill 

production, exportation and storage of round logs. 

In South West of France, different methods were used to store the maritime pine windthrows. The different 

methods were (1) on site conservation of blown trees, (2) wet storage and (3) dry storage. Regarding the lack of 

experience of such conservation techniques on maritime pine, a sampling procedure was adapted to follow up the 

evolution of wood and fibre properties on the storage sites : moisture content, pulping yield and Kraft paper 

properties were assessed every month. 

Several years after the hurricane, significant experience and expertise is acquired. Blown trees stored on site 

were well preserved until the end of the first summer. Fibre and paper properties were firstly affected, then 

pulping yield, but much lower than harvested logs. The degradation between stands was heterogeneous, so that 

practical methods of selection should be set up to define different qualities of wood assortments. Two years after 

the hurricane, a major part of trees left on site could still be used for pulp and paper issues. 

The storage under water sprinkling, if it is well carried out, preserves the wood quality. After a 18 to 24 month 

period of wet storage, the quality of pulping logs of maritime pine is maintained. But the quality of debarked 

logs of maritime pine windthrows stored in compact piles can be worrying. The drying rate of these logs was not 

fast enough to ensure an optimal protection against the fungus attacks. 

Analysis of wood and fibre characteristics helps to understand the progressive and heterogeneous alteration of 

the wood papermaking potential, and contributes to enhance the experience for the maritime pine log storage 

techniques. 

19 




Annexe 8: Assessment of beech (Fagus sylvatica) storage under humid 

conditions: compact piles covered with plastic sheets (PVC) and 

polyethylene sheets 


TYPE OF DOCUMENT : Intermediary project report 

THEME : 3. Storage under humid conditions. 3.4.2. Compact pile covered with plastic sheets (logs with 

bark) 

3. Storage under humid conditions. 3.4.3. Compact pile covered with geo textile fabric (logs 

with bark) 

ORIGINAL TITLE : Suivi du sciage du hêtre chablis. Procédé de conservation du hêtre sous atmosphère 

confinée. 

AUTHORS : Y. Gorget; O. Snieg; P. Vautherin 

PUBLICATION DATE: February 2002 

ORGANISATION : CTBA, STIR-ONF 



This project deals with storage under humid conditions of beech (fagus sylvatica), namely ‘compact pile covered 

with plastic sheets’ (with oxygen exclusion) and ‘compact pile covered with polyethylene sheets’. The aim was 

to assess these methods in terms of wood quality. A first assessment was made 10 months after the beginning of 

the conservation. 

1. Compact pile covered with plastic sheets 

With regard to the results obtained after kiln drying, no significant differences appeared between fresh timbers 

and beech conserved under compact piles covered with plastic sheets (PVC). Slightly less deformations in the 

case of beech wrapped in plastic sheets, final Moisture Content homogenous , drying time similar, no 

discoloration after sanding. 

Concerning mechanical and physical properties, a decrease by 15% seems to occur 

concerning the modulus of elasticity in flexion and 20% with regard to the modulus of rupture 

in flexion compared to the literature. Nevertheless, these results needs to be confirmed since 

no information was given concerning the wood quality and its origins. In other terms, no 

conclusion can be drawn from these results. 

As far as veneer manufacture is concerned, no particular difficulties were encountered during the process and the 

quality of the veneer was similar to the one manufactured from fresh wood. 

Finally, concerning the visual aspects of the planks sawn from the conserved logs, 4% were stained (brown 

stains), 1.5% were attacked by white rot, no soft rot attacks neither dote were obvious. In other terms, after 10 

months of conservation, the conserved logs were still in perfect conditions. 

2. compact pile covered with polyethylene sheets 

After 10 months of conservation, the overall results were quite bad (white rot attack, blue stain, bad bark 

condition, dote). This method should not be applied in the future to conserve beech. 

20 




Annexe 9 : Assessment of storage under drying conditions (compact pile / 

log without barked) of spruce (Picea abies) and fir (Abies alba) 



THEME : 3.3. Storage under drying conditions. 

ORIGINAL TITLE : Suivi du sciage de sapin epicéa chablis / grumes écorcées stockées sans arrosage 

AUTHORS : S. Faure; J. Parrot 

PUBLICATION DATE: January 2001 

ORGANISATION : CTBA, ONF 



This project deals with storage under drying conditions (compact pile / log without barked) of spruce (Picea 

abies) and fir (Abies alba). 

After a 6 months period of conservation, the measured loss in yield was 2% in average compared with the yield 

that would have been obtained with green sawn timbers. With regard to the economic loss due to downgrading of 

the planks (according to the European standardisation), the average loss was 18.5% in prices. 

21 




Annexe 10 : Log conservation in France by water spraying / Economic 

aspects 



THEME : 2.1. Economic aspects 

3.2.1. Compact piles with water sprinkling (logs with bark) 

ORIGINAL TITLE : Le stockage des bois en France après les tempêtes de Lothar et Martin / Approche 

économique 

AUTHORS : S. Costa; L. Ibanez 


ORGANISATION : LEF (Economic Laboratory of Forestry of the ENGREF) 



Economic study of water sprinkling conservation method according to the type of companies (sawmill, forest 

owner, paper industry, trader-transport company, forester, etc.). This study also answers the species that have 

been conserved, the type of wood (industrial wood or lumber), the input and output on the storage yard, the 

grants that have been attributed by the government in terms of equipment, loan and transport. 

When nothing was previously done on site, the total cost of the conservation method based on 38 different sites 

and calculated over a 3 years period, is estimated to 13€/m 3 . Provided that the site is already built up, the cost 

would be 9€/m 3 . A recycling water system is expected to increase the price by 1.6€/m 3 in average. 

22 




Annexe 11: Oxygen exclusion method: 2000-2001 


TYPE OF DOCUMENT : Ongoing experiment/research project 

THEME : 3.5.1 “Special methods; Log conservation under oxygen exclusion, compact pile wrapped in plastic 

sheets 

ORIGINAL TITLE : Konservierung von Sturmholz unter Sauerstoffabschluss 2000 und 2001 

AUTHORS : D. Schleier; M. Wurster; Dr. G. Mahler 


ORGANISATION : Forest Research Institute of Baden-Württemberg 

COUNTRY: Germany 


1.Introduction: 

In the years 2000 and 2001 were made several tests concerning conservation of wood in 

plastic film. First it was necessary to teach the teams who should pack up the piles with the 

plastic film, in order to get an air proof atmosphere inside the pile. Besides the teaching of the 

manipulation technique there must have been provided the tools and material for the packing. 

Then there were created plastic film protected piles in 7 different places in the south of the 

black forest. 

2.Methods: 

For the packing of the piles were needed special machines, that was provided by the Forest Administration of 

Baden-Württemberg. The tools that were needed were inter alia welding apparatuses, gas measures and tools for 

technical manipulating of the plastic film roll. The piles were wrapped in plastic film first and afterwards welded 

to get an air proof atmosphere inside the pile. 

3.Participants: 

Forest Offices: 

• Bad Liebenzell 

Spruce and fir 10.400m³ in 45 piles (230m³/pile) 

• Nordrach 

Spruce and Fir 8572m³ in 35 piles (245m³/pile) 

• Bad Peterstal 

Spruce and Fir 4300m³ in 22 piles (195m³/pile) 

• Durbach 

Beech veneer quality 3500m³ in 37 piles (95m³/pile) 

• Aalen 

Spruce 1600m³ in 11 piles (145m³/pile) 

• Bühl 

Larch and douglas fir 1260m³ in 7 piles (180m³/pile) 

23 




• Kandern 

Spruce and fir 1000m³ in 4 piles (250m³/pile) 

4.Research period: 

The method named before were made in the period of the years 2000-2001 

24 




Annexe 12 : Storm damaged forest: Efficient and safe harvesting and log 

conservation methods 



THEME : 1.4 Basic principles ; Choice of conservation method 

2.4 General considerations; Management / Operation 

ORIGINAL TITLE : Holzlagerung/Konservierung (Darstellung der verschiedenen Lagermöglichkeiten nach 

Baumarten und deren Einsatz nach Lothar, Bewertung der Lagermöglichkeiten für verschiedene Baumarten 

AUTHORS : M. Wurster; Dr. G. Mahler 





1. Introduction 

At the beginning of the year 2000 the Forest Research Institute of Baden-Württemberg arranged a staff position 

storm "Lothar". The task was to consult state and private forest administration in a capacious way 

and to act as an information point. Afterwords there was started the project conservation of logs wrapped with 

plastic film under realistic conditions (e.g. 2500 m3 beech roundwood for production of veneer were packed up 

for industries in plastic film) 

2. Methods 

• Collection and administration of literature concerning subjects with log conservation (e.g. consultancy 

in 

questions of consequences of wet storage for the chemical water quality). 

• Controlling and consulting of "reclamation" cases concerning conserved wood from storage. 

• Documentation and estimation of wood damages after storage with protocols: 

1.Theme/problem 

2.Location 

3.Type of sample 

4.Result 

5.Conclusion 

• Composing of guidelines for practical use in storage areas. 

• Description of the different storage methods: 

o The goal of the wet storage is saving of quality and the conservation of value of permanent 

available log. Considering a long term and environmental aspects. 

25 




o The idea with the plastic film conservation method is to test an alternative way to the wet 

storage. 

o Furthermore there will be made a monitoring of the reaction of the bark beetles under 

conditions in piles, that are wrapped with plastic film. 

• Assessment of the plastic film conservation method - conservation of logs under removal of oxygen 

o after the storms in the 90´s the idea was born to store wood under removal of oxygen to set all 

3. Participants 

organism in an oxygen free and carbon dioxide rich atmosphere to avoid especially bark beetle 

attack. 

o considering the conservation of broad-leafed trees and conifers concerning the possible loss of 

quality and other damages after storage. 

o In case of the broad-leafed trees the product was veneer, that should be bompared with 

products from fresh wood 

o the empirical study concerning the quality of conifer sawn wood produced from log that was 

stored in plastic film is going on. 

• Forest Administration of Baden-Württemberg 

o Orderer and partner for communcation 

o Management of costs 

• Sawyers/Sawmill/Veneer producers 

o Customers representation 

o Partner for cooperation and Assessment of the products 

• Forest Research Institute of Baden-Württemberg 

o Assessment and monitoring of changes of the quality and herewith the financial value of the 

stored logs 

4. Research period 

2000 - 2003 

26 




Annexe 13 : Storm damaged forest: Efficient and safe harvesting and log 

conservation methods 




sheets 

ORIGINAL TITLE : Versuchskonzept Folienlagerung als Wald- und Holzschutzmassnahme 

AUTHORS : D. Schleier; M. Wurster; Dr. G. Mahler 






The Forest Research Institute of Baden-Württemberg was commissioned by the Forest Department of Baden- 

Württemberg. The following hypothesis was made: 

The wrapping of the wood, that was attacked by the bark beetles, can avoid the flight of the insects. Besides the 

beetles were killed as a consequence of the lack of oxygen inside the package. Thereby the more intensive way 

of plastic film storage could be an alternative for the use of insecticide. 

2.Methods: 

The use of this conservation method should serve to reach the following goal: 

Estimation of the surviving rate of wood damaging insects and fungi at conifer logs, that were stored without 

oxygen for different long times. 

Work steps: 

• Choice of research areas in regions with a high population of bark beetles. 

• Choice of conifer logs hard attacked by beetles. Test logs must be analysed with sampling methods in 

order to check the development of the bark beetle population (Number and specie of the different 

beetles). 

• 15 piles with a size of ca. 100-150 m3 logs should be wrapped oxygen proof in a plastic film. 

• Some more piles (null-version) will be wrapped with a narrow net to avoid a further gradation of 

insects. 

• The closed piles will be tested regularly for the content of oxygen an carbondioxygen, in order control 

the success of the conservation. 

• When the oxygen inside the piles sunk to non measurable values and the carbondioxygen rose - the 

piles will be opened again in defined lags. 

27 




• With every pile opening there must be picked test logs from the null-version and tested analogue to the 

conserved samples 

• After the opening of the piles the chosen test logs must be controled for bark beetle attack again. The 

development stadium of dead and living beetles must be documented. 

• Changes in colour at the logs will be controled to see if blue stain, rotor other fungi are amplified in the 

wood without oxygen. 

• Wood pieces from different stored piles should be tested for the content of farina and for other domains 


• Forest Administration of Baden-Württemberg 

o Orderer and partner for communcation 

o Management of costs 

• State Forest Executives 

o Choice of State Forest Offices for the tests 

o Organisation of the logs 

o Man power management 


o Leader of the tests 

o Dokumentation and monitoring of the piles 

• State Forest Offices 


o Organisation of contact persons in the offices 

o Manipulation of the logs 

o Support by packaging and monitoring of the piles 

From March 2002 until March 2003 

28 




Annexe 14 : Beech conservation under oxygen exclusion 




sheets 

ORIGINAL TITLE : Qualitätsuntersuchungen bei folienkonservierten Furnierbuchen 

AUTHORS : T. Brammer ; M. Wurster; Dr. G. Mahler 






Storm “Lothar” caused a huge amount of wind thrown round wood, which had to be processed and preserved. 

Under instruction of the Forest Research Institute of Baden-Württemberg about 3500m³ beech round wood for 

production of veneer were packed up for the “Danzer Veneer Company” into plastic film. Parts of the round 

wood were examined for different parameters in the Danzer factories of Kehl and Winsen after end of 

preservation. The results and the grading data will be represented in the following chapters. 

2.Methods: 

• The goal of the research project is to document the grade of quality considering frontal and collateral 

discolorations for a conservation period of up to 16 month. 

• For the packaging of the piles there had been used plastic film that was welded to create an air proof 

atmosphere inside the packed piles. 

• The 3500m³ beech logs were packed up in 38 piles wrapped in plastic film. The size of the piles was 50 to 

150m³. 

• After the storage period the piles were unpacked to document and assess the exterior and interior wood 

quality. Here the concentration of the assessment was the development of possible discolorations, cracks 

caused by the conservation and on the other hand caused by the storm. 



o Leader of the tests 

o Documentation and monitoring of the piles 

• Veneer Mill Danzer/Kehl 


o Buyer of the test wood 

End of 1999 until June 2000 

29 




30 




Annexe 15: Root rot in water stored piles 

ABSTRACT CONCERNING : Research project 


THEME : 3.2.1 Water Storage; Compact pile with water sprinkling/spraying (logs with bark) 

ORIGINAL TITLE : Auftreten und Ausbreitung von Hallimasch in Beregnungspoltern 

AUTHORS : M. Groß; B. Metzler 





1. Introduction: 

In the early 90s there were several research projects concerning water storage. Especially in the present case the 

project is dealing with the attack of root rot (armillaria mellea s.l.) in water stored log piles. 

2. Methods: 

a. There were analysed piles in practical conditions: 

One test pile was applied in april/may 1990 in Freiburg Kappel. There was a permanent control of the 

sprinkling site. Single logs were taken out of the pile to analyse them in detail. With a random test was 

tested per pile every meter of the length of the stem. There were acquired parts of the stem with less 

mechanical strength and the max. depth of the destroyed area. 

b. There were analysed piles in laboratory conditions: 

There was made tests over a period of 6 weeks with 168 quadrates of spruce sapwood (6 x 6cm). They 

were detracted from wood of piles that was stored over a period of 3 years. These test objects were 

treated with moisture and heat and then infected with rot root. 

3. Results 

a. With good sprinkling quality, in case of spruce and fir conservation, there is not excluded that after a 

period of 3 years an attack of root rot is probable 

b. The destruction of the wood is limited partly on the stem surface and on the peripheral area of the 

sapwood 

c. In the 4 th year there is ongoing intensive attack of root rot 

d. There is no sign of dependence on place, tree specie, dimension, moisture content and altitude 

4. Research period: 

Beginning of the 1990s, when the storm Wiebke caused a conservation problem. 

31 




Annexe 16 : Log conservation 


TYPE OF DOCUMENT : Ongoing experiment / Research project 

THEME : Log conservation - 1. Basic principles 

Log conservation - 2. General considerations 

Log conservation - 3. Conservation methods 

ORIGINAL TITLE : Rundholzlagerung 

AUTHORS : (various) 

PUBLICATION DATE : 2000 

ORGANISATION : EMPA 

COUNTRY : Switzerland 

ABSTRACT CONTENT : 

National research programme consisting of 4 projects started after the Dec. 1999 storms 

Projects: 

1. Co-ordination / integration of earlier and international experience 

2. Experience with different log conservation methods 

3. Entomology (Xylosandrus germanus) 

4. Wood quality monitoring by ultrasonic 

Overall objectives: 

1. Collection and analysis of the 'Lothar'-experiences from a scientific, economic, social and political 

point of view 

2. Compilation of a decision help to cope with future damage events (e.g. revision of 'Forest damage 

manual' and 'Decision help for storm damage in the forest') 

Contact: 

Martin ARNOLD 

Swiss Federal Laboratories for Materials Testing and Research (EMPA) 

Wood Department 

Ueberlandstr. 129 

CH-8600 Duebendorf 

Switzerland 

Phone: +41-1-823-46-83 

Fax: +41-1-821-62-44 

E-Mail: Martin.Arnold@EMPA.CH 

32 




ABSTRACT SUBMITTED BY / DATE : Martin Arnold, EMPA / 2003-02-14 

33 




Annexe 17: Susceptibility of harvested softwoods to infection by sapstaining 

fungi 


TYPE OF DOCUMENT : Scientific publication 

THEME : Conservation 1.2 and Conservation 3.4.1 

ORIGINAL TITLE : Susceptibility of harvested softwoods to infection by sap-staining fungi. 

AUTHORS : E. J. Young, R. A. Eaton and J. F. Webber 


ORGANISATION : International Research Group on Wood Preservation Doc. IRG/WP 02-10435 (IRG 

Secretariat, SE-100 44 Stockholm) 

COUNTRY: England 


In the UK a field study programme was carried out to compare the susceptibility of softwood timber from five 

different commercially important tree species to infection by sap-stain fungi. Logs cut from freshly felled Scots 

pine (Pinus sylvestris), Lodgepole pine (P. contorta var. latifolia), Sitka spruce (Picea sitchensis), Norway spruce 

(P. abies) and Japanese larch (Larix leptolepis) were exposed for 4 months (April to August 2001). Samples were 

taken 5cm and 50cm from the end of the logs after four weeks, eight weeks and 16 weeks. The percentage 

surface area of sap-stain was then measured in all samples, and isolations taken from the stained wood to identify 

the fungi causing discoloration. Sap-stain was markedly greater in the two pine species compared with the three 

other species. We concluded that the susceptibility of the tested tree species was as follows: Lodgepole pine = 

Scots pine > Norway spruce > Japanese larch > Sitka spruce. In the 5cm samples assessed after four months this 

equated to a mean stain area of 59%, 61%, 10%, 4% and

Deliverable 6: List of ongoing experiments - Ctba

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