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Class B timber selection criteria

Valuable timber for future generations

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Class B timber selection criteria

Class B- is a strategic timber reserve intended for storage for50–100 yearsIts mission is to create material and cultural capital for children and grandchildren by preserving the best timber until their technical, historical, and artistic value increases significantly.

Class B does not include a single exceptional timber of class A, buthigh-quality, large and promising lots, suitable for architecture, restoration, furniture, shipbuilding, bridge structures, musical instruments and artistic processing.

Class B is the wood capital of the next century.

1. Main breeds

Top priority

PriorityBreedReason for the team
⭐⭐⭐⭐⭐OakHigh durability, strength, tannins, ability to long-term storage in water
⭐⭐⭐⭐⭐LarchResinous, water and rot resistant, durable
⭐⭐⭐⭐ElmA tough, impact-resistant wood, historically used in damp structures
⭐⭐⭐⭐Ash treeElasticity, strength, expressive texture
⭐⭐⭐⭐Edible chestnutHigh natural persistence, tannin content
⭐⭐⭐⭐WalnutDecorative and furniture value
⭐⭐⭐MapleLight texture, furniture, music and art pieces
⭐⭐⭐PearDense, stable and valuable wood for precision products
⭐⭐⭐MerryDecorative wood and furniture
⭐⭐⭐YewExceptionally valuable timber, but only legally obtained trunks
⭐⭐Pine and spruceOnly the best proven batches and experimental programs
⭐⭐LindenSelection for carving, sculpture and restoration

The basis of class B should be:

oak;

larch;

the best batches of elm;

ash tree;

chestnut;

walnut.

2. Origin of wood

Class B timber is accepted primarily from sources that do not require special logging to create a reserve.

SourceAdmission
Windfalls and windbreaksHigh priority
Emergency treesAccepted after quality assessment
Restoration of floodplains and riverbedsHigh priority
Clearing reservoirsAllowed
Sanitary fellingOnly if there is a confirmed need
Infrastructure projectsAllowed with full traceability
Reorganization of commercial forestsAllowed
Illegal loggingNot allowed, except for confiscated timber by special decision
Cutting down healthy valuable forests exclusively for reservesNot allowed

3. Minimum barrel dimensions

Dimensions are assessed relative to the tree species, region and age.

IndicatorPreferred value
Diameter at the thin endFrom40 cm
Preferred diameter50–80 cm
Length of business areaFrom4 m
Preferred length6–12 m
Large-sized trunksFrom80 cm— a separate subcategory B+
CurvatureMinor or acceptable for special applications
EscapeModerate
Minimum calculated volumeUsually from0.8–1 m³, except for rare breeds

For walnut, pear, yew, maple and other valuable species, smaller sizes are allowed if the wood has high decorative or scientific value.

4. Barrel quality

CriterionClass B requirement
StraightnessDesirable for the main business length
KnottinessModerate; large rotten branches are undesirable
CracksMinor end and surface damage is allowed.
Internal rotNo more than local areas
DoubleAllowed to a limited extent if significant useful volume is retained
Fungal infectionOnly after assessing the depth and activity
Insect damageMinor or local
Mechanical damageShould not destroy the main business area
Metal inside woodDetection and mapping required
Radial cracksAssessed by tomography or ultrasound
Stressed woodAllowed after technological assessment
PollutionToxic or radioactive contamination is not permitted.

5. Permissible defects

Class B shouldn't be reduced to a warehouse of only perfect logs. Some defects can enhance the artistic value of the wood.

Allowed:

moderate curvature;

curly grain;

burl formations;

wavy texture;

contrast nucleus;

old, overgrown lesions;

local mineralization;

inactive insect passages;

limited sapwood;

natural asymmetry.

Such wood is labeled as:

B-Art- artistic;

B-Figure- textured;

B-Curve- structurally curved;

B-Research- research.

6. Unacceptable defects

Class B does not include:

active deep rot;

destruction of a more significant part of the cross-section;

oil, chemical or radioactive pollution;

massive infestation of live pests;

large through cracks;

severe charring that destroyed useful volume;

unknown origin;

illegally harvested timber;

trunks that are of greater ecological interest in a river or forest than in a reserve;

wood that may pollute a water reservoir.

7. Age of the tree

Age is an important but not absolute criterion.

CategoryRating
A young, fast-growing treeNot usually accepted
Mature treeMain category
Old-growth treeHigh priority with good quality
Historical treeMay be rezoned to Class A or Heritage Reserve
Age unknownAllowed for dendrochronological assessment
Young rare breedExperimental subcategory only

For class B, the combination of:

maturity;

the size;

density;

tree ring structures;

absence of critical defects;

Prospects after 50–100 years of storage.

8. Density of annual rings

Preference is given to wood:

with uniform growth;

without sharp multi-year jumps;

with a dense structure;

without prolonged periods of severe stress;

with a well-formed core.

However, very narrow rings do not always automatically indicate better quality. The following are evaluated:

breed;

place of growth;

mechanical properties;

proportion of late wood;

presence of tilt reactions;

internal stresses.

9. Genetic and historical value

Additional points are awarded to wood from trees:

disease resistant;

survived severe droughts;

survived fires or frosts;

grown up in extreme conditions;

belonging to a rare local population;

originating from the historical forest;

having a documented cultural history;

grown in a multi-generation agroforestry system.

However, the genetic value of a tree is not preserved by the timber alone. It is also necessary to preserve:

seeds;

fabrics;

DNA sample;

cuttings or grafts;

information about offspring.

10. Mandatory examination

Before including a barrel in class B, the following is performed:

MethodPurpose
Visual assessmentExternal defects and shape
3D scanningGeometry and volume
Metal detectorNails, wire, fragments
Ultrasound or acousticsInternal defects
ResistographLocal density and rot
TomographyFor large and especially valuable trunks
HumidityInitial state
DensityClassification of material
DendrochronologyAge and growth history
Chemical analysisIf contamination is suspected
Photographic documentationDigital passport
Genetic sampleFor valuable lines

11. Class B grading system

Each barrel gets points.

CriterionMaximum score
Breed and natural durability20
Size and useful volume15
Quality of the main wood20
Straightforwardness and technological advancement10
Age and maturity10
Decorative value10
Origin and traceability5
Genetic or historical value5
Suitability for the selected storage5
Total100

Solution

PointsCategory
85–100Candidate for B+ or revision for A grade
70–84Class B
55–69Class C or B-Research
Less than 55Do not include or direct to current use

12. Class B subcategories

CodePurpose
B+The best barrels, close to class A
B-StructuralArchitecture, bridges, large structures
B-HeritageFuture restoration of historical sites
B-ArtSculpture, furniture, art objects
B-InstrumentMusical instruments after additional selection
B-MarineShipbuilding and wet structures
B-FigureUnusual texture and decorative pattern
B-ResearchLong-term scientific testing
B-GeneticWood from genetically valuable trees
B-CurveNaturally curved structural elements

13. Storage Selection

Not every Class B wood is suitable for every swamp or pond.

The following are taken into account:

pH;

temperature;

oxygen content;

mineralization;

iron content;

depth;

water level stability;

sludge composition;

microbiological activity;

risk of flood runoff;

accessibility for inspection.

Example

BreedPreferred conditions
OakAnaerobic water and iron-containing sediments after testing
LarchCold stable water
ElmTotal immersion and no dry-out cycles
Ash treeOnly experimentally confirmed conditions
ChestnutStable immersion; control of tannins and water chemistry
WalnutCautious parties with regular monitoring
Maple and fruit treesSmall research parties

14. Preparation of wood

Before bookmarking:

the trunk is identified;

a full examination is performed;

hazardous metal is removed;

the contaminated surface is cleaned;

the bark and sapwood are fixed;

the ends are documented;

a passive identification tag is installed;

the class and storage location are selected;

a fastening scheme is created;

floating, movement and friction of the barrels are eliminated.

Complete bark removal should not be automatic. The following batches are being compared:

with bark;

partially debarked;

completely debarked.

15. Digital passport

SectionData
Timber IDUnique number
ClassB and subcategory
BreedScientific and local name
OriginForest, river, object
Reason for seizureWindfall, accidents, restoration work
AgeConfirmed or estimated
DimensionsLength and diameters
VolumeCalculated and measured
WeightInitial and forecast
QualityDefects and tomogram
DNASample number
Bookmark dateHome meals
StorageReservoir ID
CoordinatesExact position
DepthImmersion level
ConditionspH, oxygen, temperature
InspectionsInspection history
Extraction planEstimated period
PurposeArchitecture, restoration, art or research

16. Control during storage

PeriodCheck
First yearAfter 1, 3, 6 and 12 months
2–5 yearsAnnually
5–20 yearsEvery 2-5 years
20–50 yearsEvery 5 years
50–100 yearsEvery 5-10 years, depending on stability

Controlled by:

water level;

oxygen;

temperature;

pH;

barrel position;

label state;

surfacing;

mechanical damage;

biological destruction;

change in mass and density of control samples.

17. Control samples

From each large batch the following are retained:

end sample;

cairn;

bark sample;

sapwood sample;

DNA;

dry control sample;

sample placed next to the trunks;

sample for periodic extraction.

This allows the material to be examined without raising the main shaft.

18. Decision on transfer between classes

Translation B → A

Possible if:

exceptional preservation confirmed;

the wood has acquired unique properties;

the trunk has historical significance;

the party demonstrates outstanding stability;

the shelf life is extended to 100–300 years.

Translation B → C

Possible if:

developing defects were identified;

storage conditions are unstable;

it is advisable to use the material earlier;

Further storage does not increase the value.

Exclusion from the reserve

Required if:

active destruction begins;

contamination detected;

the trunk threatens the ecosystem or structure;

traceability is lost;

storage became technically unsafe.

19. The main difference between classes

ClassDeadlineNature of selection
D5–20 yearsNew breeds and methods
C20–50 yearsGood material for the next generation
B50–100 yearsThe best large parties of strategic capital
A100–300 yearsExceptional single trunks and heritage

20. Final requirements of class B

Class B timber must:

come from a legitimate and documented source;

belong to a durable or particularly valuable breed;

have sufficient useful volume;

do not have critical active rot;

be compatible with the chosen storage method;

undergo an instrumental examination;

get a digital passport;

have control samples;

stored in a stable anaerobic environment;

be monitored regularly;

have a realistic prospect of use in 50–100 years.

The main principle

Class B is not a timber yard, but a managed portfolio of natural capital for 50-100 years.

It includes the finest lots of oak, larch, elm, ash, chestnut and walnut that are not exceptional enough for Class A but have a high probability of retaining or increasing their technical, artistic and cultural value over the next century.

DREVO Timber Reserve