TreeYesina class A

Class A timber

Class A— the highest category of strategic timber reserveDREVO Timber Reserve, intended for storage for100–300 years.

This class does not include ordinary quality lots, butexceptional single barrels and limited collections, possessing high technical, historical, genetic, cultural, scientific or artistic value.

Class A is a timber heritage that the present generation preserves for people in future centuries.

1. Class A assignment

Class A timber is reserved for:

restoration of architectural monuments;

restoration of historic bridges and buildings;

temple and public architecture;

unique engineering designs;

shipbuilding;

manufacturing of musical instruments;

creation of works of art;

museum and memorial projects;

scientific research;

preservation of rare regional breeds;

transmission to future generations.

Use of such timber for normal commercial applications is not consistent with Class A intended use.

2. Main breeds

Highest priority

It is recommended that the basis of class A be formed primarily fromoak, limited - fromlarch, and other breeds should be included only after individual expert assessment.

3. Source of wood

Class A should not become an excuse for cutting down healthy old-growth forests.

Acceptable sources

4. Ecological filter

Even an exceptional barrel is not automatically sent to the reserve.

Wood remains in the ecosystem if it:

is a habitat tree;

contains active hollows;

used by nesting birds;

is a refuge for bats;

supports rare mushrooms, mosses or lichens;

necessary for saproxylic insects;

strengthens the bank or slope;

creates important hiding places for fish;

retains water, soil and organic matter;

has greater ecological value in nature than in reserve.

A compromise is possible: part of the trunk is left in the ecosystem, and the technically valuable part is sent to the DREVO Timber Reserve.

5. Age of the tree

Age alone does not guarantee inclusion in Class A, but it is an important indicator.

Preference is given to wood from trees that:

grew slowly;

have a uniform ring structure;

formed a significant proportion of the core wood;

survived several climate cycles;

demonstrated resistance to drought, frost and disease.

6. Minimum dimensions

For the main structural category class A:

For yew, walnut, pear, maple, boxwood, fruit and other valuable species, smaller sizes are allowed if the material has exceptional decorative or cultural value.

7. Large-sized timber over 80 cm

Trunks with a diameter of more than 80 cm receive a separate status:

A-Monumental

The following are mandatory for them:

full 3D scanning;

acoustic or ultrasound tomography;

internal defects map;

assessment of residual stresses;

calculation of mass and buoyancy;

individual transportation scheme;

special support system;

separate storage area;

digital twin.

Such a log cannot be moved directly across the surface of the tree using conventional ropes. Wide, soft slings and spreader bars are used.

8. Wood quality

9. When a defect becomes an advantage

For art and museum subcategories the following are allowed:

mouthguards;

curly grain;

wavy fibers;

unusual coloration of the nucleus;

natural mineralization;

overgrown historical damage;

traces of fire;

lightning damage;

complex root wood;

natural curvature.

Such wood receives special designations:

A-Art;

A-Figure;

A-Root;

A-Fire Legacy;

A-Mineral;

A-Historical Form.

10. Invalid states

Class A does not include wood:

with active deep rot;

with destruction of a significant part of the section;

with unknown industrial pollution;

impregnated with petroleum products;

radioactively contaminated;

affected by active quarantine pests;

having large unstable cleavages;

without confirmed origin;

obtained illegally;

incompatible with the selected storage method;

posing a risk to the reservoir ecosystem;

having lost its practical and scientific value.

11. Genetic value

Trees that receive a high status are:

disease resistant;

surviving after epidemics;

survived long droughts;

frost-resistant;

originating from a rare local population;

having outstanding growth or form indicators;

being the last representatives of the local line;

that produced stable offspring.

But wood is no substitute for a living genetic reserve.

The following are saved at the same time:

seeds;

cuttings;

vaccinations;

tissue cultures;

pollen;

DNA;

offspring data;

digital genetic passport.

12. Historical and cultural value

Wood is given additional priority:

historical tree;

old park or estate;

monastery or temple site;

fields of significant historical events;

traditional agroforestry landscape;

old bridge, house or ship;

a tree associated with local culture;

wood with confirmed dating.

Such wood is classified as:

A-Heritage

It can be maintained regardless of the ideality of technical characteristics.

13. Mandatory examination

For class A, the highest diagnostic level is applied.

14. Expert Commission

The decision on inclusion is made by a committee, which includes:

forest ranger;

dendrologist;

wood science specialist;

ecologist;

design engineer;

restorer;

hydrologist - for water storage;

timber storage specialist;

representative of the local territory;

cultural heritage specialist - if necessary.

One expert should not assign class A alone.

15. Point system

Solution

Historic timber can be awarded class A by a separate decision even with a lower technical score.

16. Class A subcategories

17. Selecting a storage method

Class A can be stored not only in water.

The method is selected based on the breed and future purpose, and not according to a single rule.

18. Requirements for water storage

For A-Water you need:

complete and continuous immersion;

low oxygen content;

stable temperature;

no wetting and drying cycles;

controlled pH;

suitable composition of bottom sediments;

absence of strong current;

protection against surfacing;

possibility of safe inspection;

reserve hydrological regime.

A natural swamp cannot be used without assessing the damage to the ecosystem.

19. Air storage requirements

For A-Air you need:

slow primary drying;

protection from direct sunlight;

stable ventilation;

gradual equalization of humidity;

climate stabilization;

insect protection;

fire department;

minimal temperature fluctuations;

distribution of copies and batches between multiple objects.

20. Preparing the barrel

Before bookmarking:

the legitimacy of origin is confirmed;

an environmental assessment is being carried out;

a digital passport is created;

a full diagnosis is performed;

defects are recorded;

dangerous metal inclusions are removed;

control samples are taken;

genetic materials are preserved;

the storage method is selected;

an individual transportation scheme is created;

durable identification is established;

The inspection schedule is determined.

21. Control samples

For each class A barrel the following are retained:

cairn;

end sample;

bark sample;

sapwood sample;

core wood sample;

DNA;

dry control;

sample in a similar storage environment;

samples for future laboratories.

The main trunk should not be regularly damaged for research purposes.

22. Digital passport

23. Digital twin

For each major trunk, a digital twin is created:

three-dimensional model;

internal defects map;

humidity history;

position data;

deformation model;

safety forecast;

history of all movements;

virtual breakdown into future blanks;

scenarios of possible application.

24. Control schedule

The sensors can be operated continuously, but physical intervention should be minimal.

25. Reasons for maintaining class A

The barrel remains in class A if:

maintains structural integrity;

storage conditions are stable;

the value of the material does not decrease;

identification is not lost;

documented history is preserved;

there is no environmental risk;

the future scope of application remains realistic.

26. Translation A → B

Possible if:

developing defects were detected;

the shelf life should be reduced;

reservoir conditions become unstable;

the material is best used for 50-100 years;

the historical or technical value turned out to be lower than the original estimate.

Relegation to Class B isn't a failure. It's adaptive reserve management.

27. Extraction of Class A wood

Extraction is permitted only for:

restoration of an object of outstanding cultural significance;

unique scientific project;

creation of a work of national heritage;

preventing wood loss;

transfer to a more secure storage;

pre-approved rotation of the reserve.

The decision must be documented and made by the committee.

28. What not to do

The following is not allowed:

include wood in class A only because of its large diameter;

cut down living healthy old trees for reserves;

remove tree habitat without environmental assessment;

store the barrel without control samples;

use an unknown natural swamp as a warehouse;

publicly disclose the exact location of particularly valuable lots;

store the entire reserve in one place;

use class A to speculatively increase the price;

saw the trunk until the survey is completed;

consider the old age of a tree as a guarantee of quality;

storing material for centuries without an established future purpose.

29. The main difference between classes

30. Final criteria of class A

Class A timber must:

have a legitimate and fully confirmed origin;

pass an environmental assessment;

belong to a durable, rare or particularly valuable breed;

be of exceptional size, quality or historical significance;

have a realistic value in 100-300 years;

undergo a complete instrumental diagnostics;

have a digital and physical passport;

be accompanied by control and genetic samples;

stored in a specially selected stable environment;

be monitored regularly;

be protected from fire, theft and loss of data;

have a predetermined strategy for use.

The main principle

Class A does not include the largest or oldest tree, but rather the wood whose loss would be a loss for future generations.

Class A must remain limited and exclusive. Its value is determined not by the quantity of accumulated trunks, but by the quality of selection, the authenticity of provenance, the stability of storage, and the ability to preserve outstanding material for generations.

DREVO Heritage Timber Standard — DHTS 1.0 (Project Standard / Draft)