or lumber - лесоматериалы

In the US and Canada, timber is typically used to collectively refer to trees—or the wood of such trees—that have yet to be cut or processed, while lumber typically refers to wood that has been processed as a building material (boards and planks). Elsewhere, especially in the UK, the word timber is used to mean the same thing as lumber.
https://www.dictionary.com/e/timber-vs-lumber/

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Note added at 33 мин (2022-04-27 21:39:23 GMT)
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Examples of timber and lumber used in a sentence

To help you understand the difference, take a look at these examples of timber and lumber in a sentence.

The processing of timber into lumber requires heavy machinery.
The timber industry has been the target of criticism for unsustainable logging practices.
The lumberjack yelled “Timber!” as the tree fell.
A large load of lumber, mostly two-by-fours, was delivered to build the house.
Fortunately, the wildfire didn’t reach the vast stands of timber on the other side of the mountain.
https://www.dictionary.com/e/timber-vs-lumber/

Surely not 'lumber', as the context clearly is about harvested wood, which is not yet processed. Maybe 'harvested timber', but in this case not just 'timber', becasue there is also such as thing as 'standing timber'.