This paper presents a new microcharcoal record from Mongolia, along with 23 published charcoal records, to provide a regional synthesis of biomass burning in the Altai-Sayan Mountains, Siberia. These published records originate from relatively recent publications; I assume macro-charcoal records and may have reasonable chronological control. Given the rarity of records in Siberia, such new pieces of evidence will undoubtedly advance our understanding of regional patterns and drivers of biomass burning. However, upon close inspection, the paper appears to be of poor quality in the sense that it relies heavily on bold statements rather than providing a typical scientific explanation of the findings and suffers from insufficient information in the methods section.

It therefore requires a truly major makeover before publication. A detailed, but not exhaustive,  list of comments is provided below.

1. 25-26” …vegetation zones of the Altai-Sayan Mountains and adjacent plains…” which adjacent plains? This information should be provided already in the abstract
2. 27, since when in the Holocene? Such statements are common throughout the manuscript 
3. 30 What is a “combustible component”?
4. 120-126. The aim to include 23 records comes abruptly, without providing a regional context for where these records originate. Upon further examination of the manuscript, it presents a synthesis of a large part of western and central Siberia, Asia; however, the introduction of these sites into a broader spatial context is not provided.

l.139-147, these lines belong to results, not methods?

L 150-151 “A 2100-year reservoir correction was primary forest coverplied to all radiocarbon ages prior to calibration (Sun et al., 2013)”

???? This sentence does not make sense. Please extend the explanation of why a 2100-year reservoir was applied.

L156 24 or 23 sites as an introduction?

l.210  such method was applied for all records?  Please provide the type of charcoal used in other records (micro and macrocharcoal). Please separate more clearly what has been done at the new site from what has been done at all sites.

L 220 This part describes what GAM is, but not what is being achieved with GAM in this study. Which are the dependent variables? Was the percentage of pollen used? Which species are included in the primary forest?

3.3. Data processing for comparison. This part is extremely poorly written. What is meat synthesized? What is the average method?

Results and discussions. Generally, the chapters are very general and imprecisely described. They are made of many bold sentences rather than explanations of potential drivers of biomass burning. Particularly, the link with the amount and type of biomass available is very superficially discussed. Furthermore, the jumps from single to cumulative charcoal record (Z-score) make the story difficult to follow. Why not focus on the trend in cumulative charcoal record, thus regional biomass burning and the potential drivers, followed by sites that show exceptions from the regional trends and explanations? I picked a few major inconsistencies, but the whole chapter should be rewritten.

(p=0.00)?

 It contains a mix of charcoal and biomass burning, as they will represent different things.  Ideally, use the same terminology.  

l 251, which multi-proxy records?  Only charcoal was used here.

l271 How can microcharcoal morphology signify anthropogenic fire?

The 297 Rybanya site does show the dominance of Larix in the original pollen record, nor are the increases in fire at 4 ka linked to megadroughts; instead, they are associated with dry peatland conditions (l 299).

l.301-304. I am puzzled by the superficiality of these statements: “ The GAMs analysis reveal the divergent fire-vegetation relationships: (1) Negative correlation at Rybnaya/Plotnikovo (canopy >75%): Reduced understory fuels and microclimatic humidity limit fire spread; (2) Positive correlation at Shchuchye Lake (canopy <65%):Open structure promotes flammable grass undergrowth.”

L 436-438 could you provide an approximate location of timber and treeline limit, consequently, the amount of biomass available

L 440 ff, do you imply here that the steppe provided more biomass than the forest? Sometimes this study suggests that a low forest cover resulted in reduced biomass burning, while at others, it indicates that a steppe contributed to an increase. Could you provide a finer interpretation of biomass amount and the fuel type?

L493 and elsewhere, where you talk about human impact. Through what type of activities can humans increase their burning activity?

L 505. These sentences do not make sense: “Specifically, the increase in Siberian pine and European larch since the Holocene has led to a significant decline in fir, birch, larch, and spruce components,  resulting in a notable decrease in combustible materials at the three sites” and

505 ff  does not make sense: "Although Holocene biomass burning in the Khangai Mountains exhibits an overall gradual decline, it can be categorized into two distinct phases: an increase over the past 2,000 years, followed by a gradual decline post-2000 year (Unkelbach et al., 2021; Barhoumi et al., 2024)"

L540 Wrong, please see above.

Fig. 1: How was this regionalization produced? It is nowhere described the basis for grouping the sites into these regions. Was it the site's proximity? Similarity in climate or vegetation cover?

Fig. 3, and the results of the paper. The new record is located in the steppe region. Why was only the tree composition presented and discussed in the manuscript, when the herbaceous composition and diversity provided the most biomass to burn? Are these trees long-distance transported?

Fig 4. The records in panel c seem to stop at 8-9 ka, but why does the average value extend to 12 ka?

Region C seems to average sites stretching along an elevation gradient, thus lots of climatic conditions and vegetation composition

I have attached my comments in a PDF file.