A High Accumulation of Dissolved Organic Matter in the Water Resulting from Terrestrial Input into a Large, Shallow Steppe Lake

Round 1

Reviewer 1 Report

Authors analyzed the source and composition of dissolved organic matter in different rivers and lakes comprehensively through field sampling and application of the EEM-PARAFAC method, which is of great significance to the water ecological environment protection of steppe lakes. The manuscript is well written and the results are interesting, however, there is several suggestions for authors to better improve the manuscript before being published.

Detailed questions:

1. Could authors explain why they chose sampling sites, and please describe the environmental characteristics around these sites.

2. I recommend authors to change some recent references to highlight the importance of this study.

3. The author puts forward that approximately 82% of the DOM in Lake Hulun is derived from terrigenous material, it is suggested to carry out comparative analysis of sources among different rivers to determine which river has the greatest impact, and further analyze the key areas, so as to provide a basis for guiding the next accurate protection measures.

4. It is suggested to rewrite the research results in the conclusion part, and remove duplicate information from the and abstract sections.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript titled by A high accumulation of dissolved organic matter in the water 2 from terrestrial input of a large shallow steppe lake was written concisely and was well organized. The topic of DOM sources of lakes are now drawing more attention on Carbon cycling and nutrients sources for lake management. So I think this is an important topic. This research take Hurun lake as a case, choose the main inflow rivers and lake waters for investigation. C/N ratio and three-dimensional excitation emission matrix was used to identify the source and contribution of DOM. The method is fine and the results is interested to the readers, not only for this lake, but for other lakes.

several problems here are for further revision:

1. L104, the first "," comma should be deleted.

2. method 2.3 Here total nitrogen (TN) and dissolved total nitrogen (DTN) are both analyzed. please clarify whether TN and DTN was used for calculation of C/N. 

3. L168-175 and Fig. 2, we need to know how did you calculate the C/N. and if this is DOC/DON, can this refer to C/N?

4. fig. 3. I didn't see any mark on Peak C and Peak T. Since the main composition was divided by C/T, it is needed to make mark on the fig and also discuss correspondingly.

5. part 4.2 This is our interest part. But how did you calculate the contribution of DOM is still not clear. Please make more explanation on this part or in the methods part.

6. Table 4. the line within the table should be deleted. See journal's requirement.

Author Response

Please see the attachment.

Author Response File: Author Response.docx