Winter Decomposition of Emergent Macrophytes Affects Water Quality under Ice in a Temperate Shallow Lake
, Lijuan Cui 1,2, Xu Pan 1,2, Weiwei Liu 1,2,3, Wei Li 1,2 and Yinru Lei 1,2Round 1
Reviewer 1 Report
The manuscript
Winter Decomposition of Emergent Macrophytes Affects Water Quality under Ice in a Nemperate Shallow Lake
The manuscript introduces the results of research at a high level which may be interesting for readers of journal.
But I have some questions and comments to authors.
- Table 1. What means "Treatment (Tr)", "Time (t)","Tr x t"? What data were compared with each other and presented in the Table?
- What kind of sediments were used in experiments? What is their composition?
General conclusion.
The manuscript contents very interesting results, which are well designed and discussed.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Review of: Water decomposition of emergent macrophytes affects water quality under ice in a temperate shallow lake.
The authors were interested in the rates of decomposition of emergent macrophyte tissues and subsequent changes in chemical variables in lake water under the ice in winter. They used an experimental approach with artificial microcosms containing two species of emergent plants as well as controls with no plants that were incubated for 120 days while covered with ice. Periodic samples were taken to track the loss of plant biomass and the levels of several chemical variables over time. They found that most of the decomposition took place in the first 10 days of the experiment. Dissolved oxygen declined in the containers with plant materials and at the end of the experiment there were increases in the concentrations of DOC, TN, and NO3-N in the water. They concluded that winter decomposition of emergent macrophytes produces negative influences on water quality under ice that lasts for the whole winter.
The study confirms what we already knew: that dead macrophytes decompose in lake water and consume dissolved oxygen and release DOC, TN and TP. The original part is that the studies were undertaken under the ice and provided some quantitative information on rates of change in plant weights and in the chemical environment of the lake water. In general, the results of the study support their conclusions.
Line 13 of the abstract
Pollution usually is referred to the artificial introduction of some foreign material into a waterbody such as pesticides or sewage effluents. In this case the release of materials by the decomposition of natural vegetation in a lake is not pollution. This study is dealing with a natural process.
Line 21
The verb should be “were” and not “was” because the subject is plural. This problem in English usage is found in several places in the manuscript and needs to be addressed. It would help to have an English speaking editor go through the manuscript and make corrections.
Line 21
Replace “lose” with “loss”.
Lines 86-91
I found the order of the sentences confusing. The description of the filling of the containers was interrupted by a discussion of the harvesting of the macrophytes and then the next sentence went back to filling the containers.
I would take the sentence on line 88 starting with “Two comment species…” and move it to Line 91 right before the sentence that begins with “After that plant…”. Some adjustments in the wording would be necessary.
Line 128
It is not clear what the concentration refers to. I would add “in the dried plant material” after P.
Table 2
The font size is too small.
Figure 6
The dashed lines do not stand out.
Lines 324-325
The sentence starting with “Our research…” states a conclusion that is not supported by the study presented. There is no discussion of lake management in the paper. There is no discussion of the role of plant harvest. This sentence should be removed.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
