Roth's Peer Review
editThis review is for the Global Oxygen Cycle image and caption created by Pengxiao Xu with the aim of providing constructive feedback to improve them both. This review assignment requests and is divided into five separate sections that include one paragraph each. These paragraphs are outlined below.
The scientific accuracy of the current figure is difficult to assess because there is no indication of which of the five sources referenced is intended for which part of the figure. It could be beneficial to intermix the references within the text rather than placing them all at the end. From the Fundamental of Geobiology textbook reference 1 Table 7.1, oxygen production from burial is at 17.9 x 10^12 mol/yr and oxygen loss from weathering plus a little outgassing and serpentinization is 17.0 x 10^12 mol/yr. This appears to be switched in the current figure. Another suggestion for scientific accuracy is to label the figure as the modern global oxygen cycle to separate it from the early earth oxygen cycle which matches the designation in the literature. Lastly, I think it is also important to illustrate that there is a small mismatch between oxygen production from photosynthesis and oxygen use by respiration. This amount is small but very important. More oxygen is produced by photosynthesis than is consumed in respiration due to the burial of organic carbon referred to as the biological pump. In the current figure, photosynthesis and respiration are exactly matched.
The presentation and neatness of the figure are ok. Aesthetically the figure is really neat, but maybe it is too neat and presents as a little too simplistic. My preference is for figures that I can read and navigate without needing to consult the caption to decode it. When I look at this figure I do not understand anything about it without reading the caption. Since the figure has a lot of extra room, maybe it could include the full spelling rather than abbreviations as well as units for the data. Also, it is not clearly stated that the arrows and numbers refer to flux. Non-science readers may not understand this.
The quality and completeness level of this figure could use some work. It is a great start but would benefit from some more details. Maybe the figure could also include reservoir totals and a mid-ocean ridge system mention in the first paragraph of your reference 1 textbook chapter 7. Also, the figure does not give me a strong feeling of a cycle. I think non-science readers may not connect an up and down arrow with cycling. I also think it might be fun to try and include an illustration somehow of the 7000 yr resonance time of an oxygen molecule through the terrestrial biosphere. Although this might be quite complicated.
The figure caption explains the abbreviations and units but does not walk the reader through the cycle. I think a non-science reader will not be able to follow along. Maybe you could explain more what is happening on each side of the arrows?
The figure and caption have 5 citations at the end of the caption. I think it could be useful to expand the caption to explain more the processes outlined in the figure and to move/link the citations to specific statements. This way when a non-science reader reads a single statement they can understand better where that statement came from. It seems that all the information for this figure comes from reference 1. The other 4 references appear to be highly relevant to the oxygen cycle but I am unclear on how they are included in the figure.