Inter-Annual Variability of Peatland Vegetation Captured Using Phenocam- and UAV Imagery
, Tom Wade 1, Carole Helfter 2, Matthew R. Jones 2, Karen Yeung 2 and Caroline J. Nichol 1Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
It is an effective approach for monitoring the inter-annual variability of peatland vegetation across a range of spatial and temporal scales using dense time series of imagery captured by a phenology camera and multispectral imagery from a UAV-based camera. This study uses the phenocam imagery and multispectral UAV multispectral data to track vegetation phenology in peatlands and examine species-level changes in greenness metrics in response to GPP and the weather anomalies. The data used are sufficient and the procedure of the data processing procedure were explained in detail, which can support the analysis and conclusions. Overall, the general idea and methodology are not innovative enough, but the manuscript is well written.
Detailed comments:
1. Title: phenocam- => phenology camera
2. Too many keywords make the focus of the study confused.
3. A month scale should be added to the time axis in Figure 4.
4. Figure 5: When analyzing the correlation between UAV-derived VIs and phenocam-derived greenness, were the greenness and vegetation indices extracted from the entire growing season? How were the 26 plots determined?
5. Several vegetation indices derived from UAV multispectral imagery were calculated and their correlation with the greenness and GPP was analyzed in the results section. If the indicative vegetation index could be determined through these comparisons, the significance of this study will be highlighted.
6. Discussion in 4.1.2: It seems unnecessary to discuss the advantages of UAV-based monitoring.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper provides valuable information on the peatland RS greenness dynamics and carbon exchange. I recommend to publish it aftre addressing a few questions below. I also propose to consider some minor modifications as below.
Questions:
Please state explicitly how you define a „dry spell” (start and end) in the study (I am sorry having not found it ) perhaps in the method section. Please give arguments why you consider a specific date as a start and end of a dry spell.
Please discuss why the GPP-Gcc coreltions are higher during the green-down than during the green-up periods.
Please compare (discuss) Reco values during active (~sink) and stressed (~source periods).
Minor issues:
l 22. If it allows you - then have a statement about it, please (in the abstract, too).
l. 37-39. : Vegetation period might become longer - but could you please mention here the droughts, interrupting/shortening the VP length? Chance of longer growing season is not real for perhaps the majority of the communities. Increased GSL in northern ecosystems still may happen - but you also mention drought spells affecting your study site.
l 63 – Have you addressed the mediator role of phenology in the study?
l. 246, Table 2. Proper spelling of Juncus effusus (i.e. not „effuses”). Same two lines above: change „caerulea” to „coerulea”
l 300. Did you mean local extremes?
l. 350-352. Please explain why the GPP90 is better used than average or total (GPP) to reduce the impacts of gaps (why one would use daily average GPP instead of GPP90 as indicator of max,. photosynthetic uptake?).
l. 475 From May to August, not the reverse (or not in the same year?)
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
