Phenological Response in the Trophic Levels to Climate Change in Korea
Round 1
Reviewer 1 Report
This paper presents a study to evaluate the phenological changes of trophic groups in representative species inhabiting in Korea, which has experienced rapid global warming. It analyzed the phenological shifts resulting from temperature changes, along with differences in phenological variations by trophic levels and phenological sensitivities to climate by group and period. We also identified time-series trends about the day difference of phenological events between species that interact with each other. The subject of the paper is important for contributing to the climate change discussions. The paper is clearly presented and is based on data and knowledge available in the literature.
Some comments and suggestions:
Conclusions section:
L.277 - According to the Korea Climate Change Assessment Report 2020, which analyzed more than 1900 papers and reports, it is clear that since 1920 South Korea has experienced a higher rate of temperature increase compared to the global average, and since 1973 the trend of increasing temperature has been stronger [1]. In addition, there is a consensus that climate change is caused by human activities [38], and Korea is under high pressure for ecosystem changes such as human intervention [39]. --- These statements are not derived from this study, and then I suggest to move this part to the discussion section.
Author Response
Reviewer 1’s Comments:
This paper presents a study to evaluate the phenological changes of trophic groups in representative species inhabiting in Korea, which has experienced rapid global warming. It analyzed the phenological shifts resulting from temperature changes, along with differences in phenological variations by trophic levels and phenological sensitivities to climate by group and period. We also identified time-series trends about the day difference of phenological events between species that interact with each other. The subject of the paper is important for contributing to the climate change discussions. The paper is clearly presented and is based on data and knowledge available in the literature.
- Some comments and suggestions:
Conclusions section:
L.277 - According to the Korea Climate Change Assessment Report 2020, which analyzed more than 1900 papers and reports, it is clear that since 1920 South Korea has experienced a higher rate of temperature increase compared to the global average, and since 1973 the trend of increasing temperature has been stronger [1]. In addition, there is a consensus that climate change is caused by human activities [38], and Korea is under high pressure for ecosystem changes such as human intervention [39].
--- These statements are not derived from this study, and then I suggest to move this part to the discussion section.
- We agreed your suggestions. Thank you (P8 line 196-200).
Reviewer 2 Report
This study examined the phenological shifts and responses to spring temperature of multiple plant and animal species in a long-term observation dataset in Korea. Interesting temporal trends and the differences between interacting species were found, suggesting the possibility of phenological mismatch. The manuscript has some flaws of unclear statements or expression in writing, which should be improved. Analysis of temperature sensitivity and day difference should be conducted at site level to rule out the impact from site variations. Results should be presented more precisely and clearly to support the research finding of phenological mismatch. Discussion should add more explanations of insignificant trends and differences of phenological responses between plant and animal species.
Major issues:
Did the temperature sensitivity regression analysis include all data in multiple sites? As sites variations were included if multiple sites data were included in regression, better to examine the sensitivity at each site. Previous studies reported greater sensitivities in the southern area suggesting the spatial variations. It would be interesting and important research finding to see if the spatial pattern exists for both plants and animal species.
Line 196-197. Not clear. If the day difference was always negative, it did not suggest the change of order. The change of sign of day difference suggested the change of order of phenophases from the interacting species, not just negative values.
Did the analysis of day difference use the average values of 6 sites? Why not analyze the day difference at each site? Variation among sites may dilute the interactions between species. Should conduct the analysis at site level. If significant tests were done, need to show the specific results as Table 3, other than Figure 3, to clearly support the point of possibility of phenological mismatch.
Again, in addition to the results showed in current manuscript, it would be interesting to see if there is any spatial pattern of temporal trends and the temperature sensitivities for each species.
What is the possible explanation of insignificant phenological shifts in plants and animals? Any previous studies about other environmental cues (e.g. photoperiod) of animal phenology?
Minor issues:
Line 101 should be ‘two’ bird species, not ‘three’
Line 124 and 133 better to use ‘temporal trend’ instead of ‘time series trend’
Line 137-138. The sentence is not clear here. Better to say you conducted the temporal trend analysis for two different time periods, 1936-1975 and 1976-2015, in order to compare the changes in day differences between interacted species under different warming conditions.
Line 143-144. Not clear. I think the sentence means ‘the species at each observation point were divided into two groups based on the slope values from regression analysis’.
Line 160-161. Not clear. I think Fig 2 showed variation of statistically significant temporal trends of phenological dates of all species across 61 sites. Within each species, the variation of boxplot represented spatial variation of phenlogical shifts. Across species, the differences between plants and animals were clear.
Line 162. What does ‘time’ mean in the sentence? Is it the mean date of phenology observations or something else? Need to clearly explain.
Line 167-170. Standard deviation of slope values can be easily calculated to support the statement here. Small standard deviation indicates small variation.
Line 184-186. Not clear. I think it means ‘for all species except secondary consumers, the R-square value of regression analysis with temperatures for 1976-2015 was higher than that for 1935-1975’.
Figure 3. Put the x axis to the bottom of plots.
Line 216-217. Make it simple. First flowering dates of all plant species in this study showed advanced temporal shifts during 1935-1975 and 1976-2015.
Author Response
Please find the revised version of our manuscript that has been submitted to IJERPH and our response to the comments of yours and the reviewer. Please refer to our response letter for the detail. We appreciate your concern on our manuscript.
Author Response File: 
Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
