Research Progress in the Application of Google Earth Engine for Grasslands Based on a Bibliometric Analysis

Round 1

Reviewer 1 Report

Auhtors have presented a bibliometric analysis of the grassland monitoring using Google Earth for a period of five years. I have few concerns about the choice of keywords for retrieving the data. My major conerns are:

1. Why was the literature reviewed for only five years? Any rationale? In fact, a robust explanation for the keywords and study period is missing.

2. Why only Savannahs and not any other grassland types, particularly from cold environment? In the absence of these details, the work has limited scope.

3. What about the correlation with impacts of climate change? In my opinion, this aspect along with anthropogenic factors need to be examined.

4. What is the outcome/conclusions that can be sued in the future?

A minor language editing is required.

Author Response

1. Why was the literature reviewed for only five years? Any rationale? In fact, a robust explanation for the keywords and study period is missing.

Reply:

An attempt has been made to increase the study period from  five years (2017-2022) to start from 2010 when GEE was launched. However, it was not possible to extend the study period since earlier articles which use GEE for grasslands start from 2016. So the authors used this as a starting point. The end period was extended from 2022 to 2023 because the current year of 2024 is not finished and more articles applying GEE for grasslands can still be released. An explanation of how the current study period was established is added to the Materials and Methods section.

2. Why only Savannahs and not any other grassland types, particularly from cold environment? In the absence of these details, the work has limited scope.

Reply:

Agreed, the synonyms  for grasslands have been broadened to cover the topic more comprehensively. The list of search terms used to refer to grasslands include: grassland, prairie, steppe, savanna, rangeland, meadow, pampas, veld, pasture, heath, scrubland, tundra (Arctic grasslands), fernland, fescue grassland, bromegrass, sward, wild grass, cereal pasture and herbaceous cover. Table A1. lists these Search terms that were used in WOS and Scopus on databases.

3. What about the correlation with impacts of climate change? In my opinion, this aspect along with anthropogenic factors need to be examined.

Yes we agree, grasslands and climate change are related including anthropogenic effects. However, we understand that this is a separate topic on its own, which is well addressed by the following research:

Hou, Q., Ji, Z., Yang, H. and Yu, X., 2022. Impacts of climate change and human activities on different degraded grassland based on NDVI. Scientific reports, 12(1), p.15918.

Hopkins, A. and Del Prado, A., 2007. Implications of climate change for grassland in Europe: impacts, adaptations and mitigation options: a review. Grass and Forage Science, 62(2), pp.118-126.

Bai, Y. and Cotrufo, M.F., 2022. Grassland soil carbon sequestration: Current understanding, challenges, and solutions. Science, 377(6606), pp.603-608.

Gaskin, J.F., Espeland, E., Johnson, C.D., Larson, D.L., Mangold, J.M., McGee, R.A., Milner, C., Paudel, S., Pearson, D.E., Perkins, L.B. and Prosser, C.W., 2021. Managing invasive plants on Great Plains grasslands: A discussion of current challenges. Rangeland Ecology & Management, 78, pp.235-249.

Bi, X., Li, B., Zhang, L., Nan, B., Zhang, X. and Yang, Z., 2020. Response of grassland productivity to climate change and anthropogenic activities in arid regions of Central Asia. PeerJ, 8, p.e9797.

4. What is the outcome/conclusions that can be sued in the future?

Reply:

Future studies are recommended in the discussion section of the paper.

Reviewer 2 Report

comments added in PDF file

Comments for author File: Comments.pdf

No comments

Author Response

Good day,

Thanks for reviewing the paper, please see attached document for responses.

Regards

Authors

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Authors have addressed to all the queries and incorporated the suggested changes. The manuscript has been revised thoroughly.

By and large, it is fine.

Reviewer 2 Report

I am satisfied with the revision. Authors have addressed all the major points in a sufficient way.