Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna

Levick, Shaun R.; Richards, Anna E.; Cook, Garry D.; Schatz, Jon; Guderle, Marcus; Williams, Richard J.; Subedi, Parash; Trumbore, Susan E.; Andersen, Alan N.

doi:https://doi.org/10.5194/bg-16-1493-2019

Articles | Volume 16, issue 7

https://doi.org/10.5194/bg-16-1493-2019

© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/bg-16-1493-2019

© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 16, issue 7

Research article

|

10 Apr 2019

Research article |

| 10 Apr 2019

Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna

Shaun R. Levick, Anna E. Richards, Garry D. Cook, Jon Schatz, Marcus Guderle, Richard J. Williams, Parash Subedi, Susan E. Trumbore, and Alan N. Andersen

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Final revised paper (published on 10 Apr 2019)
Preprint (discussion started on 27 Apr 2018)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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- Supplement

RC1: 'Anonymous referee comments for authors', Anonymous Referee #1, 29 Jun 2018
- AC1: 'Author response to Reviewer 1 (Shaun Levick on behalf of co-authors)', Shaun Levick, 09 Aug 2018
RC2: 'bg-2018-188', Anonymous Referee #2, 03 Jul 2018
- AC2: 'Author response to Reviewer 2 (Shaun Levick on behalf of co-authors)', Shaun Levick, 09 Aug 2018

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

ED: Reconsider after major revisions (25 Aug 2018) by Christopher Still

AR by Shaun Levick on behalf of the Authors (27 Sep 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (22 Oct 2018) by Christopher Still

RR by Anonymous Referee #3 (04 Jan 2019)

Suggestions for revision or reasons for rejection

The authors present a straightforward interpretation of their approach to quantifying savanna structure and biomass using ground-based and lidar observations. In my view they have made appropriate changes to the manuscript and largely addressed the concerns of prior reviewers. However, I think the discussion of the statistical approaches used and the reporting of the results of the analyses remain insufficient.

First, Table 1 presenting the model selection results appears to be incomplete since it does not include AIC values for canopy height. In addition, while the model selection criteria are reported, the models themselves are not. Since these are ANOVAs it would seem appropriate to report the f-statistics and be clear about what model was selected in the end and why (for example, is the "best" model really one where just the interaction term is included and not the associate main effects?). More clarity in the statistical approach is needed along with a more complete reporting of the statistical results.

Second, it would appear that the vertical structure treatment comparisons were based on visual assessments of the degree of overlap of confidence intervals from Figure 6. Is this the case? Key statements in the results have unclear statistical support, for example: "Compared with no fire, early season biennial fires reduced cover across all heights, but especially below 7m, and late season biennial fire reduced cover even further throughout, generating a vertical profile similar in shape but with much lower frequency of occurrence (Figure 7). The late season fire profile contained significantly less canopy in all height classes compared to the unburnt (no overlap of error bars), but the most marked effects were in the lower height classes (shrub layer)." The authors should be clear about how these conclusions are drawn, specifically which statistical results are used for these inferences and justify the statistical approach. In my view, this is lacking in the current version of the manuscript.

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ED: Publish subject to minor revisions (review by editor) (20 Jan 2019) by Christopher Still

AR by Shaun Levick on behalf of the Authors (08 Feb 2019) Author's response Manuscript

ED: Publish as is (05 Mar 2019) by Christopher Still

AR by Shaun Levick on behalf of the Authors (15 Mar 2019) Manuscript

Short summary

We used airborne lidar to map the three-dimensional structure and model the biomass of plant canopies across a long-term fire experiment in the Northern Territory of Australia. Our results show that late season fires occurring every 2 years reduce the amount of carbon stored above-ground by 50 % relative to unburnt control plots. We also show how increased fire intensity removes the shrub layer from savannas and discuss the implications for biodiversity conservation.