Implementing spatially explicit wind-driven seed and pollen dispersal in the individual-based larch simulation model: LAVESI-WIND 1.0

Kruse, Stefan; Gerdes, Alexander; Kath, Nadja J.; Herzschuh, Ulrike

doi:https://doi.org/10.5194/gmd-11-4451-2018

Articles | Volume 11, issue 11

https://doi.org/10.5194/gmd-11-4451-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/gmd-11-4451-2018

© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 11, issue 11

Development and technical paper

|

05 Nov 2018

Development and technical paper |

| 05 Nov 2018

Implementing spatially explicit wind-driven seed and pollen dispersal in the individual-based larch simulation model: LAVESI-WIND 1.0

Stefan Kruse, Alexander Gerdes, Nadja J. Kath, and Ulrike Herzschuh

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Final revised paper (published on 05 Nov 2018)
Supplement to the final revised paper
Preprint (discussion started on 07 Mar 2018)
Supplement to the preprint

Interactive discussion

Status: closed

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

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RC1: 'Review Kruse et al. : Implementing spatially explicit seed and pollen dispersal in the individual-based larch simulation model: LAVESI-WIND 1.0', Anonymous Referee #1, 17 Apr 2018
- AC1: 'Responses to general comments of referee #1', Stefan Kruse, 30 Jun 2018
- AC2: 'Responses to specific comments of referee #1', Stefan Kruse, 30 Jun 2018
RC2: 'Review for 'Implementing spatially explicit seed and pollen dispersal in the individual-based larch simulation model: LAVESI-WIND 1.0'', Anonymous Referee #2, 19 Apr 2018
- AC3: 'Responses to general comments and recommendations for the different sections of referee #2', Stefan Kruse, 30 Jun 2018
- AC4: 'Responses to minor comments of referee #2', Stefan Kruse, 30 Jun 2018

Peer-review completion

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

AR by Stefan Kruse on behalf of the Authors (30 Jun 2018) Author's response Manuscript

ED: Referee Nomination & Report Request started (10 Jul 2018) by Hisashi Sato

RR by Anonymous Referee #1 (07 Aug 2018)

Suggestions for revision or reasons for rejection

My comments have been addressed. Some of the changes result in inconsistencies in the formulation. I’ve tried to mention them, but the authors should check their text again.
My remaining minor comments
44: In Epstein 2007 the FLM TreeMig has been applied on a 2200 km transect from boreal to arctic conditions in Central Siberia, not exactly a small area. Forest landscape models are indeed what you seem to aim for in your outlook part in the discussion. So I would rather stress the novelty of including wind and pollen into such models.
78-86: Mention the importance of pollen modelling, and smooth the transition to the follow-up sentence. (“Besides---traits”)
130: is randomly determined according to this probability
147: pollination probability, omit mathematical form
148: Just to make sure: p is the probability that a pollen donor standing in distance r to the mother tree is the father? If so, write probability p in line 129. Or is this probability normalized by the sum of the probabilities of all father trees?
211: does climate only influence tree growth or also survival and establishment (which are much more important)?
264: parametrisation
309: hand over? Unclear. I guess you distribute different tree individuals to different CPUs?
405-407: How can the simulation of a single species help to overcome the difficulties introduced by lumping several species into one artificial PFT??? Either explain or omit.
413-415: But how? You would still have the problem of intra-grid migration and the discretization error by the large grid cells. Have a look on the newest migration upscaling modelling approaches, which keep a fine resolution for the dispersal and simulate the local dynamics only in selected cells, e.g. Nabel 2015, and in particular Lehsten et al. 2018, GMD, Simulating migration in dynamic vegetation models efficiently with LPJ-GM

Referee Report: PDF

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RR by Julia Nabel (17 Aug 2018)

Suggestions for revision or reasons for rejection

I appreciate the sensitivity study and the adapted discussion of the results a lot. In my opinion most comments have been adequately addressed and I am only left with a few smaller questions/suggestions:
(1) What is the exact transect for the sensitivity study – are these 10 100x100m plots with homogeneous climate (on each/all plots) or is this one 1000? It’s a north-south transect, correct? In the review response the authors state that “seed dispersal was allowed on the meridional borders but not the latitudinal limits”. I think this information is still missing in the current manuscript.
(2) In the review response the authors state that pollination only happens within a plot, i.e. if a transect is really made up of 10 100x100m plots pollination would not happen throughout the whole simulation area? I guess this is due to computational expenses? I would appreciate if the authors could mention this in 2.2.1 and add a few sentences on the limitations of this assumption for the potential model applications in 4.4.
(3) From current formula (2) – the authors seem to not have reordered the eq numbers – and the surrounding text I understand that Ht is the releasing tree top in m. However, in Table 2 it is listed as the factor 0.75. Furthermore, in the review response the authors state that lambda is a conversion factor from m to cm. Why is this conversion necessary? Aren’t all the parameters and the result in m? Please clarify and also add the information about lambda to the manuscript.
(4) Section 2.3 could benefit from a bit reordering, since information required to understand the first paragraph is only given in the second paragraph, namely that the lowermost 100 x 100 area (plot?) is the initialisation area and that each setting has been repeated 30 times.
(5) As already mentioned in (2) I would strongly appreciate if the authors could expand section 4.4 a bit more to state the limitations of LAVESI-WIND with regards to the advertised model applications. E.g. the authors state that migration behaviour could be influenced by shrubs which respond faster to climate change, but LAVESI is a one species model and might probably currently not be able to represent inter-species competition.

Additionally, I list a couple of minor comments/suggestions which I think might improve the clarity of the paper some more.
[l46] maybe add that they have higher computational expenses, e.g. “... effort for parameterisation, have higher computational expenses, and are therefor typically not applied over larger areas”
[l47] Further problems: of DGVMs?!
[l64] I would move “during the past decades” to the start of the sentence
[l77] "this pollination function" has no clear reference anymore, since sentences before have been deleted -- Maybe restructure sentence, e.g. "The new pollination function tracks ... and furthermore allows ..."
[105] Could you explain the new “periodic boundary conditions” a bit more? Is this the dispersal “allowed on the meridional borders but not the latitudinal limits” that you mention in the review responses? (In the sentence you also state that you use this for all simulations in the manuscript?).
[112] individually -> individual ?
[123] EQ numbers not reordered.
[125] maybe add further symbols and reorder the sentence a bit : “... velocity V_d_pollen... and wind speed Vw, and Gregory’s parameters C and m
[148] Please add information on lambda.
[150] Why again wind speed, and how?
[189] eq (5): is S the average of the 30 repetitions?
[201] 10 100 x 100 plots?
[260] Thus, which are the most sensitive parameters?
[266] The ->max<- sensitivities increases?
[280] Line 282/283 state that “trees ” are the most important variable, why is it then “number of seeds and combination of ... trees&seeds”?
[289] “four to eight ... using only four”? Maybe “one to four ... using eight”?
[298] responses of the
[299] What exactly could be overcome?
[302] Maybe move parts of this to section 4.4., since it deals with potential applications
[339] I do not understand this sentence – the authors do have the data on the wind direction, thus they would know if this would have limited the recent migration rate?
[365] I would move this last paragraph to 4.4, since its a limitation of the potential application
[390] factor of six? results state a factor of 2!
[Table 3] Could you please add the mean absolute sensitivity referred to in the text? Could you add the information on bold/italic values from Table 4 also here in Table 3?

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ED: Publish subject to minor revisions (review by editor) (20 Aug 2018) by Hisashi Sato

AR by Stefan Kruse on behalf of the Authors (14 Sep 2018) Author's response Manuscript

ED: Publish subject to minor revisions (review by editor) (20 Sep 2018) by Hisashi Sato

AR by Stefan Kruse on behalf of the Authors (02 Oct 2018) Author's response Manuscript

ED: Publish as is (04 Oct 2018) by Hisashi Sato

AR by Stefan Kruse on behalf of the Authors (12 Oct 2018)

Short summary

It is of major interest to estimate feedbacks of arctic ecosystems to global warming in the upcoming decades. However, the speed of this response is driven by the potential of species to migrate and the timing and spatial scale for this is rather uncertain. To close this knowledge gap, we updated a very detailed vegetation model by including seed and pollen dispersal driven by wind speed and direction. The new model can substantially help in unveiling the important drivers of migration dynamics.