Saturday, March 31, 2012

3010.txt

cc: J.A.MatthewsatXYZxyznsea.ac.uk
date: Mon Jul 28 12:11:09 2008
from: Keith Briffa <k.briffaatXYZxyz.ac.uk>
subject: Paper submitted to Holocene
to: weidneratXYZxyz-potsdam.de

Dear Kathrin
First let me apologise for the long time it has taken to get referees comments and then to
discuss with the editor.
Unfortunately, I have to say straight away that we have decided not to publish this article
in The Holocene.
The reason is not to do with the scientific rigour of the results you describe but rather
because we feel (with strong guidance from the referees) that the content and implications
of the work are too specialised for this journal. Both referees ( and other informal
opinions) agree that this paper is more suited to a tree or tree-ring specialist journal .
I copy below some comments, one more detailed than the other , in the hope that these may
be useful in considering a re-submission perhaps to a journal like Tree-Ring Research ,
Dendrochronologia or Trees. I realise this this decision is likely to be disappointing ,
particularly as no fundamental objections have been raised regarding the science. However,
with strong pressure on space and a truly interdisciplinary audience we must take a rather
strict line on general relevance of the articles published. I hope you will understand and
accept the reasons for this decision. I am sure the paper would be rapidly accepted in a
more specialist journal. Again I am sorry that it has taken us this long to reach this
decision , but we wished to consult widely before reaching it.
with best wishes and thanks for the submission.
Keith
Comments
Referee 1
The important bit of this paper is the observation that larch bud moth attacks do not seem
to have much impact on carbon isotope ratios. Other groups have found the same, and
Matthias Saurer has a PhD student working on this. She may be working at the same site.
This is an interesting finding for the dendro community, since Larch is such an important
archive species, but I am not sure it is important enough to warrant publication in an
interdisciplinary journal like The Holocene. One of the forestry or tree ring journals
would be more appropriate.

The important observation is only a small part of this manuscript. The rest includes a bit
of statistical treatment, which I did not find very convincing. There are better ways to
deal with discreet events. There is also a large section trying to explain the influence
of bud moth attack on the carbon and oxygen isotopes, which I found very speculative.

In conclusion I think it would be best to reject on the grounds that the material is not
suitable for publication in The Holocene.

Referee 2
Consequences of larch budmoth outbreaks on the climate significance of ring width and
stable isotopes in larch

Weidner et al.

Referee 1

This is a small but interesting study on the problems caused by larch budmoth for climate
reconstruction, and the potential of stable isotopes for overcoming them. To my mind the
most interesting and novel aspect of the study are the observations of the effects of LBM
attack on isotopic discrimination and the discussion of the possible physiological factors
causing the effects. There is little or nothing in the literature on the effect of insect
attack on stable isotopes in trees.

The paper is generally well written but would benefit from editing by a native English
speaker. In some places the language obscures the meaning. I have made some suggestions
on phraseology in the comments below.

The results are of broad interest, but the manuscript requires modification before it is
acceptable for publication.


Main Points

1. The authors initially use filtered (standardized) tree ring data to examine the
effects of LBM outbreaks on these parameters (Fig. 3). They also use standardized isotope
and temperature data in Fig.5; but no results using standardized precipitation data are
presented. Standardized data, however, are not used to investigate climate relationship;
instead, raw data are used. The authors do not give a reason for this, and it provides
grounds for confusion. It would not be standard practice to use only 10 trees and raw
ring width data to examine ring width/climate relationships. The confusion is compounded
by Figs 6A and B, one using standardized values and the other raw values of data. The
figures are merely cited in the text (line 256) without any discussion, and I therefore see
no point in their inclusion. I am somewhat surprised that the correlation coefficients for
filtered standardized data and raw data are so similar. It looks like the r value for the
standardized data would be significantly higher if it were not for one particularly deviant
point in Fig. 6A. In fact, I cannot see a corresponding point in Fig. 6b; perhaps it is a
result of the filtering process, but I would not have expected this.

2. The discussion on the possible physiological effects on LBM on isotopic
discrimination seems generally well founded. However, the statement in line 325 (Since
most the late years photosynthates ) raises some issues. The use of previous years
photosynthates in conifers for earlywood growth, and the consequent effects on isotope
values is a moot point in the literature, and there seems no overall consensus. The
authors need to provide some evidence for this being the case in their trees. If the
previous years photosynthates were a major contributor to earlywood, then one would expect
a correlation with the previous years temperatures, especially in years of type 2 outbreak.

3. I cannot agree with the final sentence on the Conclusion (line393). It is only
carbon isotopes that are hardly affected. Oxygen isotopes are significantly affected, but
probably not to an extent that makes them unusable. We have no idea about hydrogen
isotopes.

4. The main finding is that carbon isotope ratios seem little affected by outbreaks
of LBM in that removal of values during outbreak years does not significantly change that
value of the correlation coefficient with temperature (lines 251-258). This certainly
seems true for their observation; but I suspect that the authors were lucky in that
outbreak years tended to coincide with years of near average temperature, where effects on
r values would be minimized. It may be that outbreaks (particularly of type 1) during
years with abnormally high or low temperatures would have a much more significant effect on
d^13C values.


Other Points:

Line

23 Suggest less instead of rather little
24 In particular instead of Especially
27 ; instead of ,
31 importantly
44 connected to rather than connected with
54 the following called outbreak.. does not make sense
127 It would be helpful to refer to Fig 2 during the discussion of the various
types of LBM attack.
129 The suggestion that trees are defoliated runs counter to the statement (line
56) that the leaves are not eaten away.
150 Comma required after behaviour
154 Sentence is unclear. Suggest: similarity in behaviour between cellulose
and wood isotopes, we decided
172 Some details are required of how the atmospheric correction was carried out.
187 Delete . after and.
242 Highly rather than strongly
247 Delete do and insert generally after though (Fig. 4 shows that some
individual trees give higher r values than the mean of the trees.
275 Delete do
276 proof of rather than proof for
289-91 This sentence need rewording. Suggest: As e[D] and e[C] are constant, changes in
C[i] during infestation are decisive in determining the effects on d^13C; however,
the physiological basis for this has not been investigated in detail.
294 Delete therewith andinsert subsequently after stomates.
296 Suggest as indicated by instead of observation
297 Insert brackets around D.
299 A very awkward sentence needs rephrasing
308 The latter, however, have rather than has.
Of more importance rather than essential
320 years of weak outbreak.
332 Delete f. ex.
336 Rearrange sentence. The time during the growth..starts should be decisive
348 Delete a before removal.
353 measure
357-8 Unclear. Does it mean that some of the processes involved in fractionation are
lost?
358 In particular rather than Especially.
361 More closely rather than closer.
367 In contrast to rather than contrary to
373 during rather than along; prevent rather than aggravate
412 Rubli not Rublin

--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.

Phone: +44-1603-593909
Fax: +44-1603-507784
[1]http://www.cru.uea.ac.uk/cru/people/briffa/

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