Structure and Abundance of Fusarium Communities Inhabiting the Litter of Beech Forests in Central Europe

Round 1

Reviewer 1 Report

Here is the review of the paper entitled "Structure and Abundance of Fusarium Communities Inhabiting the Litter of Beech Forests in Central Europe written by Hanna Stępniewska and co-authors.

The aim of the paper was to study species diversity and abundance of plant pathogenic genus Fusarium occurring in the litter of old mixed beech-fir forests in the Carpathians (Poland) and the Alps (Austria), and in a managed beech stand (Poland). The species pathogenicity was assessed by inoculating beech germinants with Fusarium cultures. Fusarium spp. were identified using morphological and molecular approaches (based on RPB2 and TEF1-α genes). Twelve fungal species were identified from 402 isolates, including nine known and three putatively new species. The isolates belong to the three species complexes within the genus Fusarium ( F. oxysporum (1 sp.), F. sambucinum (3 sp.), and F. tricinctum (6 sp.), while one isolate belong to the genus Neocosmospora and one to the genus Fusicolla. The most frequently isolated fungi in the study were F. avenaceum, F. sporotrichioides, and Fusarium sp. B. The structure and abundance of Fusarium species were variable within three forests. The species richness of Fusarium spp. was greatest in old mixed beech-conifer stands, while abundances of Fusarium spp. were higher in managed beech-dominated stand.

It is interesting study of underexplored fungal genus which is important pathogen in European forests. The paper seems scientifically sound. The research methods are suitable and well conducted. The paper does not include any statistical analysis. There are some minor corrections, mostly in methods part, that need to be properly explained in the text.

Best,

Reviewer

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The whole article is coherent and represents a significant amount of work. The fact that it is a little studied fungi in this type of forest is really very interesting.  However, there are still some points to correct.

In the introduction, the objectives are not clearly defined.

The materials and methods need to be revisited. This is the part where the most information is missing. I agree to go to another article to have details but I still want to understand just with this article.

The results are very long and difficult to read. And we don't understand why you don't talk more about mixed forests.

The discussion is not detailed enough. The conclusions are put forward without really being justified or not justified enough. A division into sub-paragraphs could help the reader to better understand the development of the discussion.

 

General

Introduction

The objectives are not clearly defined in the introduction. We have the impression that this is simply a continuation of article (13) and not a new article. The assumptions made in L88 are not in the right place. It would be more appropriate to group them with the objectives of the study.

 

Materials and Methods

2.1 For the "study area" paragraph, even if the information is given in another study, a brief description of the types of forests studied would help in understanding the study. Give the types of species, the age of the majority of trees, the measurements of the areas studied, the climate of the different regions... Maybe make a summary table of the 3 studied areas? Without this it is very complicated to visualize the sites and their differences.

2.2 Experiment 1: How many repetitions? How many beechnut per plastic box? How many grams of litter or how thick of litter? "Afeter wintering" L132, this means how many months? The explanation of this experiment is not detailed enough.

Figure 1: Rework the legend to avoid repeating by Fusarium spp.

L146: Even though the experiments were described in detail in this study, a little more explanation is still needed here for more coherence.The reader should understand directly what you are doing without having to read another publication.  The details can be in this other publication but you need a little more description in this study anyway.

The connection with the paragraph of experiment 2 is not well done (L146). It is difficult to understand that we are moving on to the treatment of the collected samples.

 

Results

3.1 To be placed in the materials and methods

3.3 Here you talk about "pine seedlings" but in your title and in your objectives there is no mention of this study on pine seeds. For me, it is necessary to present them better. It is like having mixed forests. For the moment we still don't know why you chose mixed forests instead of only beech forests.

 

Discussion

The first paragraph (A337) is a good summary of the results. I understood it better than what was in the results. In view of this remark, trying to lighten the writing of the results might highlight them better.

364: "Our work showed that Fusarium spp. inhabiting beech litter may be disseminated via seed and spread within forest nurseries" I don't quite agree because this was not really highlighted in the results.

377: "Our results indicate that F. avenaceum is a major agent responsible for the decline of beechnuts in Central Europe" This sentence should come after explaining your results L370 and discussion with what has already been seen in subsequent studies.

404 to 417: This paragraph is very interesting but a bit under-exploited. To better compare forests and understand why we have these differences, make a table with the climate and litter composition of each site studied in the material and method. This would allow to develop this paragraph and to discuss the environment of these fungi.

 

 

Specific

63 to 69 – « Germinating seeds and young seedlings in nurseries can be challenged by a variety of Fusarium species such as F. oxysporum Schltdl. sensu lato, F. commune K. Skovg., O’Donnell & Nirenberg, F.  proliferatum (Matsush.) Nirenberg, F. circinatum, F. acuminatum Ellis & Everh., F. avenaceum  (Fr.) Sacc., F. equiseti (Corda) Sacc., F. chlamydosporum Wollenw. & Reinking, F. tricinctum (Corda) Sacc., F. moniliforme J. Sheld., and Necosmospora solani (Mart.) L. Lombard & Crous (formerly known as Fusarium solani (Mart.) Sacc.). »

Very difficult to read, as I'm not really a microbiologist I don't understand the quote of the authors which weighs down the text. Maybe removing them will make the reading more fluid (same remark for the whole paper)

71 - Soilborne or soil-borne ?

126 - how many plots ?

153 - We know the number of isolates but on how many?

198 - Skip a line

314 - and the least frequent in which area?

352 – « It seems that beechnuts lying on the litter surface or buried within litter are exposed to a wide range of potentially damaging agents »

 It seems pretty obvious...

427 – « Further studies on the presence of Fusarium spp. on different forest trees are needed » 

Not in the discussion but in the conclusion as a perspective

Table 2 - Neocosmospora spp. in one line

Author Response

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Author Response File: Author Response.pdf