Review Reports - Conservation Challenges of Endemic Plant Species Across Altitudinal Gradient in Piatra Craiului National Park (Romania)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript "Conservation Challenges of Endemic Plant Species across Altitudinal Gradient in Piatra Craiului National Park" provides valuable insights into the distribution of endemic flora in a key Carpathian protected area. The use of PCA to link species distribution with ecological indicator values is a suitable approach. However, the manuscript requires substantial revisions to address critical inconsistencies, inappropriate citations, and structural flaws before it can be considered for publication.
Major Comments
1. Numerical Inconsistencies:
There are significant discrepancies in the numbers reported throughout the text that must be clarified:
• The Abstract and Section 3 (Results) state that the dataset includes 731 vascular plant species. However, the first paragraph of the Discussion (Section 4) states: "it appears we found in Piatra Craiului National Park accounts about 24.8% (778 species) of the country's higher plant diversity." This contradiction must be resolved.
• The Abstract mentions "35 taxa endemic", but the Discussion states "Altogether, 47 taxa representing endemic species or subspecies of the Carpathians were reported in this area [32]. Of these, 35 endemic taxa (74,47%) were confirmed by the surveys analyzed in this study." This distinction between reported and confirmed taxa should be made clear earlier in the text, including in the Abstract.
2. Inappropriate and Out-of-Context Citations:
Several references are cited in contexts that do not match their content. This is a severe issue that undermines the scientific credibility of the paper and must be corrected:
• Reference [5] (Mani, 1968): This is a book titled "Ecology and Biogeography of High Altitude Insects". It is highly inappropriate to cite this work on page 13 to support the statement: "Stress tolerance traits, such as larger seed size, further enhance persistence under edaphic constraints [5, 56]."
• Reference [11] (Kovács et al., 2023): This paper is about the morphological and genetic diversity of Plantago maxima populations. It is cited in the Introduction to support a general statement about how diverse geological substrates contribute to habitat heterogeneity. A more appropriate, general ecological reference should be used here.
• Reference [17] (Silva et al., 2019): This paper is titled "Selection of Eucalyptus grandis families across contrasting environmental conditions" and focuses on forestry in Brazil and Uruguay. It is cited in the Introduction to support the statement: "These climatic gradients have resulted in the formation of distinct vegetation zones, each harboring different plant communities [16,17]." This citation is completely out of context for European mountain vegetation.
• Reference [8] (Haris et al., 2025): This paper discusses climate change influences on Central European insect fauna. It is cited in the Introduction alongside papers substantiating lists of plant species and habitats.
3. Methodological Clarifications:
• Definition of Endemism: The text states "Only taxa considered endemic at the national or regional (Carpathian) level were included in the analysis." The authors must explicitly state which reference list or authority was used to define this endemic status (e.g., a specific national flora or a Carpathian endemic checklist).
• Plot Size Heterogeneity: Section 2.2 mentions that sampling plots varied between 1 and 400 m². The authors should briefly discuss how this massive variation in sampling area might influence the results, particularly regarding species richness counts per plot, and whether any standardization or rarefaction techniques were considered.
• Missing Text: Section 2.2 ends abruptly with an incomplete sentence: "The percentage cover of each recorded species is estimated and the overall vegetation." Please complete this sentence and ensure no other methodological details are missing.
• Statistical Reporting: The results of the PCA (Figure 4) should include the percentage of variance explained by the first two principal components (PC1 and PC2) both in the text and on the axes of the figure. Furthermore, the "positive association" mentioned between endemic species frequency and species of conservation interest (Figure 8) should be supported by a formal statistical test (e.g., correlation coefficient and p-value).
4. Structural and Formatting Issues:
• Figure Numbering: The numbering of figures is inconsistent. The text refers to Figure 4, and the next figure mentioned is Figure 7. Figures 5 and 6 are missing. Additionally, there are two figures labeled "Figure 9" (one on page 11 and another on page 12) with different content and captions.
• Figure Captions vs. Text: The text describes Figure 8 as a "scatterplot", but the caption reads "The number of endemic and protected plant taxa across different habitat types for PCNP (coded according to the EU Habitats Directive)", which seems to describe a bar chart (likely the first Figure 9). Please ensure all captions accurately describe their respective figures.
• Table 2: The formatting of Table 2 is severely broken, with text fragmented across multiple lines, making it nearly unreadable. This must be reformatted into a clear, standard table.
5. Taxonomic Nomenclature:
Please verify the nomenclature and author citations for the listed endemic species against updated taxonomic databases (e.g., World Flora Online, Euro+Med PlantBase). For example:
• Papaver alpinum Salisb. subsp. corona sancti-stephani should likely be written as Papaver alpinum subsp. corona-sancti-stephani (Zapał.) Grey-Wilson (or similar accepted combination), and "salisb." is not the correct author for P. alpinum (which is L.).
Minor Comments
• Title: The title contains a grammatical error. It should be "Conservation Challenges of Endemic Plant Species..." rather than "Plants Species".
• Abstract: The abstract should be revised to ensure all numbers align perfectly with the results section.
• Conclusions: The phrase "non-native vegetation" in the conclusions is slightly ambiguous in this context. It would be clearer to specify whether this refers to ruderal/synanthropic vegetation or alien invasive species.
• References: Please check the reference list for duplicates. For instance, references [72] and [74] appear to be identical, as do [73] and [75].
English Language Quality
The English language quality of the manuscript requires significant improvement. While the overall scientific message is understandable, the text contains numerous grammatical errors, awkward phrasing, and inconsistent punctuation. Examples include expressions like "setting the shelter for very rare species" or "imprinting human civilization development," which are not standard scientific English. Many sentences are overly long and complex, reducing readability.
Recommendation regarding English: The manuscript must be rewritten and professionally proofread by a native English speaker or a professional scientific editing service before it can be accepted for publication.

Comments on the Quality of English Language

The English language quality of the manuscript requires significant improvement. While the overall scientific message is understandable, the text contains numerous grammatical errors, awkward phrasing, and inconsistent punctuation. Examples include expressions like "setting the shelter for very rare species" or "imprinting human civilization development," which are not standard scientific English. Many sentences are overly long and complex, reducing readability.
Recommendation regarding English: The manuscript must be rewritten and professionally proofread by a native English speaker or a professional scientific editing service before it can be accepted for publication.

Author Response

Thank you for your valuable comments on our manuscript. We have carefully considered all suggestions and revised the paper accordingly. All revisions are clearly indicated, and a point-by-point response is provided below.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The study by Claudia Biță-Nicolae et al. examines the distribution of endemic vascular plant species across habitats and environmental gradients within Piatra Craiului National Park in the Southern Carpathians, Romania. The authors aim to: (1) assess the distribution of endemic species across altitude and vegetation types, (2) identify ecological overlap and spatial hotspots, (3) evaluate relationships between species distribution and natural or anthropogenic threats, and (4) assess their current protection status.

Overall, the manuscript is well structured and addresses a relevant topic aligned with the journal’s scope. A key strength is the integration of floristic data with a conservation perspective, linking patterns of endemism to habitat distribution and management frameworks. This is a valuable contribution, as such integration is often lacking in descriptive floristic studies. However, despite these strengths, the manuscript presents several conceptual and methodological limitations that should be addressed before it can be considered for publication.

Major Comments

My first concern is that the study tackles four ambitious objectives, namely, description of distribution patterns, species spatial and environmental ordination, analysis of spatial overlaps of distribution and threats, and protection status assessment. Given the broad scope of these goals, and the extensive results obtained, I am concerned that the methods section is very brief, and does not provide readers with a clear rationale on how to implement the analytical strategy. Hence, I would suggest the authors consider providing a clearer description of the methods, and perhaps consider also including statistical tests that allow the readers to assess the significance of the patterns described in Figures 2 to 9.
In a related concern, I am worried about two aspects of the data set used. The first one is that it combines both current (or relatively recent) field sampling, and historical or literature based phytosociological records. However, the description provided in section 2.2 is not very clear regarding how many current versus historical releves were used, and the reference provided (35) is a link to arcgis world imagery (https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9). Thus, the readers have no means of learning more information regarding the data set´s provenance and composition. One particularly relevant aspect of this shortcoming is that the authors indicate that the plots vary in area, spanning between 1and 400 m². This is not analysed by the authors, and it is not clear whether these differences in area (and elevation) may or not bias the results presented. Furthermore,
A related concern is that no information is provided regarding the temporal scope of these data points, and whether temporal heterogeneity may be an issue. In this regard, the study assumes that all the data can be considered as representative snapshot of the study area, when they may be in fact a time aggregated data set. This may or may not be problematic insofar as the study discusses threats such as climate change and its conservation relevance. The above two concerns and this one may be summarised in the lack of an adequate description of the data set and its metadata (location, area, temporal scope). Addressing these concerns will ensure that the data set is relevant for the second part of the manuscript, namely the assessment of conservation status, threat detection and conservation guidelines derived from the data.
One additional comment is that the authors do not explicitly stat which is the taxonomic standard used to harmonize data from different sources, and indeed whether harmonization was considered at all.
Another concern is that many aspects of the results are presented in a descriptive manner, without any quantitative or statistical support. An example of this is the definition of hotspots. These are not formally described and no clear criteria is provided that may allow readers to replicate or emulate the results on different study areas or the same data set. In a related issue, the data set is not visible or available for perusal from the readers. Doing so would greatly strengthen the manuscript´s transparency and rigor.
Finally, the study relies mostly on ordination analyses (PCA) and descriptive boxplots, which allow a thorough descriptive analysis. However, no statistical tests are provided to support many of the patterns presented in the results. As an example, the pattern presented in Figure 8 lacks a formal regression analysis. Similarly, the PCA presented in the Figure 4 does not indicate the percent of variance explained by the two dimensions, nor does it provide details on the loadings and variables that make up the reported dimensions. Also, the methods section does not provide details on how the PCA was constructed and assessed,
Furthermore, patterns shown in figures 2, 3 and 7, do not support the description with appropriate statistical tests and associated assumption validation. In the case of Figure 9, no association or independence test is presented which may provide a clearer understanding of the strength (or lack thereof) in the association between habitat types and conservation status.

Minor comments

I would suggest the authors consider providing geographic coordinates in the description of the study area,and complement the satellite imagery shown in Figure 1 with coordinate grid, allowing the journal´s readers that may not be familiar with the study area to gain a better sense of its location.
The authors state that “Supplementary Materials: The following supporting information can be downloaded at: https://www.mdpi.com/article/doi/s1, Figure S1: title; Table S1: title;”. However, no supplementary materials are provided or available.
In Figure 4, you do not show the percent of variance explained by the two PCA axes or dimensions.
In Figure 8, the symbol of the figure is shown to the left of the figure legend. Please correct.
There are two Figure 9 presented in the text. The second Figure 9 is very interesting but lacks some context for readers to be able to understand it fully. I would suggest providing a means of understanding the species acronyms, which are not defined clearly in the text. In addition to that, I could not find details on how it was constructed in the methods. Please revise.

Author Response

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript deals with the conservation of endemic plants in the Piatra Craiului National Park, in Romania. The topic is interesting and inside the scope of the journal. The English used is understandable, but some improvements are necessary to make the text (especially the Discussion) more fluid.

I warmly suggest adding a Table with all the vegetation surveys, as suppl. mat.

For all my improving suggestions, see the attached file.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The English used is understandable, but some improvements are necessary to make the text (especially the Discussion) more fluid.

Author Response

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript analyzes the conservation challenges of endemic plants in Piatra Craiului National Park, located in the Romanian Carpathians. The results identify the altitudinal gradient with the highest species richness and outline the factors contributing to the area's vulnerability. This research is innovative, falls within the scope of the journal, and merits publication.

However, the authors must revise the species names, as several taxonomic inconsistencies were identified. It is also necessary to provide information regarding specimen collection and the herbaria where the records have been deposited.

The manuscript with detailed comments is attached.

Comments for author File: Comments.pdf

Author Response

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have addressed my previous comments. I thank the authors for the detailed answers and the attention to detail in this revised version

Reviewer 4 Report

Comments and Suggestions for Authors

I recommend publishing the manuscript, however, there is still a need to correct the names of some authors in Table 1. They are in italics.