Drought Stress Response of Norway Spruce Seedlings Treated with Drought-Mitigative Additives

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript Summary

The manuscript investigates the response of spruce (Picea abies) seedlings to water stress and evaluates whether two additives, a hydrogel (Agrisorb) and an ectomycorrhizal inoculum (Ectovit) can reduce the effects of drought in the early stage of seedling establishment. The experiment was carried out in pots, under three watering regimes, and the performance of the seedlings was assessed by survival, growth parameters, ectomycorrhizal colonization and chlorophyll fluorescence. The study addresses a relevant topic for forest regeneration in the context of intensifying droughts.

Evaluation of the methodology, analyses and conclusions

The experimental design, which combines watering regimes with additive treatments, is appropriate, and the topic is relevant for forestry in the context of climate change.

 

Below are the comments for the authors:

- Materials and methods should be expanded; the current description does not allow for the full reproduction of the experiment without consulting other works.

- The experimental design and experimental unit are not clearly defined enough; it is necessary to explain how the replications and individual measurements were treated.

- Survival data were not statistically analyzed, although they represent one of the main outcomes of the study.

- The statistical analysis should be described more clearly, including how the variables measured at the individual level were handled.

- The interpretation of the hydrogel treatment should be limited to the experimental conditions, as its effectiveness depends on the substrate, dose and method of application.

- The interpretation of the ectomycorrhizal inoculum should be done with caution, as the product used contains other components, not only mycorrhiza fungi.

- The identification of the ectomycorrhizal fungi was not molecularly confirmed, which reduces the certainty regarding the origin of the observed colonization.

- The results indicate that the watering regime had the dominant effect on seedling performance, while the effects of additives are limited and sometimes statistically insignificant; this difference should be emphasized more clearly.

- The limitations of the pot experiment should be explicitly discussed, as the experimental conditions differ from those in the field.

- The abstract and conclusions should be adjusted to more accurately reflect the results and limitations of the study.

Recommendation: Major revision.

Comments on the Quality of English Language

Overall, the paper is suitable for publication after making minor revisions.

Author Response

"Please see the attachment"

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This is a completely randomized block design experimental study examining the effects of two treatments, hydrogel and ectomycorrhizal fungus (EMF) on the growth  of  spruce seedlings in three-liter volume pots with four watering regimes (including a non-watered treatment). Among the main findings, the authors reported,  survival, growth and chlorophyll fluorescence of the seedlings decreased proportionally to increasing drought intensity, while the highest root-to-shoot ratio and EMF colonization of roots occurred under periodic watering and reduced watering, respectively. The non-watered seedlings died after 9 weeks of desiccation, whereas EMF inoculation prolonged the survival time by one week.

Overall, the design and statistical analyses seem appropriate, and the experimental evidence suggests a good basis for more extended field-based research to more fully explicate the efficacy of the findings in the natural environment.

There are some minor corrections recommended in the text.

Line number    comment

Abstract          The abstract is close to 300 words in length. The journal requires a length of no more than 200 words for the abstract.

65        ---- can increase the absorption area of roots via external hyphae, ---

94        -----, we carried out an experiment with spruce presented in this study -----

97        ----- seedling performance in a water-deficient environment.

126      ---- in the beginning of the growing season (at the end of April).

354      --- European beech (Fagus sylvatica L.) --- italics needed.

469      ---refers to agricultural plants; however, tree seedlings may deplete water -----

 

 

Comments for author File: Comments.pdf

Author Response

"Please see the attachment"

Author Response File: Author Response.pdf