Distribution and Potential Uses of Halophytes within the Gulf Cooperation Council States

Round 1

Reviewer 1 Report

The premises of this manuscript are very interesting, because I find that the subject is of great importance. However, expectations are then greatly disappointed by the development of the manuscript, which basically cannot be considered either as a review or as a research article. The manuscript is at length devoted to describing the areas of study, often in detail that is probably not useful for the purpose of the manuscript. But when it comes to talking about the halophytic species of interest, all the manuscript does is a simple list drawn from an already existing database. There is no detailed description of how and why the plants indicated can be used to fulfill the general purposes of the manuscript, and there is absolutely not a single line of discussion. As it stands, this article needs a major revision, but in its current form - despite the interest in the subject - this article is too short and incomplete.

Author Response

Reply Reviewer #1

We have italicised comments from Reviewer 1 that we thought required a response, which follows.

“not useful for the purpose of the manuscript”

Our aim was to highlight the issues around water in the countries of the GCC and so we feel some climatic information is central to our argument that agriculturalists in those countries should evaluate the use of halophytes.

“There is no detailed description of how and why the plants indicated can be used to fulfil the general purposes of the manuscript”

The aim of the manuscript was to remind “plant breeders, agriculturists, farmers and others in the region” of the “possible uses of halophytes” and we do provide potential uses for individual species. We are not expert in the practicalities of their use: that is for others to develop. However, we have added a commentary in lines 199 to 230.

“this article is too short and incomplete”

We assume that the incompleteness hinted at by the Reviewer relates to the absence of detailed descriptions of how and why the species listed can be used. We have argued that this was not our purpose, but have added the Commentary mentioned above.

Author Response File: Author Response.docx

Reviewer 2 Report

Overall, this paper provides a thorough description of the climate conditions that the Arabian Peninsula is dealing with in terms of water availability and the potential for significant inundation of salt water into its agricultural land. Given the topic of the article is the use of halophytes in saline agriculture, I think more attention should be paid to the plants themselves rather than the climate and soil conditions by shortening sections 1-5 and increasing the discussion of Section 6. 

There are several specific points that could be better addressed: 

At the end of Section 3, the authors mention that dust exacerbates the challenge to plant growth presented by aridity. How exactly is dust reducing plant growth? In Section 5, the deposition of dust increasing salt conditions in the soil is mentioned. Is this the aspect that the authors are referring to in Section 3, or something more physical such as coating of the leaf surfaces, reducing light penetration or blocking gas exchange? From the description of the conditions provided by the authors, dust appears to be a significant factor that should be considered with regard to the plants cultivated. 

In Section 6, the authors introduce the idea of using saline waters for irrigation. Is this direct irrigation to soils with saline waters? or hydroponic agriculture? Are there concerns regarding the application of saline waters to land that is already experiencing gradually increasing salt levels? Are there situations when this would not be feasible? Good drainage is mentioned as an important consideration, but is there a risk for exacerbating the salinity of soil?

The last line of the abstract mentions the potential of halophytes for nutraceuticals or pharmaceuticals, but there is no discussion of that in the body of the article. This could be a valuable motivation for increasing the use of halophytes in areas like the Arabian Peninsula that are already dealing with saline soils. What information is known about this aspect? Do nutritional properties change under irrigation with saline waters? 

Table 4 is a very useful summary of the information gathered by the authors. However a couple of additional columns should be added that would further its utility: 1) a mention of the edible portions of the plant and 2) the mechanism for salt tolerance that each particular plant has demonstrated if it is known. The authors have described several instances where salt tolerant halophytes could be used as fodder for animals, but it could potentially create problems for their health if the portion of the plant that they are consuming is high in sodium and the mechanism for tolerance is the plant's ability to sequester high concentrations of Na in the vacuoles of the edible leaves.

Also, the column widths of Table 4 should be adjusted, especially for the columns with the titles 'Economic values' and Natural habitat. If the table is to be printed as it is in the current orientation, there is space to adjust the columns. 'References' could be abbreviated to 'Ref. and condensed. The species names could be condensed as well, to Genus over the species name, to save more space. 

Author Response

Reply Reviewer #2

Again, we have drawn comments from the Reviewer (italicised) and followed these by our responses.

I think more attention should be paid to the plants themselves rather than the climate and soil conditions by shortening sections 1-5 and increasing the discussion of Section 6.

We have shortened Sections 2, 3 and 4 (deleting Table 2) and added a Commentary (Section 7).

How exactly is dust reducing plant growth? In Section 5, the deposition of dust increasing salt conditions in the soil is mentioned. Is this the aspect that the authors are referring to in Section 3, or something more physical such as coating of the leaf surfaces, reducing light penetration or blocking gas exchange? From the description of the conditions provided by the authors, dust appears to be a significant factor that should be considered with regard to the plants cultivated.

We have added a short commentary on the effect of dust (lines 219 to 224).

Is this direct irrigation to soils with saline waters? or hydroponic agriculture? Are there concerns regarding the application of saline waters to land that is already experiencing gradually increasing salt levels? Are there situations when this would not be feasible? Good drainage is mentioned as an important consideration, but is there a risk for exacerbating the salinity of soil?

We have added a short commentary on the effect of the consequences of irrigation with saline water (lines 199 to 209).

nutraceuticals or pharmaceuticals, …. What information is known about this aspect? Do nutritional properties change under irrigation with saline waters?

We have added a short commentary on the effect of the changes in external salinity on the concentration of chemicals within the plant (lines 225 to 230).

Table 4 is a very useful summary of the information gathered by the authors. .. additional columns …: 1) a mention of the edible portions of the plant and 2) the mechanism for salt tolerance that each particular plant has demonstrated if it is known.

We have replaced the column “Family” with information on the “Part used”. We have not added the mechanism of tolerance as that cannot be reduced to one or two words.

fodder for animals, but it could potentially create problems for their health if the portion of the plant that they are consuming is high in sodium and the mechanism for tolerance is the plant's ability to sequester high concentrations of Na in the vacuoles of the edible leaves.

We have added a short commentary on the use of halophytes as fodder (lines 210 to 218).

“ column widths of Table 4 should be adjusted, especially for the columns with the titles 'Economic values' and Natural habitat. If the table is to be printed as it is in the current orientation, there is space to adjust the columns. 'References' could be abbreviated to 'Ref. and condensed. The species names could be condensed as well, to Genus over the species name, to save more space.”

We have adjusted the layout of the Table.