Long-Term Sustainability Implications of Diverse Commercial Pollinator Mixtures for the Conservation Reserve Program

Round 1

Reviewer 1 Report

In this study, Ashworthet al. present the effect of different ecological disturbances on pollinator plants growth of three different species mixtures.

The work objective is well defined, being the results interpreted appropriately and the conclusion justified. However, as the work is focused on a pollinator’s conservation program, I consider that authors should discuss the effect of those disturbances on the insect community and whether their benefits on the maintenance of plant species are more than the perturbation on the pollinator insects.

 

 

Just some minor details should be revised (see detailed comments below).

 

Line 42: delete conservation

Line 45: is it a different program? (Pollinator Habitat program vs CRP, or it is included in the previous one?)

Line: 97: distances between replicas? And between treatments?

Was the insect community sampled from the mixtures?

Line 123: Were there no previous samplings on the composition of the plant community?

Were the soil properties measured before mixtures were sown? or do they all have the same starting point?

Figure 2: is it the percentage average between both years?

Why is it not included the percentage of plant community composition in the previous years to compare differences along years?

It seems that the number of flowers is lower in the years after the disturbances, why do authors think that happens?

Line 283: which 2 treatments?

Line 287: but bloom counts were lower than the first two years, weren’t they?

 

I would like to read in the conclusion whether the ecological disturbances are more beneficial to the maintenance of plant species (and therefore in the pollinator community) than the negative implications they may produce in the insect community.

Author Response

"The work objective is well defined, being the results interpreted appropriately and the conclusion justified. However, as the work is focused on a pollinator’s conservation program, I consider that authors should discuss the effect of those disturbances on the insect community and whether their benefits on the maintenance of plant species are more than the perturbation on the pollinator insects."

Thank you for the time and consideration, as well as the comment regarding this work being interpreted properly. As outlined in the manuscript " this study set out to evaluate how ecological disturbance (prescribed burn, light disking, or a fallow control) and commercially available diverse species mixtures ('Hamilton', 'Bamert', and 'Holland') affects pollinator habitat and flowering period of commonly used CRP species mixtures." The effects of mixtures and ecological disturbance regimes on insect pollinators is beyond the scope of this study and is not in line with the focus of this work. This research was only interested in pollinator habitat (via bloom counts), soil health, and dual-use pollinator lignocellulosic feedstock potential. Therefore, pollinator community evaluations would be an additional manuscript (although these data have not been collected on these experimental plots). Therefore, if this paper is not in line with this special issue because it does not observe pollinator communities, it can be withdrawn and put either in another special issue in Agronomy or in Agronomy (no special issue).

"Just some minor details should be revised (see detailed comments below)."

Thank you for these comments, they have improved the manuscript.

"Line 42: delete conservation"

Thank you, this was carried out.

"Line 45: is it a different program? (Pollinator Habitat program vs CRP, or it is included in the previous one?)"

Same one; wording was altered to clarify this.

"Line: 97: distances between replicas? And between treatments?"

There were 9 m buffers around each plot; this information is now added in L99.

"Was the insect community sampled from the mixtures?"

As stated above, no, they were not sampled. This paper evaluates pollinator habitat, soil health, and biomass yields of diverse pollinator mixtures and disturbance regimes.

"Line 123: Were there no previous samplings on the composition of the plant community?"

No this was the first.

"Were the soil properties measured before mixtures were sown? or do they all have the same starting point?"

This site has the same soil type, history, and management and thus is assumed to have consistent physiochemical properties. No baseline sampling occurred.

 

"Figure 2: is it the percentage average between both years?"

Yes, since year was not significant data were analyzed across years. This is now clarified in Figure 2's (now Figure 1) caption.

"Why is it not included the percentage of plant community composition in the previous years to compare differences along years?"

Because at the 5-year mark, is considered mid-contract for the CP42 Pollinator Habitat. This was clarified in the revised version.

"It seems that the number of flowers is lower in the years after the disturbances, why do authors think that happens?"

This is a really good point, one that was not properly addressed in the previous submission. Results and discussion are now added around this point in L240-241; 259-265.

"Line 283: which 2 treatments?"

Good point, this needed to be clarified.

"Line 287: but bloom counts were lower than the first two years, weren’t they?"

This analysis is across years for all seeding mixtures and disturbance regimes. Yes, lower than the first two years as indicated in this sentence 'lowest counts..... in 2015...".

"I would like to read in the conclusion whether the ecological disturbances are more beneficial to the maintenance of plant species (and therefore in the pollinator community) than the negative implications they may produce in the insect community."

Authors cannot make conclusions about how insect communities were impacted since this was not measured in this study. However, authors have added a caveat that these disturbance regimes may be adversely impacting some bloom counts. A statement is made how future work should incorporate actual pollinator diversity surveys.

Reviewer 2 Report

This is an interesting paper demonstrating the biomass and chemical content of different seed mixtures under different disturbance regimes. The authors compare three seed mixes and three disturbance regimes for a treatment size of nine, which adequately covers a range of possibilities. The methods are robust and thorough, the manuscript is well-written and the material is relevant. The finding that pollinator services would be highest in the first two years after disturbance, regardless of seed mixture or disturbance is unsurprising but useful. 

That said, the manuscript tries to cover too much and the authors should reconsider how they present and analyze their data. Some things need to be improved or omitted, which will either increase or decrease the relevance. I think the authors will be able to make the required revisions easily enough.

Major Revisions:

The seed mixes need species composition lists. Ideally, the bloom measures would include which flower species are blooming. What you are seeing between years 2 and 3 is a loss of species diversity due to competition. This is a normal ecological process and, with the right arguments, could play well into your prediction that annual disturbance would increase production. The list of species in the seed mixes could allow the more botanically-minded readers to understand why you see differences in how the mixes act.

Streamline the organization between agronomic measurements and ecological ones in the results section.

Unless you intend to use the rainfall/precipitation data, remove it. Without a statistical treatment, it devolves into talking about the weather. While that appeals to the farmer, it clutters up the manuscript.

Sample size needs to be more clearly articulated (especially for figure 3). The way I read it sounded like pseudoreplication. 

Figure 3 is trying to show too many things at once and has far too many variables. There are too many comparisons made with too many factors for me to be confident in the comparisons. There are a lot of ways to improve the presentation of these results and I am confident you can find a good one.

The major finding that the Hamilton mixture should be burned annually and the Holland mixture should be disked is not supported by the data. The data was only on ONE cycle of disturbance. Repeated disturbances will not automatically improve results.

Minor revisions:

Thank you for writing this clearly and articulating your methods well.

Lines 64-75 have an over-enrichment of sentences that start with a word, comma, and then main clause (Although, thus, specifically). Improve the variability to make this more decisive and powerful.

Lines 179-197 are too detailed and do not end up contributing to the statistical findings of the manuscript.

Figure 2: Please define the difference between flowering species and broadleaf species. A dandelion is technically both.

The language in the conclusion is too similar to the previous paragraphs.

Any chance you captured and identified the pollinators?

Author Response

"This is an interesting paper demonstrating the biomass and chemical content of different seed mixtures under different disturbance regimes. The authors compare three seed mixes and three disturbance regimes for a treatment size of nine, which adequately covers a range of possibilities. The methods are robust and thorough, the manuscript is well-written and the material is relevant. The finding that pollinator services would be highest in the first two years after disturbance, regardless of seed mixture or disturbance is unsurprising but useful."

Thank you for taking the time to review this paper and provide input to ultimately improve the manuscript. Thank you also for the comment regarding this paper being well written and some of the findings useful.

"That said, the manuscript tries to cover too much and the authors should reconsider how they present and analyze their data. Some things need to be improved or omitted, which will either increase or decrease the relevance. I think the authors will be able to make the required revisions easily enough."

Thank you, please specify what needs to be improved or omitted and it can be taken into consideration by authors.

Major Revisions:

"The seed mixes need species composition lists. Ideally, the bloom measures would include which flower species are blooming. What you are seeing between years 2 and 3 is a loss of species diversity due to competition. This is a normal ecological process and, with the right arguments, could play well into your prediction that annual disturbance would increase production. The list of species in the seed mixes could allow the more botanically-minded readers to understand why you see differences in how the mixes act."

Detailed seed mixtures were indeed included (as supplementary tables 1 and 2 due to length). Authors agree that decreased blooming species is likely due to competition and that exact species lists would be of interest, although that information is not available for each of the four years of bloom count data collection.  Again, please see supplementary tables 1 and 2.

"Streamline the organization between agronomic measurements and ecological ones in the results section."

Throughout this paper, authors tried to not 'silo' agronomy and ecology per this special issue, as well as due to the nature of this research.  Nonetheless, a paragraph was added in the revised version describing how ecological disturbance regimes may be detrimental to stand longevity, as well has a header changed per this point.

"Unless you intend to use the rainfall/precipitation data, remove it. Without a statistical treatment, it devolves into talking about the weather. While that appeals to the farmer, it clutters up the manuscript."

This figure was referenced throughout this paper as it highlighted the interaction between the environmental response and pollinator habitat persistence and is common in agroecology studies. However, it is now erased per Reviewer #2's request. Authors are requesting that the AE weigh in on this.

"Sample size needs to be more clearly articulated (especially for figure 3). The way I read it sounded like pseudoreplication."

Experimental unit size is the same for each response variable. Details on plot size and buffer area were added in L99 and L112. No pseudo-replication in this experiment. Please explain what further details need to be described in the data collection and design of this study.

"Figure 3 is trying to show too many things at once and has far too many variables. There are too many comparisons made with too many factors for me to be confident in the comparisons. There are a lot of ways to improve the presentation of these results and I am confident you can find a good one."

Figure 3 (now 2 per the aforementioned request) is properly illustrating the highest order interaction for bloom counts (disturbance regime X seeding mixture X Year) following correct statistical procedures.  Presentation of highest order, significant interactions is aligned with this journals' data presentation policy. Authors respectfully disagree that this graphic is too complex.

"The major finding that the Hamilton mixture should be burned annually and the Holland mixture should be disked is not supported by the data. The data was only on ONE cycle of disturbance. Repeated disturbances will not automatically improve results."

The purpose of disturbance regimes seems to be misunderstood. Per the NRCS Code CP42, disturbance regimes "plantings must be maintained for 10 years, with a mid-contract management requirement, i.e., implementing a cultural disturbance to stimulate herbaceous blooming plant species, limit woody plant encroachment, and limit surface plant residue". Hence the year 5 (and only year 5 disturbance regime) is required. However, authors are grateful for the 'annual' statement being caught in the conclusions, it is now replaced with 'mid-contract'.

Minor revisions:

"Thank you for writing this clearly and articulating your methods well."

Thank you for this complement!

"Lines 64-75 have an over-enrichment of sentences that start with a word, comma, and then main clause (Although, thus, specifically). Improve the variability to make this more decisive and powerful."

Agreed; this statement needed some work, thank you.

"Lines 179-197 are too detailed and do not end up contributing to the statistical findings of the manuscript."

OK this whole paragraph was erased.

"Figure 2: Please define the difference between flowering species and broadleaf species. A dandelion is technically both."

Broadleaf non-flowing weeds is now defined in L232.

"The language in the conclusion is too similar to the previous paragraphs."

The conclusions section has been edited, although authors are unclear where there is duplicate wording in this section.

"Any chance you captured and identified the pollinators?"

Unfortunately, no. As authors stated to Reviewer 1: " this study set out to evaluate how ecological disturbance (prescribed burn, light disking, or a fallow control) and commercially available diverse species mixtures ('Hamilton', 'Bamert', and 'Holland') affects pollinator habitat and flowering period of commonly used CRP species mixtures." The effects of mixtures and ecological disturbance regimes on insect pollinators is beyond the scope of this study and is not in line with the focus of this work. This research was only interested in pollinator habitat (via bloom counts), soil health, and dual-use pollinator lignocellulosic feedstock potential. Therefore, pollinator community evaluations would be an additional manuscript (although these data have not been collected on these experimental plots).

Round 2

Reviewer 2 Report

The authors did not make many changes, but the changes that were made were sufficient to increase clarity and brevity enough for publication. I still think Figure 3 (now Figure 2) should be broken down into separate figures showing differences between treatments, mixtures and years rather than a single figure showing all three variables. Having up to seven letters indicating that one treatment is not different from all the others with those seven letters is confusing. There are no error bars.

A spell-check is needed. At a simple glance, I caught some glaring errors and I can imagine there are more.

-Line 177- bEvery

-Line 222- Non-flowing weeds

 

 

Author Response

"The authors did not make many changes, but the changes that were made were sufficient to increase clarity and brevity enough for publication. I still think Figure 3 (now Figure 2) should be broken down into separate figures showing differences between treatments, mixtures and years rather than a single figure showing all three variables. Having up to seven letters indicating that one treatment is not different from all the others with those seven letters is confusing. There are no error bars."

Thank you for taking the time to review this paper again. Authors agree that Figure 2 was missing error bars and the mean separation letters needed to be changed to vertical to reduce space. Both of these changes have been made in the revised version. Authors agree that these two changes were absolutely needed and apologize for this oversight.

If this Figure was broken into four separate panels (by year), readers would be confused as mean separation letters are for across years, which is not correct. As noted previously, Figure 3 (now 2 per the aforementioned request) is properly illustrating the highest order interaction for bloom counts (disturbance regime X seeding mixture X Year) following correct statistical procedures.  Presentation of highest order, significant interactions is aligned with this journals' data presentation policy. Authors request that the Editor weigh in on this issue.

"A spell-check is needed. At a simple glance, I caught some glaring errors and I can imagine there are more."

Authors apologize for any errors; this has been amended in the revised version.

"-Line 177- bEvery"

Thank you for this correction and authors apologize for this oversight.

"-Line 222- Non-flowing weeds"

Again, authors apologize; the entire manuscript has been reviewed for errors in the amended version.