More NSDNR research on Nova Scotia forest soils published in science journals but not publicized by NSDNR

And we continue to harvest intensively on landscapes with some of the poorest soils in North America, and NSDNR continues to be mum on the whole topic.

NSDNR’s soil scientist Kevin Keys continues to publish the results of his research on NS forest soils in recognized, peer reviewed scientific journals but otherwise the results of his highly relevant research have not yet been announced or otherwise translated into take-home messages on the NSDNR (soon to be NSLF) website.

In the fall of 2016, Keys published A Simple Geospatial Nutrient Budget Model for Assessing Forest Harvest Sustainability across Nova Scotia, Canada with a number of co-authors including 2nd author Joshua Noseworthy whose 2011 NSDNR supported thesis  on that topic was never highlighted or made available on the NSDNR website. Of particular note in the 2016 paper are data showing large declines in %BS (% Base Saturation) compared to earlier soil surveys (for 25 sites, the declines ranged from −37% to −82%)*. Very low %BS values (5-10%) are seen over a large part of the landscape, notably over most of SW Nova Scotia where new harvesting operations are focussed. They tested their model with site specific data for 25 plantations and found that “Based on comparisons with NBM-NS output, approximately 1/4 to 1/2 of the assessed plantation sites have non-sustainable MMAI yield expectations…”
*The low values reflect unusually low amounts of base cations Ca++, Mg++ K+, important nutrients for the vegetation.

They identified calcium and nitrogen as the most common limiting nutrients and noted that “Ca has long been considered a nutrient of concern in eastern North America…”, also concluding that “Nutrient assessments are even more important in areas that have been impacted by long-term acid deposition since harvest removals can exacerbate declines in base cation levels (especially Ca) in affected soils.”

I was glad to see that last statement, which was perhaps the first formal acknowledgment from DNR that forest harvests can worsen the effects of acid rain. As significant as this research is for Nova Scotia, it was not even mentioned in the 2016 State of the Forest Report (dated April 2016, it appeared on the NSDNR website sometime after April 14, 2017), nor is it mentioned in a State of the Forest Update 2017.

Keys’ latest paper:
Forest floor chemistry and mineral soil ion exposure after surface application of alkaline-treated biosolids under two white spruce (Picea glauca) plantations in Nova Scotia, Canada
by Kevin Keys, David L. Burton, G.W. Price, Peter N. Duinker, published in Forest Ecology and Management Volume 417, 15 May 2018, Pages 208-221.

It’s essentially a followup to the results cited above for plantations; from the introduction:

…based on outputs from a new steady-state nutrient budget model described by Keys et al. (2016), many plantation sites in Nova Scotia may not be able to continuously meet desired yield targets over time without the use of soil amendments, with Ca identified as a main limiting nutrient.

To evaluate the potential for ATB [alkaline-treated biosolids] to offset current or predicted Ca deficits in Nova Scotia forest soils, two field trials were established to measure impacts of surface-applied ATB on white spruce (Picea glauca) plantation soils and vegetation. To our knowledge, this is the first time ATB has been applied to conifer plantations in northeastern North America to assess its potential role in plantation nutrient management.

Unlike the 2016 paper which is “open access” and available in full to all, a subscription is required for access to this 2018 paper (or the individual article can be purchased for US $35.95).

However, Kevin Keys’ PhD thesis on IMPACTS OF SURFACE APPLIED ALKALINE-TREATED BIOSOLIDS ON SPRUCE PLANTATION SOILS AND VEGETATION IN NOVA SCOTIA, CANADA, completed in 2018, includes the same materials and is available in full on Dalspace (an academic archive site for Dalhousie University). The co-authors on the 2018 paper are listed as members of the supervisory committee for Keys’ PhD thesis.

The Introduction (ch 1 in the thesis) provides the kind of background information about NS forest soils that is sorely lacking in publicly available NSDNR documents. Chapter 2 is “A SIMPLE GEOSPATIAL NUTRIENT BUDGET MODEL FOR ASSESSING FOREST HARVEST SUSTAINABILITY ACROSS NOVA SCOTIA, CANADA, i.e. the material published in Keys’s 2016 paper cited above. Chapters 3-6 deal with the experiments on use of ATBs.

Support from Northern Pulp is acknowledged in the paper: “Financial support for this project came from a National Sciences and Engineering Research Council (NSERC) CRD grant in partnership with Dalhousie University Agricultural Campus and Northern Pulp Nova Scotia Corporation (CRD=Collaborative Research and Development Grants).”

The significance of the research for Northern Pulp, as a holder and supplier of forest plantations in NS  is pretty clear. I can’t begrudge either KK or NP for the funding association as industrial sponsors are a “reality” of university based research these days,  but it does detract from the perception, if not the fact, of independence. (view a recent CBC item on this topic: Academic research should be funded by public tax dollars — not corporations, says ethicist). Other government and private partners acknowledged in the thesis: N-Viro Systems Canada, Nova Scotia Environment, Halifax Water, Western Ag Innovations Inc.

However that should put more onus on NSDNR to be more forthright about their soils research and the association with Northern Pulp, also to move more quickly to apply the nutrient budget model, at least in a precautionary way, to harvests on all lands. The potential for an appearance of a conflict of interest is high, withNorthern Pulp a major player in WestFor, so anxious to harvest the Western Crown Lands, a large proportion of which is acid stressed and nutrient poor.

The application of nutrient budgeting to biomass harvests, the stated objective when the studies began 10 years ago, remains elusive.

For more on DNR elusiveness about the soil nutrient research, view:
What’s left in Nova Scotia’s forest soil bank account?
Jamie Simpson in Atlantic Forestry Review, July 2017
DNR and the disappearing science
by Robert Devet in Halifax Media Co-op Aug 29, 2014
Calcium Depletion
Section  under Current Issues on this website

Regardless of funding sources, Kevin Keys’ research going back 20+ years is first class. Indeed,  Kevin Keys is a perfectionist*, which is good for DNR Science, but may also account in part or a lot for NSDNR’s reticence to make more hay about their soil nutrient research in their PR, technical and educational documents. In a NSDNR information session held in June of 2016 to present the NSFNBM (NS Forest Nutrient Budget Model) and in a  meeting of myself and Donna Crossland with Kevin Keys and Bruce Stewart to discuss the model further in Oct 2016, Keys was adamant about not releasing or applying the model (or, apparently,  even reporting on the objectives and preliminary results as it unfolded)  until they had updated the soil data and the model is much more robust for application at the stand level (i.e. at a specific site). We still don’t know when that will be.
*A subjective assessment based on my reading of his research reports, and his response to questions at the 2016 Information Session and Oct meeting referenced in the same paragraph. It is no way a criticism; I admire the rigour of his research.

In the meantime, we continue to harvest intensively on landscapes with some of the poorest soils in North America, and NSDNR continues to be mum on the whole topic.


COMMENT & REPLY (Jul 26, 2018)


…I wonder in Keys work if he will, upon finding upsides to application of CaBS to forest soils, there is anywhere near enough of the product to make a difference overall. Might be helpful on a small scale, seems to me; unrealistic and very expensive on anything larger.

NSFN reply:

I have argued that the nutrient stuff should be done at the watershed level and regulations applied at the watershed level; they could done that right now

See this blog piece which I think explains it OK: What’s good for salmon is good for trees in Nova Scotia…and v. versa!

Basically I am saying that clearcutting (or shelterwood/2-stage clearcut) should be severely restricted in watersheds severely stressed by acid rain; even if an individual stand could take it OK, that same stand is a source of calcium for the watershed. This is what I mean by a precautionary approach…Keys refined what the aquatic scientists had already documented, in fact his newer data show the problem to be worse still.

I have discussed this approach with some leading aquatic scientists…they agreed that it would be a sensible approach. I have also discussed it with Kevin Keys and Bruce Stewart at NSDNR.

Note added July 30, 2018

Kevin Keys’ comment that “this is the first time ATB has been applied to conifer plantations in northeastern North America to assess its potential role in plantation nutrient management” is prob correct, but it is not the first time that treated sewage has been applied experimentally to forest stands in NS. I remember visiting such an experiment with Prof Pete Ogden of Dal Univ, sometime in the late 70s. It was on a farm woodlot as I remember. I have not been able to locate any specific reference to it but I did find some comments of Pete Ogden on this topic, interestingly enough in a report by forest ecologist Barrie Goldsmith on a symposium held on Oct 28,1978, hosted by the The Nova Scotia Resources Council; the theme:Forests for Energy: The Potential and the Problems for Nova Scotia. BG’s report is published in the Halifax Field Naturalists Newsletter #18, Nov-Dec 1978, pp 7-8.

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