Forest cover loss in a section of land just south of New Glascow, Nova Scotia, from map at forests.foundryspatial.com
Click on image for larger version.
Is it conceivable that clearcutting in Nova Scotia, likely the most intensive in Canada, is not a major threat to biodiversity?
Early in the year, I attended the first stakeholder meeting held by DNR (now L&F) for the new Biodiversity Act (still to be hatched) as a rep for Nature Nova Scotia. The potential areas for Regulation Development were listed as
– Invasive Species
– Biodiversity Management Sites
– Wildlife health and disease
– Non-traditional use of biodiversity
(View Slides)
I expressed some dismay that “habitat loss” (mainly associated with clearcutting) was not in that list. Several others participating also expressed concern and there followed an extended discussion around this topic.
There was no acknowledgment from DNR/NSE staff that loss of biodiversity associated with clearcutting is a matter of concern. Nor did they see any need for it to be addressed in the Biodiversity Act – DNR staff said that was not necessary because there are already regulations that address this issue, the Report of the AG apparently notwithstanding.
I later expressed some hope (Post Jun 4, 2018) that a new Nova Scotia Biodiversity Council, announced May 22, 2018, would take a more nuanced view of biodiversity issues in NS.
I was also expecting that the Independent Review would recognize impacts of the extensive clearcutting in Nova Scotia on biodiversity and indeed the Report issued on Aug 21, 2018 did so. Thus a key conclusion was that
Ecosystems and biodiversity require preservation and restoration of multi-aged mixed-species forests conservation to be the exclusive or objective of equal importance for a substantial portion of the landscape – From Prof. Lahey Slides; see p 5 of Vol 1 of the Report on the Independent Review, item 4 and many other pages in both volumes for more details.
The Independent Review recommended a triad system* of forestry management to achieve this objective, with conservation a priority in two of the three legs of the triad:
The report recommended implementation of a triad model of ecological forestry and the triad model would require as much forest as possible to be managed either exclusively for conservation, or for providing timber for the forest industry [but] the vast majority of the forest [would be] in a third category where it would be managed for a combination of conservation and production objectives… – Bill Lahey on CBC Nov 16, 2018
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*“The triad forest management concept (Seymour and Hunter 1992) involves designating forest reserves and intensively managed areas within a landscape matrix managed by silvicultural systems patterned after natural disturbance regimes (Franklin 1989, Gillis 1990).The triad concept is based on earlier work of Clawson (1974, 1977), furthered by Seymour and McCormack (1989). These authors argued that concentrating timber production in selected areas would allow increased non-timber value availability from the remaining forests.” – Source: Montigny and MacLean 2006.
So I was again dismayed to hear Dr. Donna Hurlburt, the new Manager of Biodiversity for the Department of Lands and Forestry (and a member of the Biodiversity Council), downplay the impacts of clearcutting on biodiversity in a CBC Information Morning Interview on Nov 22, 2018 (the 8th interview in their Species-At-Risk Series):
CBC: Many of the people we talked to and mentioned habitat loss singled out tree harvesting, forestry as a threat to some species; how much is clearcutting a concern for you?
DH: The vast majority of species have more than one threat, certainly habitat loss and alteration of habitat is a significant threat for some species but also increasingly we are seeing things like invasive species and diseases, intentional persecution, pollution and climate change affecting species as well
CBC: How do you place clearcutting in context with those as a threat?
DH: There are actually relatively few species where habitat loss is the primary threat in Nova Scotia…its often things like roads, pollution; there are a couple of invasive species that have had extremely large impacts, one that we have fully realized already in NS is white nosed syndrome in bats… another one just on our radar is emerald ash borer that has recently been discovered in NS that has been causing extremely high mortality of all ash species… and we are particularly worried about Black Ash, a threatened species in NS.
CBC: The first guest we talked to, Dalhousie University Professor Karen Beazley says scientific research shows that in NS we need to protect 67% of our land to recover and maintain the species that we have, that was her estimate, while the government has set a target of 13%.
DH: I haven’t had the opportunity to review Dr Bezley’s work so I am not sure where the 67% arose so I really can’t comment on that and I have not seen any indication that any particular Species-At-Risk in Nova Scotia would require that much habitat.
In the interview, CBC paraphrased the Nov 13 discussion with Prof Beazley. Here is more of what she said (italics are mine):
Nova Scotia is committed to protecting 13% of the landscape, the country has committed to protecting 17% but these are political targets, science will tell us we need 25 to 75% for the other species… it depends on how biologically diverse your area is. I had done studies across NS and the calculations… of planning, mapping the species we have here… we would have to set aside or at least manage 67% of our landscape for wildlife species in order to maintain or recover the species that we have here.
So Prof. Beazley was not saying that the whole 67% has to be formally protected, but that it at least needs to be managed for biodiversity conservation.
The key papers were published by Prof. Beazley in the early 2000s in well recognized journals and those papers are really the only scientific work to address the question of how land needs to be managed for biodiversity in Nova Scotia. Dr. Beazley and her collaborators’ estimates are consistent with other research in other areas and her estimates are foundational to the Independent Review’s recommendation to adopt the triad system of forest management in Nova Scotia. View Prof. Beazley’s submission to the Independent Review (posted on NSFN with her permission) for more on her research and perspectives.
In the discussion on CBC, I suspect that Dr. Hurlburt was thinking in terms of what species are at risk now, and yes in that regard she is probably right that of the species currently listed, only a few of those can be considered at risk in significant part because of clearcutting (e.g., rusty blackbird, Canada warbler, boreal felt lichen).
I was relieved to hear that Dr. Hurlburt recognizes the magnitude of species losses globally, commenting that “we are in the middle of one of the largest extinction events on earth that ever have been documented”. It’s widely acknowledged in the scientific community that habitat loss is the #1 cause.
What’s not well understood and/or appreciated within DNR/L&F, apparently, is that while right now only a few of the currently classified Species-At-Risk are associated with intact forest landscapes/older forests, there has unquestionably been declines in populations of many species associated with intact forest landscapes/older forests (such as forest interior birds) – and those declines, combined with fragmentation of habitats, generate what conservation ecologists call an “extinction debt”.
That means that some species are on track to go locally extinct. Think of it like a zoo that has only three lions, two female and one male, and no means of replacing them if they all die from disease or a catastrophic event or fail to reproduce (so eventually they all grow old and die). It may be difficult to say exactly when, but sooner or later, there will be no more lions at that zoo. For more on the concept of “extinction debt”, view Loss of habitats and local species extinctions in Science News, July 25, 2016.
Pileated woodpecker on large snag
One criticism in the Auditor General’s 2016 Review of Species at Risk: Management of Conservation and Recovery was insufficient monitoring. Where there has been substantive monitoring, there are some discouraging signs that an extinction debt is a reality, e.g., the decline of boreal felt lichen even with Special Management Guidelines in place. Nova Scotia Environment’s Robert Cameron attributed that to acid rain and commented on CBC that “The research shows that the amount of acid rain that we’re getting from those sources is beyond the capacity of the ecosystem to buffer”.
As acknowledged in research by DNR/L&F, clearcutting exacerbates effects of acid rain. Yet we are still not taking that into consideration when clearcuts are approved on Crown lands severely affected by acid rain, which undermines aquatic as well as terrestrial biodiversity. (View What’s good for salmon is good for trees in Nova Scotia…and v. versa!, Post Dec 13, 2016)
In one of the recent CBC Species-At-Risk series, lichenologist Francis Anderson commented on the direct loss of lichens due to forest harvesting – particularly harvesting of red maple for biomass , and underscored that we are not “seeing” the declines of a At-Risk species that are not, like the boreal felt lichen, legally protected.
DNR’s apparent lack of understanding or appreciation of longer term, larger scale and perhaps more subtle conservation issues may explain the department’s contention that house cats pose a much greater risk to songbirds in Nova Scotia than habitat loss associated with clearcutting:
“Bird populations and habitat are impacted by many human activities on the landscape and forestry is not among the most significant source of impacts” compared to cat predation, housing and road development, and vehicle collisions.” – NSDNR spokesman Bruce Nunn
See Are cats more destructive to Nova Scotia’s forest birds than clearcutting? (Post on NSFN, Jun 8, 2018) for more on this topic and how far removed DNR’s thinking on this topic is from the broader scientific community.
Many Nova Scotians have been expecting that The “Lahey Report” will trigger a needed change in perspective in NSDNR/L&F, but a response to the report has been slow in coming. As Prof. Lahey has remarked, the longer it takes L&F to respond to the Report of the Independent Review, the more skepticism there will be that L&F is really prepared to adopt the recommendations. Pretty well the only response that has been made to date is the comment from L&F Minister Iain Rankin back in September following their apparent giant faux pas in actually beginning to implement some of the recommendations:
The minister said his department is still going through the report and considering the recommendations, which include a drastic reduction in the amount of clear cutting on Crown land. Rankin said he accepts “the premise that we could do more for ecological-based forestry.”
“We’re not really prepared to say which recommendations we will fully accept but in general we do accept the spirit of the report.”
I would like to think there has been broad, open discussion of the Lahey Report by foresters and wildlife people within L&F, but if there had been, I think Dr. Hurlburt would have quite readily cited the concerns and recommendations of the Independent Review in response to the CBC questions about clearcutting. So I have to wonder if the discussions of the Lahey Report that are taking place within L&F are mostly strategic and behind closed doors.
It’s possible, even likely, that Dr. Hurlburt is well aware of the impacts of extensive clearcutting on biodiversity but in her new position has had to be quite focussed on Species-At-Risk and probably many other assignments and is still finding her way in a department undergoing (I would guess) some turmoil.
Dr. Hurlburt is also, as the title on the CBC article highlighted, “One woman in charge of biodiversity in province with 71 at-risk species “, emphasis on “one”. It’s an immense task and she could likely use all the support she can get from within DNR and from the rest of us. In that context I hope that my comments will be taken as those of a scientist evaluating the statements she made in a public interview and offered as part of an open scientific process.
I hope we will hear more from Dr, Hurlburt and from others in L&F on how past and current forest management is affecting biodiversity in Nova Scotia, and how that is going to change!
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In the process of preparing this post, I searched the DNR/L&F website for comments on habitat loss and managed to find a document that cites habitat loss as a major threat to biodiversity and underscores the importance of “intact, healthy forests”: See the Module Introduction to Biodiversity in Nova Scotia
It’s in a section of the website worth keeping an eye on:
Biodiversity – State of Biodiversity Reporting
There is also an invitation:
If you have any comments or questions regarding biodiversity in Nova Scotia, please contact us: biodiversity@novascotia.ca
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Some comments on social media:
BW:… we wouldn’t have declines in Chimney Swifts if we didn’t have such a loss of large old hollow trees as there used to be — which is why Swifts began to use chimneys. To blame declines on traffic, cats, etc… is to evade the real cause, which is habitat loss, driving birds to nest closer to human habitation. Another example is Cowbirds (brood parasites) that lay their eggs in songbird nests and cause their decline as young Cowbirds displace the real young. Research has shown that, the more a forest is chopped away at, the more the Cowbirds will infiltrate and lay eggs in forest-dwelling songbird’s nests. This is because the Cowbirds normally hang out in pastures and nest within a certain distance of those places. If you cut up the forest into many openings, that extends the Cowbird range into the forest so that they do even more damage.
SL: Common sense prevails….If you destroy an animals habitat – repeatedly, eventually it destroys the animals existence. You don’t need to be a scientist to know clear cutting must be stopped.