What’s wrong with clearcutting?

To be more specific: Whats wrong with clearcutting the Acadian Forest in Nova Scotia?

Outside of Nova Scotia, apparently, “we spend 80 to 150 years growing a tree in Canada – some of the longest growth rates in the world”… according to Dr. Trevor Stuthridge of FP innovations.

Two approaches to forestry in Nova Scotia. One produces high value wood as well as sequestering carbon, providing habitat for wildlife and peace of mind to visitors.

I am a bit skeptical about the generality of that statement but regardless, it clearly does not apply to Nova Scotia where we are cutting on rotations of 40-60 years (and even less). There are a lot of other factors that make Nova Scotia exceptional and clearcutting particularly detrimental.

1. Nova Scotia’s forests are amongst the most, if not the most, intensively harvested in Canada, currently and historically. Read More.

The volume per hectare harvested from NS forests has been cited as the lowest in Canada (95m3/ha compared to 124 for Ontario, 234 for Saskatchewan, 394 for B.C.; Newfoundland and N.B. are also low at 100 m3/ha each)* so more land is harvested per unit of product in Nova Scotia compared to the rest of Canada.

OK, but can our forests “take it”?

NO.

2. Nova Scotia has some of the naturally poorest soils in North America and Europe, most notably the Gibralter soils which cover much of SW Nova Scotia.

As well, Nova Scotia is a high rainfall area and has generally shallow soils over hard bedrock making the soils highly susceptible to enhanced nutrient losses following clearcutting. As in the humid tropics, forests still grow on these poor soils, but maintenance of productivity is dependent on tight nutrient cycling in the organic horizons and within the vegetation.

The base-poor, acidic nature of the bedrock has made SW Nova Scotia especially susceptible to even moderate levels of acid rain, resulting in severe degradation in habitat for salmonids and other aquatic life. Loss of calcium in the forested soils is likewise probably contributing to declines in ecosystem health and biodiversity as reported elsewhere. Read more.

NSDNR has finally acknowledged that such losses are exacerbated by clearcutting and found that “1/4 to 1/2 of the assessed plantation sites have non-sustainable MMAI yield expectations…(read more) yet we forge ahead with the cutting of the Western Crown lands.

Old Growth hardwood stand (red oak/yellow birch/red maple) on granitic, nutrient-poor drumlin in the Five Bridge Lakes Protected Wilderness Area.

Diverse, productive forests can develop on such soils, and have in the past but it takes time, hundreds of years at least, possibly much more and if some critical thresholds are crossed, perhaps not again (as in much of Scotland). We can still harvest wood from our native forest, but not on the scale and intensity that we are now.

3. The Acadian forest that predominates on Nova Scotia landscape is not boreal forest, so the clearcut/even-aged management model that is said to simulate natural disturbance (mostly fire) in the boreal forest does not apply in NS (except in a limited area of fir-dominated forest in Cape Breton where the disturbance is budworm); clearcutting changes rather then maintains the natural forest in Nova Scotia. NSDNR claims that it manages forests to simulate natural disturbances, but the numbers do not back that up. Read more

Some of the more deleterious impacts of clearcutting Acadian forest:

(i) Because of the extent of clearcutting on 40-60 year (or even less) rotations we have drastically reduced habitat for species associated with older forests. Read more.

Pileated woodpecker on large snag

Also view: Scorched Earth by Bob Bancroft in Saltscapes, 2011. A quick, readable overview by a respected Nova Scotian elder who knows well our forests and their inhabitants. In Wealth of fauna call N.S. forests home CH Sep 12, 2014) Bob elaborates on habitats and habits of wildlife in older forests. As we cut vast tracts of forested land at 50 year intervals, we are losing many of these species locally, eventually to be lost province-wide, and contribute towards global extinctions. We do not need to.

View more info on the flora and fauna and related conservation issues under Natural History, and its subpages: Forest Vegetation, Conservation, Conservation Links, NSDNR Old Forest Policy.

(ii) The “borealized forest” that is promoted by clearcutting and use of herbicides is NOT the one we should be choosing to adapt to climate change; rather we should be promoting and augmenting the natural Acadian forest with species from the south. Read more

(iii) Because of the extent of clearcutting on 40-60 year (or even less) rotations we have drastically reduced many other “ecosystems services” – those things that natural systems do for us that we end up paying for when we lose them. Two key ones: carbon sequestration (uptake and retention of CO2, a greenhouse gas); and the recreational/psychological values of the Acadian forest that are not provided by clearcut forests.

For more about carbon sequestration by the Acadian forest, view Mitch Lansky’s Double Bottom Line.

I think most of us are keenly aware of the social/psychological values that are lost when we clearcut forests. The impact is exacerbated in Nova Scotia by our dispersed population in rural areas combined with a high density of clearcutting.

Occasional yellow birch amongst spruce and fir on abandoned farmland

Clearcutting may be the most appropriate harvesting system in the Canadian boreal forest (although even that view requires modification); it is clearly not the most appropriate tool for the majority of the Nova Scotia forests. The one forest type where there may be some justification for clearcutting: the white spruce/balsam fir dominated forests that have come back on land once cleared for agriculture and then abandoned, although the classic study by Drinkwater (1957) advised 2 or 3-stage shelterwood cuts and only small clearcuts. However, even there, patience and some intervention could allow more of the hardwoods and mixed Acadian forest to eventually return.

Does compaction by clearcutting affecting >10% of the area impact future species composition and productivity?

I also wonder if there isn’t a lesson to be learned from that particular successional sequence (mixed Acadian forest–>farmland–>white spuce/fir—?—>mixed Acadian forest). Is it compaction from farming that favoured white spruce/fir and slowed down the succession to hardwoods or mixed Acadian forest? Are there implications for the future species and productivity of the 10-70% of clearcut land** that is impacted by large vehicles and heavy machinery involved in clearcutting?

Is NSDNR looking at such impacts? Are they included in their long term strategic modelling of wood supply? I would like to think so.

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*Table 10 in Canada’s Forests at a Crossroads: An Assessment in the Year 2000. Global Forest Watch.
**The impact of heavy traffic on forest soils: A review Martina Cambia et al. Forest Ecology and Management Volume 338, 15 February 2015, Pages 124–138

Page posted March 10th; minor addition March 12, 2017.



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