Second Growth: black spruce forests provide fibre and caribou habitat in northwestern Ontario


When I got my start in forestry, as a tree planter in Alberta and BC, the only black spruce I saw was in the swamp.  As a student at the University of Alberta and later working as a forester in BC, black spruce was a species we never really talked about.  Who would want such a slow growing runt of a tree?  Towering lodgepole pine, Douglas fir and white spruce were generally the silvicultural objective.  That all changed when I moved to Northwestern Ontario to begin my research career.  Here black spruce grows bigger than anywhere in North America, and dominates or shares many of the most productive upland sites available.  Last summer, while surveying stands in the northern boreal forest I found what I think is the biggest black spruce tree ever measured, 26.4m tall and 34.7cm in diameter. This is the tree with the club-like crown that you will recall from the forests flying past along the trans-Canada highway, if you have ever driven through Ontario’s northern boreal shield. 


Black spruce is the ‘signature’ species of Northwestern Ontario’s boreal forests, which dominates the landscape between thousands of rocky lakes.  It is a truly vast and rugged country that has long been an important source of natural resources.  The rocky cliffs and rushing rivers around Lake Nipigon were one of the last challenges that were overcome in the development of the trans-Canada railway.  The crossing of the Nipigon River by the trans-Canada highway wasn’t completed until 1937. Long cold winters and summers filled with clouds of black flies only made working in these areas an even greater challenge.  This seemingly inhospitable environment is nevertheless ideal for black spruce, which produces the highest value softwood pulp, ideal for making everything from newsprint to premium facial tissue, as well as high value dimensional lumber.  It was this abundant resource that first attracted investment in silviculture.   


These forests are also home to woodland caribou.  The animal that graces the Canadian quarter is listed as threatened under Ontario’s Endangered Species Act (2007), and is the focus of concern for foresters and environmentalists alike.  Where anthropogenic development has moved forward these ‘grey ghosts’ have tended to vanish. Their northward retreat has been well documented by wildlife researchers across Canada.  There are many possible causes, but pinpointing one or more contributing factor is made difficult by the fact that an individual animal can travel over 2,000km in a single year. The Lake Nipigon area also offers a unique opportunity to unravel this mystery as it is one of the few places where woodland caribou have been seen to re-occupy previously harvested stands. What is it about this area that has allowed woodland caribou to persist within a managed landscape?  Something about the silvicultural history has resulted in stands that provide at least some woodland caribou habitat. 


In the years between 1928 and the start of the World War II, harvesting was done by hand and thousands of men were employed in bush camps. Within the stands that were harvested, spruce was the target.  Loggers were expected to cut and pile 2 cords of wood, cut into 8 foot lengths, per day.  Other species were either left standing, or sometimes taken and used for heating the camps. The seed bearing cones from the spruce were generally left where each tree was felled, providing a source for regeneration. The second growth that now occupies these sites is typical of northwestern Ontario’s boreal forest, containing a mix of black spruce, jack pine, aspen, birch and balsam fir.  The wood was moved out onto the lake during winter, and moved to mills in Red Rock and Thunder Bay via huge river drives and massive log booms.  The last log drive down the Nipigon River took place in 1973. Before Canada entered WWII, logging and the log drive were primary employers across Northwestern Ontario.



Most of those men enlisted once Canada entered the war on the side of the Allies.  Mills had to curtail their operations not due to a lack of fiber, but because there just wasn’t enough manpower available.  Prisoners of War (POWs) replaced the young men who had left to join the fight against the Nazis, and their contributions kept the mills operating, though at less than capacity. This was the time when large scale logging operations got going in the area where woodland caribou can be found east of Lake Nipigon.  The oldest cuts in this area date back to 1938, when a POW camp was located about 3 miles upstream from Lake Nipigon on the Onaman River.  Large areas were harvested by the interned German soldiers in the nearby vicinity. After the war, operations ramped up as the pulp and paper industry came into its heyday.  Once again thousands of men (and a few women) headed up to camps and small communities like Auden to supply fiber to various mills. Natural regeneration was still relied upon until the mid to late 1960s when modern silvicultural approaches like planting and seeding first started to be used.


Fortunately, staff at the Nipigon District office in Nipigon retained maps showing the locations of the old cuts.  Today we see a wide range of conditions resulting from this very basic silvicultural approach; everything from pure conifer, to mixtures of aspen birch, fir, pine and spruce. Modern silvicultural practices, including planting and seeding of cutovers came later, beginning in the early 1960s.  We have seen, through GPS collar locations, woodland caribou occupying stands harvested in the mid 1950’s near the Ombabika River and others harvested in the late 1970’s near Fullerton Lake. These stands are currently conifer dominated or conifer / deciduous mixedwoods, with black spruce part of the conifer component.


To better understand how the caribou that live near Lake Nipigon have managed to persist within this managed landscape, the Ontario Ministry of Natural Resources, along with partners from the University of Guelph, the Canadian Forest Service, the Forest Ecosystem Science Co-operative and Trent University are engaged in a wide ranging study of woodland caribou, their competitors, predators, stressors and habitats.  This work is being led by Dr. John Fryxell of the University of Guelph through an NSERC Collaborative Research Development grant.  We are studying both the habitats that have emerged following logging as well as those that emerged from natural disturbances.  Some subtle differences in the understory plant community between logged and naturally disturbed habitats have been observed, but we are only at the early stages of our analysis.  The historical records of silvicultural activity in this area are vital to allow us to evaluate the long term effects of forest management on the stands that may provide habitat, and by extension the animals that occupy them.


Due to changes in government policy, the records we are using were at one time in danger of being lost.  In the early 1990’s, all silviculture records were handed over to the forest industry. Some used them, some left them in boxes and some even threw them away or lost them in catastrophic fires. As a result, when the modern digital inventory was developed, the historical records were not explicitly incorporated.  By digitizing the old maps, we have been able to confirm not only that woodland caribou are in fact using some of these “second growth” forests, but that they are starting to find their way into the harvest queue.  For example, in the latest draft of the Forest Management Plan for the Kenogami Forest, over 23,000 ha of second growth are identified for possible harvest over the next 10 years. We are very fortunate that the silviculture records for our study area were maintained by dedicated foresters from both industry and government.  Hopefully all the old records that have been saved from across northern Ontario can be moved into the digital age so they can more easily be incorporated into our planning, research and practical activities.


In terms of silviculture, this area also has a lot to teach us about the long term effects of forest management activities on growth and regeneration of black spruce. Some of the intensively managed plantations established in the early 1960’s have been maintained and are currently producing nearly twice the regional average in terms of merchantable yield.  These were established at very high density (2500-3000 stems per hectare) on a range of soil conditions.  While there are differences in individual tree size associated with site quality, all are producing similar yields.  Taking a closer look at the quality of the wood from these thrifty plantations revealed that over 80% is likely to meet the No.2 or better visual grade.  If there was a mill in the area that was properly equipped, 48-98% of this wood would meet a machine stress rating, allowing it to be sold at a premium.  This after only 43 years of growth! Where intensively managed plantations were not established, aerial seeding and herbicide were used to favor spruce regeneration. We have also been able to use these records to show a definite increase in the amount of ground lichen (important food for woodland caribou) in stands where prescribed burning was used instead of mechanical site preparation, to establish spruce and pine plantations. 


The forests around Lake Nipigon are thus yet another example of how managed forests can provide for multiple benefits to the public.  In 1999 the Lake Nipigon Basin Signature Site was identified as part of Ontario’s Living Legacy Land Use Strategy (1999) as it provides a broad suite of natural and recreational values.  Lake Nipigon has long been known for its fantastic sport fishery, and has been drawing visitors from around the world for over 100 years.  In 1919 Edward, Prince of Wales, visited the Nipigon River for three days of speckled trout fly fishing. For almost as long, forest harvesting has been conducted in the area to provide timber resources. This area remains popular today for outdoor recreation, and it’s special status seems appropriate given the fact that it is one of the few extensively logged areas that continues to support a woodland caribou population.  Whether producing high value second growth black spruce plantations, or high value habitat for rare species like woodland caribou, these forests will continue to provide Ontarians and Canadians with a multitude of values now and into the future.



Douglas E.B. Reid is Boreal Silviculture Research Scientist, Centre for Northern Forest Ecosystem Research, Ontario Ministry of Natural Resources. Doug has a PhD in Forest Biology and Management from the University of Alberta and is an Adjunct Professor in the Faculty of Natural Resources Management at Lakehead University.  He can be reached at 807-343-4008