The fire season is upon us. Fires in natural areas, that is, and many of them are appropriate. I have been a long-time staunch supporter of the correct use of fires to maintain the integrity and quality of natural areas. Tallgrass prairie and oak savanna are two of the natural vegetation types that require regular fire for their long-term survival.
I first got introduced to tallgrass prairie and oak savanna back in 1973. The bits of prairie and savanna I got to know back then were at Rondeau Provincial Park. As my career unfolded, I became greatly involved in the vegetation management of a new provincial park: Ojibway Prairie Provincial Nature Reserve, within the city limits of Windsor. As a result, I got introduced to the North American Prairie Conferences, which were held every other year at a university or college in some US prairie state. Over the years, I participated in various ways at 9 of these conferences, ranging from Nebraska, North Dakota, Iowa, Kansas, Minnesota, Wisconsin and even Windsor, ON where in 1992 I was part of a team that organized and hosted the first conference to be held outside of the USA. The last conference I participated in was in Winona, MN. And over the years I have visited 114 tallgrass prairie sites in 11 different states.
These conferences were amazing opportunities to learn practical and scientific ways of managing tallgrass prairie, and associated oak savanna. Field trips were a highlight also to see the examples of some of the finest and best managed prairie and savanna habitats remaining on the continent. Researchers, managers and enthusiasts came together and generously shared experiences and knowledge about these incredible vegetation types. Invariably the role of fire was a major topic. And as the years went by, I became increasingly supportive of the need for the use of fire to maintain the prairies and savannas here in the areas I had some responsibility for.
Fire seems dramatic and terrifying to the uninitiated, and it certainly is not something to be taken lightly.
However in just a few short weeks, the landscape takes on a new and lush look, with hints of the later season glory that tallgrass prairie is known for.
The use of fire became a sort of bandwagon for some land managers to climb on to. In the early 1970s, there were virtually no fires intentionally set in Ontario for the purpose of managing the prairie and savanna, other than on Walpole Island, where the indigenous inhabitants there knew the value of fire and used it to great effect. But elsewhere in Ontario, fire for the purpose of managing prairie and savanna was nonexistent. By the late 1980s and into the 1990s, however, it was not uncommon for a dozen or more natural areas to be put to the torch every year, mostly in the spring. Some were quite high profile, such as Stone Road Alvar on Pelee Island, the Karner Blue Sanctuary in north Lambton, Rondeau Provincial Park, Pinery Provincial Park, Turkey Point Provincial Park, and others. It was all done with good intentions, but as the years went by I became increasingly concerned that just maybe some of it was done for the wrong reasons. Just because some of the landscapes looked like prairie and/or savanna vegetation did not necessarily mean that the historical and regular occurrence of fire was the reason for their origin.
I became more and more convinced that there were other causes, and hesitatingly raised my voice in concern. Towards the end of my career with the Ministry of Natural Resources, the lead author of the proposed vegetation management plan for Point Pelee National Park asked me to comment on it. I did, and he was more than a little surprised by what I had to say about the parts that recommended the use of fire. And in the last year of my career, I gave a presentation to MNR's southern regional natural heritage forum entitled
The Role of Fire on the Southern Ontario Landscape...has the pendulum swung too far? I focused on three areas: Stone Road Alvar on Pelee Island, Point Pelee National Park and the Grand Bend to Port Franks region.
With all of that as background, I will next focus on the vegetation of the Grand Bend to Port Franks region.
Too often we take a brief look at the landscape and conclude we know why it is like it is, and what has to be done to manage it. Unfortunately, we seldom look at the history of even the previous hundred years or so, to determine what, if any, factors were the reason for what we see today. So in the case of the Grand Bend to Port Franks (GB-PF) region, I decided to look into some history.
There is clearly a lot of historical evidence that at the time of settlement, the GB-PF area was more of a pine-oak forest than a black oak savanna. But about 80 years of lumbering until the early 1900s changed all that.
In 1763 and again in 1775, the British declared all of the high quality pine and oak in many areas of Ontario to be retained solely for their shipbuilding industry, since all ships of that era were of course wooden. Pine for masts and oak for decks and hulls were never in plentiful enough supply for an island country that relied heavily on ships for its navy as well as for commerce.
This area of Lambton was owned and managed by the Canada Company, which was a British chartered land development company. In 1832, a fellow by the name of Brewster purchased a mill site from the Canada Company at the big bend in the Ausauble River, where Grand Bend is now located. The first governor of the Canada Company, Charles Bosanquet, stipulated that Brewster was to build a mill and a dam at the site, and the settlement that was established was to be called Brewster.
Port Franks, where the Ausable River outlets into Lake Huron, was one of the few decent ports along the shoreline, especially with its sheltered harbour that was up to 50' deep.
The upstream portions of the Ausable River meandered across the landscape in a general northerly direction, making a big turn at Brewster. At that point, the river turned and followed southwest through the impressive dune system, down to Port Franks.
There was eventually a change in the markets from squared timber and masts for the British, to sawn lumber for American markets. The Ausable River and Port Franks were instrumental in meeting those market demands for such high quality timber available from the sand dune system and in the general vicinity. In about 1850, Brewster reported that Port Franks was at one time a "prosperous centre of the lumbering industry based on the great oaks and pines of the primeval forest behind the village". In 1850 alone, Brewster, Pettis & Company harvested three million board feet of timber for the American market. Undoubtedly the markets lasted for more than one year, and many more millions of board feet were harvested.
In the early 1900s, the Hamilton Bros operated a sawmill at the west side of Grand Bend, and in 1910 they reported that they " cleared off what remained of the virgin forest along the lakeshore from the (Grand) Bend to Port Franks".
Piecing together the historical information
In the early 1800s, there were virtually no roads in this part of Ontario. Rivers were the main source of travel, and the Ausable River, at least for a ways upstream from Port Franks to Brewster/Grand Bend, was quite navigable. Port Franks, with a harbour up to 50' deep, would be invaluable to the shipping industry.
The sand dune vegetation between Grand Bend and Port Franks was covered with pines and oaks, right adjacent to the Ausauble River, making the timber readily accessible.
Due to the flooding in the upper reaches of the Ausable River believed to be caused by the Brewster dam and mill site, 'The Cut' was constructed, which eliminated the flow of the river through the Grand Bend area and was re-channeled in a more direct way to Port Franks. The map above shows where the cut was made, at the orange arrow. For more detailed information on the reasons and politics behind this cut,
check out this link. This next photo shows the cut. It was taken just above the 'b' in Lambton Shores on the above map.
Port Franks became less important as a harbour, due to the sedimentation from the increased agricultural activity upstream, as well as the decline in the lumbering industry after the forests had been clear cut.
The lumbering industry was quite evident in this area, due to the high quality of red and white pine as well as oak. But here is where it gets a bit complicated. It is important to know that if the forest was an oak savanna, the timber would not have been nearly as valuable. Savannas have open grown trees, with the oaks having numerous large branches quite low on the trunk, as shown in the next two photos. They would not be as tall and straight as a forest grown tree, where the much needed sunlight is only available to those trees that grow tall and as fast as possible.
Where oaks are open grown as in a savanna, they aren't valuable for much more than firewood. It is also important to understand that the impressive dunes of this GD-PF region were sandy, well drained and relatively sterile. The trees growing here would not grow quickly. The timber would be fine-grained and of exceptional quality, but they would be slow to grow.
By the early 1900s the remaining timber companies declared that they "completed clear cutting what remained of the virgin forest". As a result of the clear cutting there would be quite a lot of branch material, fine twigs and wood
chips left on the sand dune. The dunal system can be quite hot especially in the summer, when exposed to full sun, which a clear cut would be. This, especially considering the flammability of the resinous pine chips and needles left from cutting, would be conducive for periodic and likely accidental fire. After the occasional fire, there would be some germination of pine and oak seedlings. However pines readily succumb to fire, whereas oaks are more resistant. Over the decades, with periodic fire (and due to the xeric conditions and sterility of the soils on these dunes, it wouldn't have to be all that frequent), the vegetation gradually changed from a pine-oak forest into an oak savanna. Some pines may have survived, especially on the downward side of the dunes where fire would not have been as intense.
There is still evidence in existence today, of the clear cutting done about a century ago. This next photo was taken in 2010 at the Karner Blue Sanctuary, at Port Franks. As is often the case, oaks would have sprouted up following their harvest, and several of the surviving sprouts have become tree like. Some multi-stemmed trees have as many as 7 stems. I am not aware of anyone doing any aging of these stems via increment cores, but given the dry sterile soils, they are not fast growing and could easily be a hundred years old or more (I know of some oaks on the harsh parts of Pelee Island that were more than 125 years old, but were less than 15 cm in diameter).
What is known today as Pinery Provincial Park was known as the small 'p' pinery for decades earlier, indicating that pines were readily known. (If it was an oak savanna, would it be called an oakery?) And so after it became a provincial park in 1957, the first land managers realized that pines were important, and had been lost from the site due to clear cutting in previous decades, and actually began a pine planting program. By the early 1980s, however, the fire bandwagon was gaining momentum in natural areas across southern Ontario, and since the park's vegetation had developed significant savanna characteristics due to the past lumbering, it was believed by some of the park's managers that pines were bad and needed to be greatly reduced. Therefore great efforts were made to remove pines via prescribed burns as well as mechanical removal.
But it begs the question: what should the management targets of this provincially significant area be? Should it be to maintain an
artificially created vegetation as an oak savanna? Or should it be restored to something closer to the pine-oak forest which is what it was like at the time of settlement? As significant as an oak savanna is, in reality a pine-oak forest of this make-up is probably even more significant, especially when one considers that it is probably the only locality in Canada where Red Pine, White Pine and Black Oak can be considered co-dominants in a forest, and certainly is one of the more southern locations for that on the entire continent. What is even more ironic is that for years, parts of this GB-PF area where oaks and pines dominate, have been an important refuge for the endangered (now extirpated) Karner Blue Butterfly (KBB). Indeed it has been a flagship species. The KBB is absolutely dependent on a healthy population of Wild Lupine.
But the population of lupine has to be in a good, healthy condition over the entire season, not just an early season flush. Lupine does much better over the growing season in a cooler, pine-oak vegetation type than a warmer, oak savanna. And that is critical for the KBB, as the larvae of the second brood of the KBB require the availability of lupine even in the later summer to survive until the following year. If the second brood is unable to survive until the following year, the population dies out. So in theland managers' haste to treat and manage this area as an oak savanna, they unintentionally contributed to the decline and eventual loss of this rare butterfly.
I have never seen a KBB in Ontario. I got this photo when visiting a site in Wisconsin in 2007.
The bottom line is that there have been some major disturbances on the GB-PF landscape in the last 150 years or so. Clear cutting on a sand dune system is very definitely a major disturbance, and the ensuing conditions have resulted in a major shift in the vegetation present. Ignoring these historical influences have resulted in land managers making decisions that may not reflect the natural vegetation type, but perpetuate this anthropogenic vegetation to the detriment of the KBB and other invertebrate fauna.
Should fire continue to be used in these situations? That is somewhat of a philosophical and ethical question. I continue to be a strong supporter for the use of fire in managing natural landscapes. But I strongly recommend it being used as a tool for the right reasons.
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