By Terry Carleton
Although forests are the main focus of my attention, prairies have held a fascination for me since the age of ten. My family lived on the edge of a council house estate in southeast London, UK, as did my precocious and talented cousin five years my senior, 500 yards up the road. He decided to increase the value of his parent’s house, still a rental property at the time, by painting a mural of a prairie fire occupying one whole wall of his bedroom. Unfortunately, he also contributed to decreasing the value of the house through a precocious interest in homemade gunpowder and fireworks. Furthermore, he had ingeniously put together a short-wave radio system, from accumulated army surplus parts, in the same bedroom. This he used to communicate with Radio Moscow, on a regular basis, at the height of the cold war period. To the best of my knowledge, MI5 never discovered it!
To a boy whose daily schedule revolved around playing “Cowboys-and-Indians” amongst rather dull suburban houses, parks and playgrounds, the mural was breathtaking. Multicoloured flames licked at the heels of terrified, fleeing antelope, bison, coyotes, Indian ponies with their bare-backed, war-painted riders and prairie dogs retreating to their burrows. All this fueled by tall grass burning at speed across the treeless and unfenced landscape. Such prairies have now disappeared under the plough of Euramerican settlement in almost all of the rural areas of central North America. The high plains were dominated by short-grass prairie and the mid-west by tall-grass prairie. Eastern outliers of these tall grasslands extended into southern Michigan and southern Ontario. They persisted in the face of woody plant invasion through being burnt, usually by native peoples, every five to fifteen years. Real tall-grass prairie is one of the most floristically diverse ecosystems in North America, with as many as 100 species of flowering plant in a 10 x 10m plot and many of the flowers provide beautiful displays in the late summer.
Imagine my excitement, therefore, at seeing the word “prairie” describing an area on the map, generously supplied by Mike Daly for his 2006 Rendezvous workshop on “piloting” (as against “navigation”), at the Cape Croker Indian Reserve. After all, the best tall-grass prairie in southern Ontario is to be found on another native reserve at Walpole Island in the St. Clair River. Thanks to the confusions of Sunday morning, several of us missed out on the planned trips, so Mike organized an ad hoc trip over to MacGregor Harbour and back. We stopped for lunch at the “prairie” to investigate. What we found was largely treeless but did not really qualify as “prairie.” The vegetation fell into plant communities that were either marl shoreline, ice-disturbed beach bar, gravel beach ridge or coastal alvar.
After a leisurely paddle across the bay, from our campsite below Sydney Bay Bluff to Prairie Point on Cape Croker proper, we did a brief stop at what proved to be a marl meadow/shoreline. This was in a relatively protected area, from heavy wave and ice incursion, and was typified by a profusion of that mucky, brownish, slithery stuff all along the shoreline near the campsite. This is a cocktail of organic matter and diatomaceous marl, created by single-celled algae that produce exoskeletons of calcium carbonate, which they precipitate from bicarbonate solution in the lake water. The stuff gets dumped high up the shoreline by waves and high spring water levels and many shoreline and emergent aquatic plants seem to love it. Mike and I discovered pretty little gerardias (Gerardia tenuifolia) and lobelias (Lobelia kalmii) in amongst various graminoid (grass-like) plants including the pipewort (Eriocaulon septangulare). Farther back, against the shingle ridge, the last remnant of bright blue flowering blue-eyed grass (Sisirhynchium montanum) persisted and fresh, abundant indian paintbrushes (Castilleja septentrionalis) were showing their brilliant splashes of scarlet.
Because of poor communication from the leaders the other paddlers had not disembarked (de-kayaked? de-canoed?) so Mike and I saddled up in order to push on further round the point to a suitable lunch stop. After a bit of debate and some wry remarks about the whiteness of my legs, we ate lunch on an exposed and less interesting beach bar, dominated by sandbar willow (Salix interior) and a smattering of other willows with some red osier dogwood (Cornus stolonifera). Now the whiteness business requires some explanation. Being English originally, the wearing of shorts in temperate climes was only done prior to the age of twelve years, after which one graduated to manhood and long trousers. No one of my generation would dream of reversing this rite of passage unless legitimately engaged in sporting activity. Look around at the macho nations of the World. How many of the men habitually wear shorts, even in hot climates? The day was warm and I had shed the outer neoprene, during our legitimate sporting activity. Besides, I don’t go brown, I go lobster red!
Funny how, after trekking solo inland for a post-lunch pee, one discovers the most interesting botanical finds. Indeed, mid-micturition, for the male of the species at least, seems to be a pause for reflection and acute observation of what is growing immediately beyond one’s feet. Could that be because it is the target zone and one wishes to bestow the liquid nitrogen on the most needy or deserving recipients, or is it simply to avoid the self-embarrassment of pretending not to be doing anything? Either way, the very low shrubby sand cherry (Prunus pumila), creeping juniper (Juniperus horizontalis) and grass of parnassus (Parnassia palustris) got equal shares of the fertilizer. These were on the leeward of the shingle bar separating the beach bar from an alvar plant community immediately inland. “Alvar” is a Swedish word for the type of vegetation which is typified by a mosaic of herbs, low shrubs, some taller shrubs a few trees and sometimes exposed rock. Alvars are usually on limestone and can support a wide diversity of plant life including some species found in prairies. Alvars are common in the Kawartha region and also on the plateau of the Bruce Peninsular as well as Manitoulin Island. This one was primarily on limestone (actually dolostone) beach gravel – my first.
I went back, clothing adjusted, to share my enthusiasm with the others and this time the message from the leaders was clearer and everyone got it. We did a communal gee-whiz little nature hike back in. Most of the ground was covered with the creeping juniper but the much larger common juniper (Juniperus communis) dotted the all natural garden. Even more noticeable were the brilliant red flowering day lilies (Lilium philadelphicum) everywhere. Although yellow lady’s slipper orchids (Cypripedium calceolus) were dotted throughout, they had finished flowering and did not offer much visual excitement. Other goodies included harebell (Campanula rotundifolia) in flower; New Jersey tea (Ceanothus americanus) – a prairie plant in flower; fragrant sumac (Rhus aromatica) – in fruit, closely related to poison ivy but harmless and fragrant; buffalo berry (Shepherdia canadensis); and more flowering Indian paintbrush. In addition, there were a few white spruce (Picea glauca) trees dotted around and some stunted jack pines (Pinus banksiana) – named after the both famous and notorious Sir Joseph Banks: botanist with Captain Cook and founder of Kew Gardens. Now the Ceanothus, the jack pine, as well as an inconspicuous little grass (Danthonia spicata), which was also present, share an important need. They usually require fire to reproduce under natural conditions. Heat causes the grass and N.J. tea seed to break dormancy. In addition, the Ceanothus resprouts vigorously from belowground parts after fire. The pine has cone serotiny. That is, the cone scales remain closed and glued together by resin after the seed inside has matured and gone dormant. It is important to remember that these same cone scales had to be open at an earlier stage of development in order to allow pollen to enter for eventual fertilization. So this is not merely a case of arrested development but a true fire adaptation. The cones remain closed, harbouring their aboveground dormant seed bank until the parent tree either dies of natural causes or, more likely under natural conditions, it gets burnt. The heat of the fire may melt the resin “glue” on the cones. Also, on tree death, the transpiration stream ceases, the cone scales dry out and reflex, releasing the seed days after the fire has passed through. Germination then occurs following the next rainfall.
Fires are thought to contribute to the structure and diversity of alvars and this may explain some of their mosaic patchiness. Fire disturbance is a feature shared with native prairie vegetation, which is why some plant species are found in both community types. Before industrial logging became dominant, forest fire was the main natural disturbance/regenerating agent in our northern boreal forests. Consequently some species are in common between alvars and the northern forests, notably jack pine and the spruces. The natives of Cape Croker, therefore, have probably used fire as a vegetation management tool to maintain, if not create, the coastal alvar that we saw that day. In the absence of logging machinery, fire was the least labour intensive way of managing vegetation, clearing underbrush and creating favourable browse/grazing conditions for game. This was especially important around native settlements and for keeping open portage routes throughout the Great Lakes region. Isolated, often small, prairie remnants can be found at a number of strategic locations, which mark the beginning, or terminii of aboriginal portage routes. One, at De Grassi Point on the western shore of Lake Simcoe, marks the beginning of the carry westwards to the Nottawasaga valley and thence northwards down to Georgian Bay. Also, southwards into the Humber and out to Lake Ontario at Toronto – which is why the city is where it is today. Not surprisingly, therefore, Toronto has a major bit of prairie near the mouth of the Humber River, in High Park. Actually, it’s more of a black oak savanna – patches of prairie vegetation interspersed with occasional black oaks (Quercus velutina). (For urbanites of the GTA who wish to investigate, the best development is on the west flank of the park overlooking Grenadier Pond. Worth a visit, especially in late summer when the big bluestem (Andropogon gerardii), the wild panic grass (Panicum virgatum), azure asters (Aster azureus), the prairie cup plants (Silphium perfoliatum) and woodland sunflowers (Helianthus divaricatus) reach their peak. Instead of native fire management, the City of Toronto has introduced a programme of prescribed burning in the park. This usually happens each April.)
After our ecological fire lecture, we saddled up once more and briefly poked our noses into MacGregor Harbour, took a snap of the church, then headed back across Sydney Bay at a suitably leisurely pace through the refreshing afternoon chop. A fitting end to a most enjoyable weekend.