So we set up a hypothesis that we would find the system operating from the bottom up and that wolves would be largely free riders. Unfortunately we had no control area for comparison. No large enough place free from human influence is left in either adjacent biome.
NOBODY MADE this web. Incongruously, it made, maintains, and runs itself. More intricate than humans can ever devise, it does not claim to represent virtual reality. It is reality.
Different parts of the web provide life support for different species. The wolf draws almost totally on the large mammal strands, themselves deeply embedded in trophic connections. To understand the wolf, you need to understand its ecosystems links. You surf for them better with binoculars than with a computer. Binoculars and patience.
Hot leaf-filtered sunlight angles through the stunted ridge-line oaks while cicadas drone from somewhere below. A red-eyed vireo, the most persistent songbird in the forest, repeats its monophrasic song twenty or so times a minute until its occasional silence, not its voice, attracts attention. A languid forest wrung out by summer heat stretches to a distant blue haze.
Mary and I have climbed this rocky ridge many times. It provides a vantage point to pick up signals from the seven McDonald Creek wolves that have been on the air at various times. Often we have leaned back against the same lichen-encrusted rocks with a view over the McDonald marshes and into the folding hills beyond. At dusk, the hills look like ranks of waves from a small boat.
Up there we can imagine ourselves out of ecosystem. Not totally detached, as you are in an airplane. Most of what is going on, however, takes place down below, connected to us only by thin oak strands, a tracery of blueberry bushes among the rocks, the songs of cicadas, and the vireo. It is a good place to wonder about the web, to wonder about how soils and forests and herbivores and the Algonquin wolf all fit together, to ask questions and design ways of trying to answer them. Doing that relieved hours of down time between half-hour checks on the wolves, especially when they were somewhere beyond the hills. It turned out to be productive time.
First we needed a map of forest composition. Not all types of forest support wolves equally well. Hills marching into haze, more than seventy-five hundred square kilometres of them, would not be easy to map. Fortunately, there was a high-tech solution. Employing it required plenty of patience — Mary’s. It took her four months in front of a computer. Really, it took eight months because one summer while we were in the field, a computer technician inadvertently wiped the disk.
Mary’s computer-drawn map was made from a coded image as seen by a satellite orbiting above the Earth on May 12, 1986. She chose that image because of the cloudless conditions, and because in early May the flower colours of different hardwood species make them distinguishable by the sensors onboard the satellite.
The trick to classifying forests from such a satellite image is to know a few sites from field work with selected species of trees. This information is plugged into the computer, which then finds all similar species throughout the park and builds up a map of major forest associations. This method beats the pre-satellite approach, which involved staring down a stereoscope at black-and-white air photos and trying to detect different shades of grey.
When finished, the map showed that Algonquin’s principal energy processor on its eastern side is mostly “pine-poplar” forests. Closely coupled within these forests are white, red, and jack pines in that order of abundance, trembling and largetooth aspen, and red maple. There are also areas of black or white spruce and balsam fir, and stands of pure hemlock, all coming in seemingly chaotic combinations. However, as you stare at the computer screen, various broad groupings begin to stand out, and you realize that the forest types are not randomly situated. They reflect the roll of the hills, the warm, south-facing or cold, north-facing slopes, the cool lowlands, the wet places, and the locations of past logging or fire.
Here is the solar panel of the ecosystem, this complex canopy, capturing the energy that eventually works its way along various pathways to drive a wolf along a forest trail. The map would allow us to relate forest type to wolf activity. What species provide wolf support, where are they, and how are they connected?
The immediate “what” was obvious: moose, deer, and beaver. Our scat analysis gave us seasonal details. One step removed are the plants that provide these herbivores with food and shelter: primarily the two species of poplars, red maple, beaked hazel, balsam fir, the pines, and hemlock.
Recognizing where these components are found and connected, however, is more difficult; that came into focus only gradually. First to appear were the broad outlines of the conifer component.
Balsam fir share the lowlands with spruce. Graham’s task in his master’s research was to search for a relationship between spruce-fir forests and wolves. His examination of aerial moose surveys flown in fifteen consecutive winters by Mike Wilton or his staff showed that moose densities were highest where the spruce-fir forests had been disturbed sometime in the previous ten to fifteen years.
Two agents of disturbance had been at work. The first, spruce budworm, is a seemingly innocuous, drab, one-centimetre-long larva. Its assault on the forest in countless, voracious millions, as occurred during an epidemic in the mid-1970s, results in the death of extensive spruce-fir stands. After a budworm epidemic, young balsam fir normally grows aggressively, outcompeting spruce for a time because fir grows better in full sunlight. That is just what moose want. Fir is a favourite moose food; spruce is ignored. By promoting the growth of fir, budworm changes the forest in favour of moose — and wolves. So important is spruce budworm to the wolf subsystem that, along with winter tick, we gave it the dignified label of “invertebrate agitator.”
The other important agent of disturbance that favours moose does not eat its way to prominence. It uses chain saws, log skidders, bulldozers, eighteen-wheelers. Graham discovered that lowland areas logged within fifteen years held more moose and, for the same reason, more young balsam fir.
That should have been good news for forest managers. They can log in a park and create better moose browse. Ironically, Graham’s thesis and its recommendations almost cost us our research permit. The trouble arose over hemlock.
Uncut, undefiled old-growth hemlock stands are north-country cathedrals. Graceful limbs, bowing branches, fluted trunks. Tiers of delicate dark-green archways filter the sunlight like a stained-glass window.
Hemlock logs lying on the forest floor, the skeletons of generations past, decompose slowly because of their tannin- and resin-embalmed trunks. Among the logs grow shade-loving goldthread, the pale flowers of wood sorrel, flushes of red moccasin flowers. Blackburnian warblers nest here, repeating their thin, upwelling notes from the hemlock spires. Sapsuckers embroider the trunks with neatly aligned holes. Few places are more enchanted.
Hemlock stands such as these are cut down, even in a park, to make wharf pilings, railway ties, and little wooden crates used to store and ship commercially grown mushrooms. In the past, hemlock bark provided tannin to cure leather. Once prominent in pre-crosscut saw, pre-chain saw Ontario, we have succeeded in breaking the back of this species. No longer does golden hemlock pollen float great distances on the spring breeze. Instead, only a little is wafted into the air, too often searching in vain for a reproductive partner.
Hemlock first appeared on Earth, according to the fossil pollen record, in the Eocene Epoch, fifty-five to thirty-eight million years ago. It arose most likely in Asia, on a side branch of the evolutionary tree that earlier gave rise to the pines. A few million years later, it had radiated as far as western North America and China. Time and isolation fashioned approximately ten species, some found in Japan, China, and the Himalayan Mountains. In Canada, we have three species. One of them, eastern hemlock, makes its last, thinned-out stand today across its historic range from Nova Scotia to Ontario south of the height of land.
A desecrated hemlock cathedral near McDonald Creek alerted us to this species’ plight in Algonquin Park. One
winter day, Graham, Mary, and I followed the signals of two wolves in the Foys Lake pack into a big cut-over. After struggling over branches and treetops concealed by snow, we stopped, looked around, and realized that the standing scattered remnants consisted of hemlock. Only a few trees were left.
We photographed the carnage, resolving to return in spring to see if any hemlock seedlings were hidden beneath the snow. That was unlikely because hemlock seedlings need shade.
By the following summer we had forgotten the incident until, again tracking the Foys wolves, Mary and I recognized the raspberry-choked cut-over we had photographed before. We broke off our tracking to look for hemlock seedlings and found what we feared — none. Plenty of red maple and white birch seedlings and some aspen were coming up, but not a single hemlock. The stand was destined to become part of the extensive hardwood forest that surrounded it.
We tried to forget the McDonald Creek hemlock massacre, except for the bothersome possibility, suggested by our spring pellet and browse surveys, that moose favour these hemlock stands. Each spring, we and our field crews walk about forty kilometres of three-hundred-metre straight-line transects in various wolf-pack territories, estimating winter use by deer and moose from their droppings. On a hunch we added a few columns to the data sheets to detail hemlock regeneration.
The next spring, sure enough, we found hardly any hemlock regrowth even in uncut stands. Some bands of seedlings grew in dense, thin lines at the edges of abandoned logging roads, and some on hemlock-hardwood forest edges, always where the forest shaded them for much of each day. In contrast, we discovered many other logged-over hemlock stands growing back to hardwoods.
We still might have let what was becoming in our minds the “hemlock issue” go. Then the first drafts of Graham’s master’s thesis showed that hemlock stands were the most heavily used forest type, per hectare, by wintering moose in Algonquin Park. Moose find shallow snow and shelter from cold winds there, and can wander out into the surrounding hardwood forests to browse, an ideal arrangement.
Even more ideal is the strategic location of many hemlock stands on the west side of the park. They crown the big, rolling hardwood hills, responding to moisture trapped in shallow soils above bedrock. Smart moose hole up for the winter in these hemlock galleries, leaving no scent trail through the lowland conifers that wolves habitually hunt, daring the wolves to wade up through the deep snow to reach them.
We discussed the ramifications of this discovery one day in my office at the university. It could be risky to criticize the management of the forest because our access to much of the park depended upon the possession of a permit to drive logging roads for research purposes. But research is research. Graham agreed he had no choice but to present the findings. In the recommendations at the end of his thesis abstract, he wrote: “Due to the importance of hemlock to moose, and the threat of a significant decrease in hemlock, it is recommended that the Ontario Ministry of Natural Resources prepare and make public a policy statement regarding the cutting of hemlock as it affects ungulates in Algonquin Provincial Park.”
Feeling he should not take the heat alone, I wrote a short position paper calling for all hemlock logging to stop in Algonquin Park until it could be done in a way to allow more adequate regeneration. It was an action sure to bring a response. However, I was buttressed, even motivated, by two confidence-builders. One was an exchange of internal correspondence not meant for the public eye. I still cannot reveal how I obtained it. The exchange was between senior administrators of forestry in the MNR and the Algonquin Forest Authority (AFA), the Crown corporation responsible for logging in the park.
What the letters, the MNR to the AFA, said, paraphrasing broadly, was: You are overcutting hemlock and there is insufficient regeneration in cut-over stands. The AFA response: You know as well as we do that hemlock is difficult to bring back so instead of complaining, tell us how.
From a technical standpoint, the problem is that you cannot cut more than about 30 per cent of a hemlock stand without flooding the forest floor with too much light for these shade-loving seedlings to grow. However, to allow seeds to germinate you need to scarify the ground, scrape away the deep accumulation of needles so the tiny seeds can reach a mineral soil. Fire does this naturally, but fire is fought and extinguished almost everywhere. Alternatively, you can scarify the soil with a bulldozer, but it is difficult to drive one around if you have cut so few trees.
My other confidence-builder was the detailed technical instruction and even editorial help I received from one of the MNR’S most highly qualified forest ecologists, who totally agreed that the problem needed to be addressed. I could not reveal his name, of course.
Two weeks later I received a telephone call asking for a meeting with senior MNR and AFA staff. The meeting took place at the Algonquin Museum staff house on a cold winter’s day, appropriate to the frosty mood of the government. Right away, as people trooped in, we noticed a general lack of levity.
They questioned the quantity and quality of our seedling data and scored a point because we had begun it only the spring before. They countered our concern over the McDonald Creek stand with the explanation that they were forced to do a “salvage cut” after a windstorm. They asked why our research and the privileges it entailed gave us the right to question their management.
We let them corner us. When it became apparent the next topic might be the continuance of our research permit, I reached for my briefcase and tossed the two letters on the table. They recognized them. There was an embarrassed silence.
The meeting had two outcomes. The MNR hired a hemlock specialist to study the problem and recommend how to solve it. The other was heightening discomfort among some MNR people whose park-management practices had been criticized. That discomfort was to have future ramifications for us.
Maybe it had a third outcome. Some hemlock cathedrals may still be out there, where moose spend the winter. And there may be fewer mushroom boxes.
While the hemlock groves and fir forests are special places, the rank on rank, hill after hill of pine-poplar forests provide the main energy pathway through the ecosystem web, provisioning most abundantly the wolves’ three prey species. Beaver selectively fell the poplars close to their ponds. Moose and deer strip new leaves off poplars and red maples and browse their winter twigs. The pines provide shelter.
“Pine-poplar” rings poetically as a name for these forests, but it short-changes red maple, an equally common species, and ignores white birch as well. “Pine-intolerant” is a better name that encompasses them all. Seedlings of poplar, white birch, and red maple are intolerant of shade. In contrast, the seedlings of “tolerant” species do well in shade: sugar maple, yellow birch, and beech.
Both the shade-intolerant and -tolerant hardwood species are locked in continuous war with the pines. In various places, one or the other mounts the heaviest attack or they are evenly matched. Most of the action takes place where forests have been disturbed, providing an opportunity to gain new ground. Our entire study area has been logged up to three times except for a few small nature or shoreline reserves. The huge pines fell more than a century ago, then spruce and fir, then the hardwoods.
From the AFA we obtained a map of areas logged since 1975 and transformed it into a computer-screen product for later comparison with wolf locations. The AFA’s method of logging in the pine-intolerant forests is called “shelterwood,” a misnomer from the perspective of a moose, considering that only 40 to 60 per cent of the forest crown is left. Foresters, however, think of shelter for seedlings. Twenty years later, the chain saws and skidders will be back again, and in twenty more years the original stand will be gone. That schedule does not leave much time for forest types to replace each other in natural succession. What comes up immediately after logging will be the future forest stand.
Sometimes little pines poke up through the ubiquitous bracken fern and hazel. That is what foresters like to see; there is a good market for pine. Other times no pines sho
w up at all. Each May along our transects we collect data on these differences.
To run these transects, Mary and I, or pairs of other crew members, walk parallel to each other fifty metres apart, pacing out our distances and counting moose and deer pellets. Then we retrace our steps counting browsed and unbrowsed stems of poplar, red maple, balsam fir, oak, and hazel. Sometimes we wade through lingering soft snow in the low places. At other times, we find ourselves on sunny warm slopes where the tiny, red brushcut flowers of beaked hazel are in bloom. The forest is full of the songs of newly arrived winter wrens, hermit thrushes, and white-throated sparrows, punctuated by the staccato hammering of yellow-bellied sapsuckers. Ruffed grouse drum. Spring unfolds.
We had difficulty understanding why pines were winning here and losing there. Then one winter’s day Tom Stephenson provided an explanation that fit our data. Tom’s life in the bush fighting fires, marking trees, prescribing management plans, and, most importantly, thinking about what he sees has given him an extraordinary interpretive ability. The Jocko Lake pack had made a kill that required a fifty-kilometre snowmobile trip, and because of the general unreliability of our snowmobile, we asked Tom to accompany us. Late in the day we reached the Jocko territory and churned up a snow-filled logging spur to within two kilometres of the wolves. We stopped on a knoll, put on our snowshoes, and made the last approach in silence.
Around us was a four-year-old, pine-intolerant cut-over typical of most of the Bonnechere Valley and typical, too, in its lack of pine regeneration. The lack of new pines angered Tom.
“Look at the spacing. There’s supposed to be a half-crown opening between the pines that they leave. It’s about one and a half crowns. They butchered it. Too much light. You can’t let this much light into places like this where the soils favour poplars and red maples.”
He explained that it is okay to cut at one-and-a-half-crown spacing up in the Petawawa Valley, where it is sandier. Up there the soil is so dry and porous that intolerants have difficulty. But here with more till, the soil is slightly more moist, which is right for them. The pines are outcompeted.
Wolf Country Page 14
