High Park Field Trip Lab Report
By Paloma D`Silva
Background
On Sunday, September 30th, my classmates and I participated in a field trip to High Park. The purpose of
our field trip was to examine one of the last remaining communities of black oak (Quercus velutina) savanna
communities in Ontario1. To clarify, a savanna is a community that has 25% or less of tree covering. High Park is an
Eastern deciduous forest located in the city of Toronto, Ontario in Canada. The soil composition of the area was
once part of glacial shoreline, containing sandy, well-drained soils and upland areas. This area was once part of an
ancient lake bed which was replaced by Lake Ontario, and its shoreline went just past St. Clair Avenue W. and
Lakeshore Ave. W. in Toronto.
In some parts of the forest, where ants have dug up some parts of the area, we were able to observe the
very well-drained sandy soil composition. Naturally, forest fires occur in this park every 5-15 years, and the
purpose of these fires is to suppress invasive species and promote the regeneration of black oaks.
Currently, park conservation staff has been conducting prescribed burns since 2000 to maintain the
growth of young oaks in the area. When fires are conducted, they do best going uphill. There is a backfire (fire
break), which gets rid of vegetation in an area. When wind is in the area, the fire is started, but it cannot be too
windy. Fire is lit in the corner with a type of fuel. It creeps forward and grows out. Savanna fires are low intensity,
and low to the ground. Fire breaks are peripheral to where they are burning and releases seeds, travelling alone a
path. When fire comes through, light is sent out. The purpose of savanna fires is to preserve an ecosystem for
every species.
The park was founded by John Howard, who was responsible for the High Park Management Plan in 1840.
The oak savanna here has been extended and has been a prominent part of High Park’s vegetation. John Howard
donated the park to the City of Toronto, and most of the park has been city property ever since, except for some
private homes.
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GEOG 2500 High Park Lab Report Instructions. Hewitt, Nina. Published on behalf of York University, Toronto, ON.
2012.
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Methods
For this trip, we were in a group tour of the park with our professor, who explained the background
behind the different species in the park, as well as told us information about the species, and some park history.
Results
This paper will explain the different types of vegetation found in the area, as well as detailed information
about them. The information here was told to our group by Professor Nina Hewitt of York University in Toronto.
The species listed below are all native species.
Ragweed was one of the most common species found in the park. Its pollen has barbs on it and these
barbs irritate mucus membranes.
Black oak is a native species to the park region and contains possible evidence of fire events in the past.
Currently, High Park has more old oaks than young oaks, and this is significant to note because there is not much
reproduction. Most of the oaks in High Park were aging and deceased and many of these have been cut down over
the years. Forest fires have been instrumental in maintaining the oak populations; because they help the oak
plants reproduce by germinating and dispersing the seeds. Black oak has meristem tissue, which produces a single
stem.
An ecological consequence of the low populations of black oaks is that seedstock for squirrels is reduced,
so squirrels feed on garbage. In a healthy ecosystem, these squirrels would be feeding on the acorns from the oak
trees. However, because there is very little of it, the squirrels are forced to feed on garbage to survive.
Unfortunately, younger stages of black oaks are more vulnerable to death than older ones, because they
do not have as many defenses and adaptation as older oaks to protect themselves. On average, a tree produces
one grown tree out of all the seeds that it disperses, which is a 2% rate. A way that park conservation staff is
promoting the growth of black oaks is by collecting the seeds and planting them in various areas throughout the
park. This is known as artificial population. The benefit of this is that if a tree does not get burned for 15-20 years,
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it can make it back up to the canopy.
Upon closer observation, we noticed a stump of black oak. This stump is a great habitat for birds and
rodents, and it provides a home for them.
Black oaks and red oaks exist in the ravines, whereas white oaks exist in the rest of the area. Red oaks are tidier
than black oaks. White oaks flourish in burned areas.
Indian rye was another type of native savanna species.
Asters, which are members of the Compositae genus of plants, are another species present in the High Park
conservation area. We noticed sky blue asters, which were quite common in the area.
Bergamot has adapted to dispersing itself exozucorously, which means through animals and other plants. For
example, in the park, we got some bergamot on us, that tended to stick to our clothes. It is a native species to the
High Park area.
Lupins, a type of native species in the area, are the largest nutrient source for the blue butterfly, which has been
extirpated in most of Southern Ontario. Lupins are orange flowers with a red centre.
Milkweed, a native species is considered a noxious weed and is a food source for the monarch butterfly.
Tall grass(Andropagon gerardi) is very tall, has deep roots, and has adapted itself to the community we visited.
Silver maple (Acer saccharinum) are typically not found in a savanna area, but this area contained a few examples
of this species. Silver maples are native to Eastern deciduous forests.
Sumac, related to poison ivy, is a type of native species found in the area used to make rosehip tea.
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Other native species to the region not already mentioned here are white ash (Fraxinus americana) and sugar
maples. Sugar maples (Acer saccharum) are native to Eastern deciduous forests, and were found throughout the
park.
Invasive Species
In addition to the native species, the High Park conservation area also contained invasive species. Invasive
species are a threat to the native species in an area. Invasive species can uptake resources easily, are r-selected
species, have large numbers of well-dispersed seeds, and they are native to the larger reason. Most of the worst
invaders are typically not shade-tolerant species, and are from faraway regions. When invasive species migrate to
the area, either through seed dispersal, or other ways, they do not bring their pests with them and can flourish.
Invasive species reproduce vegetatively, by having new individuals produce off the parent plant. The invasive
species found in the High Park conservation area are explained subsequently.
Linden trees grew from seeds that germinated on their own and were found throughout the park.
Norway maples have an 180ᵒ vee shape between them, which is slightly more than the sugar maple’s vee of
approximately 140ᵒ. That is one way to recognize Norway maples from sugar maples. It exudes a white sap from it,
which is toxic, and sugar maple does not have white sap. To deal with this type of invasive species, these plants are
being left to cast some shade but park staff wants to eliminate it completely. Norway maples are allelopathic and
get rid of the competition by poisoning it.
Turf grass is a fescue grass. It is being replaced by native species due to solarisation. Solarization occurs when black
sheets of canvas on the ground in places kill the underlying plants. This has mostly been done in areas in the park
that do not have native species.
Common plantains (Plantaego major) flourishes if people or animals trample on it. Pesticides are being used in
High Park for esthetic reasons, and root systems of invasive plants are being killed, including the root systems of
the common plantain.
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Goldenrod is the worst invader in Eastern North America, and is also known as garlic mustard. It is a biennial plant,
which means it grows twice a year, and lives for two years. The first year, it grows at ground surface, and the
second year, it grows as a flowering spike and produces a lot of seeds.
The Himalayan balsam, from East Asia was an invasive species in the High Park area. They are pink flowers. It is
related to a native species known as the jewelweed, or touch-me-not, colloquially. This species has taken over High
Park, but it is not common in North America outside of this park. The species propagates when it is squeezed and
seedlings come out of the flower.
Manitoba maples (Acer negundo L.) are a native invasive species that were found in this area.
Buckthorn, a type of invasive species here, produces a lot of seeds.
Dog-strangling vines, a non-native species are found in this area.
Canvash mitts and kwudzu are examples of East Asian invasive species that are now found in Southern Ontario.
Interesting Considerations
We learned about an interesting conflict between different user groups in the area, which is the dogowners versus park restorationist battle. Currently, dog-owners want to have part of the park to walk their dogs,
and park restorationists want that area to preserve biodiversity. This has been a long conflict, but currently, the
area for dog-owners has been fenced in. Dogs are predators, and consumers of local plants. This has been the main
issue concerning user groups in the High Park conservation area.
Another example of an animal that has hindered progress towards better plant diversity is the deer. Deer
has been a scourge for the High Park oak savanna ecosystem, and their population densities have skyrocketed. This
is hazardous because deers constitute herbivory, and are consuming plants faster than they can be replaced.
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