Category Archives: Trees

Fall – as it happened.

Autumn is the time when leaves fall from the trees. It may seem like a gradual process but often, leaf loss can be sudden; especially after an overnight frost or during gale force winds.

As summer winds down, deciduous trees produce cells at the base of each leaf stem called the abscission layer. This layer weakens the attachment of the leaf to its tree while blocking nutrients from nourishing the leaf causing its chlorophyll to degrade. Since chlorophyll is green, other colours such as red or yellow can then become more prominent.

Frost can accelerate the process by further weakening the abscission layer so that leaves are very loosely attached and will fall at a slight breeze. Early frosts are the enemy of glorious fall colours as they can send leaves to the ground before colours can develop.

This video was taken in Raymore Park on the morning of November 12, 2013 and illustrates how quickly leaves can fall from trees when conditions are right. There had been an overnight temperature of -4°C the night before, severely weakening abscission layers and even the gentlest breeze was enough to send large numbers of leaves to the ground.

 

Spring advances slowly.

An Asian ladybug checks out some fragrant Willow blossoms.

An Asian ladybug clambers over some fragrant willow flowers by the Humber in Raymore Park.

Cool weather continues to make spring a long season this year. The upside to this is the ability to watch plants come to life in slow motion.

Willow trees (Latin name, Salix) are common in Raymore Park and they are native to Canada. They love watery environments and are easily propagated. They can be seen planted throughout the park, although, like walnuts, they don’t need much encouragement. Their flowers are particularly fragrant and have a lilac type smell.

The ancient Greeks knew about the medicinal abilities of willow bark extract to cut pain and reduce a fever. Native Canadians also used it in the same way. Scientists in the 19th Century extracted a chemical, which they named salicin, from the bark and converted it to salicylic acid and later still, to acetylsalicylic acid. The drug in this form is still in wide use today and more commonly known as ASA or aspirin.

As for the Asian ladybug, this was introduced by farmers in the U.S. to fight aphids and they do that job very well. Unfortunately they are not as benign as our native ladybugs and tend to find crevices in homes as well as contaminate grapes used in wines. They have to a large extent displaced our native bug. One year at a Niagara winery I drank some red wine which was ‘flavour enhanced’ with large numbers of the creatures accidentally harvested with the grapes. They have an unforgettable and bitter taste! It didn’t seem to bother anyone else so I let it go. Canadians can be very polite and forgiving.

Wineries now take precautions not to harvest ladybugs along with their grapes.

Work slows on Retaining Wall

The retaining wall base has been wrapped in plastic.

The retaining wall base has been wrapped in plastic.

Work has slowed considerably at the site because migrating steelheads (better known as rainbow trout) are spawning in the Humber and rather than disturb their progress up the river, TRCA has ordered a hiatus in work until they complete their spawning. This will depend on the water temperature and will delay the wall’s construction for a while.

More brush was removed from the site recently and the staging area has been expanded, possibly for additional storage space. Further down the river, a mysterious rope has been stretched across the river. The purpose of the rope remains to be determined.

The staging area has been expanded south to include this area.

The staging area has been expanded south to include this land.

Further down the river, a rope has been stretched across the Humber.

Further down the river, a rope has been stretched across the Humber.

The rope across the humber.

The rope across the Humber is beginning to catch driftwood.

Looking north to the temporary bridge.

Looking north to the temporary bridge.

Work begins on Humber bank stabilization and sewer rehabilitation.

More than a decade ago, the owner of a house on Sykes Avenue in Weston suddenly lost several feet off the back end of their property. The house overlooks a sharp curve of the Humber River as it turns to the south. During April rains in 2004, the rear of the property abruptly vanished along with several mature trees and other vegetation. Luckily nobody was standing near the edge.

Shortly after the landslide in April 2004.

Shortly after the landslide in April 2004.

Panorama view of the bank as it looks today.

A panorama view of the bank as it looks today. Note the current retaining wall and the precarious position of the tree on the right.

That summer, the fallen trees actually went into leaf and remained in place for most of the season but were eventually washed down the Humber. What caused the erosion? Who knows; it probably didn’t help that each autumn, the owner at the time drained the pool over the top and into the river. The likely explanation is that the slope was simply too steep to withstand the shearing forces and nature adjusted the angle. TRCA is responsible for erosion control and has a handy guide for those ‘living on the edge’. It must have been painful to update the property deeds to reflect the new reality. After this event, the owner put in some vegetation and other stabilization measures but by then the rot had started and moved downstream taking chunks of other back yards into the river.

A retaining wall of sorts is already in place, built in 1981 and it has been high enough to provide ‘toe protection’ for most flood events. Unfortunately it wasn’t tall enough to cope with major events such as the storm of July 2013.

After extensive study, TRCA has decided that in order to stabilize this stretch of the Humber, a 6.5 metre tall ‘replacement armourstone wall’ and stabilization measures need to be put in place on 170 metres of the east bank before more land disappears downstream.

Raymore Park entrance.

Raymore Park entrance. Notice that the pathway and direct footbridge access is blocked to pedestrians. This could have been avoided by fencing off a narrow gap on the left.

Looking south from the parking lot.

Looking south from the parking lot. The trail resumes further down.

Since construction from the top of the east side is impossible, the plan is to access the wall through Raymore Park.

Unfortunately the solid winter ground from the bike path to the river expected by the construction crew has failed to materialize (so far) and a steady stream of trucks has been offloading fill onto the site in order to construct a stable road down to the river.

Sadly dozens of native trees that were planted several years ago have been removed from a surprisingly large area. Presumably these will be replaced but this will delay the expected native canopy planned for this section of the park.

The new road under construction leading to the river. Notice the clearance of all trees and shrubs.

The new road under construction leading to the river. Notice the clearance of all trees and shrubs.

Another view showing the extent of the clearance.

Another view showing the extent of the clearance.

In the meantime, pedestrians are having a messy time getting access to the footbridge from Raymore Drive, the continuation of the path further down the park and there are questions regarding the replacement of trees and shrubs lost when the land was cleared.

According to the leaflet delivered to homes in the area, the work is scheduled to be completed by the end of March and restoration of the land will take place in the fall. Projected cost: up to a maximum of $250,000.

At the same time, more sewer rehabilitation work is ongoing along the Humber that will necessitate further tree clearance along the path of the sewer line between now and the end of March and this will extend along the river between Raymore Drive to well past Eglinton. The City of Toronto has more information here.

Later this spring will begin the construction (if given final approval) of the proposed leash free zone (Many dog owners seem to have declared Raymore Park leash free already). This will bring even more heavy equipment through the park. A final meeting is scheduled for February 25th at 6:30pm in Westmount Junior School, 95 Chapman Rd. Councillor Rob Ford will be in attendance.

Chapman Road Sewers set to carve up Raymore Park

Once upon a time, when infrastructure repairs were carried out in a natural setting, not much thought was given to vegetation. It was assumed that plants would take care of themselves once land was allowed to return to a natural state post-construction. Today, we are far more thoughtful and city contracts are written to specifically protect vegetation when possible and restore it if destruction is necessary.

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The sewer that runs along the Humber Creek has reached capacity and must be upgraded or ‘rehabilitated’. A stretch of vegetation has been cleared in preparation for the installation of a higher capacity sewer network that will serve residents of the area. The Chapman sanitary sewer as it is known runs from Royal York Road, roughly following the Humber Creek and crosses under Scarlett Road into Raymore Park before joining up with main sewer that runs alongside the Humber.

Amazingly, as part of the $9 million contract, every one of the hundreds of trees removed on public or private property for the project was catalogued and while only the native ones will be replaced, thousands of other native trees and shrubs will be planted. To get an idea of the modern-day eye for detail and care that will be taken, a set of plans for a small segment of the sewer can be found here.

The swath of land cleared and ready for installation of new sewer pipe and pumping station.

A swath of land between Scarlett Road and the Humber River being prepared for installation of new sewer pipe and a pumping station. Notice how rich the soil is.

The work and re-planting should be completed by next fall and the replacement native trees and vegetation will eventually make the affected land better than before it was cleared (because non-natives will not be replaced). Of course the whole point of the work will be the prevention of sewage back-up into residents’ homes as happened in July 2013. Hopefully this will allow many decades of trouble free use.

 

Native Trees continue to grow – Year 6

Seven years ago, land between the parking lot and the Humber was cleared of mainly scrub and non-native trees. A variety of native trees was planted and they are thinning out, thanks to general mortality as well as growing taller. The poplars seem to be doing best but the look has changed from fresh planting to more of a mature nursery. Here is a panorama taken recently of the area and a link to a photo of the area two years ago.

Click for larger view.

Click for larger view.

 

Winter continues

Last month’s ice storm inflicted little damage on the park. Most of the recently planted trees in the park suffered no damage while some of the older ones lost dead wood. Siberian elms at the entrance to the park seem to have suffered the most damage and as ‘Guest’ pointed out, these along with Norway maples are not natives and aren’t in their natural environment. Surprisingly, the park wasn’t planted with a lot of trees after its creation in the 1950s. If that had been done, Raymore Park would be a mature forest by now and helping to reduce flooding along the Humber. On the other hand, the trees chosen for planting may have been non-natives or even species under threat such as elm or ash.

Looking south - Siberian elms have dropped many branches.

Looking south – Siberian elms have dropped many branches near the park entrance.

Siberian elms are a particularly damaging tree in Ontario because they are so prolific and also because they are partly resistant to the Dutch elm beetle allowing it to remain a threat. No doubt the park will be low on the list for clean-up of the debris (which is not entirely a bad thing).