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.
The finished product – at this end anyway.
The finished appearance of the retaining wall is now evident at its southern end with a green vegetative planting just starting to sprout on the slope at the top of the wall. Regardless, there’s still a long way to go. It also looks as if the homeowner with riparian rights has now wisely decided to take advantage of the opportunity and so construction has begun further upstream. The original intent was to construct the wall along the full length and that now seems to be the plan.
A nice cross-section is visible from the northern end of the wall. (click to enlarge)
Astonishingly, even after all this effort, the work looks as if it’s only about 40% done and so there is a long, long way to go before this project can be signed off. The wall construction was originally scheduled for completion this past spring with brick removal from the access area and subsequent landscaping to take place this fall. Obviously, that ain’t gonna happen. My estimate at the current rate of construction is that they’ll be lucky to have the project completed and everything restored by the end of 2017. This seems to have been quite a miscalculation by the planners. The project was to cost a maximum of $250,000.
I’ll bet that marker was skated past months ago.
Much has been going on in Raymore Park over the summer although progress on the retaining wall seems to be slow. The dog leash enclosures are partly complete but not without controversy.
- The retaining wall is looking quite magnificent and it looks as if it will do the job for centuries. It looks as if the wall will be curtailed, ending before its planned end-point. This is apparently because riparian rights for the end property extend to the river and the owner feels that remediation will cause further erosion.
The wall in a completed section.
A view of the total wall so far.
2. The off leash areas.
Two areas are being built, one for smaller dogs and one for larger breeds. One section has been built (topsoil removed, drainage completed and topped with limestone chippings).
Sadly, a sanctuary for birds and small animals has been removed to create the area. It was basically a couple of trees surrounded by dense shrubs that were impenetrable to all but small animals. It was a bit of an island or small thicket in the park but it has been removed in what seems like callous disregard for wildlife. Surely there was room to place the leash free zones without destruction of a natural resource like this? It speaks to a lack of care for the environment and a distinct lack of planning. Let’s hope there are no more unpleasant surprises from Toronto Parks who don’t own but manage Raymore Park.
The shrub island (to the right of the old baseball diamond) from Google Earth.
This thicket is no more, sacrificed for the dog enclosure.
The island site shortly after its destruction.
One of the dog enclosures; further north than anticipated.
More temporary fencing and drainage pipes for the next area.
There seems to be little going on at the retaining wall site these days. It may have to do with negotiations ongoing with the owner at the north end of the wall. If the owner withholds permission for the wall to be completed on the end property, plans will need to be adjusted.
Old retaining wall blocks are stacked along the opposite shore.
The old retaining wall is being removed in preparation for a newer taller model.
Incidentally, the storm sewer pipe that is visible in the second image is one of hundreds that flow into the Humber. The structure above it may serve to prevent slope erosion.
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.
In preparation for the new off-leash area by the weir in Raymore Park city staff have removed the baseball diamond fencing that was installed a few years ago but rarely used.
The old baseball fencing has gone.
The view north from the upcoming leash free zone.
We’ll have to see if the extended deadline for work on the Humber retaining wall will delay the opening of the new dog facility. Workers did manage to remove the fencing without any logistical problems.
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 land.
Further down the river, a rope has been stretched across the Humber.
The rope across the Humber is beginning to catch driftwood.
Looking north to the temporary bridge.