Yesterday evening, I and a few others and the current owner looked at the trees on a lot proposed for subdivision just after the news about the Humewood story broke. There were a good number of large trees for a lot that’s about .6 acres, but most of them seemed ungainly and distorted. One gorgeous Horse Chestnut sat in a small meadow of its own, and looked delighted with the world, but the rest were planted around the perimeter and planted too closely together and were shading one another out now so that branches had fallen and new trunks had started and maple-type trunk shoots were everyone, even on trees that don’t usually do what large maples and alders do. Somewhat dismaying. Tree turf wars with many victims. And one beautiful tree.
Saanich has a program for Heritage Trees and is developing a new policy to increase tree preservation–even as it allows more and more houses and condos to be built. So we looked at which trees would have to be saved under the old bylaw and which additional ones would be saved by the new bylaw.
And it was clear to me that a simple law that said “any Maple with a diameter of over 5 inches has to be saved” was better than nothing, but more or less meaningless in terms of good forestry.
There are many factors that affect the “goodness” of urban trees. One is certainly carbon storage, but there are also others, positive and negative: aesthetics, proportion, shade, screening, privacy, healthiness, blocking of views, nuisances. One person’s beautiful large tree (on the next lot over) may be the owner’s nightmare when all the leaves and chestnuts fall or when the large branch falls on his Smart Car or when the annual care bill by an arborist becomes larger than the annual taxes. Most of these factors are hard to regulate.
This lot had a very large willow which spread over four lots and which, apparently, all four neighbours liked. But another quintet of trees had made one neighbour’s back yard totally useless in terms of views or the ability to grow anything edible except perhaps a few radishes. And the willow itself is so ungainly and distorted that it is unlike anything one would see in nature.
By the terms of the new bylaw most of these trees would need to be preserved for the common good—which would surely lead, over time, to few people wanting to plant any large trees and many longing for the day when their existing trees would sicken and die. Property values for lots like this one would descend and values for lots with a few small “removable” trees would grow.
So a better system is clearly required and logically it needs to be based on some kind of a minimum and some guidelines for maintenance.
It is reasonable to say that any lot should have a certain amount of greenery and if a municipality wants to encourage homeowners to go beyond that, it needs to do so in a supportive rather than a prescriptive fashion. Just because your mother planted an arbutus, a chestnut and a Western Maple in the same six foot plot thirty years ago doesn’t mean that those three trees are still healthy or happy and entitled, nay required, to continue their claustrophobic life together until death does them part.
Can Tree Planters Save us? An Ongoing Investigation of Trees and Sequestration
Can household trees save us from the more general ravages of global warming? Not very likely. Not bloody likely may be a more accurate term given the comments following. Emissions are very high now and growing and trees can only do so much. But they can do something.
Measuring carbon stored in trees is tricky. But here’s one researcher’s rules of thumbs, for smaller trees, measured at chest height.
Less than 5 cm, stores about 2 kg.
Between 5 and 8 cm: between 18 and 15 kg.
From 8 to 12 cm: between 24 and 38 kg.
Another way of looking at this is to say that each kg of dried tree contains 1. 65 kg of CO2.
Estimates of how much CO2 a North American generates directly run from 2 metric tonnes up to 10 metric tonnes depending on who is doing the estimating, so let’s take 4 tonnes as a minimum. Average carbon stored by a tree that is at least 15 years old range from 7 to 14 kg of Co2 per year and that is obviously very variable depending on the age, variety and size of the tree.
But whatever the parameters, the disjunction is clear. It takes some two to three hundred trees to recycle the average North American’s direct production of CO2. That’s quite a few trees for a single house and it assumes there’s only one person is living in the house.
The Woodlands Trust in the UK measures all this somewhat differently. It states that typical hectare of mature Woodland Trust woods will lock up around 400 tonnes of atmospheric CO2, or 108 tonnes of carbon in a year. Note that their ratio is much higher than the one I quoted above of 1.65 to 1. http://www.woodlandtrust.org.uk/en/why-woods-matter/woods-carbon/Pages/sequestration-rate.aspx#.UcXdAilrZ1s
CHECK THIS. Their figures need to be checked. 400 tonnes seems low for a lifetime but high for an annual figure.
Taking it as annual. If a Municipality such as Saanich has 100,000 inhabitants responsible for an average of 4 tonnes of CO2 each per year, then it would need to support/maintain 1,000 hectares of a Woodlands Trust type forest. Since Saanich is over 100 square kilometres in size, it could possibly do this, although about 8% of that is lakes and a very large proportion is suburban sprawl and the population is over 110,000 already. 1 Sq. Kilometer = 100 Hectares. 10 Sq. Kilometers = 1000 Hectares.
If Saanich wants an Eco-friendly tree policy rather than just taking Green Talk it should consider the following.
- Rather than specifying which sizes and types of trees need to be preserved, Saanich needs a formula which says that the norm for any lot or development is to have 10% covered in trees that are at least 15 years old and can be seen to store at least 400 kg of CO2 per year.
- This is 10% of one individual’s emissions.
- If there is more coverage (and thus more storage) the owner gets an annual carbon credit from the Municipality carbon bank.
- It there is less, then the owner pays into the municipal carbon bank.
- Each year the municipality produces a report on its own Woodland Trust type forests and contributions made or paid by the residents.
WHO OWNS URBAN TREES?
HUMEWOOD via the Globe and Mail. June 21st, 2013.
Katherine Hartley used to spend a lot of time under the sweeping maple tree in her midtown Toronto backyard, practising yoga and praying to her ancestors.
But the giant, unassuming tree she once revered slowly began to frighten her. Worried it would fall as she meditated, Ms. Hartley sought and received a permit from the city and notified her next-door neighbour in June, 2012, that she planned to cut down the maple.
That kicked off a year-long battle between the residents of 168 and 170 Humewood Dr. – one that would be fought loudly in their driveways and in court, culminating in a recent legal decision that stands to reshape the yards of residents across Ontario.
The Ontario Superior Court verdict in May, which went unnoticed by most anyone not involved in Hartley v. Scharper, not only saved the maple but created some of the most stringent and detailed law on tree preservation in Canada. Cutting down a shared tree or chopping at wayward branches without a neighbour’s approval could now be a criminal act, punishable under the provincial Forestry Act.
Many of the province’s tree-protection bylaws may need to be rewritten.
The Hartley v. Scharper ruling redefined the technical question of what constitutes a tree’s trunk, giving neighbours equal ownership over trunks that stray over property lines both above and below ground.
“There are a huge number of boundary disputes and this adds clarity,” said Clayton Ruby, a lawyer who argued for the new rules. “This decision means that a lot less trees will be cut down because it now requires the consent of both neighbours.”
With the base of the tree only three centimetres from her backyard, Hilary Scharper sought to stop Ms. Hartley from cutting down the giant. Learning of her neighbour’s plan, Ms. Scharper sat a statue of St. Francis of Assisi, the patron saint of the environment, beside the maple’s trunk.
“We were stunned,” said her husband, Stephen Scharper. “It’s a perfectly healthy tree.”
Legal documents filed by Ms. Hartley’s lawyer describe the moving of the statue under the tree. The Scharpers also posted a notice to any would-be lumberjacks that the tree’s ownership was in dispute.
Under Toronto’s Private Tree bylaw, owners are entitled to remove sick trees. Presenting a report that the tree was healthy and its removal unnecessary, the Scharpers offered to install a system of cables to secure the maple to the ground. Ms. Hartley rejected the offer.
Because the large tree sprawls over much of the Scharpers’ backyard, Ms. Hartley sued her neighbours to establish her right to cut down the tree and enter their backyard to do so.
On May 17, Justice J. Patrick Moore ruled that a shared tree under the provincial Forestry Act starts from where its roots join the trunk up to where the trunk branches out. Justice Moore dismissed the idea of defining a trunk at ground level alone as “arbitrary.”
The ruling gave the neighbours on Humewood Drive common ownership of the tree under provincial law.
“This could impact 60 per cent of Toronto’s trees,” Ms. Scharper said.
Phillip van Wassenaer, an arborist who examined the tree, in the Hartley v. Scharper case, was supportive of the ruling. “It’s more in line with how trees grow and what nature gives us,” he said.
The maple of Humewood Drive is uneven and knotted at its base. Because of surveying required by the case, the ground around the tree has been excavated and orange surveyors marks have been driven into the bark where the trunk strays into the Scharpers’ yard.
Looking to appeal the ruling, Ms. Hartley declined comment.
“A tree can now become common property simply because it grows too large,” said John Howlett, Ms. Hartley’s lawyer. “At the same time, the rights of a landowner to cut the branches or roots of a neighbour’s tree that cross over the boundary line face new restrictions.”
According to Mr. Howlett, many of Ontario’s municipal tree-protection bylaws might have to be rewritten due to the ruling.
“Maybe good things come out of nasty neighbour disputes,” Ms. Scharper said.
June 22, 2013.
The comments below illustrate some of the complexities of measuring sequestration in trees, and the costs thereof, and the size of the larger problem.