It's been that kind of winter...

"This image shows the Great Lakes on February 19, 2014, when ice covered 80.3 percent of the lakes - coverage not achieved since 1994." Credit: Jeff Schmaltz

And this year we're having post-ice storm tree thoughts. Here are some intelligent ones:

• "Trees and Ice Storms: The development of Ice Storm–Resistant Urban Tree Populations" (thanks to Darcie McKelvey, editor of the Waterloo-Wellington Wildflower Society's "Dogtooth" newsletter, for recommending it!)
• "The City’s Trees Were Hit Hard by the Ice Storm - But a Toronto arborist explains that post-storm cleanup and long-term tree care will require far more than picking up branches and wielding chainsaws"

 And then, there's this, "Winter works more on... our own physicality than the landscape – the sheer stress that the season can put on our skin and bones, making us clench and resist the environment and resent our own limitations." -Harry Wade

"U of T's forestry school faces the axe"

"U of T's forestry school faces the axe" - The Globe and Mail.

The article is from April 1st. (apologies it slipped by me).

"Student Eric Jacobsen said “We do a lot more social and integrative approaches to forestry ...and it’s also less of an industry-focused program.”"

And a choice place to learn about urban forestry.

I'm dumbfounded.

Why compromise the capacity of a faculty that already exists?

And I can't imagine a worse time to do it.

To state the obvious: currently this city and cities across this country are dealing with massive urban reforestation commitments (variations of planting X# trees, &/or achieving X% canopy cover, by Y date). It seems to me that our best urban foresters are still struggling to figure out what those targets even mean, or should mean. Will it mean x% canopy cover that will last 30 or a 130 years? Which species: indigenous, native, exotic, invasive, GM'd, mass produced cheap clones? Beyond carbon sequestration, which ecological services should be integrated into those targets? And then, how to pull together the political will and the required resources to make make intelligent policies actually happen on the ground? This current surge of tree planting funding is a sudden and massive experiment, and a responsibility and opportunity happening on our watch. And so are its impacts on a changing mix of urban forestry stewardship orgs, private and public sector urban forestry industries and its professions. All of this at time when we know our urban forests are in ecological crises, e.g. degradation from historic and changing land uses, the challenge of reducing urban sprawl so we can retain ecological heritage and functions, the need to remediate post-industrial contamination in soil and groundwater, invasive species and climate change.

An intelligent continuing commitment to develop the skills and capacity necessary to understand, conserve, restore and engineer beneficial ecological function of our forests (urban and otherwis) can only help. Which leads me to wonder, if not now, when would be a more relevant and necessary time or opportunity for us /our universities, to support and study forestry?

All I really want for Hallowe'en is a Shagbark Hickory

I love the Hallowe'en front porch displays, especially the gourds. But at this time of year what I really want in my yard is a Shagbark Hickory Carya Obvata.

I don't have any good pics of mature Shagbarks myself, but here is a perfect one - do you see what I mean?

What an unapologetically feral looking tree. In an urban residential front yard, it would stick out like a defiant middle finger among (and towards) any manicured properties around it. I'd like to meet the person who would plant this as a high wildlife value specimen tree in their front yard.

And, yes, a perfect tree for Hallowe'en. As William Cullina wrote, the bark's sheets "...hang there forlornly, so the whole tree takes on a shaggy, uneven aspect ... the bare trees seem alive and almost sinister on a wet foggy day."

Intrigued? This article is worth a read: Shagbark Hickory (Carya ovata) Ontario Arborist, May/June 2010, Michael Richardson, B.Sc.F., Consulting Arborist. Couple of highlights:

Shagbark Hickory as bat habitat:

"The bats use the trees as roost and maternal sites and apparently not only use the peeling sheets to hide under but finds that shagbarks provide excellent thermal regulation. In Ontario, species such as the little brown bat (Myotis lucifugus), the silver-haired bat (Lasionycteris noctivagans), and likely the big brown bat (Eptesicus fuscus) are found using live shagbarks. It seems clear that in forests and urban situations, the loss of dead trees with sloughing bark has lead to a decline in bats using natural roost sites. Shagbark hickories provide excellent roost sites as the bark begins to shed at 10+ years and can continue to provide outstanding habitat for two centuries or more."

Shagbark Hickory and First Nations arboriculture:

"First Nation people may have practiced arboriculture, and this, along with their agricultural practices, helps to explain the range and density of shagbark hickory. By managing individual trees and entire landscapes, these peoples have had a great influence on forests in eastern North America. First Nations were once considered to be in harmony with nature, but now many scientists believe that they were in fact a “keystone” factor in ecosystem development. [here's a wikipedia definition of 'keystone species']

Throughout the world, traditional cultures farmed various fruit and mast trees, which made survival easier than that of the constantly moving hunters and gathers. This has been termed balanoculture. In eastern North America, shade-tolerant forests (maple-beech) could not meet the dietary requirements of First Nations. The manipulation of forests – and in fact entire landscapes – using deliberately set fires was a method to help assure sufficient food stuffs.

The use of fire, planting, tree girdling and forest thinning allowed creation of “orchards” of hickory and other mast crops. Hickory nuts were one of the main foodstuffs for many First Nations throughout eastern North America. Nuts and acorns are calorie packed and could be stored. The sweet nuts of shagbark hickory seemed to be particularly favoured and are amongst the highest caloric ratings of mast crops.

In eastern North America, the distribution of early succession forests and hickory, oak and chestnut appear to be strongly predicted by First Nation occupation. This relationship is so strong that estimates of occupation is a better predictor of oak, hickory and chestnut than a number of topographic and soil variables."

Here in Toronto, I know Steve Smith / Urban Forest Associates plants them in the Don Valley (a young grove of them in Windfields Park for one). I'm already excited to see them when they mature. I especially want to walk among their silhouettes some dusky October eve.

Ontario Urban Forest Council 2010 Conference

Thurs Nov 4th -> Fri Nov 5th
Ontario Urban Forest Council 2010 conference
Healthy Communities are Rooted in Urban Forests
Thorold ON (Four Points by Sheraton, St. Catharines Niagara Suites 3530 Schmon Parkway)

"This conference will be focusing on the relationship between urban forests and community health. Registration is not yet open. This is a save the date announcement. We are finalizing the list of speakers. As information becomes available, it will be posted on our website www.oufc.org.

We have confirmed our keynote speaker: Diana Beresford-Kroeger is a botanist and medical biochemist who is an expert on the medicinal, environmental, and nutritional properties of trees. She is the author of several books including Arboretum America: A Philosophy of the Forest (2003), its sister book Arboretum Borealis, and The Global Forest (2010).

Aside:
Hey OUFC speakers coordinators: good call! Folks have been enthusiastically recommending Diana Beresford-Kroeger's books to me since spring, and I've been going through a "I am so hard-up for intro plant biochemistry (and so are you, because a lot of it is emerging knowledge)" phase, so thank you! :)

Bud Burst: Silver Maples

Silver Maple female flowers (left) with pollen on them
from male flowers (right)

Silver Maples Acer saccharinum can have both sexes on the same tree. The red flowers in the foreground are female. The "pom-pom" looking flowers on the right are male and loaded with pollen. If you look close (or click on the pic) you can see the male's yellow pollen grains have already been wind blown onto the female flowers.

Most of my street's trees are mature Silver Maples. Just sitting on my front porch, I can see at least a dozen 100-year-old-big Silver Maples currently in bloom, so it's looking very "birds do it, bees do it, the flowers and the trees do it" randy-in-the-skies to me right now.

They're not the only mating game going on this early in the season: I saw a female squirrel eating the Silver Maples' flower buds. She needs their early nutrition: she already has her whitish patchy "jacket" on. It's not mange, it's motherhood. She's already mated and plucked fur from her upper body to insulate her and her brood's nest.

Silver Maple are early bloomers. Before the Red Maples. Although the two bloom periods do overlap and naturally cross to become what's called Swamp Maple aka Freeman Maple Acer x fremmanii. They're trying them now up the street from here, say they're less brittle. I'm thinking about getting one for my neighbourhood park.

Here in southern Ontario, our earliest native blooms open in this order:

1. Skunk Cabbage
2. Silver Maples
3. Harbingers-of-Spring Erigenia bulbosa (rare)
4. Spring Beauty
5. then a blur of hepatica (see comments), ginger, trout lily, toothwort, bloodroot, dwarf ginseng and foamflower. I still can't figure out their order because at exactly "spring woodland ephemeral" time, I'm usually happily hiking all over southern Ontario between places where the bloom times might be different by five days.

I'm grateful to whoever chose to plant my street with Silver Maples. I know they were a popular street tree all over the city ("were" = now some of the urban forestry and hydro guys complain that they overmature too fast, are too brittle, drop limbs, too much debris), but they're especially appropriate to this area, and what it was: the backwater of the former Ashbridges Bay, Lake Ontario. Despite the area since being landfilled, these trees are appropriate to what this area's buried soils and gullies and hydrology and high water table still are. "Silver maple appears as a dominant species only in streamside communities or on the fringes of lakes or backwaters of streams. Occasionally it is found in swamps, gullies, and small depressions of slow drainage. Though it generally cannot compete with other species in upland environments, silver maple seedlings are adapted to survive long periods of inundation in bottom lands, where flooding is one of the factors that determine the makeup of individual stands..." Read the source of that quote here, it's a good one. Just how water-edge adapted are Silver Maples? Check out this pic (above right) from U of Wisconsin's Herbarium.

The Silver Maples' second act is the helicopter show. All June long. Yup. Tip: if your garden is already well mulched w/ leaves and wood chip or bark mulch, most of the keys will just decompose to become mulch themselves. Then later i just pull out any seedlings that did germinate.

Silver Maples' third act? A subtle sleeper: a breezy, big and balmy, sweet summer song.

It took me years to recognize it, but the sound of warm summer winds swirling around the leaves of big old Silver Maple is one my best childhood memories. Especially in concert with the leaves of willows and cottonwoods. All shoreline species. If you don't know those sounds, come a warm day in summer, they're worth a listen.

Myself, I'm so used to hearing all of those leaves along water edges and shorelines -- creek, riverbank, bay, beach -- on cue I can imagine a common concurrent sound: the slow rhythm of waves: crestfall or gentler lick-and-lap. Pause. Swash back out. repeat.

Sometimes even now, when I'm in those sounds, for split seconds I am 3, 5, 9, 12 or 15 (often all-of-them-at-once), sun/mud/silt-browned, forearms sparkled with sand, my barefoot and bathing suited body is small and close to the ground, running along southwestern Ontario water edges and shorelines. The wind smells of small fires, fish (pickerel, perch, catfish, sunfish and the throw-'em-back sheephead: unless we kept the "j" stones / otoliths from behind their eyes for good luck) and some times charcoal from a hibatchi BBQ. Salamanders, turtles, muskrats were common sights.

Cool ground on my back when I'd lay down under those trees, those leaves, half closing my eyes so i could look up into the changing blurs of dappled sunlight. What a lullabye that seems now.

"...Down the rivers of the windfall light ...I ran my heedless ways ...Time held me green and dying / Though I sang in my chains like the sea" -Dylan Thomas, Fern Hill.

Funny now, how I had to move all the way to this street in Toronto, to learn for the first time that "Silver Maples" was the name for a windsong I had already always known.

Events

Old sugar maple canopy at Baker's Sugar Bush, Vaughn

LEAF Tree Tenders Training
Register NOW
Sat Nov 21 10-4
Tues Nov 24 5:30-8:15pm
Sat Nov 28 10-4
This 15 hour training program is designed for individuals who want to gain tree-related knowledge and skills. If you’ve always wanted to learn more about how trees work, tree planting and tree care, this is the course for you! Riverdale Library (Broadview and Gerrard), Toronto. $50 plus GST. Course manuals are available for $10 (highly recommended but not mandatory).

The 16th Annual A.D. Latornell Conservation Symposium
Weds-Fri Nov 18-20th
Alliston ON
This is a gathering of mostly folks from Ontario's Conservation Authorities (CA's) but open to everyone. Also noticed that this year's symposium is preceded by "Groundwater & Geology: Foundation for Watershed Planning" on Tues Nov 17th

Ontario Urban Forest Council (OUFC) Annual Conference and AGM
"Tree Preservation and the Planning Process: Moving Ahead"
Nov 12th, U of Guelph Arboretum
Here's the conference programme. They sold out by the way (the good kind of sold out, I mean). If they post links to the presentations like they did last year (I'm still loving a few of those), I'll add that here. Links relevant to this year's theme: Ontario Heritage Tree Alliance and their Heritage Trees Protection Toolkit.

Three things strike me about the conferences:

1. Accessibility / cost: While I'm annually priced out of Latornell, the OUFC conference even has an "unwaged" rate. But, regarding Latornell, now I notice this (also dated) piece of information: “Are you a student registered in an Ontario university or college or an individual affiliated with an Ontario not-for profit/community conservation organization interested in attending Ontario’s premier conservation symposium? Successful grant recipients receive a 3 day registration, 2 nights shared accommodation and a special grant recipient networking session. Check out the grant application form. Applications due September 28, 2009. For additional information please contact Clare Mitchell at latornellgrant@conservationontario.ca“ ...Uh, there's a grant? Like me, you might want to copy and paste this as a reminder into your calendar for next year.

2. The speakers and presentations still work after the conferences are over: like any other AGM or conference, the programmes (both current and previous years) direct you to speakers / presenters and workshop leaders. I saw High Park Volunteer Stewardship Program's Jane Schmidt tap this vein beautifully last year when she invited a few recent OUFC conference presenters over to the park's Winter Speaker's Series, where each adjusted their presentations to fit the park and the audience. It was an excellent series and there was more time for direct questions and discussion with the presenters too.

3. My embarrassment at posting them at-the-last-minute or too late: if you subscribe to these newsletters (or follow them online), you'll have plenty of notice about these conferences, and other cool events too!

• Ontario Nature Network News. Click here to submit your e-mail to their listserve
• Carolinian Canada Coalition's free monthly e-news. Click here to submit your e-mail to their listserve, or see their archives here
• OUFC's Tree Whispers
• LEAF's Newsletter

And please help yourself to this ongoing list of events calendars too!

Forest Gardening

I know next to nothing useful about agriculture, so I can usually resist writing about it.

But I recently saw someone cut and regrade their yard's globally endangered forest so they could put in what only amounted to a few square meters of hobby veggie garden beds. It's nothing new but it made me think, wow... there have got to be better agricultural models that would have included that forest.

Also in the last 3 years I've seen urban agriculture and native plant naturalization sharing tight spaces here in Toronto, and ask each other what's possible.

I've read about prairie ecosystem models for sustainable agriculture from the US midwest. Good stuff, especially for existing field crop areas where the forests are already gone.

But, lately my mind keeps heading toward a woodland->forest agricultural concept.

I started imagining, composing and recomposing them and their species in my mind (I was trying to stick entirely to native for the longest time, but now I'm ready to accept some integration) for our region.

It's not exactly urban agriculture or any orchards as I've known them, and it's certainly not wild-crafting, or foraging, or nomadic seasonal wild gathering. It's a deliberate integration of naturalization and conservation + sustainable human agriculture, vertically layered, that could work on smaller landscapes (e.g. 1 acre) and larger areas too. Trying to suss it out, I found out I liked Norfolk Alternative Land Use Services, and then bingo: I stumble across a diagram that looked a lot like the same of the idea I had in my mind:

Apparently it's called "Forest Gardening". Check it out.

First thing I did was laugh! :) because just looking at that diagram with its different forest vegetation layers, you can see how easily anyone with a native plant / field naturalist bent raised in "mixedwood plains" would come up with this as a potential agriculture model. Made me realize how impossible it is for me to even imagine how anyone ever developed our current conventional agricultural models.

I can see it working in some back yard gardens, or even a research site, as a forest restoration + agriculture joint project. But I'd be hesitant to advocate it for some public org's sites because I simply don't know how it road-tests with food security and hunger: I have no idea how much nutrition and energy/calories it provides and requires per acre compared to common organic agriculture alternatives like an average small plot heirloom annual veggie garden, or prairie ecosystem agriculture models. The other thing that confounds me are our suitable nut species, e.g. chestnut blight and butternut fungus thins the ranks.

At the very least it's something worth considering when folks are deciding how to share limited land desired, or needed, for food and forest.

Goulding Estate with Steve Smith

Steve Smith - Urban Forest Associates Inc.,

Goulding Estate, Taylor Massey Creek

Along with volunteers from FODE and Ontario Nature I recently had a chance to work alongside Steve Smith at a recent tree and shrub planting at Goulding Estate in Taylor Massey Creek, an east lower Don tributary here in Toronto. That day was a lot of cool riparian woody and his smart range of plants and super-specific site selections really took me to school. I especially appreciated the bitternut hickory, red oak (there are existing remnants on the uplands), butternuts (keep planting those nuts), yellow birch - oh and maybe twenty more species. Blew my mind really, and reshuffled my deck: I don't know about you, but I tend to see or accidentally fall into patterns / ruts / limited repetoires of the same species. Even better? Steve's been involved with the plants on this site for 20 years. Exactly the kind of eyes you want to see the place through. Reminded me of a quote from Lily Tomlin: "If Tom Waits ever invites you to get drunk at his trailer in the desert for a week - do it!" What I mean is, volunteering out in the field and being with folks who know a place and have applied more than a few of their skills there, will teach you things you just will not learn in school (especially when some of the folks you want to learn from right now are too busy out in the field to write or teach). So get out there (or take your chances waiting for them to retire and hopefully have the health and the desire to write a book or teach a course). See the list of "Volunteer" links lower down in the right sidebar, and check out our local Event Calendars.

BTW: One gem I learned from Steve that day: when you're trying to restore our mixedwood forests (remember: we used to have an overstorey of red and white pine here, above our deciduous canopy species - and if you look at the horizon, you still see a few remnant examples of this in the Credit and the Rouge), plant the conifers together with shrubs (ie: not right up against near new or existing deciduous trees) because the deciduous/hardwoods will out shade them too fast. So smart it seemed dead obvious once he told me, but I had never seen, read or realized it myself. That's some cool stuff Steve. Thank you!

Vole @ Downsview tree planting says "Thanks for all the new eats!"

Not just the couple/few thousand new tasty young trees and shrubs either. I bet he appreciates how we broke up that insane clay to expose so many yummy weed roots & rhizomes, because that's what he really seemed intent to chew on. :)

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Tree guard tip: we handled the tree guards (yup those white coiled plastic things) a little different on this site. Because of the voles, we screwed the guards in the ground a little. also, because we were concerned about vole damage (wee dudes, not bigger guys like beavers) I was mystified by the height (long length) of the tree guards ... until it was explained that come winter (of course, but why i hadn't i thought of this before?) the voles will go on top the snow to chew on the bark.

Happy holly days!

Winter just officially arrived two days ago, with 30+cms of recent snow and -23C windchills, so I know it takes a little faith and optimism to celebrate that our patch of the planet really has begun returning toward the sun. But, yes, it's true: field season 2009 has just been conceived!

And here in Toronto, today, December 23rd, is the first day we'll see an extra minute of sunlight:Solstice season in the city always reminds me of the essay Lost Rites - Searching for an authentic way to worship nature where Maria T. Stadtmueller looks for, and finds, her own honest way to celebrate winter solstice in New York City.

Here are some excerpts:

"Like a lot of people seeking some spiritual connection to the natural world, I read up on Native American spirituality, but it felt like a cultural trespassing to demand a seat for my white ass in the sweat lodge. What I am, I realized, is spiritually hungry and European.

[I've also] attended pagan rites... and the scenario is inevitably the same, with much ado about robes, men who like to wear Maybelline, and no detectable spiritual substance. ...I can't keep a straight face at pagan pageants.

Surely, I thought, I'm not the only one here with years of environmental activism under her belt. Surely I'm not the only one who, in working to protect them, has made herself learn more than she ever intended to know about monarch butterflies, coral reefs, or old-growth root systems. Then why aren't we celebrating what we know about the natural world? Why instead are we beseeching the sun to return in the spring when we all learned in fourth grade why it will?

There was one solstice gathering a few years ago that felt truly celebratory. There was no ceremony, no costumes, just ten shivering strangers bundled up for a Central Park tour titled "Winter Solstice in New York: Who Survives?"

As we headed into the park that Saturday morning, our two female park rangers occasionally stopped us to describe how particular birds or bushes withstand a Northeast winter. These women knew their turf: They pointed out lofty holes in oak trees where a half-hidden raccoon would be sleeping off a rough night in Upper West Side alleys; they knew where to spot a hawk when all we had noticed was the scattering sparrows. We stopped in front of a glossy green holly tree, a real extrovert against December's taupe and gray. Holly leaves survive, one guide explained, because the tree stores water not in the leaf cells, but in interstices between cells; there the water can freeze and expand, and the cells remain intact. A thrill bubbled up through my half-frozen marrow at the genius and beauty of this little system. Oh, you are wise, I thought. You are glorious! This tree, and these women who knew it, and the light that clicked on in our faces when we knew it too--this was a catechism of sorts, nature's Magnificent in which science could sing its stanza."

Stadtmueller is talking about a holly like the one pictured above, perhaps a European or hopefully a American Holly ilex opaca, whose native range includes New York, but doesn't reach this far north.

Our native holly is the Common Winterberry Ilex verticillata (below).

Unlike the typical Christmas season hollies most of us are familiar with, Winterberry is deciduous, losing its leaves in the autumn, which is fine because those bright red berries are their charm. Winterberry is a “very common” native in our Ecodistrict (7E-4), and "regionally rare" (L3) in the Toronto and Region Conservation Authority area. Come Novemeber it's easy to spot growing in wet areas. How wet? In this pic, where it was one among many along roadside ditches NW of Carden Plain, you'll notice it's growing between a wet ditch and a swamp. Although I haven't tried it yet, apparently it's also an adaptable garden plant too.

Tip: If you do decide to bring Winterberry to your garden, remember, like all holly trees and shrubs, it's dioecious, with male and female flowers on separate plants. And, as always, don't settle for cultivars or distantly sourced plants. Why? One example is that even among plants of the same species, in the same garden, those sourced from different local eco-types may bloom or fruit at different times, but our local animals, pollinators or migrating birds depend on our plants, the plants they co-evolved with, to flower and fruit at their unique specific time. Besides, you don't have to settle: our area has some excellent native plant nurseries (see the list of "native plant nurseries & sources" in the links at the right) who can help you source ethically propagated local Winterberry.

Again, happy holly days, merry Solstice, and all the best in garden and field season 2009!

Events this week!

• Oct 16: Ontario Urban Forest Council's workshop and AGM at the Toronto Botanical Gardens
• Sat Oct 18, 12-4PM - NANPS AGM and Native Plant Sale. This year’s theme is “The Role of Plants in Water Conservation.” Toronto Botanical Gardens
• Sun Oct 19, 11-1PM - Wildlfower Seed Collecting and stewardship, Evergreen Brick Works
• Sun Oct 19, 10:30 - Seed collecting, fence repair and trail work with the High Park Volunteer Stewardship Program. Meet at the Grenadier Café and Teahouse.

LEAF - Tree Tenders Workshop: May 13, 20 and 24th

This 11 hour training program is designed for individuals who want to gain tree-related knowledge and skills. If you have had some experience at tree planting or gardening, but want more in-depth training, this series is for you! Only $35.00 plus GST for all three sessions. Details on the program and to register.

This was just announced today. If you're into it, SIGN UP NOW because it fills super quick. I took it, and Todd Irvine taught most of it and the manual was amazing too!

Bringing back Ontario's Elms ... and Butternuts too.

photo by Martha Macy

The only elm tree I’ve ever seen is the American Elm in front of the Manulife Insurance building on Bloor Street.

I have to admit, it's an impressive and elegant bit of marketing for an insurance company. The tree was planted in 1934 and Dutch elm disease hit Ontario in the 60's, so I don't know how they've pulled it off; although when it came up at a LEAF workshop, I heard Todd Irvine say “that tree is on A LOT of drugs.”

Drug-addled or otherwise, turns out that tree isn't as lonely as I thought. Apparently 1,600 surviving White or American Elm trees have been reported across Ontario. One's even estimated at 250 years old.

This is what I'm reading in two recent articles by Sharon Oostenhoek: "One Night Stands" in Ontario Nature magazine's Winter 2007 issue and "A dating service for lonely elms" in yesterday's Globe and Mail.

Problem is, these elms are too far apart to breed with each other. That’s where University of Guelph professor Alan Watson elm “dating service” comes in.

Watson tells Oostenhoek that 600 of the 1,600 trees have been visited and confirmed and cuttings have been taken from the most “eligible”. The cuttings (clones) are now saplings. The saplings are being exposed to the fungus that causes Dutch elm disease, to find the ones with the best immunity responses. Once they’re mature enough to breed (about 10 years from now), they’ll be cross-pollinated with each other (more genetic diversity than clones = better chances of surviving this and other diseases). Their offspring will then also be exposed to the fungus, with the hopes that some of them, like their parents -- who "were able to seal off infected branches" -- will also have "the right mix of genes" that provide immunity.

If you have an elm to report or just want to know more about U of Guelph's work, check out their Elm Recovery Project.

Butternut Juglans cinerea

When you look at the range of the Butternut you'll see it's one of our native Southern Ontario "Carolinian" forest trees.

Hopefully, like some elms were able to defend themselves, more than a few butternuts will be immune to the fungus that causes Butternut canker (which BTW is also impacting Black Walnut too).

You can still buy a native butternut tree at Acorus Restoration. Visit their online catalogue and you'll read: "the Butternut tree has come under threat. A disease has killed most mature specimens and some trees are showing resistance. We must plant more to keep finding resistant genes.”

You can find more info and other ways to help out Butternut conservation efforts at the Forest Gene Conservation Association's information on butternut and the butternut canker in Canada.

Emerald Ash Borer Confirmed in Toronto

It was reported in North York, at Shepherd & the 403.

Here's a Q&A from the Canadian Food Inspection Agency.

It was also recently found in Norfolk County at Turkey Point too: "Norfolk County boasts about 27 per cent forest cover and 15 to 20 per cent of its trees are ash trees... (including) the rare blue ash and pumpkin ash that is only found in Norfolk County in Ontario."

Note: The Emerald Ash Borer is the insect we knew about in Essex and Kent. It is not to be confused with the Asian Long-horned beetle, which has already been in the Vaughn area of Toronto since 2003.

Don Watcher John Routh offered this analysis yesterday:

"Efforts are underway to contain the outbreak but there is little anyone can do. They are very difficult to detect. As a introduced insect it has no natural enemies and no pesticides are known to kill it. Unless a miracle fix is found, we may be looking at a permanent change to our forest."

The City of Toronto's Urban Foresty Services had already suspended planting of Ash trees, and offers more information about these and other tree pests in Toronto.

The best thing to plant under a street tree?

MULCH.

Weirdly this was not initially intuitive to me. Instead I tried solomon's seal, wild strawberry, ginger, violets ... even mints. Then one day I realized: this tree wants me to FEED it. And there began the mulch pile. I occasionally rake it, keep it clean (errant dog poop, odd bits of litter) & of course, I leave some space around the bottom of the trunk so it won't rot.

I've gone this route for about 4 years now. The tree is growing fabulously. And I don't have to worry about bagging leaves in the fall, or the tree's roots getting dinged by too much heat (the mulch keeps them cooler) or drought in the summers because of poor soils that are unable to hold organic matter (& thus not able to hold moisture.) What-do-the-neighbours-say? "Smart." Last year at the height of summer (when the mulch pile is low, brown & decaying) one neighbour said "I like the natural look of it, let's continue it down 3 properties." :)

BTW: This tree is a basswood, and as it turns out, basswoods make exceptionally good leaf mulch and they require it too. "Basswood is a soil enhancer. Its leaves are very rich in calcium and magnesium, and well above average in nitrogen, potassium, and phosphorus content. They are living, breathing, non-polluting fertilizer factories. Decomposed basswood leaves nourish and neutralize the soil, boosting the growth of basswoods themselves, as well as surrounding trees and other flora ... [it uses it leaves to] ...ensure its own health and growth." - Glen Blouin, An Eclectic Guide to Trees east of the Rockies.

Though a tree grows ever so high, the falling leaves return to the root.- Malay proverb

Update:

• Spacing Magazine's Fall 2007 "Green Issue" has an entire article by Todd Irvine about mulching around street trees.
• More of Todd Irvine's writing can be found on Tuesdays at Spacing Wire

Growing trees.

An excellent article about Toronto's urban forest by LEAF's Todd Irvine appeared last Sunday in the Toronto Star. Excerpted from greenTOpia: Towards a Sustainable Toronto Vol.3

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"Carolinian Canada" is a big place. A lot of plants are actually very regionally specific. For example Redbud is only really native down near Point Pelee, and Winged Sumach only occurs in Norfolk and Prince Edward Counties. Ever tried to find which tree and shrub species are really indigenous to your region? Check out Forest Gene Conservation Association's list of trees and shrubs native to the Toronto area / eco-district 7E4. Also see this site for native trees and shrubs elsewhere in South-central Ontario.

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We're not just growing plants, we're growing soils and the biota who live there. This is especially important in urban and suburban areas where so much of our soil-life has been heavily disturbed and destroyed. In past few years we've started to clue-in to the necessary role of mycorrhiza fungi in tree health. Check out Mycorrhizae: Unsung Heros of Forest Health from the Ontario Arborist.

LEAF - Local Enhancement and Appreciation of Forests

Trees are good -- this you already know, but it takes a little learning to know how to be good back to them. Growing trees in cities is another set of skills too. Luckily here in Toronto we have the good folks at LEAF to walk us through it all!

If you aren't already a fan of this non-profit, local, grassroots, urban forest advocacy group, check out the LEAF site. Not-to-be-missed: their Tree Tenders workshop, Toronto Tree Tours, Backyard Tree Planting Program & factsheets. While you're there, sign up for their newsletter. You don't want to miss out!

I've used some of their resources before (love 'em), but last night was my first experience with their Tree Tenders workshop. Already I can't recommend it enough. And I can't imagine a more sincere, interesting and knowledgable instructor than Todd Irvine. If Todd hugs trees, I hope the trees hug him back!

Garlic Mustard: Negative impact on hardwood trees, seedlings, mycorrhiza & rare West Virginia White butterflies

A Perspective on the Ecological Ramifications Of Garlic Mustard
by Donald A. Sutherland - Biodiversity Section of the OMNR

“The garlic mustard/sugar maple relationship would give Norway maple an additional competitive advantage, particularly in the ravines of Toronto and other riparian areas of southern Ontario where garlic mustard is abundant. Garlic mustard could reduce or eliminate the soil mycorrhizae necessary for the survival of sugar maple seedlings and thereby give a competitive advantage to Norway maple. I have no idea whether Norway maple seedlings are similarly dependent on soil mycorrhizae for their survival, but both exotic, Norway maple and garlic mustard have presumably evolved together. Norway maple produces abundant seed with high viability rates and is tolerant of air pollution such that it has already a competitive advantage over the native Sugar Maple in urban and near-urban areas. In more native forest situations, a loss of sugar maple could in the long term have grave implications for forest song birds which are dependent on the many sugar maple-obligate invertebrate species which feed on the maple. Many forest lepidopteran species, for example Bruce's Spanworm, are largely dependent on sugar maple and the loss of these species (and particularly their larvae) could considerably reduce available food for forest birds and their nestlings.

Garlic mustard is already posing a serious problem for one of the province's SAR butterfly species. The West Virginia White, currently a special concern species in Ontario, is a relatively widespread but uncommon forest butterfly throughout its eastern North American range. The larval host of the West Virginia White is a native member of the mustard family, called toothwort. Increasingly, West Virginia White is being observed nectaring on the closely-related, early-flowering garlic mustard; however, not only is garlic mustard a common source of nectar for the butterfly, but the West Virginia White is preferentially laying its eggs on the exotic mustard. The eggs hatch, but the mustard is evidently unpalatable to the maturing larvae and the butterfly larvae don't survive beyond their first instar - thus garlic mustard is effectively an ecological cul-de-sac for the West Virginia White. Never abundant, the West Virginia White has recently been placed among the ranks of globally rare taxa by NatureServe, largely thanks to problems with garlic mustard.

There is often the perception that some exotic species are benign. Exotic species are never benign they only appear so because their impacts haven’t yet been recognized.”

Please also see:

• Invasive Plant Suppresses the Growth of Native Tree Seedlings by Disrupting Below ground Mutualisms. Stinson KA, Campbell SA, Powell JR, Wolfe BE, Callaway RM, et al. (2006) PLoS Biol 4(5): e140
• Invasive species harms native hardwoods by killing soil fungus - Steve Bradt, Harvard University, Apr 26/06 “Find is first to identify specific mechanism by which invasive plants harm native species”
• Garlic Mustard photos & information: Global Invasive Species Database – ISSG – Garlic Mustard

• For more information please see other Garlic Mustard, mycorrhiza or invasive plant resources posted on this blog.

Since we're talking about tree health & beneficial mycorrhizal fungi...

Case for inoculating urban trees with a diversity of beneficial mycorrhizal fungi:

"Urban trees, in particular, are subject to many environmental stresses. Many harmful chemicals are deposited on the trees and directly on the soil, and the ground they are growing on is typically heavily compacted. Also, let's face it, they don't exactly grow on great quality soil. Furthermore, young tree seedlings and sapling growing in nurseries are typically fertilized, which further eliminates many beneficial mycorrhizal fungi. Some of our preliminary research in the cities of Guelph and Toronto shows that trees in streetscapes are heavily infected by mycorrhizal fungi (a good thing), but fungal diversity is very low (not a good thing). Many species normally associated with these trees in forests have become extinct from urban environments.

In a recent field-trial we tried to bring back some of these fungal species. We inoculated black maples with a cocktail of mycorrhizal fungi to see if this would improve their growth. During the first year, there was no sign that inoculation helped at all. All trees were similar is size and overall health, and we began re-evaluating our story. But then came the big summer drought of 1998. This placed a lot of stress on our experimental trees, and right now, the inoculated trees are the only ones that have survived. This suggests that things may be fine during normal years, but that this diversity of fungi may be important during years with extremes in climate. As climate is expected to be less predictable in the coming years, mycorrhizal inoculations may prove to be more necessary."

Excerpt - Mycorrhizae Research Information Dr. John Klironomos, University of Guelph

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Care about Toronto's urban trees? Visit LEAF and Urban Forestry Services.

You might also like Trees of the Carolinian Forest by Gerry Waldron