Re­port on po­ten­tial col­lapse of ravines hits North Toronto hard

Mid­town ecosys­tems are suf­fer­ing; lo­cal res­i­dents and the city are des­per­ately search­ing for an­swers by Ron John­son

Bayview Post - - News -

Toronto’s ravines, which cover 17,000 acres, are valu­able in so many ways. They pro­vide es­sen­tial eco­log­i­cal ser­vices, in­clud­ing flood pro­tec­tion and clean­ing the air; they make our prop­er­ties more valu­able and pro­vide abun­dant men­tal health ben­e­fits. And for a few kids that can peel their eye­balls from In­sta­gram for an af­ter­noon, they are an un­par­al­leled place of recre­ation and imag­i­na­tion.

Yet if you head into any ravine in the Don Val­ley to­day, along­side a myr­iad of na­tive species from tow­er­ing oak to brightly coloured sumac there are in­vaders storm­ing the flora gates. Ac­cord­ing to a new ravine study, the growth of in­va­sive species is one of the main cul­prits push­ing the ravines to the verge of col­lapse and putting at risk one of the city’s defin­ing and most beloved fea­tures.

A few years back, TD Canada Trust val­ued the city’s ur­ban for­est at a whop­ping $7 bil­lion. So why is the city let­ting it all hap­pen?

Sure, Toronto has pro­duced a ravine strat­egy, but it is, ac­cord­ing to some crit­ics, more fo­cused on hu­man con­nec­tion to the ravine and less on the science that would pre­serve the ecosys­tems for fu­ture gen­er­a­tions.

This new re­al­ity prompted a group of res­i­dents and forestry stu­dents to pro­duce the Toronto Ravines Re­vi­tal­iza­tion Study that has just been pub­lished. The study’s con­clu­sion calls for, amongst other rec­om­men­da­tions, es­tab­lish­ing a Toronto Ravine Con­ser­vancy to bet­ter fa­cil­i­tate the much-needed restora­tion work be­fore it’s too late.

But will the city al­low such a thing to oc­cur?

The study has a his­tory that dates back more than 40 years when, the first bat­tles oc­curred in Rosedale, pit­ting lo­cal res­i­dents against de­vel­op­ers hun­gry to max­i­mize the bot­tom line by edg­ing their new apart­ment build­ings as far down the slope of the Rosedale Val­ley Ravine as pos­si­ble. Sound fa­mil­iar?

It was a bat­tle led by the South Rosedale Ratepay­ers’ As­so­ci­a­tion and lo­cal res­i­dent Mar­garet Scrivener, who would go on to be­come an MPP and cab­i­net min­is­ter. (Scrivener Square was named to salute her work in pro­tect­ing lo­cal ravines).

Her son Paul grew up tromp­ing the ravine trails and got in­volved with the Toronto Field Nat­u­ral­ists when he was older. He soon be­came ac­tive in the North Rosedale Ratepay­ers As­so­ci­a­tion and con­tin­ued the same fight first led by his mother.

He and Dale Tay­lor ini­ti­ated the first Rosedale Ravine Study, pub­lished in 1977, which looked at the Park Drive, Moore Park, Rosedale Val­ley and Burke Brook ravines in the Don Val­ley.

“We went out to the com­mu­nity and raised money, got cor­po­rate do­na­tions and got to work,” said Scrivener. “At the end of the day, we had a study. A sci­en­tific piece of work that counted and as­sessed and rec­og­nized there were in­va­sive species.”

In 2014, Tay­lor and Scrivener, re­al­ized al­most 40 years had passed and the ravines were get­ting worse, so they de­cided it was time to re­visit their work. The new study was led by Uni­ver­sity of Toronto forestry stu­dents Eric Davies, a PhD stu­dent, and Anqi Dong, who has a masters de­gree in for­est con­ser­va­tion.

The team lim­ited their study to five dif­fer­ent ar­eas of the Don.

“The one thing that re­ally jumps out is in­va­sive species,” said Davies. Whereas the orig­i­nal study in­di­cated a 10 per cent rate of in­va­sive species, a few decades later that num­ber had grown to 40. The chief cul­prits are Nor­way maple, dog-stran­gling vine, Ja­panese knotweed and gar­lic mus­tard.

Na­tive plants have no nat­u­ral de­fences against these in­va­sive species and in­evitably lose more

Clock­wise from left: Paul Scrivener of the Toronto Ravine Study team, and two im­ages of the park sys­tem that stretches along the ravines of the Don Val­ley

Newspapers in English

Newspapers from Canada

© PressReader. All rights reserved.