Today is Day 5 of Invasive Species Awareness Week (ISAW), an annual campaign in Canada led by the Invasive Species Centre and its partners. The goal of ISAW is for communities and individuals to come together to raise awareness about the impacts of invasive species and the importance of preventing
Jan. 13, 2026. If you love to get outdoors and enjoy the beauty of winter, our recently updated Winter Discovery Walk might pique your interest! Next time you head outdoors this winter, turn your adventure into a nature scavenger hunt—spot trees, shrubs, seed pods, animal tracks, and more! Happy winter
Ever wonder where the water in your tap comes from, or where rain goes once it hits the ground? Every drop of water belongs to a watershed. Across Canada, watersheds quietly support life, shape ecosystems, and sustain our communities. And…did you know? Canada supplies about 20% of the world’s freshwater,
Sept. 26 2025: In honour of National Forest Week, ACER is excited to announce our latest TREEVIA quiz—Canada’s Forests and Climate Change! Test your knowledge about the challenges that Canada’s forests face from climate change and the vital role they play in fighting it by taking the quiz HERE today! Or, visit our
Sept. 24, 2025: Happy National Tree Day! This special day is a day dedicated to celebrating the beauty and benefits of Canada’s trees and forests! Planting even just a single tree offers hope for future generations and the survival of the planet. And, ACER has been helping communities plant trees
Our 2025 Spring/Summer newsletter is here—download the PDF here today to read all about ACER’s news and activities over the past 6 months! Note: if you are an ACER email subscriber, you should have already received an electronic version of the newsletter on Sept. 21, but feel free to download
On April 30th, 2025, I experienced a little bit of magic. From organized chaos, a baby urban forest—a micro-forest—was born. Right before my eyes. In hours. At Brian W. Fleming Public School in Mississauga. And it wasn’t the first time. In fact, it was the 70th time a Southern Ontario school implemented ACER’s Planting
Canada is home to some of the most diverse ecosystems in the world, from boreal forests and grasslands to riparian zones and urban green spaces. But these ecosystems and all that live within, including humans, are increasingly under threat from a highly damaging force of nature: invasive plants. According to
August 8, 2025—Congratulations to Alice Casselman, ACER Founder and President, on being one of four recipients of the 2025 Credit Valley Conservation (CVC) Environmental Awareness Award, presented by CVC at a special celebration event in Caledon on June 19, 2025! This award is given to those who connect communities with
What are wetlands?Wetlands are “lands that are saturated with water long enough to promote wetland or aquatic processes as indicated by poorly drained soils, hydrophytic vegetation and various kinds of biological activity which are adapted to a wet environment”, as defined by the Canadian National Wetlands Working Group. Wetlands encompass
Breathe in the Magic of Green! To keep breathing—we breathe around 16 times per minute—we depend on oxygen from TREES! This life-sustaining oxygen is produced by the incredible process of photosynthesis that is carried out in tree leaves, green plants, and aquatic plants. Photosynthesis, named from the Greek for “light”
On Sunday, June 8, ACER held its annual general meeting, with both members and guests in attendance. The meeting kicked off informally with presentations by Alice Casselman, ACER Founder and President, Sadia Butt, ACER Program Manager, Marianne Karsh, ACER Scientific Advisor, Jonathan Brown, Director of Education for GO Open Data,
Written by Patricia Pidoux, long-time ACER friend and supporter, and abstract artist! Is there any colour that sparks as many associations for us as the colour green? In spring, our happy anticipation of new green growth and floral abundance is rewarded with plants and flowers bursting from the ground with
May 22, 2025: Happy International Day for Biological Diversity! This year’s theme, as set out by the Secretariat for the Convention on Biological Diversity is Harmony with nature and sustainable development. And, did you know that ACER has been a pioneer in urban and riparian forest biodiversity monitoring in Ontario
What is urban biodiversity and why does it matter? Urban biodiversity refers to the variety and variability of living organisms, from genes to species to ecosystems, found within urban and peri-urban areas. As urbanization increases, more and more natural spaces, and the invaluable ecosystem services they provide; for example, trees
Introducing our new “In the Spotlight” series — first up: container gardening! Traditional garden not an option? Dig into container gardening! Besides being a great alternative for growing vegetables, herbs, flowers and other small plants when gardening space is limited or the ground isn’t garden-friendly, container gardens help expand green
April 22, 2025: Happy Earth Day from ACER! This year’s international theme is OUR POWER, OUR PLANET, which calls for the tripling of global renewable energy capacity by 2030 and challenges governments and corporations to step up with the bold commitments and decisive actions necessary to meet this goal. It’s
Interested in learning more about forestry/forestry research, trees and plants, invasive species, biodiversity, or climate change and climate action but don’t know where to start? Click here to check out our newly updated Useful Web Resources page today!
Our Fall/Winter newsletter is finally here! Download and read the PDF here today! Also, if you would like to automatically receive notifications of a new ACER newsletter issue, subscribe to our email list using the form at the bottom of any of our website pages! Note: if you are already
Feb. 28, 2025. Yes, we all know it – winter is not over yet! If you love to get outdoors in winter to immerse yourself in nature and enjoy the fresh, crisp air, or take a walk as snowflakes softly fall, our new Winter Discovery Walk might pique your interest!
For many of us, it is the first snowfall that marks the true arrival of winter. The delicate and beautiful snowflakes add brightness to the colder, shorter days of the season, and bring on a host of winter activities and sports – think tobogganing, skating, skiing, snowshoeing, or simply taking
Building on the success of our 2023-2024 Seniors Measure UP! initiative, ACER has kicked off a new initiative under the Measure UP! program in collaboration with Retired Teachers of Ontario (RTOERO) District 22. The project will run through to Spring 2025 and include three hands-on measure and mulch field events
On October 18th, 2024 ACER came together with organisers, municipal officials, volunteers and local students for an activity-packed celebration marking the successful completion of ACER’s 2023 GLLAF Ganaraska Tree Planting and Caring For Trees Initiative. During this year-long initiative, completed in partnership with the Ganaraska Conservation Authority, Sustainable Cobourg, the
By Alice Casselman, ACER Founder and President — October 2024 To me, one of the best parts of fall is the whole new colour palette I see as I walk along roadsides and ditch-lined streets. Fall is a royal display of gold and purple – gold from goldenrod, jewelweed, and
Sept. 24, 2024. Happy Fall from ACER! If you love to get outdoors to enjoy and explore the beauty of autumn, our recently updated Fall Discovery Walk might pique your interest! Discover why leaves change colour, uncover the science behind fall aromas, test your skills in identifying fall trees and
October is Pawpaw Month, a time to celebrate the beautiful but rare pawpaw tree! This unique tree, native to Southwestern Ontario, bears the largest native fruit in North America, fruit that is edible with a custard-like texture and flavour tones of mango, banana and melon! To help kick off the
Our Spring/Summer Newsletter is Here! Download and read the PDF here today! Also, if you would like to automatically receive notifications of a new ACER newsletter issue, subscribe to our email list using the form at the bottom of any of our website pages! Note: if you are already an
Did you know that Sunday July 28 was World Nature Conservation Day? This special day recognizes the importance of the ecosystems and natural resources that sustain life on our planet. All species on Earth depend on healthy habitats to survive and grow, making it vital we protect and preserve them.
July 11, 2024: ACER is excited to announce the launch of our new TREEVIA quiz series! Test your knowledge of trees, so essential to the health of our environment, beginning with our first instalment: the TREEVIA Forest Ecology Quiz, which focuses on the biology of trees and the forest ecosystem.
On Sunday, June 9, ACER held its annual general meeting of members. The meeting was virtual with many people, both members and guests, in attendance. The meeting kicked off informally with presentations by Alice Casselman, ACER Founder and President, Sadia Butt, ACER Program Manager, Jonathan Brown, GIS Coordinator for Sustainable
June 20, 2024: Did you know that June 17-23 is Pollinator Week? Pollinator Week was initiated and is managed by Pollinator Partnership (P2), a charity founded to promote the health of pollinators through conservation, education, and research. This special week is dedicated to celebrating the vital role that pollinators play
ACER is pleased to announce the completion of our collaboration with the Brampton Environmental Alliance and their 2023-2024 Rooted in Hope initiative! ACER’s role in this initiative was leading training on tree monitoring and training on environmental outreach and educational leadership. The tree monitoring training included how to use tree
May 28, 2024: ACER is pleased to announce our updated Mission and Vision Statements, revised earlier this year to reflect our current priorities and focus as we continue our work in the community to support local climate action in response to global climate change.
May 22, 2024: Happy International Day for Biological Diversity! Did you know that ACER has been a pioneer in forest biodiversity monitoring in Ontario ever since the 1993 Convention on Biodiversity that arose from the 1992 United Nations Conference on Environment and Development in Rio de Janeiro? Over the past
April 22, 2024: Did you know that International Mother Earth Day, established by the United Nations General Assembly in 2009, has roots that go back all the way to the 1970’s? It was during the time that environmental issues started getting global attention culminating in the first ever world conference,
Join us Thursday April 4 from 1:30-2:30 PM for “Challenging Conversations”, our latest Seniors Measure UP online webinar with guest speaker Laura Tamblyn Watts, President and CEO of CanAge. Laura will talk about CanAge, her new book and answer your questions about elder care rights/elder well-being! All are welcome to
Take a walk outdoors this spring with ACER’s Spring Discovery Walk as your guide! For our full Exploring the Outdoors collection, click here! Includes two new additions to our tree, shrub and flower activity suites: tulip and crab apple!
Join us Sunday Feb. 25 from 1:30-2:30 PM for our “Get Tech Savvy” online webinar brought to you by our Seniors Measure UP Program. Sign up to learn some tips from an expert on how to use your Apple iPhone and iPad efficiently like a pro! All are welcome to attend.
We are happy to announce that our newsletter is back! 2023 was a very productive year for ACER, and also a year of celebration of ACER’s 35th anniversary! To look inside, check it out here!
Join us this February and March for a special live webinar series designed especially for seniors as part of our Seniors Measure UP program, funded by the New Horizons for Seniors Program (Government of Canada). See below for details! All are welcome to attend. If you are interested please fill
January 2024: ACER is excited to announce completion of all tree plantings in the Ganaraska River Watershed for the provincially funded Great Lakes Local Action Fund (GLLAF) project that kicked off last November at Sylvan Glen Conservation Area. This region was chosen for this project because it has many streams
After 35 years of planting trees with schools and communities across Ontario, ACER founder and President Alice Casselman was celebrated this past August with a maple tree planted in her honour at Mississauga’s Fleetwood Park. At the ceremony, Mississauga City Councillors Stephen Dasko (Ward 1) and Chris Fonseca (Ward 3)
November 2023 – Winter is fast approaching and replenishing the mulch around our trees ahead of winter is good practice, to ensure its continuing benefits. Mulching adds nutrition to the soil, helps aerate it, regulates its temperature, holds in moisture, and suppresses weed growth. And, when added in the autumn,
November 2023 – ACER is very excited to announce the latest addition to our “Exploring the Outdoors” resource collection: our new Fall Discovery Walk. Have a look inside and get outside! Depending on where you live, there are still some beautiful colours and other fall changes to be seen and
AGM 2023 Livestream Find out more about ACER’s successes in 2022 and the exciting plans for 2023! Click below to view our live-streamed presentation that kicked-off the 2023 Annual General Meeting on Sunday June 11. https://www.youtube.com/watch?v=HcYItHJYuoM&t=316s
ACER is very excited to launch our new “Exploring the Outdoors” resource collection, starting with our Spring Discovery Walk and our Maple, Forsythia and Dandelion Activity Suites. Click here to look inside, and then get outdoors!
Well, we made it through another amazing year despite the persistence of COVID-19! Under the pandemic’s radar, ACER managed to plant P4C tree suites in three schoolyards; complete our federally funded Canadian Healthy Communities Initiative project in Mississauga and launch our newest Riparian Rangers initiative in the Ganaraska River watershed,
Support ACER! Your special donation to ACER’s new Climate Action Incentive “Donate Back” fund will help ACER continue to support science-based climate action in our communities. ACER plants and cares for trees. Donate Today, for Climate’s Sake!
November, 2022: ACER is excited to announce our latest Riparian Rangers initiative in the Ganaraska region funded by the Great Lakes Local Action Fund, kicked off on November 12 at the Sylvan Glen Conservation Area east of Toronto. During this one-year initiative ACER will take the lead working with the Ganaraska
On October 15, 2022, ACER celebrated 1000 trees planted in Mississauga Wards 1, 3 and 7, in collaboration with communities and the City of Mississauga, funded by the Canada Healthy Communities Initiative. Left to right in the photo:Chris Fonseca, Ward 3 CouncillorStephen Dasko, Ward 1 CouncillorAlice Casselman, ACER FounderLinda Casselman,