I will open by assuming the term “invasive species” is well known to readers of this column. Southern Ontario is now the new home of almost 500 aggressive species of plants, animals and fungi that are causing major disruptions to the ecological functions of natural communities.
From this unfortunately long list, today just one of these invaders will be discussed: European Common Reed, also known as Elephant Grass, also known as Phragmites australis… but perhaps best known simply as ‘phrag’ by those who are involved with its control and eradication.
This very tall and robust grass is unmistakable in identification: often three to four metres in height with large corn-like leaves and topped with a heavy purplish, feathery-looking seed head. Not only is it tall, each stem grows so close to another that it is impossible to see through the stand.
It is believed that this particular species, Phragmites australis, arrived in North America in 1910 in Nova Scotia, as bedding or food for elephants in a travelling circus from Europe.
It was later found, in the 1920s, to be growing along train tracks paralleling the St. Lawrence River, and arrived in southern Ontario in the 1940s. Nowadays it can be found in most wetlands and ditches all across the southern portion of our province.
As I’m sure you can imagine, a plant that is so vigorous will quickly overshadow the area, displacing all other plants and creating a travel barrier for wildlife. But those reasons are only the tip of the iceberg in understanding why this plant is such a threat to both natural and man-made habitats.
At first, this grass was viewed as a nuisance, showing up here and there, looking somewhat exotic due its towering presence. Landscape designers began deliberately adding this odd-ball to delineate the sides of lanes or give drainage ditches a more pleasing look. It did not take this adventuresome plant very long to jump free of the confines of a tightly-coiffed lawn and run freely through the neighbourhood.
Phrag prefers wet soils to set down its roots. And massive roots they are, sometimes as thick as a person’s wrist and running for many metres in all directions. The sandier the soil, or more disturbed the area, the greater the spread of phragmites. These rhizomes can easily enlarge a patch of phrag by a metre a year.
The plant also has above-ground reproductive structures called stolons, which can grow up to 30 metres a year and set down new rootlets every 20 centimetres! And ... those mighty broom-sized seed heads contain thousands of seeds per plant.
Okay, so European phrag is well adapted to both survive and thrive on this continent, so what’s the big concern? As mentioned, it can overpower local plant diversity and create large monocultures of pure phragmites. In doing so, the roots create a chemical imbalance in the soil that prohibits other plants to take in essential soil nutrients.
The leaves of phrag are huge, looking very much like corn, which allows for a great volume of water to be transpired into the air. In shallow wetlands this transpiration can actually dry out the area! Bye-bye frogs, newts and many other wetland animals.
To carry on with this list of characteristics (all of which will come together by the end of this column) is that the stems of phrag are almost wood-like. Which means that it remains standing longer (even when dead) than most other wetland plants, and withholds nutrient cycling that the softer tissues of the usual fast-rotting plants supply to the area.
Up to this point it was the ecologists who have been wringing their hands in a woeful manner (“Nobody’s listening to us!”), but a couple of tragic events soon caught the attention of the general public.
There was a phragmites wildfire in a municipal drain that wound its way through a housing subdivision where each of the backyards touched this stormwater pathway.
Being tall, dry, thick and woody, the phrag stems blazed fiercely, melting backyard garden sheds, pool houses and threatening the vinyl sidings of the residential structures. Due the myriad of property line and pool safety fences, the firefighters could not access the ditch ... the fire had to burn itself out with substantial damage to the area.
The second situation was along a Great Lakes shoreline where beachfront owners were complaining about lack of view and access to their once sandy beach. A local municipality tried to conduct a controlled burn to rid the area of the unsightly dead stems. An unanticipated breeze came up and soon several kilometres of shoreline were merrily blazing away like a festive celebration of sorts. Neighbouring fire departments were not impressed.
As just about every ditch and drain now has phragmites growing in it, that means many road intersections have blocked visibility, resulting in the need for municipal road crews to switch from cold-patching potholes to removing this obstructive jungle.
Firefighting, roadside maintenance, property damage insurance claims, and highway closures due to smoke impeding visibility, all lead to a new budget line added to many municipal plans. Turns out it is cheaper to control the spread of phragmites than it is to pay the piper after a disaster. Funding became available to fight phrag!
For the last three years the Marl-Tiny-Matchedash Conservation Association has been conducting a “phrag-free” project at the Tiny Marsh Provincial Wildlife Area (wherein I have the position of Site Coordinator) and between a small army of volunteers and concerted effort by a company that specializes in phrag control (see attached photo), we are making a dent in the population.
As with any invasive species initiative, the goal is control. Total eradication is not possible, as there will always be that one little hidden patch that "suddenly" shows itself in a year or two; this is true with garlic mustard, dog-strangling vine, buckthorn shrubs, yellow iris, periwinkle, purple loosestrife and any other invasive species that shows up.
Today there are many groups, both volunteer and government-run, that are engaged in the control of invasives. We are running a bit late and behind the front, but with concerted effort we can, and are, preventing the total takeover of our local environment by these tough invaders.
