One of the finest features of eastern Ontario is the muskeg-like Long Swamp Orchid Fen that's crossed by the North Augusta Road, 2 km NNW Manhard, 44.69421N 75.74379W. After a series of purchases of land by Nature Conservancy Canada, the site "is currently undergoing regulation under the Provincial Parks and Conservation Reserves Act. Once the regulation is completed, it will be a provincial park." (Corina Brdar, by e-mail, 5 Jan 2012).
We have worried for decades about the progress of invasive Narrowleaf Cattails, Typha angustifolia, along the roadside ditches there, and then massively into the fen, which is a muskeg-like wonderland of small twisted Cedars and Tamaracks, with a wide variety of Bog Ericaceae, and other bog flora, including Pitcherplants, wonderfully diverse lichens, and, if you're there in the right season, the Orchids for which it is named, and also a rare Pondweed in the interior.
"T. angustifolia generally favours drier, higher-calcium, sites than other Cattails. It hybridizes with the native Typha latifolia to produce the robust Typha x glauca, which makes up most of the plants in many marshes. Long thought to be a native species -- albeit spreading inexplicably northwest during the 20th century, and inexplicably absent from the fossil record -- it has recently been concluded that T. angustifolia was likely an early invader from Europe, though more recently doubt has been thrown on this (Shih, Jessica G. and Sarah A. Finkelstein. 2008 http://www.bioone.org/doi/abs/10.1672/07-40.1 ).
"It's not clear why T. angustifolia is moving into the peat of the Fen so aggressively, but it first spread along the margins of the road embankment, where conditions at the edge of the embankment may have been drier than in the Fen, and may be favoured by road salting, and mobilizing nutrients and calcium from rhizome-oxidized peat as it moves into the Fen. The presence of scattered T. latifolia in the Fen shows that T. angustifolia has some substantial advantage over its congener here.
"As Aleta painted, the warm temperatures, shallow snow, and solid ice made it convenient for me to waypoint the perimeter of the Cattails in the bog, to compare with a few previous waypoints of their spread. This survey was confined to the east side of the road, the only area where the fen is an open muskeg, presumably because the North Augusta Road impedes the westward flow of drainage, and allows trees to grow up in the downstream west side of the road, while enforcing bog-like conditions in the impounded east side. I headed north along the road, first waypointing the few Broadleaf Cattails in the roadside ditch, and then going into the interior, waypointing the outliers of the stand in the fen, sheltering my notebook inside my jacket from the rain, and coming out to the road where the Cattails end at the brushy border of the Fen.
"When I came back out onto the road, the Narrowleaf Cattails were a solid stand, and as I walked back south to the van where Aleta was painting, I refound a small stand of invasive Phragmites that she'd tentatively noted in the early fall, but which we haven't managed to notice in drive-by visits. They're on the east side of the road embankment, near the new plastic culvert which was installed not long before June 2008, so it's plausible to associate the establishment of the stand with earth-moving during the installation of the culvert.
"This is only a 6 m stand of 28 heads, but I hope that whichever agency will be managing the Fen won't want to see if the Phragmites can outdo the Cattails in obliterating the fen and its flora. The stand could be removed by shovel work this spring and summer, though each subsequent year this will get more difficult, and once removed they'd need annual checkups to be sure no rhizomes remain."
Because Typha angustifolia mostly displaces other Cattails, and because it's been around for so long, it is not generally controlled, but in this case, where it's marching into such a diverse plant community, increasing landscape homogeneity and displacing rare species and a distinctive community, control would seem to be warranted, whether it's originally a native species of restricted range or a European introduction.
It would be interesting to send a team of Typha-pullers into the bog each August, and pull up the tonne or two of the most peripheral shoots, which, because there's a 30m wide fringe of sparse shoots, might effectively hold back the advance.