Knowing and expecting doesn’t adequately prepare you for the reality of loss. Yesterday I lost some of the beautiful trees who were my backyard friends and sentinels. Pickering’s Altona Forest is like all green-space in this region affected by the emerald ash borer (EAB). I have known for a long time that the ashes living in Altona Forest would die and stand as stark snags in a forest that would only remember what ash trees were like. The damage started years ago: the insects are here. However yesterday, TRCA foresters came along the edges where Altona Forest meets backyards and cut down any ash tree within falling distance of the fence line.
It began with the sounds of chainsaws echoing through the forest a few days back. For those who love the untouched beauty of nature, this is never a happy sound. Yesterday it became personal when 2 of the trees within touching distance from my fence were felled – one a tall 3-story ash and another smaller one. The tall straight tree was mildly infected but a favourite of the birds – especially woodpeckers. They would use it as the stopping spot on the way to my bird feeders. The hummingbirds had a favourite branch on that tree to guard their territory and my nectar feeder. The foresters were careful in pulling down the even larger ash trees – using ropes to guide their fall and break as few smaller trees and branches as possible. At my fence, the other little dead trees were also taken down. I know I am too sentimental about the forest at my doorstep, but it is a sad moment for the woods.
The emerald ash borer is an Asian invasive species that likely arrived in North America in the wood skids used to transport freight. In the 7 years it has been in our region, it has had devastating effects on all 5 species of Ontario ashes and its range continues to spread. (Mountain ashes are not genetically ash trees, so they are safe) The larvae form of the beetle attacks healthy or weak ashes indiscriminately. Ash trees – either as curb-side favourites or forest staples – are in their final days. This foreign invasive pest is voracious, without local enemies, and a serious threat to our forests. Biodiversity, local species’ food and habitat, air quality, and furniture makers are all affected with the loss of millions of our ash trees.
In ashes through the Rouge Park and Altona Forest, you can see the tell-tale signs of the EAB with holes on the trunk of the tree in a ‘D’ shape – about 4mm is size. These are the exit holes of the beetle larvae. The infected tree shows a thinned crown, epicormic shoots (green leaves emerging from the tree’s bark), and vertical cracks on the trunk – with the life-giving sap-wood inside eaten, there is little chance of survival. The tree starves because nutrients are no longer available due to it’s ‘eaten’ circulatory system and will die in 3-5 years. While the EAB adults feed on the tree’s leaves, that is not nearly as damaging as the larval stages. It’s hard to spot the damage until the tree is very compromised.
It’s thought that this pest arrived in the Detroit area even before 2002 when it was discovered – and it was found in Windsor later that year. Packing and other wood is not always treated and with shipping, trains and trucks, the modern world of imported goods is an easy conduit for emerald ash borers (and Asian long-horned beetles… and who knows what else!). To slow the rapid spread, southern Ontario has federally restricted movement of specific goods regulated by the Canadian Food Inspection Agency (CFIA). Stateside, similar regulations are in play.
So far, the best hope for natural forests and Canadian ashes is the complete ban of moving wood from one area to the next. It takes only one ignorant person taking firewood from the GTA to Muskoka or Haliburton to begin devastation on an even larger scale. We have to think ‘containment’ because it is already too late for our region.
Realistically nothing can stop this spread. There are only faint glimmers of hope for the future of ash trees. One is an expensive treatment that can be given to a non-infected ash to protect it against the EAB. While effective, this is cost-prohibitive and labour intensive treating one tree at a time. Another is that there is a tiny percentage (1% or less) of ash trees that are not killed by the EAB – and perhaps we can breed those resistant trees and begin to re-forest. However, that is a long shot and not even on the horizon of conservation. There is an Asian wasp that kills the EAB – but there is always a huge problem of what would happen if yet another invasive species was released into our woods.
For now, we can all enjoy Altona Forest – and the few ashes still standing. Point them out, enjoy them, and celebrate them because we will not see them for long.
Resources ~ Begin your reading here:
In the Wake of the Emerald Ash Borer ~ © 2015 Natasha G