building a forest
I heard this story on the news a while ago, but it took a while to figure out the keywords necessary to find it again. In the lunar landscape that is the old Sudbury nickel mines and smelters there has, over the last 40 years, been a massive tree planting program, however because the soil is so acidic and toxic, there is no forest floor – that blanket of leaf mould, seeds, bugs, little animals, lilies and orchids, wild flowers, birds, from which new trees grow.
When new roads are hacked out of the wilderness, such as the twinning of the Trans-Canada highway through Banff National Park, first the forest is logged, then bulldozers come and shovel and grade the top metre of ground into road bed. All the little seedlings and mice die instantly.
What Sudbury is doing is removing mats of ground cover and top soil from nearby road construction sites and placing them in the reforested areas that lack that essential floor that sustains a biodiverse ecology.
Pictures show the depth of these mats as about 4". Is that enough? Is the soil still toxic underneath? I'm sure someone has figured all this out otherwise the project wouldn't be so extensive, however it does make one realise how very thin the skin is that supports life. It also questions the expectation that it will be technology that reconstructs the toxic landscape of the oil sands: cutting and laying turf is not high technology. It hardly even low technology. Plants and insects are perhaps more powerful agents in reconstruction than we realise.
there is a short video on this CBC report of the programme: http://www.cbc.ca/news/technology/story/2011/06/06/environment-sudbury-forest-floor-transplant.html