How the SPRUCE project is helping assess what the future holds for the world’s boreal forests
“There is simply nothing else like this in the world.”
Danielle Way, a plant biologist and associate professor at Western University in London, Ont., could be talking about the boreal forest — the Earth’s largest land biome, 75 per cent of Canada’s forest cover and the world’s biggest storehouse of carbon, the integrity and stability of which are crucial to the fight against climate change. But in fact, she’s describing the Spruce and Peatland Responses Under Changing Environments (SPRUCE) project, an 8.1-hectare whole-ecosystem boreal experiment initiated by Oak Ridge National Laboratory in 2014 in northern Minnesota’s Marcell Experimental Forest. There, in a set of glass enclosures built atop a black spruce and peat bog, more than 100 researchers — including Way and several other Canadians — are measuring how the trees, plants, soil, insects and micro-organisms respond to simulated climate conditions of tomorrow. The knowledge can help shape resource management planning and practices for forestry and recreation, as well as predict how climate change will affect biodiversity, conservation practices and the release of stored carbon in the boreal forest.
“By providing us with a picture of what our forests will look like in the next 80 years,” says Way, “SPRUCE can help us decide if that future is really where we want to go.” Here is what you’ll find inside one of the domes.
VEGETATION IS the same inside and out: three- to seven-metre-tall black spruce and larch trees; sphagnum and other mosses; and plants such as Labrador tea, bog rosemary, leatherleaf and cotton grass.
TEN IDENTICAL acrylic-and-aluminum-frame open- topped enclosures are arranged among 17 plots on three short lanes connected by metal boardwalks. Each octagonal enclosure is eight metres high and 12 metres wide, and their open tops provide exposure to snow, rain and other environmental elements.
IN FIVE ENCLOSURES, carbon dioxide levels match ambient levels; the other five are kept at roughly double present day (800 to 900 parts per million). For both CO2 regimes, there are five different soil and air temperature settings relative to outside: ambient, 2.25 C, 4.5 C, 6.75 C and 9 C.
ALONG WITH HEATERS and the carbon dioxide supply, critical instruments include sensors that measure: light beyond the visible spectrum as a measure of plant health; photosynthesis and respiration rates; CO2 and methane emissions and levels in the soil; below ground temperatures and changes in moisture levels.
SPECIFIC PLOTS and sampling areas measure growth rates and other energy/production indicators for vegetation, soil, insects and other micro-organisms.
Photography courtesy of Oak Ridge National Laboratory.