How Christmas trees can become a low-carbon source of protein

Planting forests while growing protein-rich food seems to be a win-win, so are there any potential drawbacks? Lynn Boddy, professor of fungal ecology at Cardiff University, believes fungal forests “absolutely” have the potential to produce significant food crops while sequestering carbon. However, it calls for “great care” in doing so. “In my opinion, when we inoculate anything, it should be sourced locally,” she says of the fungi. “There’s a concern about an invasive genotype if it comes from somewhere else. Even if it comes from Britain, and you’re growing the same thing in an area, there’s a concern about diluting the gene pool. And potentially also reducing the diversity of native species.”

Thomas says these are valid questions, but points out that this project focuses on using fungal species native to the planting area, and with strains that are less aggressive than those currently inoculated by many nurseries to encourage tree growth — although he admits there could be potential for a company. Others may look to use some form of genetic modification in the future, which would require regulatory approval.

There is also the question of what happens to the trees. If left standing or producing timber used as building materials, it pulls carbon out of the atmosphere in the long term. But if the wood ends up decomposing or burning — as is often the case with Christmas trees — much of the drawn carbon could end up back into the atmosphere. However, this cycle will still produce protein with a lower net carbon footprint.

Jump believes this process could make future Christmas trees more sustainable. The traditional way of growing Christmas trees is “a completely inefficient system, if you look at it from a carbon perspective,” he says. “You might be absorbing carbon into the tree, but then you’re destroying the trees after Christmas. Getting fungi associated with Christmas trees is actually a great way to reduce your carbon impact.”

Milk cap mushroom.Courtesy of Mycorrhizal Systems Ltd.

But the main question should be, how do mushrooms taste? “Amazing,” says Thomas. Some of their common names refer to their flavor and appearance, including “savory milk cap” and — Gump’s favorite — “little cake.” “They are very nice,” he explains. But Thomas won’t be tempted to pick a favorite. “I love them all,” he says with a laugh. “There are a lot of really great ones.”