Planting forests while growing protein-rich foods seems like a win-win, so are there potential downsides? Lynne Boddy, professor of fungal ecology at Cardiff University, believes mycoforestry “absolutely” has the potential to produce important food crops while sequestering carbon. However, he advocates taking “great care” when doing so. “In my opinion, whenever we inoculate something, it has to be locally sourced,” he says of the mushrooms. “There is concern that it may be an invasive genotype if it comes from somewhere else. Even if it comes from Britain and you’re just planting the same thing in an area, there’s a risk of diluting the gene pool. “Local species diversity is also likely to decrease.”
Thomas says these are valid questions, but points out that this project focuses on using fungal species native to the planting area and with less aggressive strains than those already currently inoculated in many nurseries to stimulate tree growth, although it acknowledges that there could be potential for another company to seek 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 they are left standing or produce wood that is used as building material, that removes carbon from the atmosphere in the long term. But if the wood ends up decomposing or burning (as Christmas trees often do), much of the extracted carbon could return to the atmosphere. Even so, this cycle would still produce proteins with a low net carbon footprint.
Jump believes this process could make future Christmas trees more sustainable. The conventional way of growing Christmas trees is “a pretty inefficient system, if you look at it from a carbon perspective,” he says. “You may be absorbing carbon from the tree, but then destroy them after Christmas. Getting the mushrooms associated with Christmas trees is actually a good way to reduce your carbon impact.”
A milk mushroom.Courtesy of Mycorrhizal Systems Ltd.
But the main question is: what do mushrooms taste like? “Unbelievable,” says Thomas. Some of their common names suggest their taste and appearance, including “delicious milk cap” and, Jump’s favorite, “penny buns.” “They’re so cute,” he explains. But Thomas won’t be forced to pick a favorite. “I love them all,” he says, laughing. “There are too many really interesting ones.”