Worldwide research has been suggesting for years that trees will be moving north. However, a paper “Soil abiotic and biotic properties constrain the establishment of a dominant temperate tree into boreal forests”, published in the Journal of Ecology, 2020 doesn’t expect sugar maples, Canada’s sweet, iconic tree will make the trip.
Researchers found, “sugar maples grown in soil from the boreal forest had substantially poorer performance than those grown in the transition zone between temperate and boreal forests. Likewise, sugar maple trees grown in boreal forest soil and inoculated boreal forest soil performed 37 per cent and 44% worse respectively than those grown in temperate forest soil.”
The researchers also noted that the pH of boreal forest soil might have negatively affected sugar maple survival rates. Meanwhile, soil from temperate forests, where sugar maples typically grow, allowed for better arbuscular mycorrhizal fungal colonization in the trees' roots, which can promote tree survival and growth.
The researchers said, "Due to the interaction of biotic and abiotic factors, boreal forest soil seems to offer a less hospitable environment for sugar maple trees than other soil types. While global warming might have made it physiologically possible for sugar maple trees to grow in more northern areas, the soil conditions in these areas make a northern migration less likely."
Cal Gilbertson, an Algoma maple syrup producer said, “Why move maples north at all? Due to better technology, we have higher production than ever before. We’ve seen some erratic swings, trees go through cycles.”
Ray Bonenberg, Chair of Communications for the Ontario Maple Syrup Producer’s Association said, “Soil is key to syrup production. Maples don’t like acid soil. However, they also don’t like cold. If it is minus 35 for a couple days they die. I don’t buy that we will see maple forests in James Bay. Trees don’t adjust that fast. With the variations in weather, we are seeing drought, heat spells, and wind events. What the books told us 30 or 40 years ago doesn’t work anymore. We just don’t know. We are seeing breakage. Trees that looked healthy just die. I am so careful thinning now. Don’t go hog wild. Thinning allows in heat, wind and drought. It is the combination. We don’t have enough research anymore to put it all together. Maple syrup is an agricultural crop. This is a high risk game.”
— Pat Kerr