Softwood trees in Canada’s Maritime provinces declining due to global warming – “By the end of the century, those species that industry relies on heavily won’t be performing as well as they are today”

Desdemona Despair

By Michael Tutton
27 October 2017

HALIFAX (The Canadian Press) – A new federal study says climate change in the Maritimes may lead to a gradual reduction in the growth of softwood trees, which are crucial to the region’s pulp industry.

Using computer models, the Natural Resources Canada study marks the first regionwide assessment of the composition and growth of the Acadian Forest to the end of this century.

The forest is carefully watched in forestry circles, as it is a unique mix temperate forests, with warmer weather trees like red maples, and boreal forests that include fir and spruce.

Assuming that greenhouse gas emissions continue at “business as usual” levels, the study says the woodlands will experience an average temperature rise of 7 C by the end of the 21st Century.

As a result, in the latter half of the century trees like red spruce will decline in abundance between 10 to 20 per cent when compared with 2011, while the hardwoods that prefer warmer climates will increase.

The study’s author, scientist Anthony Taylor, says there are still some uncertainties about the model because some factors are still being studied.

Still, he says the model presents some causes for concern for the forestry industry.

“It’s suggesting … by the end of the century those particular species that the industry relies heavily on will not be performing as well as they are today,” he said in an interview. […]

The study, published in the journal Forest Ecology and Management, predicts there will be an overall decline in the size of the Acadian forest because the increase in hardwoods like red maples won’t make up for the lost softwoods. […]

“It’s very worrying. … When the timber supply is reduced by a certain percentage you get a similar reduction in the forestry sector and that’s a lot of money.” [more]

Maritimes’ softwood trees in decline due to global warming, study warns

ABSTRACT: The impact of climate change on forests is expected to vary globally and regionally. Canada’s Acadian Forest Region lies in the transition between the North American boreal and temperate forest biomes and may be particularly sensitive to changes in climate because many of its component species are currently at their southern or northern climatic range limits. Although some species may be lost, others may exhibit major productivity boosts—affecting the goods and services we derive from them. In this study, we use a well-established forest ecosystem simulation model, PICUS, to provide the first exploration of the impact of climate change on the composition and growth of the Acadian Forest Region for the period 2011 to 2100 under two radiative forcing scenarios, RCP 2.6 and RCP 8.5.

In the short term (2011–2040), little to no changes in forest composition or growth were projected under either forcing scenario compared with current forest conditions (simulated for 1981–2010 baseline climate); however, by mid-century, PICUS projected increasing departures from the baseline simulations in both composition and growth, with the greatest changes occurring under RCP 8.5 during the late 21st century (2071–2100). Our study indicates that under rapid 21st century warming, Canada’s Acadian Forest Region will begin to lose its boreal character (i.e., “deborealize”) as key tree species fail to regenerate and survive. Furthermore, increased growth and establishment by warm-adapted, temperate tree species may be unable to keep pace with the rapid loss of boreal species. This potential “lag effect” may lead to a temporary decrease in forest growth and wood supply during the late 21st century.

Rapid 21st century climate change projected to shift composition and growth of Canada’s Acadian Forest Region