Research snapshot: Modelling effects of climate change on diameter growth of jack pine and black spruce + facts about jack pine and black spruce

Highlight

 

This research was published in Global Change Biology, a prestigious climate change journal.

 

What question did researchers ask and why?

 

How will climate change affect future stem diameter growth of Ontario's two most important commercial tree species (black spruce and jack pine)? 

 

Tree cookies are an important source of data for modelling stem diameter growth in the boreal forest. OFRI researchers are also ensuring these models reflect expected climate change, so forest managers have a more accurate picture of Ontario's future forest.

What did they do?

 

They modified diameter growth models to include climate variables, using data from tree rings from black spruce and jack pine growing in Ontario's boreal forest.

 

What did they learn?

 

Based on their modelling results, jack pine will likely grow better in a warmer climate, while black spruce growth will likely decrease. Growth of both species would benefit from more precipitation during the wettest months of the year but not from overall wetter growing seasons. Overall, if the climate changes as expected, conditions will favour jack pine over black spruce.

  

Who can use these research results?

 

Those studying the effects of climate change on the boreal forest—as well as those responsible for planning future forests and modelling wood supply—can use these models to:

• explore the effects of future climate on tree diameter growth
• reduce uncertainties about the future sustainable supply of forest products and ecosystem services from Ontario’s boreal forest under a changing climate

Where to get more information:  

• Contact Mahadev Sharma or read the article entitled Climate-Diameter Growth Relationships of Black Spruce and Jack Pine Trees in Boreal Ontario, Canada (Global Change Biology), available from OFRI.
• Former OFRI Researcher Nirmal Subedi was also involved in this research. 

Did you know...? Facts about black spruce

Black spruce often have scraggly form, with drooping branches with upturned tips, often festooned with lichens, as well as a characteristic full cluster of branches at the top called the club or crow’s nest.

This skinny conifer is tough as nails, the Survivorman of the northern forest. It grows in the coldest, harshest climates and sites in Ontario, from bogs to dry slopes. Black spruce grows the farthest north of any conifer except larch. Also found throughout the boreal forest and into central Ontario, black spruce is the most common tree in Ontario and the most widely distributed, most cold-hardy conifer in Canada.

 

More about black spruce:

• The scientific name for this species is Picea mariana. It was named after Maryland (mariana = of Maryland), although it doesn’t grow there!
• Black spruce is the most important tree species to Ontario’s forest industry. Its wood has long, soft, twistable fibres, so it’s perfect for paper making.
• This species is one of the shortest Ontario conifers; in some places, it looks more like a shrub than a tree. And black spruce don’t live all that long (60-200 years), because they regularly burn or get blown over by the wind. But they are used to disturbance; fire helps renew black spruce stands by causing cones to release seed.
• Black spruce grow slowly, often in pure stands (groups of one species) and have shallow root systems that allow them to grow in places other trees cannot, such as permafrost, bogs, and shallow soil over bedrock.
• Black spruce growing on higher, dryer sites tend to be taller and thicker. Those growing in wet areas are more scrubby.
• The easiest way to tell a spruce from a pine hemlock, fir, or larch is…you don’t want to shake hands with a spruce! Spruce needles are prickly!
• Also:
  • Spruce have shorter needles than pines and they grow individually from the stem, while pines have much longer needles in clusters of 2, 3, or 5.
  • Spruce needles grow densely all around the branch tip while hemlock and fir needles grow out from the sides of the twigs.
  • Spruce needles are very short and solid, compared with larch needles, which are longer and very soft.
• Telling a spruce from a pine is easy. But even foresters and botanists can have trouble distinguishing the spruces. Some tips:
  • Norway and blue spruce (not native to Ontario) have square needles that are difficult to roll between your thumb and forefinger.
  • Black, white, and red spruce have more rounded needles that you can roll.
  • Try crushing some needles: If it smells like menthol, it’s a black spruce; skunk or cat pee, it’s a white spruce; and orange rind, it’s a red spruce (relatively rare in Ontario).

  Thanks to Northern Woodlands magazine for permission to adapt their photo; see their informative article about identifying spruces at http://northernwoodlands.org/knots_and_bolts/spruce-up-your-id-skills.

  • Black spruce have very short needles, red spruce needles are slightly longer, and white spruce needles are the longest.
  • Black spruce are more likely to grow on poor sites, and white spruce are usually better looking. Black spruce often have scraggly form, with drooping branches with upturned tips, often festooned with lichens, as well as a characteristic full cluster of branches at the top called the club or crow’s nest.
  • Black spruce have the smallest cones of the three Ontario native spruces (about 3 cm long). Old cones hang on trees for several years. Viable seeds have been found in 20 year old cones! Pollen cones are dark red.
• Two pests that often affect black spruce are dwarf mistletoe and spruce budworm. The former is a parasitic plant that engulfs the crown and forms what are called witches’ brooms.
• Aboriginal people used black spruce in many ways:
  • Wood: to make shelters, canoes, fish traps, snowshoe frames, drying racks
  • Roots: to bind birch bark canoes and baskets and make fishing nets
  • Sap, resin, and inner bark: to heal wounds, burns, rashes, and inflammation
  • Spruce beer: to prevent scurvy and treat other ailments, such as diarrhea and sore throats (also made by European colonists and still made in some parts of North America today!)
  • Spruce gum: for chewing! Was very popular among the general public a century ago
• Wildlife love spruce! Dense spruce stands create cool shade that provides cover for wildlife. Black spruce provide food for moose, caribou, spruce grouse, snowshoe hare, and many rodents, birds, and insects.