Research snapshot: Dooks needle blight on the rise in white pine; Macedonian pine hit especially hard + facts about eastern white pine

What question did researchers ask and why?  

In 2010, an outbreak of Dooks needle blight was discovered in a five-needle pine genetic archive* in OFRI's arboretum near Sault Ste. Marie. This outbreak gave OFRI research pathologist John McLaughlin, research geneticist Pengxin Lu, and their colleagues the opportunity to determine how susceptible various pine species are to this disease, which is native to North America.

Dooks needle blight killed this Macedonian pine in OFRI's arboretum.

What did they do?

They surveyed all the trees in this archive to see which were diseased and how severe the infection was.

What did they learn?

Western and Himalayan blue pine were found to be susceptible to Dooks needle blight, a first for these species. Also, Macedonian pine and hybrids that were partly Macedonian pine were shown to be very susceptible and most damaged by the infection. Japanese and Korean pine showed no symptoms, nor did hybrids between eastern white pine and Himalayan blue pine, which OFRI researchers had bred for resistance to the invasive alien disease known as blister rust (read more about blister rust resistant hybrids).  

Who can use these research results?  

These results are important to those who are considering planting Macedonian pine for ornamental purposes or breeding for resistance to blister rust (this species is no longer used in blister rust breeding research in Ontario because it did not offer a useful level of resistance). Researchers, landscapers, and homeowners should not plant Macedonian pine in North America because it could increase the vulnerability of other white pine species to Dooks needle blight by contaminating their gene pool with susceptible genes.
 

Where to get more information:  

See the article entitled New Hosts and Differential Susceptibility of Five-Needle Pine Species to Dooks Needle Blight (Lophophacidium dooksii) (Journal of Plant Pathology), available from OFRI, or contact John McLaughlin or Pengxin Lu at OFRI.

*A genetic archive is a plantation of trees with known, high-value genetic traits such as superior growth or disease resistance.

Did you know…? Facts about eastern white pine

“Like the land, the white pine was also a provider. Its pale, light, easily worked wood quickly gave us a livelihood, a prosperous economy, shelter, something to sit on – even matchsticks. The white pine also taught us that even plentiful natural resources have to be carefully managed. The great pine forests that challenged and rewarded our first settlers are gone. But the white pine will never die out.” From White Pine: Ontario Celebrates Its History (1984)

• Eastern white pine is Ontario’s provincial tree and the king of the eastern North American forest. No other eastern species grows as tall.
• Eastern white pine can live to be more than 500 years old. And white pine logs can be even older! In the mid-1990s, OFRI researchers discovered that some white and red pine logs lying around lake shorelines in Algonquin and Lady Evelyn Smoothwater provincial parks are a thousand or more years old, with the oldest having germinated in the late 800s, lived up to 500 years or more on land, died, and fallen into the water, where they’ve been floating ever since. Researchers suspect that logs submerged in the muck at the bottom of these lakes are even older! So protect those old logs along your cottage shoreline: They might have been around since the time of the Vikings!

Giant white pine in Algonquin Park in about 1910. These trees were probably at least 40 metres tall and more than a metre and a half in diameter. "For more than a hundred years, the white pine was the dominant factor in the growth and development of Ontario." ~ From White Pine: Ontario Celebrates Its History (1984)

• The tallest known tree in Ontario is an eastern white pine near Haliburton that’s about 50 metres tall. That’s as tall as a 15-story building!
• Eastern white pine is sometimes confused with red and jack pine. But white pine is the only native eastern North American pine species with five needles per cluster and long cones. Red pines have two needles per cluster and short, fat cones. Jack pine needles also grow in clusters of two, but their needles are shorter, spread out in a V shape, and tend to be slightly twisted. And jack pine have small cones that grow in pairs that look like rams’ horns.
• Fire is important to white pine ecosystems: White pine seeds germinate well on burned seedbeds, and white pine seedlings grow better in forests where some of the overstory trees have been killed (a closed canopy offers too little light).
• In the early 1800s, European settlers marvelled at the white pine’s tall, straight trunk with few lower branches. They began harvesting them to ship back to England for use as masts initially for British naval ships. They also used eastern white pine to build everything from cradles to cabins to coffins. It is still used for flooring, furniture, window frames, fencing, panelling, log homes, and more.
• Many birds and small mammals use eastern white pine for food and shelter. Bald eagles, osprey, and other birds of prey love to use large white pines for their nests. Black bears also eat white pine seeds, and mother black bears use white pines as day care centres, sending their cubs up these trees to keep them safe.
• First Nations people valued eastern white pine highly; the Iroquois called it the Tree of Peace because of its size and grace. First Nations use of white pine include:
  
  • For food: The tribe name Adirondack likely comes from the Iroquois word for “bark eaters,” referring to Algonquian people who ate the inner bark during winter famines.
  • For medicine: First Nations people used both the needles and resin for medicines, including utilizing the antiseptic properties of pine resin in ointments and tonics. (Pine was also a popular ingredient in many patent medicines sold during the 1800s; some cough syrups still contain pine oil.)
  • For transportation: White pine resin was useful for sealing seams of canoes, and various First Nations around eastern North America used large white pine trunks to make dugout canoes that could hold up to 40 people.
• Eastern white pine is targeted by dozens of insects and diseases. One of the most challenging is blister rust, an invasive non-native fungal disease that eastern white pine has no resistance to.
• Also see Ontario's Tree Atlas: Eastern White Pine (Pinus strobus)

 

Large white pines are a popular nesting site for eagles and other large raptors. Photo: Lyn Thompson, MNR's Southern Science and Information Section.

In the early days, loggers squared off giant pine so they would stack neatly in the holds of timber ships. The loss of up to half the timber from each tree was not seen as a big deal, as the supply of pine seemed inexhaustible. "Wherever white pine stood, railways were built to reach it. Wherever railways went, sawmills followed. And wherever there were mills, communities grew up." ~ From White Pine: Ontario Celebrates Its History (1984)