From Pine Tree to Pine Tar (and a bit about baseball)

Scots pine (Pinus sylvestris) is a Eurasian native, distributed across Europe into Eastern Siberia. It is the national tree of Scotland, and the only native pine in northern Europe. Human activity has pushed native populations to extinction; while, at the same time, appreciation for this tree has led to widespread introduction in other parts of the world. Like other pines, humans and Scots pine have a long relationship going back millennia. Pines are incredibly useful trees, which explains both the overexploitation and mass planting of Scots pine.

Scots pine (Pinus sylvestris) via wikimedia commons

In Sweden and other Scandinavian countries, Scots pine not only has a long history of being used as a building material, but also for producing pine tar. As the name suggests, pine tar is a dark, sticky substance extracted from pine wood. Wood tar production dates back centuries and has been made from a number of tree species, including pines and other conifers as well as deciduous trees like birch and beech. Wood tar has myriad uses – as an ingredient in soaps, shampoos, and cosmetics; as medicine; as a food additive; as waterproofing for ships, roofs, and ropes; in hoof care products for horses. It’s no wonder that as demand for pine tar increased in Scandinavia, it became a cash crop for peasants, earning it the nickname “peasant tar.”

Pine tar soap – a decent soap if you can tolerate the intense smell. Regarding the smell of pine tar, Theodore Kaye writes, “The aroma produces reactions that are as strong as the scent; few people are ambivalent about its distinctive smell.”

A study published in the Journal of Archaeological Science examines small and large funnel-shaped pits in Sweden determined to be used for making pine tar. The smaller pits date back to between 240 – 540 AD, the Late Roman Iron Age. They would have been used by Swedes living in small scale settlements. The larger pits date back to 680 – 1160 AD and signify a shift towards large scale production during the Viking Age. As the centuries proceeded, Sweden became a major exporter of pine tar. Their product set the standard. Even today “Stockholm Tar” refers to pine tar of the highest quality.

As Europeans colonized North America, they were introduced to several new pine tree species from which to extract pine tar, including longleaf pine (Pinus palustris), a southeastern native with exceptionally long needles. Pine tar production was especially prolific in the southeastern states, thanks in part to the abundance of longleaf pine and others. North and South Carolina were dominating production by the 1800’s, which helps explain North Carolina’s nickname, The Tar Heel State.

Extracting pine tar from pine wood is fairly simple. The process is called destructive distillation. Pine wood is placed in a contained, oxygen-free environment and subjected to high heat. As the pine tar is released from the wood, the wood turns to charcoal. This is what was happening in the small and large funnel-shaped pits discussed earlier. Root pieces and stumps of Scots pine were placed into the pits. Brush wood was piled on top and then set on fire. As the brush burned, the pine wood below carbonized, and pine tar collected at the bottom of the pit. In larger pits, the pine tar was piped out and deposited into a barrel – a set up known as a pine tar dale.

pine tar dale illustration

Modern production of pine tar is done in kilns (or in laboratories). The concept is the same – wood is enclosed in the kiln, heat is applied, and pine tar drips from the bottom of the kiln. Heartwood, also known as fatwood, is the best part of the pine tree for making pine tar, particularly the heartwood of old stumps. Making pine tar is such a simple process that anyone can do it, and there are numerous tutorials available online.

My familiarity with pine tar comes from being a baseball fan. Pine tar is a useful, albeit controversial, substance in this sport. Batters have a variety of means to help them get a better grip on the bat in order to improve their hitting. Rubbing pine tar on the bat handle is one of them. However, according to Major League Baseball rules, anything applied to, adhered to, or wrapped around the bat to help with grip is not allowed past the bottom 18 inches of the bat. Pine tar is allowed on the bat handle, but if applied past that 18 inches mark, the bat becomes illegal.

pine tar stick for baseball bat handles

This rule goes mostly ignored; unless, of course, someone on the other team rats you out. Which is exactly what happened in 1983 to the Kansas City Royals in a game against the New York Yankees. Royals batter, George Brett, had just hit a home run, which put the Royals in the lead. It had been suspected for a while that Brett had been tarring his bat beyond the legal limit, and this home run was the last straw for Yankees manager, Billy Martin. He brought the suspected illegal bat to the attention of the umpires, and after measuring the bat’s pine tar stain they found it to be well beyond 18 inches. The home run was recalled, and the Yankees went on to win the game.

It doesn’t end there though. After a repeal, it was decided that the dismissal of the home run was the wrong call. If an illegal bat is in play, it should be removed. That’s all. The home run still stands. The Royals and Yankees were ordered to replay the game, starting at the point where Brett had hit his home run. This time the Royals won.

This saga is well known in baseball. There is even a book all about it, as well as a country song and t-shirts. But that’s only part of baseball’s pine tar controversy. While batters are allowed to use it on their bats, pitchers are not allowed to use it to better grip the ball while pitching (however, they can use rosin, which curiously enough, is also made from pine trees). Of course, that doesn’t stop them from trying to get away with it. Sometimes they get caught, like Michael Pineda infamously did in 2014. There are arguments for allowing its use – and perhaps in the future the rules will change – but for now pine tar use by pitchers remains prohibited.

Further Reading – Medicinal Uses for Pine Tar:


Lichen-eating Reindeer vs. Chernobyl Nuclear Disaster

Earlier this year I wrote about a lichen that was named after President Barack Obama in which I included a brief introduction to lichens. They are fascinating organisms that are actually two organisms in one – a fungus and an algae or cyanobacteria. They are not plants, but are often appreciated by plant enthusiasts, probably due to their plant-like appearances and behaviors and because they commonly associate with plants. Lichens have great ecological importance and are regularly used by a variety of animals for food and shelter. Their sensitivity to air pollution and acid rain is well documented, which brings me to a more tragic story about lichens.

As Heloise Rheault puts it in the book, Nature All Around Us, “Lichens live essentially from the light and water they obtain directly from their environment. Because they have no way to regulate or filter these resources, they directly absorb all particles suspended in the air and in rain, including all pollutants.” Absorbing enough pollutants over time can lead to the death of lichens, which is why researchers can use the presence or absence of lichens to map polluted areas. Lichens that have absorbed high levels of pollutants might also be eaten by animals, which moves these toxic substances up the food chain.

On April 26, 1986, the world’s worst nuclear disaster occurred at the Chernobyl Nuclear Power Plant in what at the time was the Ukrainian Soviet Socialist Republic. An explosion and fire completely destroyed one of the reactors and sent massive amounts of radioactive particles into the atmosphere. The radioactive fallout quickly spread across western USSR and Europe. Areas in close proximity obviously suffered the most dramatic effects of the explosion, but effects were also felt hundreds of miles away.

One distant area where effects were felt was Lapland, a region in northern Finland where the Sami people have lived for thousands of years. Lapland is about 2300 kilometers (1430 miles) north of Chernobyl, yet the fallout was detected shortly after the blast. Due to atmospheric nuclear weapons testing, regular monitoring of radiation levels in Lapland and the surrounding areas had been taking place long before the Chernobyl disaster. In Lapland, studies were focused on radiocesium concentrations in lichens and reindeer. Lichens are the main food source for reindeer during the winter when little else is available, and reindeer are regularly consumed by the Sami people. Threatened by fallout from Chernobyl, monitoring intensified in the area.

Reindeer in Lapland, Finland (photo credit: wikimedia commons)

Reindeer in Lapland, Finland (photo credit: wikimedia commons)

A report published in Rangifer in 1990 summarized results of sampling that was carried out in Lapland in 1986 – 1987. Hundreds of samples were taken from three species of lichens in the genus Cladonia (C. stellaris, C. mitis, and C. rangiferina). These species were selected because they are “the most important ground lichen species used as winter fodder by the reindeer.” Thousands of samples were also taken from the meat of slaughtered reindeer during this period. Researchers found that higher radiocesium concentrations in lichens within the sampling area correlated with higher radiocesium concentrations in reindeer within the same area. The test results were used to determine “whether the meat could be delivered for consumption or not.”

The researchers also found that contamination of the reindeer meat varied depending on when the reindeer were slaughtered. They determined that “lichens contain higher amounts of [radiation] activity than other forage,” so in the fall after the reindeer had spent the summer eating tree leaves and other plant material, “the activity concentration in the meat decreases rapidly.” Harvesting the reindeer from December through March, after they had spent the winter eating mostly lichens, resulted in meat with higher radiocesium concentrations.

Star reindeer lichen (Cladonia stallaris) - researchers found that the concentrations of radioactivity in this species of lichen was unevenly distributed in that "the top layer of the lichen was twice the concentration of the middle layer." (photo credit:

Star reindeer lichen (Cladonia stellaris) – Researchers found that the concentration of radioactivity in this species of lichen was unevenly distributed, in that “the top layer of the lichen was twice the concentration of the middle layer.” (photo credit:

An article published in the New York Times in September 1986 told a similar story. Laplanders in Sweden lamented that 97% of the first 1000 reindeer slaughtered so far that fall “measured in excess of permissible radiation levels and [were] declared unfit for human consumption.” The reindeer had spent the summer browsing “vegetation watered by the nuclear rains,” including “rain-sopped renlav lichen savored by the deer.” This was the first year of many in which contaminated meat would have to be disposed off. The article reports on the concerns of the Sami people that “their way of life is slipping into an irradiated limbo,” especially considering that the worst of the contamination has a half-life of 30 years and “the affected lichen will linger for a decade.” A paper published in the Journal of Environmental Radioactivity in 2005 reported that high levels of radioactivity were still being detected in this region’s “soil – plant/lichen – reindeer food chain” in the late 1990’s.

This is, of course, only one of many tragic and horrendous results of the Chernobyl disaster. Even now, 30 years after the event, effects are still being felt and clean up is ongoing.

Additional Resources: