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	<strong>Question: </strong>Allow me to set the stage: &nbsp;You&#39;re on a walk through the woods. &nbsp;It&#39;s wet. Autumn lake-effect rain and snow falls in temperamental waves dampening everything. &nbsp;Looking up from the trail you notice something white on a pine tree. &nbsp;Snow perhaps? &nbsp;You walk closer to investigate. &nbsp;Bubbles! &nbsp;As you look around you spot several more trees all exuding similar bubbles. &nbsp;What is going on? &nbsp;Why are bubbles forming on the bark of these pine trees?</p>
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	<img alt="" src="{filedir_5}Tree Foam(1).jpg" style="width: 300px; height: 201px; " /></p>
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	<strong>Answer:&nbsp;</strong>The bubbles on the trees above is actually the formation of a &quot;crude&quot; soap compound. When it is dry, particles from the air deposit themselves on the surface of tree bark (like dust). This dust includes bits of salts, acids and other particles in the air. When it rains, these particles dissolve into a liquid solution. Soap is essentially a chemical mixture of salts and acids formed into a molecule. The primitive soap then foams as it moves down the trunk and hits a rough patch. You can also see this phenomenon on paved roads after a long dry spell followed by rain, where the tires on cars are what stirs up the soap bubbles*. &nbsp;&nbsp;</p>
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	<strong>Additional insight (from our Field Botany professor, <a href="/news_and_resources/blog/faculty_profiles_ken_sytsma_field_botany#.Uymz7_ldVIE">Ken Sytsma</a>):</strong> Pines produce a whole array of natural hydrocarbons for herbivory defense. One set of these is &quot;pine tars&quot; that have been used in the past to make soap. As precipitation works its way down trunks of pines, they accumulate these compounds. What you may be seeing is natural pine soap in the making.</p>
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	<strong>Thanks to Vermont State Parks and Ken Sytsma for providing the answers!</strong></p>
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	*Phelps, Rebecca. &quot;What&#39;s with the Foam I Saw on the Trees Yesterday?&quot;&nbsp;Vermont State Parks. Vermont State Parks, 9 May 2012. Web. 11 Mar. 2014.</p>
