Lodgepole pine dominates the Greater Yellowstone landscape. The drastically varying heights of the trees are a poignant reminder of a powerful force in the ecosystem, that of fire. This remaining stand of trees high above the Madison River has always impressed me. These few trees somehow survived while everything around them burned to the ground. Though we feel a sense of loss after a major burn, fire is not necessarily a bad thing, nor does it get the last say when it comes to these trees.
The lodgepole pine is equipped to respond to fire in a remarkable way. Their secret is found in a condition called serotiny. Now that we got the fancy word out of the way, what does it even mean? Many of the female cones produced by lodgepole pine remain closed, until they are met with the extreme heat of a fire, at which time the cones open and disperse seeds all over the forest floor. This is why you see such a high density of young trees growing in areas that have previously burned. The smaller trees pictured in the foreground here are 30 years old! They have a long way to go before reaching the heights of their forbears.
The lodgepole pine, making up 80% of the Yellowstone forest, is remarkably resilient in its ability to grow in less than ideal conditions. Here, the poor conditions eventually took their toll. The wet and mineral laden sulfuric soil around hydrothermal features is a tough place to survive.
These trees are known as bobby socks trees because of the white section on the lower trunk which resembles bobby socks. As the trees absorb the water from hydrothermal runoff they also take in minerals. When the water evaporates, the minerals remain and turn the bottom of the trees white.