We all enjoy finding that amazing corner of the woods to call our temporary home for the night, or week; however, there might be a party pooper waiting to ruin your stay. Let’s face it, there are several things that can put a damper on your experience outdoors but there is one that is not spoken of as much as it should be…hazard trees.

In a rush? Skip to the 9 Signs of Tree Hazards.

Identifying Hazard Trees Before They Find You

Having taken several safety courses such as Emergency Medical Technician (EMT), Occupational Health and Safety Administration (OSHA) training, Mine Safety and Health Administration (MSHA) training, and others, one begins to formulate a common theme, proactive scene safety. There are things that we can do to make sure we approach a situation as safely as possible and reduce our chances of a dangerous or potentially fatal situation. Why should this be any different when we are enjoying the outdoors?

You might be telling yourself at this point, “Well, of course I am not going to camp under a tree that is waiting to fall over.” That is good and you are on the right track, but what about a tree that looks like a healthy tree?

We have all been there, whether car camping at a campground, or backpacking miles from the nearest car…the campsite in the woods. How many times do we look at our surroundings rather than what area is the flattest or most comfortable to place our bivy, tent, or sleeping bag. This is an important consideration as the environment you are setting up your temporary home has neighbors and these neighbors have likely been there for decades, or even centuries, and they have a pretty good handle on what type of things go on in those neck of the woods.

Most people do not innately find hazard trees, unless you know what to look for. I remember in graduate school taking a wonderful class called “Forest Tree Diseases.” I remember the professor telling the class one day that a former student approached him and said that he now constantly sees diseased and attacked trees when he is out recreating in the forest. Now, having taken this class, I too have a much higher awareness of diseased and weakened trees. In this course we learned a plethora of useful information but perhaps the most useful was the ability to identify hazard trees.

What is a Hazard Tree?

What exactly is a hazard tree? If you are envisioning a tree that has potential to not be where it was last night, you are barking up the right tree. A hazard tree is exactly that, a tree that presents a hazard to the persons, animals, gear, cars, et cetera that may be in the fall path of that tree or neighboring trees.

You might be telling yourself at this point, “Well, of course I am not going to camp under a tree that is waiting to fall over.” That is good and you are on the right track, but what about a tree that looks like a healthy tree? The fact is there are numerous biotic (living) and abiotic (not living) factors that can create the conditions needed for a tree, or parts of a tree, to fall.

Some of the biotic factors to consider may include mistletoe, decay disease (trunk rot and root rot), cankers, bark beetles, and others. Though these agents may not directly kill a tree, or directly weaken a tree to the point it will fall over, they can lead to mortality of the tree. However, in some cases like with root rot, a green, healthy looking tree can fall over with a little amount of force. It is important to note that heart rot can turn the heartwood (the wood in the middle of the trunk) to mush and essentially rot the tree from the inside out, just because a tree appears sound and solid on the outside, it might have the interior of mushy balsa wood.

How about abiotic agents of mortality, how do non-living things kill trees? This one may seem a little bit trickier; however, I am sure many of you have seen this in action. Some examples of abiotic agents are: freezing temperatures and snow (especially early or late season), windstorms (including hurricanes), drought, lightning, road chemicals (e.g. salt), and avalanches to name a few. It is important to acknowledge that many of these agents act in unison and often have a synergistic effect on trees, for example a prolonged drought will reduce the ability of a tree to pitch out (with sap) a bark beetle attack as the limited water the tree takes up is redirected to more imperative tasks.

9 Signs of Hazard Trees

Below is a starter list of obvious signs and also less obvious signs to be aware of when you are setting up camp.

Obvious Signs:

1) Dead and leaning trees. Pay attention to numerous dead trees on the ground as this could be a sign that some disturbance may have been, or still is present in the area. Remember they do not have to be right next to camp. If a dead tree falls, it has the potential to fall other trees it might hit. Remember, that even live, leaning trees can present a potential hazard.

2) Weather; do your research before you leave on a trip. Will there be strong winds? Lightning? Has there been a lot of rain or snowmelt? These are things that can fall even healthy trees, especially if the ground is wet. I’ve seen a mature 150 year old healthy ponderosa pine that had fallen over in a mild wind event because the ground was saturated and it wasn’t even a lone tree.

Tree felled by weather
Tree felled by weather

3) Damage to the trunk; have the trees been cut, sawed, wrapped with barb wire, clawed by bears, or hit with a vehicle? This is especially true with aspen, be very careful camping in the aspen. Damage to an aspen tree is often an entry port for disease or biotic agents, another reason not to carve them.

Tree trunk damage from bear clawing.
Tree trunk damage from bear clawing.

Less Obvious Signs:

4) Trees left standing after most trees are dead or fallen over. Lone trees that may be surrounded by similar-sized downed trees could be an indicator that something is happening, or has happened, in that stand (common group of trees) of trees. What you might not realize is the remaining trees were established in a much denser stand that were adapted to less windy conditions because there were so many more trees to distribute the force of the wind; therefore, there is now a much greater wind force on the remaining trees.

Thinning trees
Thinning trees

5) Root or trunk rot. Are there any conks (a rounded, fruiting body that can be various colors or sizes) present? These external reproductive structures that are usually visible can be a great indicator of what is going on to a tree. Phellinus tremulae, is a common one in aspen that can indicate that the aspen is rotting from the inside out. Be especially wary of conks near the bottom (also called the butt) of a tree, this can mean the roots may be unable to do their job holding the tree upright.

Colorful tree conk. Not all conks are vivid.
Colorful tree conk. Not all conks are vivid.

6) Dead branches. This is not just when the whole tree is covered with them and the tree is obviously dead, but also when there are dead or defoliated branches in a live tree. Also, do not forget about disconnected dead branches that may have been caught in other tree branches and are waiting to fall.

7) Cracks. Be observant of cracks in branches and trunks, this can definitely introduce a potential hazard.

8) Saw dust piles and/or peeling bark or piles of bark surrounding a tree. This may be an indication that bark beetles or wood borers are present in a tree, even if the tree looks alive and healthy something is likely going on.

Saw dust piles and/or peeling bark or piles of bark surrounding a tree. This may be an indication that bark beetles or wood borers are present in a tree

9) Mushrooms at or close to the base of the tree. Like the conks, this could be the fruiting body of a disease pathogen and in some cases may even be on the ground next to a tree. Their presence might be one of the few signs that there is something attacking the roots of what appears to be a healthy tree.

It is important to consider that these traits listed above should be noted whenever you spend time around trees. In other words, do not just put on the hazard tree vision when you are camping, think about these items when you park at a trailhead, are having a picnic at the park, camp in an established campground, take a break on a hike or climb, or even in your own yard.

Be safe out there and use your head, or should I say eyes and ears.

Keep it a great trip!