Fallen Leaf Management

Every year around the middle of October, the trails begin to vanish under a cover of fallen leaves, and every year as the leaves come down, the debate about whether they should be removed from the trail or left alone arises. After years of discussion, experiments, and first-hand observations, we have arrived in support of generally doing nothing about the leaves with only a few noted exceptions. This isn’t to say that many of the arguments for leaf removal aren’t valid, because they are often solid arguments. But the arguments for doing nothing about the leaves tend to outweigh those for removal.

When the leaves begin to fall in earnest and autumn winds scatter them equally throughout the woods, the trails truly can be difficult to discern, especially if you are unfamiliar with them. And even if you are familiar with the trails, heavy leaf cover during a night ride can make the trail vanish under your tires. This results in riders going off-course, creating confusing dead-end spurs near curves and intersections. However, it only takes the passage of a few riders down the trail to create a concave “trough” in the center of the trail tread. From that point forward the trail gets easier to spot with each passing rider. The total amount of time during which the trails are really tough to see typically does not exceed three weeks.

A layer of slick leaves over already tricky obstacles may be frustrating to the novice rider but seasoned riders find great reward in the variety and seasonal challenge. A leaf-slick trail requires a much higher level of attention and skill, meaning that the reward of successfully riding each section of trail is enhanced. Riders convinced that all of the trails should be blown totally clean in order to make them easy should perhaps consider riding on the sidewalk instead of the trails. (Of course a beginner trail is the exception here since they are supposed to be easy.)

The fact is, the above arguments for and against leaf removal really come down to not much more than personal opinion. However, one argument against leaf removal happens to be the most valid in context of trail management and is not simply a matter of opinion. It is the argument that a thick layer of leaves protects the trail tread during the times of year when it is most likely to be damaged by user-sourced erosion.

Late fall through early spring is when much of the year’s precipitation occurs. This is also the time period during which repeated freeze-thaw cycles and frost heave result in severe vulnerability. The best solution for avoiding damage to the trails during this time period is to stay off the trails completely, but years of experience demonstrate that the trail using community does not adequately self-regulate for this to be an acceptable approach to trail management. Fortunately, fallen leaves offer a valuable layer of protection between tires and the trail. When a leaf-covered trail is damp and a rider loses traction, the skid/spin-out disturbs only the leaves on the surface while the trail tread beneath remains un-impacted.

Also of great value is the water dispersing and slowing effect of a good leaf cover. During heavy rain events, water will maintain the greatest velocity on a bare trail. Leaf litter on the trail will slow the water, providing dual benefits. First, the slower water travels, the less erosive power it has. Second, when water slows down it drops any sediment load that it was carrying. So leaf litter on a trail helps to prevent erosion and allows any eroded soils to be deposited on the trail where they can perhaps even reverse some effects of erosion.

Having said all of this, there are times when a leaf blower is appropriate. New trail construction is one example. In order to properly cut and compact a new trail, the organic material must first be removed from the trail tread. A leaf blower makes short work of this. Another example is on trails clearly meant for beginners where slick leaf cover could create dangerous conditions or worse yet, make the trail so challenging that the beginner rider may get frustrated enough to quit the sport. And finally, when spring time rolls back around and the nearly composted leaf detritus is holding moisture in the trail tread, removing the leaves allows the trail to dry properly.

So while you may be temporarily frustrated by a thick blanket of leaves in the trail, know that they’re there for good reasons. Also take comfort in knowing that they’ll quickly pack down to almost nothing. And most of all, enjoy the seasonal variety and beauty.