Leave the Leaves on the Hiking Trails!

A layer of leaves protecting the trails
from freeze/thaw cycles at Boehm Pond

It makes perfect sense to blow leaves off the hiking trails, except that it doesn't. The trail is suddenly easier to walk for a few weeks. What could be bad about that? 

For one thing, erosion. Here in southern Connecticut, we'll likely have months of freeze/thaw cycles. It freezes at night and the top of the soil thaws in the afternoon. Hoar frost crystals often form through the top layer of damp soil, loosening the particles, then melt. Over and over, all winter. In between will be some rain storms that can wash away those loosened soil particles. Over the course of ten or twenty years, the damage may be significant. As the soil washes away, rocks and tree roots are exposed. No one wants to walk on a trail full of rocks and roots. A layer of leaves on the trail insulates the soil from many of the daily freeze/thaw cycles. 

Hoar frost is common on damp trails
where the soil is exposed

Winter "greasy" mud: Another impact of removing leaves is that after the ground freezes, and the afternoon sun comes out, the top quarter inch or so of soil tends to melt in some spots.  That top wet layer over the icy ground makes the trail slick and "greasy."  On our hillier trails at places like Indian Well or Birchbank, you can see long slide marks down the mud if there are no leaves. Someone was going down a hill and took a nice long slide when they weren't expecting it. When conditions are like that, hikers seek out leaves to step on rather than exposed soil. 

Leaves protecting the Paugussett tread

Footfall impacts: Then there is just the normal impact of feet hitting the ground. When there is a nice layer of leaf mulch over the soil, those feet aren't landing directly on the soil or on plant roots. Those roots, especially the small ones, are holding the soil together, and the more you step on them, the more they die back and let go of the soil they're holding on to. Imagine a planting bed at home with tomatoes or shrubs. A nice layer of mulch protects those roots and the soil. 

Garlic Mustard taking over
the Paugussett Trail

Invasive Species: There are a few invasive species that are notorious for traveling up and down hiking trails, especially Stiltgrass and Garlic Mustard. These are annual species that die after a year or two, but not before spilling out millions of seeds all over the trails. Hiker boots pick up the seeds and carry them down the trail. If the seed lands on bare ground and is exposed to the sun, it can sprout. If it lands on a layer of leaves, it can't. These species come in so thick and so fast that they can obscure a hiking trail in just a couple weeks. The seed heads may be 5 feet tall and they flop over the trail. 

Loss of future soil: Today's leaves break down into tomorrow's soil. When you leave the leaves, they eventually break down into new soil that help to counteract the soil compaction from people's feet as well as soil loss from erosion. Note this will take years for oak leaves but only a few months for some areas with maples and birch if there are invasive jumping worms (think lower Birchbank). 

EXCEPTIONS: For every rule, there are exceptions. This doesn't apply to our multi-use trails like the Rec Path, which has a crushed stone surface. Stairs and switchbacks, especially in areas with a lot of oak trees, are simply too hazardous when covered with leaves, and people often can't even see the stairs because of all the leaves. This happens every year along the Paugussett Trail, especially going up the steep hill from Princess Wenonah Drive. Those tricky spots will get raked off.  New trails are raked out to remove years of rotting sticks and to help establish the new tread. Tricky spots where a trail is hard to see near houses might get hit with a leaf blower so that the trail tread is obvious to both hikers and the adjacent homeowner. It's a judgement call, and no two trail managers will make the same call.