Trail Cutting and Maintenance Guidelines
Allelopathy is a process where one plant species uses chemicals to inhibit the growth of other plant species.
Follow the Ferns
In northeastern forests, Hayscented fern (Dennstaedtia punctilobula) pictured to right, and New York fern (Thelypteris noveboracensis) are known allelopathic species for northeast forest trees. A chemical leaches from these ferns into the soil that inhibits tree seedling growth. Thus once trees and other woody plants are cut where the ground is dominated by these ferns, little can grow back and the ferns proliferate. Typically deer and moose browsing are the agents that tip the balance in favor of the ferns, but cutting by humans with hand tools can accomplish the same.
At Mad River Glen it has been found that after two or more maintenance cycles of cutting hobblebush and undesirable trees from lines with contiguous patches of ferns underneath, maintenance needs drop dramatically. In addition, the ferns spread, and distinct patches grow together.
Therefore, when laying out a woods line, look for large groups of ferns and lay out the line from one group to the next. There are many fern species in the northeast, and many are not allelopathic, but it is a good rule of thumb to "follow the ferns". The result can be wide, flowing powder lines requiring minimal maintenance.
A Word of Caution
Once allelopathic ferns take over, few trees can reproduce and grow underneath. For this reason allelopathic ferns are a nemesis for foresters trying to harvest and reproduce a stand of trees. Once overstory trees die, getting new trees established and growing becomes difficult. This means woods ski/ride lines can become treeless and open. Hand-pulling and digging up ferns has shown some success in the literature, but there does not seem to be an easy answer. Allelopathic ferns can define wonderful woods terrain requiring minimal maintenance. What is not known is if this will create a snow-retention problem in the long term.