A new study by the University of California Davis has determined that creating a ski run by clearing trees and foliage manually but leaving the underlying eco-system otherwise intact is better than using heavy machinery to re-grade the slope.

The findings are not just on environmental grounds, but also found that operating cost of machine-cut slopes were higher than those of slopes which had been left in a more natural state.

The report authors believe that this makes the slopes more expensive to maintain to, offsetting and extra income that may be made by being able to open a machine cur slope a week or so earlier in the season as machine-cleared slopes require 20% less snow cover to be able to open.

Ski slope grading by heavy machinery is worse for plant abundance and diversity, reduces soil depth and fertility, and promotes erosion.

The study was compiled by UC Davis ecologist Jennifer Burt and professor of plant sciences Kevin Rice.