On average, 85% of trees with shelters survive, while 50% survive if no shelter is used.
This means that to get one tree to the point of being established at five years, surviving into adulthood, you would have to plant 1.18 trees if using shelters and two trees without shelters.
In areas with very high levels of damage by grazing animals such as rabbits, deer and sheep, the study found it was better to use tree guards.
Tree guards are generally left to degrade because it is time-consuming to collect and recycle them.
With no viable recyclable tree protectors yet available, my policy is to continue to use them, but recycle them.