Oliver Frost, studying part time for a foundation degree at Kingston Maurward College, Dorchester, spoke at the Tree Diseases Conference.
"Natural systems must be supported and emulated wherever possible," he said. "Diversity equals stability and reduces the chance of catastrophe within the system."
The event, hosted by the RFS and the Royal Agricultural Society of England, looked at the human potential to inadvertently spread new and potentially devastating pests and diseases to a wide range of trees including acute oak decline.
Dr Joan Webber, principal pathologist for Forest Research, warned that introductions of new pests and diseases appeared to be "increasing in tempo".
Acute oak decline could change the face of the UK landscape the way Dutch elm disease did, the conference heard. Other problems included sudden oak death, oak processionary moth, horse chestnut leaf miner and bleeding canker.
Frost works in woodland management and has started a small nursery growing amenity trees in Somerset.