The lombardy poplar in the south-east corner of the park is the biggest of its type on record, while the maritime pine close by also clocks in at No.1.

The title of "biggest tree of its type" is based on a three- dimensional formula using height, girth and crown spread.

Mr McIntosh said he found the system in the US, where people took great pride in nominating big trees they thought might be the biggest in the country.

Trees are given a points score based on the three measurements, and Tasmania scores highly.

Five of the six biggest trees in the country are in Tasmania, including the Tahune Airwalk's mountain ash, which is also the tallest tree in Australia.

Mr McIntosh said he had always been interested in trees and decided last year to travel the country looking for the biggest ones.

"What made it possible was the internet," he said.

Mr McIntosh's website allows people to nominate a big tree in their region and sort trees by state, size, name, town and age.

Mr McIntosh said he would be in Tasmania until Tuesday checking out trees that could claim the title of biggest of their type.

•Mr McIntosh's website is nationalregisterofbigtrees.com.au .

- ANGUS LIVINGSTON