55000 hectares(just under 136000 acres)This has them as 8th: Who owns England?
The Minister for Transport as them as 4th: Jo Johnson on Twitter
Some rail mag has them as 4th: DfT launches review as Network Rail told to stop axing trees this season
The Government has them as 4th: Rail Minister launches review of tree cutting alongside rail lines
I'm going to be quietly confident they're somwhere around 4th.
https://cdn.networkrail.co.uk/wp-co...-Rail-Property-Open-for-Business-brochure.pdf
So outside the top 10.