Mr Sauro was originally found guilty of wilfully destroying the trees by a district judge, following a trial at Swansea Magistrates’ Court in 2019.
But addressing the appeal hearing on Friday, Judge Christopher John Vosper said: "We take the view that this was not, as the district judge judged it to be, a deliberate act, calculated to make a profit for the company.
“It seems to us that there was no financial advantage to Mr Sauro in having these trees cut down.”
A fine of £180,000 for Mr Sauro and a further £120,000 for his company was reduced to a total of £100,000, with £32,500 in legal costs.
His barrister told the court the developer had “suffered greatly” due to a “highly publicised” trial and deeply regretted" what had happened.
The contractor Arwyn Morgan had pleaded guilty to breaching the preservation order and was initially fined £120,000. This has now been reduced to £6,000.