Peregrine Cavendish told The Daily Telegraph Chatsworth's trees are under attack from everything from ash dieback and bleeding canker to Phytopthora ramorum, which kills larch trees, and Dothistroma needle blight, an enemy of Scottish pines. The estate has also lost around one third of its cedars, some centuries old.
Cavendish said the level of plant material being imported is at "crazy levels" but was pragmatic about measures that could be taken to stop disease spreading, short of overly-strict biosecurity measures such as "demanding that all our visitors disinfect their footwear".
And he suggested people look further within the UK or even abroad for species to replace diseased trees, rather than relying on material sourced locally.
"It seems to me we should be looking at a far wider palette as we set about replacing the familiar trees we have now lost. We need to imagine a different, not inferior landscape for the future," he said.
Woodland Trust head of conservation Christine Reid, writing in the Telegraph, said the "devastating" level of tree loss at Chatsworth was likely to be repeated across the country.
"We urgently need the support of landowners across the country to encourage a greater diversity of native trees."
Quickly planting and protecting new trees would help woodland wildlife cope with the loss of the old diseased trees, she added.