A remarkable father-and-son research project has revealed how rising temperatures are affecting fungi in southern England.
Fungus enthusiast Edward Gange amassed 52,000 sightings of mushroom and toadstools during walks around Salisbury over a 50-year period.
Analysis by his son Alan, published in the journal Science, shows some fungi have started to fruit twice a year.
It is among the first studies to show a biological impact of warming in autumn.
"My father was a stonemason, and his hobby was mycology," recounted Alan Gange, an ecology professor at Royal Holloway, University of London.
"For 50 years of his life, he went out and recorded the appearance of mushrooms and toadstools around Salisbury, and he also got his friends in the local natural history group to bring back samples they found when they were out walking.
"When he retired, he bought himself a computer, taught himself (the spreadsheet program) Excel, and typed in all these 52,000 records."
Now Mr Gange senior finds his enthusiasm and diligence rewarded as a named author on a paper in one of the two most eminent scientific journals in the world.
"I'm on top of the world, I can't quite believe it yet," he told the BBC News website.
The records included sightings of 315 species of mushrooms and toadstools which appear in the autumn, being the seasonal fruiting parts of fungi that live in the soil, on rotting wood or in tree roots.
One of the changes Professor Gange turned up was that the autumnal fruiting period has expanded. Some mushrooms and toadstools are emerging earlier each year, others later, which he thinks are responses to warmer temperatures and higher rainfall.
More spectacularly, he found that more than one third of the species recorded have started to fruit twice per year. There was no record of this before 1976; but since then, 120 species have shown an additional fruiting in spring.
"I looked up the data on the average temperature for February in southern England during the 1950s, and it was 3.5C," he said.
"In the current decade it's 5.2C. We used to get cold days and nights in February which caused fungi to be dormant; these days we get very little of that."
In recent years a significant number of studies have found changes in species' behaviour during springtime apparently related to climate change, with growing seasons starting earlier, and young animals born in months which would, in previous years, have been too cold.
This is one of the first studies to show a parallel trend in autumn.
After more than 50 years of observing the natural world, Edward Gange is convinced that the climate is changing - at least within a 30km radius of Salisbury - though he prefers to attribute the warming to natural cycles rather than humanity's production of greenhouse gases.
"When I was a lad, it was an absolutely categorical fact that Red Admirals would not survive the winter," he said.
"This year we saw them on 19 January. That's a heck of a change, and it's not the only one."