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An exotic plant has produced male and female cones outside Britain, which seems to be the first time in 60 years. Botanists say that the event is a sign of global warming.
Two cycads (Cycas revoluta), a type of primitive tree that dominated the planet 280 million years ago, produced cones on the sheltered cliffs of Ventnor's Ventnor Botanic Garden on the Isle of Wight.
The species is native to Japan and is usually found only inside as an ornamental plant inside Great Britain, but one of the garden plants produced what would be the first female outdoor cone ever recorded UK.
The cycads once lived in what Britain was millions of years ago, with fossils of plants found in the Jurassic strata stretching from the Isle of Wight to the Dorset coast, a time when the Earth's climate naturally displayed high levels of carbon dioxide.
A plant growing outdoors in Ventnor produced a male cone seven years ago, but this year, different plants have produced flower-shaped male and female cones, giving botanists the opportunity to transfer pollen. and to generate seeds.
"For the first time in 60 years in the UK, we have a cone and a cone at the same time," said Chris Kidd, curator of the Ventnor Botanic Gardens. "This is a strong indicator of climate change demonstrated, not from the empirical evidence provided by scientists but by plants."
According to Kidd, last summer's heat wave and this year's record temperatures led to the plant's production of cones, as well as milder winters. He added that records kept at the Botanical Garden show that the highest average temperatures recorded in January 100 years ago were below the lowest average recorded today. As a result, the 27-hectare (67-acre) garden, with a milder climate than any other part of Britain, with the exception of the Scilly Islands, produces temperate plants that would have been unable to survive for a long time. British winter.
"It's not something that has happened with a mild period in the short term, it's a long-term warming that makes these things possible," he said. [cycad] The factory will have made the decision to engage in the production of cones [in summer 2018], and that production is set up to last in winter and produce the following year.
"Thirty years ago, we could not cultivate them. But these plants grow outdoors in gardens for 15 years, following their natural cycle. "
Cycads are a relic of an era prior to the flowering of plants. In his native Japan, Cycas revoluta is believed to be pollinated by beetles. In the botanical garden, the plant with a male cone is at a distance from the female and the pollen must be transferred by hand in about a week.
"By crossing them and producing seeds, we are doing something that has never been done before in the UK," said Kidd. "Here we consider sub-precipitation as a predictor of the wider British landscape in 20 to 30 years."
The species of cycads are composed of three families, the only surviving members of an ancient and largely extinct lineage having changed little since the Jurassic, and are therefore considered "living fossils". All cycads come from the hottest regions of the world, but are naturally absent from Europe and Antarctica. Fossils of Jurassic specimens remarkably similar to current plants have been found on both continents.
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