The flowers, which experience a “peak bloom” that lasts only a few days, have been honored in Japan for more than a thousand years. The crowd celebrates with parties, check out the most popular places to take photos and have picnics under the branches.
But this year, the cherry blossom season came in the blink of an eye and went into one of the earliest blooms recorded – and scientists warn that it is a symptom of the larger climate crisis that threatens ecosystems everywhere.
And in the capital Tokyo, cherry blossoms reached full bloom on March 22, the second earliest date recorded.
“As the global temperature warms, the last spring frost occurs earlier and blooms sooner,” said Dr. Lewis Ziska of Columbia Universities Environmental Health Sciences said.
The peak flower dates shift each year, depending on numerous factors, including weather and rainfall, but show a general trend to move earlier and earlier. According to Kyoto data, the peak date hovered in Kyoto for centuries, but it began to move during the 1800s. The date has only been recorded several times in history until the end of March.
“Sakura flowers are very temperature sensitive,” Aono said. “Blooms and full blooms can be sooner or later, depending on the temperature alone,” he said. “The temperature was low in the 1820s, but it has risen by about 3.5 degrees Celsius (6.3 degrees Fahrenheit) to this day.”
Especially this year’s seasons affected the heyday, he added. The winter was very cold, but the spring came quickly and extraordinarily hot, so ‘the buds are fully awake after enough rest’.
However, their early flowering is just the tip of the iceberg of a global phenomenon that could destabilize natural systems and countries’ economies, said Amos Tai, assistant professor of earth science at the Chinese University of Hong Kong.
There are two sources of increased heat, which is the most important factor that causes the flowers to bloom earlier: urbanization and climate change. With increasing urbanization, cities tend to become warmer than the surrounding rural area, which is called the heat island effect. But a bigger reason is climate change, which has caused rising temperatures around the world and the world.
And these earlier dates are not just a matter of tourists catching the bloom before the petals fall – it can have a lasting impact on entire ecosystems and threaten the survival of many species.
For every action there is a reaction
Plants and insects rely heavily on each other, and both use environmental cues to ‘regulate the timing of different life stages,’ Tai said. For example, plants feel the temperature around them and when it is warm enough for a constant period, they start flowering and their leaves start to come up. Insects and other animals are also dependent on temperature during their life cycles, which means that higher heat can cause faster growth.
“The relationship between plants and insects and other organisms has evolved over many years – thousands to millions of years,” Tai said. “But in the last century, climate change really destroys everything and disturbs all these relationships.”
Different plants and insects can respond to the increase in heat at different rates, dropping their life cycles out of action. While they once determined their growth once every spring, flowers can now bloom before insects are ready, and vice versa – meaning that the insects may not find enough food to eat from the plants, and that the plants do not have enough pollinators did not (to reproduce), ‘he said.
“Ecosystems are not used to such large fluctuations, they cause a lot of stress,” Tai said. “Productivity can be reduced, and ecosystems may even collapse in the future.”
Not limited to cherry blossoms
And the effects of climate change are not just limited to cherry blossoms. ‘Cherry blossoms catch the attention, people like to go and see them, but many other plants also experience changes in their life cycle and can have an even stronger impact. about the stability of their ecosystems, ”Tai said.
In some regions, farmers may be forced to change the types of crops they grow. Some climates will get too hot for what they are growing now, while other climates will see more flooding, more snow, more moisture in the air, which may also limit what can be grown.
“(Farmers) have a much harder time predicting when they are going to have a good year, when they are going to have a bad year,” Tai added. “Agriculture is now more like a gamble, because climate change is randomizing the things that are happening in our ecological systems.”