In the long-term average, those affected usually feel the allergic symptoms caused by the hazel pollen from the last week of January. This year, the stress started on January 2nd, according to Berger.
At the beginning of the pollen season, the immune system of allergy sufferers generally reacts particularly strongly, says Berger. “The mild time caught many allergy sufferers off guard,” says the expert. Many of those affected have not recognized their allergic symptoms as such and have not yet stocked up on antihistamines.
Purple alder additional stress factor
In addition to SARS-CoV-2, influenza and the respiratory syncytial virus (RSV), numerous cold viruses are currently rampant. The symptoms of some of the triggered flu infections are often difficult to distinguish from allergy symptoms, especially in the early stages.
An additional stress factor in some regions is the flowering of the purple alder, said Berger. This tree species does not occur naturally in Austria, but has been planted in Vienna and Vorarlberg, for example. The flowering of the purple alder starts in December, “when the Christmas markets are still open,” says Berger.
Switzerland and Germany are also affected
On the pollution map of the pollen warning service, rashes have already been recorded in Vienna, Upper Austria and Tyrol. Further reports came from southern Germany and Switzerland. The card is fed from the pollen diaries, in which those affected can enter symptoms online.
Reports from those affected are also increasing at the Swiss Allergy Center, reports “Argovia Today”. There it says: “What is thought to be a cold can currently also be hay fever.” After all, the hazel blooms 20 to 30 days earlier than the average of the past three decades. Allergy sufferers are therefore advised to take antihistamines sooner rather than later.
“Nothing unusual anymore” due to the climate crisis
The same applies to Germany, where, according to the German Weather Service, hazelnuts have been blooming in some places since December. “This is no longer unusual,” said agricultural meteorologist Wolfgang Janssen, referring to the climate crisis.
If, as expected, it stays mild for the next few weeks, all the hazelnut bushes would be in bloom as early as January 25th and distribute plenty of pollen. The average day for this has been February 10 since the 1990s, before that it was only February 25 on average.
Climate crisis affects season
According to Berger, the climate crisis primarily affects the duration of flowering: early bloomers would bloom earlier, late bloomers longer – this would make the pollen season longer. According to GeoSphere Austria, there are similar changes in the seasons: winters are getting shorter, spring starts earlier and autumn ends later.
phenology
Phenology studies the evolution of nature in relation to climate.
It is a development that is also evident in other plants. According to experts, the alder has not yet progressed as far as the hazel, but in view of the mild temperatures it can be assumed that the flowering time will start earlier this year as well.
According to the phenologist at GeoSphere Austria, Helfried Scheifinger, the shifting of the seasons will continue in the future, but not indefinitely, since the plants’ seasonal cycle is not only controlled by the temperature, but also by the length of the day.
