Climate change: consequences on the pollination of grasses in Perugia (Central Italy). A 33-year-long study

Abstract

Many works carried out in the last decades have shown that the pollen season for taxa flowering in winter and spring, in temperate regions, has tended to be earlier, probably due to the continuous rise in temperature. The mean annual temperature in Perugia, Central Italy, was about 0.5 °C higher in the last three decades compared with that registered from 1952 to 1981. The increase of temperature took place mainly in winter and spring, while no significant variation was recorded during the summer and autumn. This scenario shows variations in the timing and behavior of flowering of many spontaneous plants such as grasses, whose phenology is strongly influenced by air temperature. This work reports fluctuations in the airborne grass pollen presence in Perugia over a 33-year period (1982-2014), in order to study the influence of the warming registered in recent years on the behavior of pollen release of this taxon. The grass pollen season in Perugia typically lasts from the beginning of May to late July. The start dates showed a marked trend to an earlier beginning of the season (-0.4 day/year), as well as a strong correlation with the average temperatures of March and April. The peak is reached around 30th May, but the annual pollen index (API) is following a decreasing trend. The correlation between starting dates and spring temperatures could be interesting for the constitution of a forecasting model capable of predicting the presence of airborne grass pollen, helping to plan therapies for allergic people.

Consequences of climate change on airborne pollen in Bavaria, Central Europe

“…On the other hand, most of the significant results for airborne Poaceae pollen in Bavaria indicated decreases in pollen amounts, and number of days of allergenic risk (above a threshold of 30 pollen grains/m 3 ). The intensity of grass pollen seasons was governed by precipitation in spring, which is in agreement with previous work (Ghitarrini et al 2017). This weather-based behaviour of grasses could explain the negative trend in the magnitude of grass pollen seasons in Munich.…”

Correlation of Pollen Concentration and Meteorological Factors with Medical Condition of Allergic Rhinitis in Shenyang Area

“…Studies have shown that changes in weather conditions such as rainfall, atmospheric temperature, humidity, wind speed, and wind direction can change the seasonality and concentration of plant pollen, thus inducing allergic symptoms and leading to the occurrence and development of AR [36][37][38]. Temperature plays a very important role in increasing the pollen concentration in the air and is the main factor controlling the start of grass pollen season and the peak duration of pollen [21,39,40]. In the present study, we found that total pollen amount in Shenyang significantly correlated with daily minimum temperature, daily average precipitation, and daily average relative humidity but not with daily average temperature, maximum temperature, average atmospheric pressure, and wind scale.…”

Aerobiology in the International Journal of Biometeorology, 1957–2017

“…Other research on the impacts of climate change on pollen season characteristics has subsequently been published in IJB, including Galán et al (2005), Frei and Gassner (2008), Newnham et al (2013) and Sofia et al (2017), to name but a few. As noteworthy as the IJB contribution to this area of research has been, it has not been the sole domain of such work.…”