ИСТИНА

Allergy is considered as one of the most common diseases. According to the WHO, about 40% of the world's population suffer from various allergic reactions (Khaitov, Ilyina, 2009). One of the most widespread allergic diseases is pollinosis, an illness caused by the pollen of different plants. Pollinosis causes sniffle, cough, tearing and swelling of the eyelids, bronchial asthma attacks. More than 700 species of pollen allergy plants are known. About 120 species are widespread in Russia (Dikareva, Rumyantsev, 2015). One of the main specific features of pollinosis is the seasonality of the manifestation of the disease, which coincides with the period of flowering of certain plants. The season of flowering of allergy plants begin in early spring, when alder gray (Alnus incana) and common hazel (Corylus avellana) start to blossom. Later, the flowering of common birch (Betula pendula) begins. Birch plays the role of the main spring allergy trees due to its cosmopolitan spread within its natural habitat. Plant flowering is closely related to some important climatic indices, such as the average daily temperature and stable transitions of average daily temperatures through threshold values, indicating certain phenological periods. Thus, the transition of temperatures through +5°C coincides with the beginning of the growing season and flowering of alder and hazel. Correlation links between the phenological phases of birch and the seasons’ temperature regimes have been well studied (Minin et al., 2000, 2014, 2016). Flowering of birch corresponds to the transition of average daily temperature through the threshold of +10°С. In accordance with above stated, on the basis of annual average climate indicators, it is possible to determine the beginning of various phenological phases of trees, including the terms of the beginning of flowering, and to forecast the occurrence of pollinosis in different regions. Taking into account the urgency of pollinosis problem, the terms of flowering of allergy plants (http://pollen.club/) is determined substantionally for each region. There are maps reflecting the spatial dynamics of the terms of hazel flowering on the European Russia (Questions ..., 1972). Agroclimatic maps reflecting the periods of stable temperature transitions through the threshold values also exist (Agroecological Atlas, 2009). However, the global environmental changes occurring in recent decades lead to a shift in the terms of the onset of phenomena, both climatic and phenological, to earlier dates. There is a need in constant updating the average annual indicators on a regular basis, taking into account up-to-date data. In connection with this, the aim of this work is to build a map that reflects the spatial dynamics of the terms of the beginning of pollen allergy trees flowering in the plains of European Russia, based on the long-term average daily temperatures with due regard to present knowledge.