Alena A. Kochubey’s research while affiliated with Botanical Garden-Institute of the Far Eastern Branch of the Russian Academy of Sciences and other places

The Trans-Ural region is the southern point of the common heather (C. vulgaris) range. Field ecophysiological study of C. vulgaris plants transpiration intensity (IT) was carried out in connection with the problem of marginal populations adaptation to arid climate. The research was carried out in the forest-steppe of the Trans-Ural region (Kurgan region), where an abundant population of heather grows. The dailyvariation of IT was studied taking into account a set of recorded ecoclimate limiting factors (wind speed, illumination, dynamics of air temperature and humidity, soil temperature) during one growing season (from April to September 2016) under the canopy of a pine forest and in the adjacent clearing. To study IT, annual apical shoots of plants 4 cm long were used in triplicate for each time period. The total sample size on one day of measurements ranged from 30-35 shoots. The transpiration rate was determined by the rapid weighing method, which takes into account the water lost by the shoot over a certain time period. When processing the data, we used correlation analysis (Pearson's correlation coefficient r), which made it possible to clarify the strength and direction of two continuous (metric) variables interaction. Differences in IT daily changes were revealed in plants growing under the forest canopy and in the open areas. Under conditions of long-term atmospheric and soil drought, which is common for the region, in 2016 a sharp decrease in heather water content was observed, starting from 10 a.m. throughout the entire growing season, with the exception of April, when the moisture deficit in the soil and heather tissues was still minimal. In May, maximum IT values in the clearing were noted at 14:00 (8.5 mg/h×10 –4) whereas under the canopy of the tree stand, peak IT values begin at 10 a.m. (12.7 mg/h×10 –4). Daytime summer transpiration in common heather (C. vulgaris) is even less intense than spring transpiration ((3–5 mg/h×10–4).It was revealed that meteorological factors play a decisive role in IT in various types of forest. In open felled areas, the determining factor is PAR (0.81, p < 0.05) and, to a lesser extent, atmospheric temperature (0.69, p < 0.05), and under the canopy - only PAR (0.96, p <0.05). A decrease in IT and, accordingly, photosynthesis leads to a decrease in the population’s vitality and non-ripening of seeds, which is an ecophysiological factor of the heather absence south of Kurgan city.

There is a direct linear relationship between the total amount of carbon emitted by human activities and the level of warming on the Earth’s surface. At the same time, warming in the northern regions of Eurasia is faster than in the southern ones. In this work, we considered changes in atmospheric temperature and accumulation of precipitation in the Urals and their influence on the number and area of fires in the region. We assessed the combined effect of elevated atmospheric temperatures and high humidity on the pollen fertility of P. sylvestris L. The Ural region has faced the trend of climate warming and fixing of new records of high temperatures. Thus, the average annual temperature in the region has increased by 3 °C since 2020. A decrease in the thickness of the snow cover in early spring leads to dryness in May, which increases forests burning. The most dangerous weather in the Urals was in 2010, which led to growth in the number of forest fires. The decrease in spring humidity has led to almost 10 times increase in the number of fires. High atmospheric temperature led to a sharp decrease in the proportion of fertile pollen, which was almost three times lower compared to climatically normal years. Sharp changes in climatic factors lead to the transformation of the ecosystems. In the long term, broad-leaved tree species have the greatest adaptive potential in the Ural region.