Climatic Causes of Plant Flowering Time Displacement in the Central Forest Reserve

Abstract

Meteorological series and phenological data in the framework of our environmental monitoring in the South taiga Central Forest Reserve were analyzed. During 1984– 2017, the average annual air temperature was 4.63±0.41°C, and the average annual rainfall was 2.14±0.12 mm/day. For eight of the 43 (19%) climatic parameters, reliable linear trends of variability were found: an increase of air temperature in July, August, September, and December; an increase of soil temperature in December; an increase of precipitation in November and December; and a decrease of precipitation in September. Three causes of their directed long-term changes were revealed, namely: a shift of the winter timing, violation of the annual dynamics of climatic parameters and a change in the precipitation type during a longer autumn – snow to be replaced by rain. Of the 11 species of vascular plants, the statistical significance of the long-term displacement of phenological dates was proven for Anemone nemorosa: the longer the autumn and softer the beginning of the winter, the earlier the onset of its flowering. Two classification types of vascular plants in identifying interspecific synchrony in the phenological events variation were considered. Variability components of phenological phenomena occurrence was estimated: the share of long-term trends of the shift in phenological dates timing due to changes in reserve climatic system is from 20 to 68% of the total sign dispersion; interannual climatic fluctuations explain 5–34% of its variability; and the proportion of variability under unaccounted factors influence is high (21–64%). Species with a high proportion of their long-term variability components (Anemone nemorosa: more than 60%) are recommended to use as indicators of climate change under the conditions of the study area.